diff --git a/src/Extensions/FamilySearch/Platform/Tree/AdditionalAttribution.php b/src/Extensions/FamilySearch/Platform/Tree/AdditionalAttribution.php
new file mode 100644
index 00000000..17f45d15
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/AdditionalAttribution.php
@@ -0,0 +1,133 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+use Gedcomx\Common\Attribution;
+
+/**
+ * Class AdditionalAttribution
+ *
+ * Extension element for capturing additional attributions on an already-attributed object.
+ *
+ * In genealogical data, objects like persons, relationships, and facts typically have
+ * a primary attribution indicating who created or last modified the data. However, there
+ * are cases where multiple contributors have made significant contributions that should
+ * be acknowledged separately. AdditionalAttribution provides a way to record these
+ * supplementary attributions.
+ *
+ * ## Use Cases
+ *
+ * **Multiple Contributors:**
+ * When several people have contributed to building out a person's profile, you may want
+ * to attribute specific contributions to specific people beyond the primary contributor.
+ *
+ * **Source Transcription:**
+ * When one person transcribes a source and another person reviews and corrects it,
+ * both contributors can be acknowledged.
+ *
+ * **Collaborative Research:**
+ * In group research projects, you may want to track all contributors who have added
+ * information to a record, not just the most recent editor.
+ *
+ * **Historical Context:**
+ * Preserving the history of who contributed what helps maintain data provenance and
+ * gives proper credit to genealogical researchers.
+ *
+ * ## Properties (Inherited from Attribution)
+ *
+ * All properties are inherited from the base Attribution class:
+ * - `contributor` (ResourceReference) - Reference to the person who contributed
+ * - `modified` (timestamp) - When this contribution was made
+ * - `changeMessage` (string) - Optional message explaining the contribution
+ *
+ * ## Example Usage
+ *
+ * ```php
+ * use Gedcomx\Common\ResourceReference;
+ * use Gedcomx\Extensions\FamilySearch\Platform\Tree\AdditionalAttribution;
+ *
+ * // Create an additional attribution for a supplementary contributor
+ * $additionalAttr = new AdditionalAttribution();
+ *
+ * $contributor = new ResourceReference();
+ * $contributor->setResource('https://familysearch.org/platform/users/USER123');
+ * $additionalAttr->setContributor($contributor);
+ *
+ * $additionalAttr->setModified(time() * 1000); // milliseconds
+ * $additionalAttr->setChangeMessage('Added birth date from parish records');
+ *
+ * // This can then be attached to a person, fact, or relationship
+ * ```
+ *
+ * ## XML Example
+ *
+ * ```xml
+ * <fs:additionalAttribution xmlns:fs="http://familysearch.org/v1/">
+ *   <contributor resource="https://familysearch.org/platform/users/USER123"/>
+ *   <modified>1625097600000</modified>
+ *   <changeMessage>Added birth date from parish records</changeMessage>
+ * </fs:additionalAttribution>
+ * ```
+ *
+ * ## JSON Example
+ *
+ * ```json
+ * {
+ *   "contributor": {
+ *     "resource": "https://familysearch.org/platform/users/USER123"
+ *   },
+ *   "modified": 1625097600000,
+ *   "changeMessage": "Added birth date from parish records"
+ * }
+ * ```
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class AdditionalAttribution extends Attribution
+{
+    /**
+     * Constructs an AdditionalAttribution from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        parent::__construct($o);
+    }
+
+    /**
+     * Writes this AdditionalAttribution to an XML writer.
+     *
+     * Overrides the parent method to use the FamilySearch-specific element name.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'additionalAttribution', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+            $writer->writeAttributeNs('xmlns', 'gx', null, 'http://gedcomx.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/ChangeType.php b/src/Extensions/FamilySearch/Platform/Tree/ChangeType.php
new file mode 100644
index 00000000..92e8bf4a
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/ChangeType.php
@@ -0,0 +1,279 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of change types in the FamilySearch Family Tree.
+ *
+ * These constants represent the various types of changes that can occur in the
+ * FamilySearch Family Tree, including person operations, relationship operations,
+ * fact changes, name changes, source attachments, and more.
+ *
+ * Each change type combines an operation (Create, Update, Delete, Merge, etc.)
+ * with an object type (Person, Name, Fact, etc.) and optionally a modifier
+ * indicating the context (Person, Couple, ChildAndParentsRelationship).
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class ChangeType
+{
+    // Person Operations
+    const CREATE_PERSON = "http://familysearch.org/v1/CreatePerson";
+    const DELETE_PERSON = "http://familysearch.org/v1/DeletePerson";
+    const MERGE_PERSON = "http://familysearch.org/v1/MergePerson";
+    const UNMERGE_PERSON = "http://familysearch.org/v1/UnmergePerson";
+    const UNTOMBSTONE_PERSON = "http://familysearch.org/v1/UntombstonePerson";
+    const ADD_PERSON_NOT_A_MATCH = "http://familysearch.org/v1/AddPersonNotAMatch";
+    const REMOVE_PERSON_NOT_A_MATCH = "http://familysearch.org/v1/RemovePersonNotAMatch";
+
+    // Couple Relationship Operations
+    const CREATE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/CreateCoupleRelationship";
+    const UPDATE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/UpdateCoupleRelationship";
+    const DELETE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/DeleteCoupleRelationship";
+    const ADD_SPOUSE1 = "http://familysearch.org/v1/AddSpouse1";
+    const EDIT_SPOUSE1 = "http://familysearch.org/v1/EditSpouse1";
+    const ADD_SPOUSE2 = "http://familysearch.org/v1/AddSpouse2";
+    const EDIT_SPOUSE2 = "http://familysearch.org/v1/EditSpouse2";
+    const MERGE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/MergeCoupleRelationship";
+    const UNMERGE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/UnmergeCoupleRelationship";
+    const UNTOMBSTONE_COUPLE_RELATIONSHIP = "http://familysearch.org/v1/UntombstoneCoupleRelationship";
+
+    // Child and Parents Relationship Operations
+    const CREATE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/CreateChildAndParentsRelationship";
+    const UPDATE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/UpdateChildAndParentsRelationship";
+    const DELETE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/DeleteChildAndParentsRelationship";
+    const ADD_PARENT1 = "http://familysearch.org/v1/AddParent1";
+    const EDIT_PARENT1 = "http://familysearch.org/v1/EditParent1";
+    const REMOVE_PARENT1 = "http://familysearch.org/v1/RemoveParent1";
+    const ADD_PARENT2 = "http://familysearch.org/v1/AddParent2";
+    const EDIT_PARENT2 = "http://familysearch.org/v1/EditParent2";
+    const REMOVE_PARENT2 = "http://familysearch.org/v1/RemoveParent2";
+    const ADD_CHILD = "http://familysearch.org/v1/AddChild";
+    const EDIT_CHILD = "http://familysearch.org/v1/EditChild";
+    const MERGE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/MergeChildAndParentsRelationship";
+    const UNMERGE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/UnmergeChildAndParentsRelationship";
+    const UNTOMBSTONE_CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/UntombstoneChildAndParentsRelationship";
+
+    // Source Reference Changes
+    const ADD_PERSON_SOURCE_REFERENCE = "http://familysearch.org/v1/AddPersonSourceReference";
+    const EDIT_PERSON_SOURCE_REFERENCE = "http://familysearch.org/v1/EditPersonSourceReference";
+    const DELETE_PERSON_SOURCE_REFERENCE = "http://familysearch.org/v1/DeletePersonSourceReference";
+    const ADD_COUPLE_SOURCE_REFERENCE = "http://familysearch.org/v1/AddCoupleSourceReference";
+    const EDIT_COUPLE_SOURCE_REFERENCE = "http://familysearch.org/v1/EditCoupleSourceReference";
+    const DELETE_COUPLE_SOURCE_REFERENCE = "http://familysearch.org/v1/DeleteCoupleSourceReference";
+    const ADD_CHILD_PARENTS_SOURCE_REFERENCE = "http://familysearch.org/v1/AddChildParentsSourceReference";
+    const EDIT_CHILD_PARENTS_SOURCE_REFERENCE = "http://familysearch.org/v1/EditChildParentsSourceReference";
+    const DELETE_CHILD_PARENTS_SOURCE_REFERENCE = "http://familysearch.org/v1/DeleteChildParentsSourceReference";
+
+    // Discussion Reference Changes
+    const ADD_PERSON_DISCUSSION_REFERENCE = "http://familysearch.org/v1/AddPersonDiscussionReference";
+    const EDIT_PERSON_DISCUSSION_REFERENCE = "http://familysearch.org/v1/EditPersonDiscussionReference";
+    const DELETE_PERSON_DISCUSSION_REFERENCE = "http://familysearch.org/v1/DeletePersonDiscussionReference";
+    const ADD_COUPLE_DISCUSSION_REFERENCE = "http://familysearch.org/v1/AddCoupleDiscussionReference";
+    const EDIT_COUPLE_DISCUSSION_REFERENCE = "http://familysearch.org/v1/EditCoupleDiscussionReference";
+    const DELETE_COUPLE_DISCUSSION_REFERENCE = "http://familysearch.org/v1/DeleteCoupleDiscussionReference";
+    const ADD_CHILD_PARENTS_DISCUSSION_REFERENCE = "http://familysearch.org/v1/AddChildParentsDiscussionReference";
+    const EDIT_CHILD_PARENTS_DISCUSSION_REFERENCE = "http://familysearch.org/v1/EditChildParentsDiscussionReference";
+    const DELETE_CHILD_PARENTS_DISCUSSION_REFERENCE = "http://familysearch.org/v1/DeleteChildParentsDiscussionReference";
+
+    // Tree Person Reference Changes
+    const ADD_TREE_PERSON_REFERENCE = "http://familysearch.org/v1/AddTreePersonReference";
+    const EDIT_TREE_PERSON_REFERENCE = "http://familysearch.org/v1/EditTreePersonReference";
+    const DELETE_TREE_PERSON_REFERENCE = "http://familysearch.org/v1/DeleteTreePersonReference";
+
+    // Evidence Reference Changes
+    const ADD_PERSON_EVIDENCE_REFERENCE = "http://familysearch.org/v1/AddPersonEvidenceReference";
+    const EDIT_PERSON_EVIDENCE_REFERENCE = "http://familysearch.org/v1/EditPersonEvidenceReference";
+    const DELETE_PERSON_EVIDENCE_REFERENCE = "http://familysearch.org/v1/DeletePersonEvidenceReference";
+    const ADD_COUPLE_EVIDENCE_REFERENCE = "http://familysearch.org/v1/AddCoupleEvidenceReference";
+    const EDIT_COUPLE_EVIDENCE_REFERENCE = "http://familysearch.org/v1/EditCoupleEvidenceReference";
+    const DELETE_COUPLE_EVIDENCE_REFERENCE = "http://familysearch.org/v1/DeleteCoupleEvidenceReference";
+    const ADD_CHILD_PARENTS_EVIDENCE_REFERENCE = "http://familysearch.org/v1/AddChildParentsEvidenceReference";
+    const EDIT_CHILD_PARENTS_EVIDENCE_REFERENCE = "http://familysearch.org/v1/EditChildParentsEvidenceReference";
+    const DELETE_CHILD_PARENTS_EVIDENCE_REFERENCE = "http://familysearch.org/v1/DeleteChildParentsEvidenceReference";
+
+    // Person Event/Fact Changes
+    const ADD_AFFILIATION = "http://familysearch.org/v1/AddAffiliation";
+    const EDIT_AFFILIATION = "http://familysearch.org/v1/EditAffiliation";
+    const DELETE_AFFILIATION = "http://familysearch.org/v1/DeleteAffiliation";
+    const ADD_BAR_MITZVAH = "http://familysearch.org/v1/AddBarMitzvah";
+    const EDIT_BAR_MITZVAH = "http://familysearch.org/v1/EditBarMitzvah";
+    const DELETE_BAR_MITZVAH = "http://familysearch.org/v1/DeleteBarMitzvah";
+    const ADD_BAS_MITZVAH = "http://familysearch.org/v1/AddBasMitzvah";
+    const EDIT_BAS_MITZVAH = "http://familysearch.org/v1/EditBasMitzvah";
+    const DELETE_BAS_MITZVAH = "http://familysearch.org/v1/DeleteBasMitzvah";
+    const ADD_BIRTH = "http://familysearch.org/v1/AddBirth";
+    const EDIT_BIRTH = "http://familysearch.org/v1/EditBirth";
+    const DELETE_BIRTH = "http://familysearch.org/v1/DeleteBirth";
+    const ADD_BURIAL = "http://familysearch.org/v1/AddBurial";
+    const EDIT_BURIAL = "http://familysearch.org/v1/EditBurial";
+    const DELETE_BURIAL = "http://familysearch.org/v1/DeleteBurial";
+    const ADD_CHRISTENING = "http://familysearch.org/v1/AddChristening";
+    const EDIT_CHRISTENING = "http://familysearch.org/v1/EditChristening";
+    const DELETE_CHRISTENING = "http://familysearch.org/v1/DeleteChristening";
+    const ADD_CREMATION = "http://familysearch.org/v1/AddCremation";
+    const EDIT_CREMATION = "http://familysearch.org/v1/EditCremation";
+    const DELETE_CREMATION = "http://familysearch.org/v1/DeleteCremation";
+    const ADD_DEATH = "http://familysearch.org/v1/AddDeath";
+    const EDIT_DEATH = "http://familysearch.org/v1/EditDeath";
+    const DELETE_DEATH = "http://familysearch.org/v1/DeleteDeath";
+    const ADD_LIVING_STATUS = "http://familysearch.org/v1/AddLivingStatus";
+    const EDIT_LIVING_STATUS = "http://familysearch.org/v1/EditLivingStatus";
+    const DELETE_LIVING_STATUS = "http://familysearch.org/v1/DeleteLivingStatus";
+    const ADD_MILITARY_SERVICE = "http://familysearch.org/v1/AddMilitaryService";
+    const EDIT_MILITARY_SERVICE = "http://familysearch.org/v1/EditMilitaryService";
+    const DELETE_MILITARY_SERVICE = "http://familysearch.org/v1/DeleteMilitaryService";
+    const ADD_NATURALIZATION = "http://familysearch.org/v1/AddNaturalization";
+    const EDIT_NATURALIZATION = "http://familysearch.org/v1/EditNaturalization";
+    const DELETE_NATURALIZATION = "http://familysearch.org/v1/DeleteNaturalization";
+    const ADD_NOBILITY_TYPE = "http://familysearch.org/v1/AddNobilityType";
+    const EDIT_NOBILITY_TYPE = "http://familysearch.org/v1/EditNobilityType";
+    const DELETE_NOBILITY_TYPE = "http://familysearch.org/v1/DeleteNobilityType";
+    const ADD_OCCUPATION = "http://familysearch.org/v1/AddOccupation";
+    const EDIT_OCCUPATION = "http://familysearch.org/v1/EditOccupation";
+    const DELETE_OCCUPATION = "http://familysearch.org/v1/DeleteOccupation";
+    const ADD_RELIGIOUS_AFFILIATION = "http://familysearch.org/v1/AddReligiousAffiliation";
+    const EDIT_RELIGIOUS_AFFILIATION = "http://familysearch.org/v1/EditReligiousAffiliation";
+    const DELETE_RELIGIOUS_AFFILIATION = "http://familysearch.org/v1/DeleteReligiousAffiliation";
+    const ADD_RESIDENCE = "http://familysearch.org/v1/AddResidence";
+    const EDIT_RESIDENCE = "http://familysearch.org/v1/EditResidence";
+    const DELETE_RESIDENCE = "http://familysearch.org/v1/DeleteResidence";
+    const ADD_STILLBORN = "http://familysearch.org/v1/AddStillborn";
+    const EDIT_STILLBORN = "http://familysearch.org/v1/EditStillborn";
+    const DELETE_STILLBORN = "http://familysearch.org/v1/DeleteStillborn";
+
+    // Couple Event/Fact Changes
+    const ADD_ANNULMENT = "http://familysearch.org/v1/AddAnnulment";
+    const EDIT_ANNULMENT = "http://familysearch.org/v1/EditAnnulment";
+    const DELETE_ANNULMENT = "http://familysearch.org/v1/DeleteAnnulment";
+    const ADD_COMMON_LAW_MARRIAGE = "http://familysearch.org/v1/AddCommonLawMarriage";
+    const EDIT_COMMON_LAW_MARRIAGE = "http://familysearch.org/v1/EditCommonLawMarriage";
+    const DELETE_COMMON_LAW_MARRIAGE = "http://familysearch.org/v1/DeleteCommonLawMarriage";
+    const ADD_DIVORCE = "http://familysearch.org/v1/AddDivorce";
+    const EDIT_DIVORCE = "http://familysearch.org/v1/EditDivorce";
+    const DELETE_DIVORCE = "http://familysearch.org/v1/DeleteDivorce";
+    const ADD_MARRIAGE = "http://familysearch.org/v1/AddMarriage";
+    const EDIT_MARRIAGE = "http://familysearch.org/v1/EditMarriage";
+    const DELETE_MARRIAGE = "http://familysearch.org/v1/DeleteMarriage";
+    const ADD_COUPLE_EVENT = "http://familysearch.org/v1/AddCoupleEvent";
+    const EDIT_COUPLE_EVENT = "http://familysearch.org/v1/EditCoupleEvent";
+    const DELETE_COUPLE_EVENT = "http://familysearch.org/v1/DeleteCoupleEvent";
+
+    // Parent-Child Fact Changes
+    const ADD_ADOPTIVE_PARENT = "http://familysearch.org/v1/AddAdoptiveParent";
+    const EDIT_ADOPTIVE_PARENT = "http://familysearch.org/v1/EditAdoptiveParent";
+    const DELETE_ADOPTIVE_PARENT = "http://familysearch.org/v1/DeleteAdoptiveParent";
+    const ADD_BIOLOGICAL_PARENT = "http://familysearch.org/v1/AddBiologicalParent";
+    const EDIT_BIOLOGICAL_PARENT = "http://familysearch.org/v1/EditBiologicalParent";
+    const DELETE_BIOLOGICAL_PARENT = "http://familysearch.org/v1/DeleteBiologicalParent";
+    const ADD_FOSTER_PARENT = "http://familysearch.org/v1/AddFosterParent";
+    const EDIT_FOSTER_PARENT = "http://familysearch.org/v1/EditFosterParent";
+    const DELETE_FOSTER_PARENT = "http://familysearch.org/v1/DeleteFosterParent";
+    const ADD_GUARDIAN_PARENT = "http://familysearch.org/v1/AddGuardianParent";
+    const EDIT_GUARDIAN_PARENT = "http://familysearch.org/v1/EditGuardianParent";
+    const DELETE_GUARDIAN_PARENT = "http://familysearch.org/v1/DeleteGuardianParent";
+    const ADD_STEP_PARENT = "http://familysearch.org/v1/AddStepParent";
+    const EDIT_STEP_PARENT = "http://familysearch.org/v1/EditStepParent";
+    const DELETE_STEP_PARENT = "http://familysearch.org/v1/DeleteStepParent";
+
+    // Other Person Event Changes
+    const ADD_OTHER_EVENT = "http://familysearch.org/v1/AddOtherEvent";
+    const EDIT_OTHER_EVENT = "http://familysearch.org/v1/EditOtherEvent";
+    const DELETE_OTHER_EVENT = "http://familysearch.org/v1/DeleteOtherEvent";
+
+    // Person Fact Changes
+    const ADD_CASTE_NAME = "http://familysearch.org/v1/AddCasteName";
+    const EDIT_CASTE_NAME = "http://familysearch.org/v1/EditCasteName";
+    const DELETE_CASTE_NAME = "http://familysearch.org/v1/DeleteCasteName";
+    const ADD_CLAN_NAME = "http://familysearch.org/v1/AddClanName";
+    const EDIT_CLAN_NAME = "http://familysearch.org/v1/EditClanName";
+    const DELETE_CLAN_NAME = "http://familysearch.org/v1/DeleteClanName";
+    const ADD_DIED_BEFORE_EIGHT = "http://familysearch.org/v1/AddDiedBeforeEight";
+    const EDIT_DIED_BEFORE_EIGHT = "http://familysearch.org/v1/EditDiedBeforeEight";
+    const DELETE_DIED_BEFORE_EIGHT = "http://familysearch.org/v1/DeleteDiedBeforeEight";
+    const ADD_LIFE_SKETCH = "http://familysearch.org/v1/AddLifeSketch";
+    const EDIT_LIFE_SKETCH = "http://familysearch.org/v1/EditLifeSketch";
+    const DELETE_LIFE_SKETCH = "http://familysearch.org/v1/DeleteLifeSketch";
+    const ADD_NATIONAL_ID = "http://familysearch.org/v1/AddNationalId";
+    const EDIT_NATIONAL_ID = "http://familysearch.org/v1/EditNationalId";
+    const DELETE_NATIONAL_ID = "http://familysearch.org/v1/DeleteNationalId";
+    const ADD_NATIONAL_ORIGIN = "http://familysearch.org/v1/AddNationalOrigin";
+    const EDIT_NATIONAL_ORIGIN = "http://familysearch.org/v1/EditNationalOrigin";
+    const DELETE_NATIONAL_ORIGIN = "http://familysearch.org/v1/DeleteNationalOrigin";
+    const ADD_PHYSICAL_DESCRIPTION = "http://familysearch.org/v1/AddPhysicalDescription";
+    const EDIT_PHYSICAL_DESCRIPTION = "http://familysearch.org/v1/EditPhysicalDescription";
+    const DELETE_PHYSICAL_DESCRIPTION = "http://familysearch.org/v1/DeletePhysicalDescription";
+    const ADD_RACE = "http://familysearch.org/v1/AddRace";
+    const EDIT_RACE = "http://familysearch.org/v1/EditRace";
+    const DELETE_RACE = "http://familysearch.org/v1/DeleteRace";
+    const ADD_TRIBE_NAME = "http://familysearch.org/v1/AddTribeName";
+    const EDIT_TRIBE_NAME = "http://familysearch.org/v1/EditTribeName";
+    const DELETE_TRIBE_NAME = "http://familysearch.org/v1/DeleteTribeName";
+    const ADD_OTHER_FACT = "http://familysearch.org/v1/AddOtherFact";
+    const EDIT_OTHER_FACT = "http://familysearch.org/v1/EditOtherFact";
+    const DELETE_OTHER_FACT = "http://familysearch.org/v1/DeleteOtherFact";
+
+    // Gender Changes
+    const ADD_GENDER = "http://familysearch.org/v1/AddGender";
+    const EDIT_GENDER = "http://familysearch.org/v1/EditGender";
+    const DELETE_GENDER = "http://familysearch.org/v1/DeleteGender";
+
+    // Name Changes
+    const ADD_BIRTH_NAME = "http://familysearch.org/v1/AddBirthName";
+    const EDIT_BIRTH_NAME = "http://familysearch.org/v1/EditBirthName";
+    const DELETE_BIRTH_NAME = "http://familysearch.org/v1/DeleteBirthName";
+    const ADD_AKA_NAME = "http://familysearch.org/v1/AddAkaName";
+    const EDIT_AKA_NAME = "http://familysearch.org/v1/EditAkaName";
+    const DELETE_AKA_NAME = "http://familysearch.org/v1/DeleteAkaName";
+    const ADD_ALTERNATE_NAME = "http://familysearch.org/v1/AddAlternateName";
+    const EDIT_ALTERNATE_NAME = "http://familysearch.org/v1/EditAlternateName";
+    const DELETE_ALTERNATE_NAME = "http://familysearch.org/v1/DeleteAlternateName";
+    const ADD_MARRIED_NAME = "http://familysearch.org/v1/AddMarriedName";
+    const EDIT_MARRIED_NAME = "http://familysearch.org/v1/EditMarriedName";
+    const DELETE_MARRIED_NAME = "http://familysearch.org/v1/DeleteMarriedName";
+    const ADD_NICK_NAME = "http://familysearch.org/v1/AddNickName";
+    const EDIT_NICK_NAME = "http://familysearch.org/v1/EditNickName";
+    const DELETE_NICK_NAME = "http://familysearch.org/v1/DeleteNickName";
+    const ADD_OTHER_NAME = "http://familysearch.org/v1/AddOtherName";
+    const EDIT_OTHER_NAME = "http://familysearch.org/v1/EditOtherName";
+    const DELETE_OTHER_NAME = "http://familysearch.org/v1/DeleteOtherName";
+
+    // Lineage Changes
+    const ADD_LINEAGE = "http://familysearch.org/v1/AddLineage";
+    const EDIT_LINEAGE = "http://familysearch.org/v1/EditLineage";
+    const DELETE_LINEAGE = "http://familysearch.org/v1/DeleteLineage";
+
+    // LDS Ordinance Changes
+    const COMPLETE_BAPTISM = "http://familysearch.org/v1/CompleteBaptism";
+    const COMPLETE_CONFIRMATION = "http://familysearch.org/v1/CompleteConfirmation";
+    const COMPLETE_INITIATORY = "http://familysearch.org/v1/CompleteInitiatory";
+    const COMPLETE_ENDOWMENT = "http://familysearch.org/v1/CompleteEndowment";
+    const COMPLETE_COUPLE_SEALING = "http://familysearch.org/v1/CompleteCoupleSealing";
+    const COMPLETE_SEALING_TO_PARENTS = "http://familysearch.org/v1/CompleteSealingToParents";
+
+    // Note Changes
+    const ADD_PERSON_NOTE = "http://familysearch.org/v1/AddPersonNote";
+    const EDIT_PERSON_NOTE = "http://familysearch.org/v1/EditPersonNote";
+    const DELETE_PERSON_NOTE = "http://familysearch.org/v1/DeletePersonNote";
+    const ADD_CHILD_PARENTS_NOTE = "http://familysearch.org/v1/AddChildParentsNote";
+    const EDIT_CHILD_PARENTS_NOTE = "http://familysearch.org/v1/EditChildParentsNote";
+    const DELETE_CHILD_PARENTS_NOTE = "http://familysearch.org/v1/DeleteChildParentsNote";
+    const ADD_COUPLE_NOTE = "http://familysearch.org/v1/AddCoupleNote";
+    const EDIT_COUPLE_NOTE = "http://familysearch.org/v1/EditCoupleNote";
+    const DELETE_COUPLE_NOTE = "http://familysearch.org/v1/DeleteCoupleNote";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/FamilySearchFactType.php b/src/Extensions/FamilySearch/Platform/Tree/FamilySearchFactType.php
new file mode 100644
index 00000000..6926c82f
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/FamilySearchFactType.php
@@ -0,0 +1,93 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of FamilySearch-specific fact types.
+ *
+ * These fact types extend the standard GEDCOM X fact types with FamilySearch-specific
+ * types used in the FamilySearch Family Tree.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class FamilySearchFactType
+{
+    /**
+     * Person fact type: Affiliation to something (e.g., organization, institution).
+     */
+    const AFFILIATION = "http://familysearch.org/v1/Affiliation";
+
+    /**
+     * Parent-Child fact type: A child's birth order relative to parents.
+     * Used to indicate the order in which children were born.
+     */
+    const BIRTH_ORDER = "http://familysearch.org/v1/BirthOrder";
+
+    /**
+     * Couple fact type: Indicates that a couple never had children.
+     * Used to document childless couples in genealogical records.
+     */
+    const COUPLE_NEVER_HAD_CHILDREN = "http://familysearch.org/v1/CoupleNeverHadChildren";
+
+    /**
+     * Person fact type: Person died before reaching age eight.
+     * Significant in LDS genealogy for ordinance work.
+     */
+    const DIED_BEFORE_EIGHT = "http://familysearch.org/v1/DiedBeforeEight";
+
+    /**
+     * Person fact type: A brief biographical narrative or "life sketch" of the person.
+     * Used to provide a summary of a person's life story.
+     */
+    const LIFE_SKETCH = "http://familysearch.org/v1/LifeSketch";
+
+    /**
+     * Couple fact type: Indicates that a couple lived together.
+     * May represent cohabitation without formal marriage.
+     */
+    const LIVED_TOGETHER = "http://familysearch.org/v1/LivedTogether";
+
+    /**
+     * Person fact type: Indicates that a person had no children.
+     * Documents the absence of offspring for genealogical completeness.
+     */
+    const NO_CHILDREN = "http://familysearch.org/v1/NoChildren";
+
+    /**
+     * Person fact type: Indicates that a person has no couple relationships.
+     * Documents that the person never married or entered a couple relationship.
+     */
+    const NO_COUPLE_RELATIONSHIPS = "http://familysearch.org/v1/NoCoupleRelationships";
+
+    /**
+     * Person fact type: A title of nobility held by the person.
+     * Examples include Duke, Baron, Earl, etc.
+     */
+    const TITLE_OF_NOBILITY = "http://familysearch.org/v1/TitleOfNobility";
+
+    /**
+     * Person fact type: The name of the tribe to which the person belongs.
+     * Used primarily for indigenous peoples and tribal affiliations.
+     */
+    const TRIBE_NAME = "http://familysearch.org/v1/TribeName";
+
+    /**
+     * Unknown or unrecognized fact type.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/FamilySearchIdentifierType.php b/src/Extensions/FamilySearch/Platform/Tree/FamilySearchIdentifierType.php
new file mode 100644
index 00000000..1f033577
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/FamilySearchIdentifierType.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of FamilySearch-specific identifier types.
+ *
+ * These identifier types are used to categorize various identifiers within the
+ * FamilySearch ecosystem, including Family Tree persons, memory persons, and
+ * child-and-parents relationships.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class FamilySearchIdentifierType
+{
+    /**
+     * The identifier for a child-and-parents relationship pair.
+     *
+     * In the FamilySearch Family Tree, this represents the unique identifier
+     * for the relationship between a child and their parent(s). This is distinct
+     * from individual person identifiers.
+     */
+    const CHILD_AND_PARENTS_RELATIONSHIP = "http://familysearch.org/v1/ChildAndParentsRelationship";
+
+    /**
+     * The identifier for a person in FamilySearch Memories.
+     *
+     * FamilySearch Memories allows users to attach photos, documents, and stories
+     * to persons. This identifier type is used for person references within the
+     * Memories system.
+     */
+    const MEMORY_PERSON = "http://familysearch.org/v1/MemoryPerson";
+
+    /**
+     * The identifier for a person in the FamilySearch Family Tree.
+     *
+     * This is the primary identifier type for persons in the collaborative
+     * FamilySearch Family Tree. These identifiers are used throughout the
+     * FamilySearch platform to reference individuals.
+     */
+    const FAMILY_TREE_PERSON = "http://familysearch.org/v1/FamilyTreePerson";
+
+    /**
+     * Unknown or unrecognized identifier type.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/FamilyTreeFactQualifierType.php b/src/Extensions/FamilySearch/Platform/Tree/FamilyTreeFactQualifierType.php
new file mode 100644
index 00000000..ea861a65
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/FamilyTreeFactQualifierType.php
@@ -0,0 +1,46 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of FamilySearch-specific fact qualifiers.
+ *
+ * Fact qualifiers provide additional context or classification for facts
+ * recorded in the FamilySearch Family Tree. These qualifiers help distinguish
+ * between different interpretations or uses of fact data.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class FamilyTreeFactQualifierType
+{
+    /**
+     * A fact is qualified as an 'event'.
+     *
+     * This qualifier indicates that a fact represents a specific event that
+     * occurred at a particular point in time, as opposed to a continuous state
+     * or characteristic. For example, a birth is an event, while a residence
+     * might be either an event (moved to a location) or a state (lived there
+     * for a period).
+     */
+    const EVENT = "http://familysearch.org/v1/Event";
+
+    /**
+     * Unknown or unrecognized qualifier type.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/Group.php b/src/Extensions/FamilySearch/Platform/Tree/Group.php
new file mode 100644
index 00000000..1181c556
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/Group.php
@@ -0,0 +1,447 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class Group
+ *
+ * A FamilySearch group for collaborative genealogy work.
+ *
+ * Groups allow multiple users to collaborate on genealogical research,
+ * sharing access to specific trees and coordinating their work. Each
+ * group has metadata, associated trees, and a list of members.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class Group
+{
+    /**
+     * The group id.
+     *
+     * Unique identifier for this group in the FamilySearch system.
+     *
+     * @var string
+     */
+    private $id;
+
+    /**
+     * The group name.
+     *
+     * Display name for the group, visible to all members.
+     *
+     * @var string
+     */
+    private $name;
+
+    /**
+     * The group description.
+     *
+     * Detailed description of the group's purpose and focus area.
+     *
+     * @var string
+     */
+    private $description;
+
+    /**
+     * The group code of conduct.
+     *
+     * Rules and guidelines for group member behavior and collaboration.
+     *
+     * @var string
+     */
+    private $codeOfConduct;
+
+    /**
+     * The ids of the trees associated with the group.
+     *
+     * Array of tree identifiers that this group has access to for
+     * collaborative work.
+     *
+     * @var string[]
+     */
+    private $treeIds;
+
+    /**
+     * The members of the group.
+     *
+     * Array of GroupMember objects representing the users who are
+     * part of this collaboration group.
+     *
+     * @var GroupMember[]
+     */
+    private $members;
+
+    /**
+     * Constructs a Group from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * Get the group id.
+     *
+     * @return string
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set the group id.
+     *
+     * @param string $id
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+    }
+
+    /**
+     * Get the group name.
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set the group name.
+     *
+     * @param string $name
+     */
+    public function setName($name)
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Get the group description.
+     *
+     * @return string
+     */
+    public function getDescription()
+    {
+        return $this->description;
+    }
+
+    /**
+     * Set the group description.
+     *
+     * @param string $description
+     */
+    public function setDescription($description)
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get the group code of conduct.
+     *
+     * @return string
+     */
+    public function getCodeOfConduct()
+    {
+        return $this->codeOfConduct;
+    }
+
+    /**
+     * Set the group code of conduct.
+     *
+     * @param string $codeOfConduct
+     */
+    public function setCodeOfConduct($codeOfConduct)
+    {
+        $this->codeOfConduct = $codeOfConduct;
+    }
+
+    /**
+     * Get the ids of the trees associated with the group.
+     *
+     * @return string[]
+     */
+    public function getTreeIds()
+    {
+        return $this->treeIds;
+    }
+
+    /**
+     * Set the ids of the trees associated with the group.
+     *
+     * @param string[] $treeIds
+     */
+    public function setTreeIds($treeIds)
+    {
+        $this->treeIds = $treeIds;
+    }
+
+    /**
+     * Get the members of the group.
+     *
+     * @return GroupMember[]
+     */
+    public function getMembers()
+    {
+        return $this->members;
+    }
+
+    /**
+     * Set the members of the group.
+     *
+     * @param GroupMember[] $members
+     */
+    public function setMembers($members)
+    {
+        $this->members = $members;
+    }
+
+    /**
+     * Add a member to the group.
+     *
+     * @param GroupMember $member
+     */
+    public function addMember($member)
+    {
+        if ($this->members === null) {
+            $this->members = array();
+        }
+        $this->members[] = $member;
+    }
+
+    /**
+     * Returns the associative array for this Group.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->id) {
+            $a["id"] = $this->id;
+        }
+        if ($this->name) {
+            $a["name"] = $this->name;
+        }
+        if ($this->description) {
+            $a["description"] = $this->description;
+        }
+        if ($this->codeOfConduct) {
+            $a["codeOfConduct"] = $this->codeOfConduct;
+        }
+        if ($this->treeIds) {
+            $a["treeIds"] = $this->treeIds;
+        }
+        if ($this->members) {
+            $ab = array();
+            foreach ($this->members as $i => $x) {
+                $ab[$i] = $x->toArray();
+            }
+            $a["members"] = $ab;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this Group.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this Group from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['id'])) {
+            $this->id = $o["id"];
+        }
+        if (isset($o['name'])) {
+            $this->name = $o["name"];
+        }
+        if (isset($o['description'])) {
+            $this->description = $o["description"];
+        }
+        if (isset($o['codeOfConduct'])) {
+            $this->codeOfConduct = $o["codeOfConduct"];
+        }
+        if (isset($o['treeIds'])) {
+            $this->treeIds = $o["treeIds"];
+        }
+        if (isset($o['members'])) {
+            $this->members = array();
+            foreach ($o['members'] as $i => $x) {
+                $this->members[$i] = new GroupMember($x);
+            }
+        }
+    }
+
+    /**
+     * Initializes this Group from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of Group from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        $happened = false;
+        if (($xml->localName == 'member') && ($xml->namespaceURI == 'http://familysearch.org/v1/')) {
+            if ($this->members === null) {
+                $this->members = array();
+            }
+            $child = new GroupMember($xml);
+            array_push($this->members, $child);
+            $happened = true;
+        }
+        else if (($xml->localName == 'treeId') && ($xml->namespaceURI == 'http://familysearch.org/v1/')) {
+            if ($this->treeIds === null) {
+                $this->treeIds = array();
+            }
+            $this->treeIds[] = $xml->readString();
+            $happened = true;
+        }
+        return $happened;
+    }
+
+    /**
+     * Sets a known attribute of Group from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Writes this Group to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'group', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this Group to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->id) {
+            $writer->writeElement('id', $this->id);
+        }
+        if ($this->name) {
+            $writer->writeElement('name', $this->name);
+        }
+        if ($this->description) {
+            $writer->writeElement('description', $this->description);
+        }
+        if ($this->codeOfConduct) {
+            $writer->writeElement('codeOfConduct', $this->codeOfConduct);
+        }
+        if ($this->treeIds) {
+            foreach ($this->treeIds as $treeId) {
+                $writer->writeElement('treeId', $treeId);
+            }
+        }
+        if ($this->members) {
+            foreach ($this->members as $member) {
+                $writer->startElementNS('fs', 'member', null);
+                $member->writeXmlContents($writer);
+                $writer->endElement();
+            }
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/GroupMember.php b/src/Extensions/FamilySearch/Platform/Tree/GroupMember.php
new file mode 100644
index 00000000..0519adc9
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/GroupMember.php
@@ -0,0 +1,327 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class GroupMember
+ *
+ * A member of a FamilySearch group.
+ *
+ * Groups in FamilySearch allow multiple users to collaborate on genealogical
+ * research. Each group has members with specific roles and permissions.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class GroupMember
+{
+    /**
+     * The id of the group.
+     *
+     * @var string
+     */
+    private $groupId;
+
+    /**
+     * The cisId of the group member.
+     *
+     * The CIS (Customer Identity System) ID is the unique identifier for
+     * the user in the FamilySearch system.
+     *
+     * @var string
+     */
+    private $cisId;
+
+    /**
+     * The contact name of the group member.
+     *
+     * The display name for the member, used in group member lists and
+     * collaboration interfaces.
+     *
+     * @var string
+     */
+    private $contactName;
+
+    /**
+     * The status of the group member.
+     *
+     * Indicates the member's current state within the group (e.g., active,
+     * invited, removed).
+     *
+     * @var string
+     */
+    private $status;
+
+    /**
+     * Constructs a GroupMember from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * Get the group id.
+     *
+     * @return string
+     */
+    public function getGroupId()
+    {
+        return $this->groupId;
+    }
+
+    /**
+     * Set the group id.
+     *
+     * @param string $groupId
+     */
+    public function setGroupId($groupId)
+    {
+        $this->groupId = $groupId;
+    }
+
+    /**
+     * Get the cisId of the group member.
+     *
+     * @return string
+     */
+    public function getCisId()
+    {
+        return $this->cisId;
+    }
+
+    /**
+     * Set the cisId of the group member.
+     *
+     * @param string $cisId
+     */
+    public function setCisId($cisId)
+    {
+        $this->cisId = $cisId;
+    }
+
+    /**
+     * Get the contact name of the group member.
+     *
+     * @return string
+     */
+    public function getContactName()
+    {
+        return $this->contactName;
+    }
+
+    /**
+     * Set the contact name of the group member.
+     *
+     * @param string $contactName
+     */
+    public function setContactName($contactName)
+    {
+        $this->contactName = $contactName;
+    }
+
+    /**
+     * Get the status of the group member.
+     *
+     * @return string
+     */
+    public function getStatus()
+    {
+        return $this->status;
+    }
+
+    /**
+     * Set the status of the group member.
+     *
+     * @param string $status
+     */
+    public function setStatus($status)
+    {
+        $this->status = $status;
+    }
+
+    /**
+     * Returns the associative array for this GroupMember.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->groupId) {
+            $a["groupId"] = $this->groupId;
+        }
+        if ($this->cisId) {
+            $a["cisId"] = $this->cisId;
+        }
+        if ($this->contactName) {
+            $a["contactName"] = $this->contactName;
+        }
+        if ($this->status) {
+            $a["status"] = $this->status;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this GroupMember.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this GroupMember from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['groupId'])) {
+            $this->groupId = $o["groupId"];
+        }
+        if (isset($o['cisId'])) {
+            $this->cisId = $o["cisId"];
+        }
+        if (isset($o['contactName'])) {
+            $this->contactName = $o["contactName"];
+        }
+        if (isset($o['status'])) {
+            $this->status = $o["status"];
+        }
+    }
+
+    /**
+     * Initializes this GroupMember from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of GroupMember from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Sets a known attribute of GroupMember from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Writes this GroupMember to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'groupMember', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this GroupMember to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->groupId) {
+            $writer->writeElement('groupId', $this->groupId);
+        }
+        if ($this->cisId) {
+            $writer->writeElement('cisId', $this->cisId);
+        }
+        if ($this->contactName) {
+            $writer->writeElement('contactName', $this->contactName);
+        }
+        if ($this->status) {
+            $writer->writeElement('status', $this->status);
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/MatchCollection.php b/src/Extensions/FamilySearch/Platform/Tree/MatchCollection.php
new file mode 100644
index 00000000..f35acf73
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/MatchCollection.php
@@ -0,0 +1,88 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Identifiers for collections that might contain match results.
+ *
+ * When performing duplicate detection or record matching in FamilySearch,
+ * results can come from various collections. This enumeration identifies
+ * the different collections that might contain matching records.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class MatchCollection
+{
+    /**
+     * The FamilySearch Public Family Tree collection.
+     *
+     * The main collaborative tree where users contribute and improve
+     * genealogical information.
+     */
+    const TREE = "https://familysearch.org/platform/collections/tree";
+
+    /**
+     * The FamilySearch Record Set collection.
+     *
+     * Historical records that have been indexed and made searchable,
+     * including vital records, census records, and other original sources.
+     */
+    const RECORDS = "https://familysearch.org/platform/collections/records";
+
+    /**
+     * The FamilySearch User-Submitted Trees collection (formerly LLS).
+     *
+     * Legacy trees submitted by users before the Public Family Tree.
+     */
+    const LLS = "https://familysearch.org/platform/collections/trees";
+
+    /**
+     * The FamilySearch CETs (deprecated).
+     *
+     * Community Extracted Trees - an older collection that has been superseded.
+     *
+     * @deprecated since 4.2.0
+     */
+    const CET = "https://familysearch.org/platform/collections/cet";
+
+    /**
+     * The FamilySearch User Trees collection.
+     *
+     * Individual user-maintained trees separate from the collaborative tree.
+     */
+    const USER_TREES = "https://familysearch.org/platform/collections/user_trees";
+
+    /**
+     * The FamilySearch Temple System collection.
+     *
+     * Records related to LDS temple ordinances.
+     */
+    const TSS = "https://familysearch.org/platform/collections/temple";
+
+    /**
+     * The FamilySearch Assisted Tree Building System.
+     *
+     * System for suggesting and building family relationships automatically.
+     */
+    const ATB = "https://familysearch.org/platform/collections/atb";
+
+    /**
+     * Unknown or custom collection.
+     */
+    const OTHER = "https://familysearch.org/platform/collections/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/NameFormInfo.php b/src/Extensions/FamilySearch/Platform/Tree/NameFormInfo.php
new file mode 100644
index 00000000..833ae4f3
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/NameFormInfo.php
@@ -0,0 +1,220 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class NameFormInfo
+ *
+ * Information about a name form, specifically its ordering convention.
+ *
+ * A name form represents a single representation of a person's name, and may
+ * have different orderings depending on cultural conventions. This class
+ * provides metadata about how the name parts should be ordered.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class NameFormInfo
+{
+    /**
+     * The ordering of the name form.
+     *
+     * Specifies whether this name form uses Eurotypic (Western) ordering
+     * where given name comes first, or Sinotypic (Eastern) ordering where
+     * surname comes first.
+     *
+     * @var string
+     */
+    private $order;
+
+    /**
+     * Constructs a NameFormInfo from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * The ordering of the name form.
+     *
+     * @return string The URI representing the name form order (Eurotypic or Sinotypic).
+     */
+    public function getOrder()
+    {
+        return $this->order;
+    }
+
+    /**
+     * The ordering of the name form.
+     *
+     * @param string $order The URI representing the name form order.
+     */
+    public function setOrder($order)
+    {
+        $this->order = $order;
+    }
+
+    /**
+     * Returns the associative array for this NameFormInfo.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->order) {
+            $a["order"] = $this->order;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this NameFormInfo.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this NameFormInfo from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['order'])) {
+            $this->order = $o["order"];
+        }
+    }
+
+    /**
+     * Initializes this NameFormInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of NameFormInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Sets a known attribute of NameFormInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        if (($xml->localName == 'order') && (empty($xml->namespaceURI))) {
+            $this->order = $xml->value;
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Writes this NameFormInfo to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'nameFormInfo', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this NameFormInfo to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->order) {
+            $writer->writeAttribute('order', $this->order);
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/NameFormOrder.php b/src/Extensions/FamilySearch/Platform/Tree/NameFormOrder.php
new file mode 100644
index 00000000..66a403e2
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/NameFormOrder.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of name form ordering types.
+ *
+ * Name forms can be ordered differently depending on cultural conventions.
+ * Eurotypic ordering places the given name first, followed by the surname
+ * (e.g., "John Smith"). Sinotypic ordering places the surname first, followed
+ * by the given name (e.g., "Smith John" or in Chinese: 李明).
+ *
+ * This is particularly important for international genealogy where different
+ * cultures have different conventions for name ordering.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class NameFormOrder
+{
+    /**
+     * Eurotypic name ordering (Western style).
+     *
+     * Given name comes first, followed by surname.
+     * Example: "John Smith"
+     *
+     * This is the standard ordering for most Western European languages
+     * and cultures, including English, Spanish, French, German, etc.
+     */
+    const EUROTYPIC = "http://familysearch.org/v1/Eurotypic";
+
+    /**
+     * Sinotypic name ordering (Eastern style).
+     *
+     * Surname comes first, followed by given name.
+     * Example: "Smith John" or in Chinese: "李明" (Li Ming)
+     *
+     * This is the standard ordering for Chinese, Japanese, Korean, Vietnamese,
+     * and Hungarian names, among others.
+     */
+    const SINOTYPIC = "http://familysearch.org/v1/Sinotypic";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/PersonInfo.php b/src/Extensions/FamilySearch/Platform/Tree/PersonInfo.php
new file mode 100644
index 00000000..7cce7f1d
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/PersonInfo.php
@@ -0,0 +1,350 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class PersonInfo
+ *
+ * Extra information about a person in the FamilySearch Family Tree.
+ *
+ * This class provides metadata about a person's permissions and visibility
+ * settings, including whether the current user can edit the person and what
+ * access restrictions are in place.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class PersonInfo
+{
+    /**
+     * True if the person is editable by the current user; false otherwise.
+     *
+     * This indicates whether the currently authenticated user has permission
+     * to make changes to this person's information in the Family Tree.
+     *
+     * @var bool
+     */
+    private $canUserEdit = false;
+
+    /**
+     * True if the person is visible to all sessions authenticated from any client; false otherwise.
+     *
+     * This controls the broadest level of visibility. When false, the person
+     * may have restricted access based on who is viewing or from what application.
+     *
+     * @var bool
+     */
+    private $visibleToAll = true;
+
+    /**
+     * True if the person is only visible to sessions authenticated from a FamilySearch client; false otherwise.
+     *
+     * This provides a middle tier of visibility restriction, allowing access only
+     * through official FamilySearch applications while still restricting third-party access.
+     *
+     * @var bool
+     */
+    private $visibleToAllWhenUsingFamilySearchApps = true;
+
+    /**
+     * The tree id for this person.
+     *
+     * Note: This attribute is prototype only and may be removed or changed at any time.
+     * Used to identify which tree (in multi-tree scenarios) this person belongs to.
+     *
+     * @var string
+     */
+    private $treeId;
+
+    /**
+     * Constructs a PersonInfo from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * True if the person is editable by the current user; false otherwise.
+     *
+     * @return bool
+     */
+    public function getCanUserEdit()
+    {
+        return $this->canUserEdit;
+    }
+
+    /**
+     * True if the person is editable by the current user; false otherwise.
+     *
+     * @param bool $canUserEdit
+     */
+    public function setCanUserEdit($canUserEdit)
+    {
+        $this->canUserEdit = $canUserEdit;
+    }
+
+    /**
+     * True if the person is visible to all sessions authenticated from any client; false otherwise.
+     *
+     * @return bool
+     */
+    public function getVisibleToAll()
+    {
+        return $this->visibleToAll;
+    }
+
+    /**
+     * True if the person is visible to all sessions authenticated from any client; false otherwise.
+     *
+     * @param bool $visibleToAll
+     */
+    public function setVisibleToAll($visibleToAll)
+    {
+        $this->visibleToAll = $visibleToAll;
+    }
+
+    /**
+     * True if the person is only visible to sessions authenticated from a FamilySearch client; false otherwise.
+     *
+     * @return bool
+     */
+    public function getVisibleToAllWhenUsingFamilySearchApps()
+    {
+        return $this->visibleToAllWhenUsingFamilySearchApps;
+    }
+
+    /**
+     * True if the person is only visible to sessions authenticated from a FamilySearch client; false otherwise.
+     *
+     * @param bool $visibleToAllWhenUsingFamilySearchApps
+     */
+    public function setVisibleToAllWhenUsingFamilySearchApps($visibleToAllWhenUsingFamilySearchApps)
+    {
+        $this->visibleToAllWhenUsingFamilySearchApps = $visibleToAllWhenUsingFamilySearchApps;
+    }
+
+    /**
+     * The tree id for this person.
+     * Note: This attribute is prototype only and may be removed or changed at any time.
+     *
+     * @return string
+     */
+    public function getTreeId()
+    {
+        return $this->treeId;
+    }
+
+    /**
+     * The tree id for this person.
+     * Note: This attribute is prototype only and may be removed or changed at any time.
+     *
+     * @param string $treeId
+     */
+    public function setTreeId($treeId)
+    {
+        $this->treeId = $treeId;
+    }
+
+    /**
+     * Returns the associative array for this PersonInfo.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->canUserEdit !== null) {
+            $a["canUserEdit"] = $this->canUserEdit;
+        }
+        if ($this->visibleToAll !== null) {
+            $a["visibleToAll"] = $this->visibleToAll;
+        }
+        if ($this->visibleToAllWhenUsingFamilySearchApps !== null) {
+            $a["visibleToAllWhenUsingFamilySearchApps"] = $this->visibleToAllWhenUsingFamilySearchApps;
+        }
+        if ($this->treeId) {
+            $a["treeId"] = $this->treeId;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this PersonInfo.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this PersonInfo from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['canUserEdit'])) {
+            $this->canUserEdit = $o["canUserEdit"];
+        }
+        if (isset($o['visibleToAll'])) {
+            $this->visibleToAll = $o["visibleToAll"];
+        }
+        if (isset($o['visibleToAllWhenUsingFamilySearchApps'])) {
+            $this->visibleToAllWhenUsingFamilySearchApps = $o["visibleToAllWhenUsingFamilySearchApps"];
+        }
+        if (isset($o['treeId'])) {
+            $this->treeId = $o["treeId"];
+        }
+    }
+
+    /**
+     * Initializes this PersonInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of PersonInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Sets a known attribute of PersonInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        if (($xml->localName == 'canUserEdit') && (empty($xml->namespaceURI))) {
+            $this->canUserEdit = (strtolower($xml->value) === 'true' || $xml->value === '1');
+            return true;
+        }
+        if (($xml->localName == 'visibleToAll') && (empty($xml->namespaceURI))) {
+            $this->visibleToAll = (strtolower($xml->value) === 'true' || $xml->value === '1');
+            return true;
+        }
+        if (($xml->localName == 'visibleToAllWhenUsingFamilySearchApps') && (empty($xml->namespaceURI))) {
+            $this->visibleToAllWhenUsingFamilySearchApps = (strtolower($xml->value) === 'true' || $xml->value === '1');
+            return true;
+        }
+        if (($xml->localName == 'treeId') && (empty($xml->namespaceURI))) {
+            $this->treeId = $xml->value;
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Writes this PersonInfo to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'personInfo', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this PersonInfo to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->canUserEdit !== null) {
+            $writer->writeAttribute('canUserEdit', $this->canUserEdit ? 'true' : 'false');
+        }
+        if ($this->visibleToAll !== null) {
+            $writer->writeAttribute('visibleToAll', $this->visibleToAll ? 'true' : 'false');
+        }
+        if ($this->visibleToAllWhenUsingFamilySearchApps !== null) {
+            $writer->writeAttribute('visibleToAllWhenUsingFamilySearchApps', $this->visibleToAllWhenUsingFamilySearchApps ? 'true' : 'false');
+        }
+        if ($this->treeId) {
+            $writer->writeAttribute('treeId', $this->treeId);
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/RelationshipRole.php b/src/Extensions/FamilySearch/Platform/Tree/RelationshipRole.php
new file mode 100644
index 00000000..20a99caf
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/RelationshipRole.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of relationship roles in the FamilySearch Family Tree.
+ *
+ * These roles define the positions individuals hold within family relationships.
+ * The FamilySearch Family Tree uses a neutral numbering system (Parent1/Parent2,
+ * Spouse1/Spouse2) to avoid gender assumptions and accommodate diverse family
+ * structures.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class RelationshipRole
+{
+    /**
+     * The first parent in a child-and-parents relationship.
+     *
+     * Parent1 is typically (but not always) the mother in traditional records,
+     * but the FamilySearch Family Tree uses this neutral terminology to avoid
+     * making assumptions about gender roles or family structure.
+     */
+    const PARENT1 = "http://familysearch.org/v1/Parent1";
+
+    /**
+     * The second parent in a child-and-parents relationship.
+     *
+     * Parent2 is typically (but not always) the father in traditional records,
+     * but the FamilySearch Family Tree uses this neutral terminology to avoid
+     * making assumptions about gender roles or family structure.
+     */
+    const PARENT2 = "http://familysearch.org/v1/Parent2";
+
+    /**
+     * The child in a child-and-parents relationship.
+     *
+     * Represents the offspring in the parent-child relationship. A person can
+     * be a child in one relationship and a parent in another.
+     */
+    const CHILD = "http://familysearch.org/v1/Child";
+
+    /**
+     * The first spouse in a couple relationship.
+     *
+     * Spouse1 represents one partner in a couple relationship. The numbering
+     * is arbitrary and does not imply any hierarchy or traditional gender roles.
+     */
+    const SPOUSE1 = "http://familysearch.org/v1/Spouse1";
+
+    /**
+     * The second spouse in a couple relationship.
+     *
+     * Spouse2 represents the other partner in a couple relationship. The numbering
+     * is arbitrary and does not imply any hierarchy or traditional gender roles.
+     */
+    const SPOUSE2 = "http://familysearch.org/v1/Spouse2";
+
+    /**
+     * Unknown or unrecognized relationship role.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/SearchCollection.php b/src/Extensions/FamilySearch/Platform/Tree/SearchCollection.php
new file mode 100644
index 00000000..44629ad3
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/SearchCollection.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Identifiers for collections that might contain search results.
+ *
+ * When performing searches in FamilySearch, results can come from various
+ * collections. This enumeration identifies the different searchable collections
+ * and provides collection IDs for API usage.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class SearchCollection
+{
+    /**
+     * The FamilySearch Public Family Tree.
+     * Collection ID: "0"
+     */
+    const TREE = "https://familysearch.org/platform/collections/tree";
+    const TREE_ID = "0";
+
+    /**
+     * The FamilySearch CETs (deprecated).
+     * Collection ID: "10"
+     *
+     * @deprecated since 4.2.0
+     */
+    const CET = "https://familysearch.org/platform/collections/cet";
+    const CET_ID = "10";
+
+    /**
+     * The FamilySearch User Trees.
+     * Collection ID: "10"
+     */
+    const USER_TREES = "https://familysearch.org/platform/collections/user_trees";
+    const USER_TREES_ID = "10";
+
+    /**
+     * Unknown or custom collection.
+     */
+    const OTHER = "https://familysearch.org/platform/collections/OTHER";
+
+    /**
+     * Get the collection ID for a given collection constant.
+     *
+     * @param string $collection The collection constant value
+     * @return string|null The collection ID, or null if unknown
+     */
+    public static function getId($collection)
+    {
+        switch ($collection) {
+            case self::TREE:
+                return self::TREE_ID;
+            case self::CET:
+                return self::CET_ID;
+            case self::USER_TREES:
+                return self::USER_TREES_ID;
+            default:
+                return null;
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/SearchInfo.php b/src/Extensions/FamilySearch/Platform/Tree/SearchInfo.php
new file mode 100644
index 00000000..32a5e7ed
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/SearchInfo.php
@@ -0,0 +1,254 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class SearchInfo
+ *
+ * Information about search results, including hit counts.
+ *
+ * This class provides metadata about search operations performed in the
+ * FamilySearch Family Tree, including the total number of matches found
+ * and how many of those are considered "close" matches with high confidence.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class SearchInfo
+{
+    /**
+     * The total number of search hits.
+     *
+     * This represents all matches found for the search query, including
+     * both high-confidence matches and lower-confidence possibilities.
+     *
+     * @var int
+     */
+    private $totalHits;
+
+    /**
+     * The number of close hits.
+     *
+     * This represents the subset of total hits that are considered
+     * high-confidence matches. These are matches that are more likely
+     * to be correct based on the search algorithm's scoring.
+     *
+     * @var int
+     */
+    private $closeHits;
+
+    /**
+     * Constructs a SearchInfo from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * The total number of search hits.
+     *
+     * @return int
+     */
+    public function getTotalHits()
+    {
+        return $this->totalHits;
+    }
+
+    /**
+     * The total number of search hits.
+     *
+     * @param int $totalHits
+     */
+    public function setTotalHits($totalHits)
+    {
+        $this->totalHits = $totalHits;
+    }
+
+    /**
+     * The number of close hits.
+     *
+     * @return int
+     */
+    public function getCloseHits()
+    {
+        return $this->closeHits;
+    }
+
+    /**
+     * The number of close hits.
+     *
+     * @param int $closeHits
+     */
+    public function setCloseHits($closeHits)
+    {
+        $this->closeHits = $closeHits;
+    }
+
+    /**
+     * Returns the associative array for this SearchInfo.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->totalHits !== null) {
+            $a["totalHits"] = $this->totalHits;
+        }
+        if ($this->closeHits !== null) {
+            $a["closeHits"] = $this->closeHits;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this SearchInfo.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this SearchInfo from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['totalHits'])) {
+            $this->totalHits = $o["totalHits"];
+        }
+        if (isset($o['closeHits'])) {
+            $this->closeHits = $o["closeHits"];
+        }
+    }
+
+    /**
+     * Initializes this SearchInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of SearchInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Sets a known attribute of SearchInfo from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Writes this SearchInfo to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'searchInfo', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this SearchInfo to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->totalHits !== null) {
+            $writer->writeElement('totalHits', $this->totalHits);
+        }
+        if ($this->closeHits !== null) {
+            $writer->writeElement('closeHits', $this->closeHits);
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/SourceReferenceTagType.php b/src/Extensions/FamilySearch/Platform/Tree/SourceReferenceTagType.php
new file mode 100644
index 00000000..4a937650
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/SourceReferenceTagType.php
@@ -0,0 +1,54 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of source reference tag types.
+ *
+ * Source reference tags categorize what type of information a source provides
+ * or verifies. This helps users understand what aspects of a person's record
+ * are supported by each source in the FamilySearch Family Tree.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class SourceReferenceTagType
+{
+    /**
+     * Source reference tag type: Name.
+     *
+     * Indicates that the source provides or verifies information about
+     * a person's name. This could include given names, surnames, nicknames,
+     * married names, or other name variations.
+     */
+    const NAME = "http://gedcomx.org/Name";
+
+    /**
+     * Source reference tag type: Gender.
+     *
+     * Indicates that the source provides or verifies information about
+     * a person's gender. This is particularly important when historical
+     * records use gender-ambiguous names or when correcting gender
+     * information in the tree.
+     */
+    const GENDER = "http://gedcomx.org/Gender";
+
+    /**
+     * Unknown or custom source reference tag type.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/ThirdPartyAccess.php b/src/Extensions/FamilySearch/Platform/Tree/ThirdPartyAccess.php
new file mode 100644
index 00000000..b0ee526a
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/ThirdPartyAccess.php
@@ -0,0 +1,61 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Enumeration of third party access restrictions that can be set on a tree.
+ *
+ * These settings control what third-party applications can access a tree
+ * and its data. Access restrictions can be set differently for the tree owner
+ * and for group members.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class ThirdPartyAccess
+{
+    /**
+     * Allows the group owner or group members to access the tree from any third-party application.
+     *
+     * This is the most permissive setting, allowing access from any application
+     * that has been granted API access to FamilySearch. Group owner access cannot
+     * be more restrictive than group member access.
+     */
+    const ANY_APPS = "http://familysearch.org/v1/AnyApps";
+
+    /**
+     * Restricts the group owner or group members to access tree only from applications
+     * owned by the company that owns the application that created the tree.
+     *
+     * This provides a middle tier of access control, allowing only applications
+     * from the same organization to access the tree data.
+     */
+    const COMPANY_APPS = "http://familysearch.org/v1/CompanyApps";
+
+    /**
+     * Disallows the group members access to the tree from all third-party applications.
+     *
+     * This is the most restrictive setting. Note that owner access cannot be set
+     * to None - the tree owner must maintain at least some level of third-party access.
+     */
+    const NONE = "http://familysearch.org/v1/None";
+
+    /**
+     * Unknown or custom access level.
+     */
+    const OTHER = "http://familysearch.org/v1/OTHER";
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/Tree.php b/src/Extensions/FamilySearch/Platform/Tree/Tree.php
new file mode 100644
index 00000000..29ed75cc
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/Tree.php
@@ -0,0 +1,610 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+/**
+ * Class Tree
+ *
+ * A FamilySearch tree for genealogical research.
+ *
+ * Trees in FamilySearch represent collections of genealogical data that can be
+ * private to an individual, shared with a group, or part of the collaborative
+ * public tree. Each tree has access controls, metadata, and relationships to
+ * groups and persons.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class Tree
+{
+    /**
+     * The tree id.
+     *
+     * Unique identifier for this tree in the FamilySearch system.
+     *
+     * @var string
+     */
+    private $id;
+
+    /**
+     * The ids of the groups this tree belongs to.
+     *
+     * Array of group identifiers that have access to this tree for
+     * collaborative research.
+     *
+     * @var string[]
+     */
+    private $groupIds;
+
+    /**
+     * The tree name.
+     *
+     * Display name for the tree, visible to users with access.
+     *
+     * @var string
+     */
+    private $name;
+
+    /**
+     * The tree description.
+     *
+     * Detailed description of the tree's scope and purpose.
+     *
+     * @var string
+     */
+    private $description;
+
+    /**
+     * The tree starting person id.
+     *
+     * The person who serves as the root or starting point for this tree,
+     * typically the tree owner or a key ancestor.
+     *
+     * @var string
+     */
+    private $startingPersonId;
+
+    /**
+     * The hidden state of the tree.
+     *
+     * If true, the tree is hidden from certain views or listings.
+     *
+     * @var bool
+     */
+    private $hidden;
+
+    /**
+     * The private state of the tree.
+     *
+     * If true, the tree is private and access is restricted. Note that
+     * "private" is a reserved word in PHP, so we use "isPrivate" internally.
+     *
+     * @var bool
+     */
+    private $isPrivate;
+
+    /**
+     * The id of the collection the tree belongs to.
+     *
+     * Identifies which FamilySearch collection this tree is part of.
+     *
+     * @var string
+     */
+    private $collectionId;
+
+    /**
+     * The owner third party access state of the tree.
+     *
+     * Controls what third-party applications the tree owner can use to
+     * access this tree. See ThirdPartyAccess for possible values.
+     *
+     * @var string
+     */
+    private $ownerAccess;
+
+    /**
+     * The group third party access state of the tree.
+     *
+     * Controls what third-party applications group members can use to
+     * access this tree. See ThirdPartyAccess for possible values.
+     *
+     * @var string
+     */
+    private $groupAccess;
+
+    /**
+     * All third party access state of the tree.
+     *
+     * Controls the broadest level of third-party access to the tree.
+     * See ThirdPartyAccess for possible values.
+     *
+     * @var string
+     */
+    private $allAccess;
+
+    /**
+     * Constructs a Tree from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        if (is_array($o)) {
+            $this->initFromArray($o);
+        }
+        else if ($o instanceof \XMLReader) {
+            $success = true;
+            while ($success && $o->nodeType != \XMLReader::ELEMENT) {
+                $success = $o->read();
+            }
+            if ($o->nodeType != \XMLReader::ELEMENT) {
+                throw new \Exception("Unable to read XML: no start element found.");
+            }
+
+            $this->initFromReader($o);
+        }
+    }
+
+    /**
+     * Get the tree id.
+     *
+     * @return string
+     */
+    public function getId()
+    {
+        return $this->id;
+    }
+
+    /**
+     * Set the tree id.
+     *
+     * @param string $id
+     */
+    public function setId($id)
+    {
+        $this->id = $id;
+    }
+
+    /**
+     * Get the ids of the groups this tree belongs to.
+     *
+     * @return string[]
+     */
+    public function getGroupIds()
+    {
+        return $this->groupIds;
+    }
+
+    /**
+     * Set the ids of the groups this tree belongs to.
+     *
+     * @param string[] $groupIds
+     */
+    public function setGroupIds($groupIds)
+    {
+        $this->groupIds = $groupIds;
+    }
+
+    /**
+     * Get the tree name.
+     *
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Set the tree name.
+     *
+     * @param string $name
+     */
+    public function setName($name)
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * Get the tree description.
+     *
+     * @return string
+     */
+    public function getDescription()
+    {
+        return $this->description;
+    }
+
+    /**
+     * Set the tree description.
+     *
+     * @param string $description
+     */
+    public function setDescription($description)
+    {
+        $this->description = $description;
+    }
+
+    /**
+     * Get the tree starting person id.
+     *
+     * @return string
+     */
+    public function getStartingPersonId()
+    {
+        return $this->startingPersonId;
+    }
+
+    /**
+     * Set the tree starting person id.
+     *
+     * @param string $startingPersonId
+     */
+    public function setStartingPersonId($startingPersonId)
+    {
+        $this->startingPersonId = $startingPersonId;
+    }
+
+    /**
+     * Get the hidden state of the tree.
+     *
+     * @return bool
+     */
+    public function getHidden()
+    {
+        return $this->hidden;
+    }
+
+    /**
+     * Set the hidden state of the tree.
+     *
+     * @param bool $hidden
+     */
+    public function setHidden($hidden)
+    {
+        $this->hidden = $hidden;
+    }
+
+    /**
+     * Get the private state of the tree.
+     *
+     * @return bool
+     */
+    public function getPrivate()
+    {
+        return $this->isPrivate;
+    }
+
+    /**
+     * Set the private state of the tree.
+     *
+     * @param bool $isPrivate
+     */
+    public function setPrivate($isPrivate)
+    {
+        $this->isPrivate = $isPrivate;
+    }
+
+    /**
+     * Get the id of the collection the tree belongs to.
+     *
+     * @return string
+     */
+    public function getCollectionId()
+    {
+        return $this->collectionId;
+    }
+
+    /**
+     * Set the id of the collection the tree belongs to.
+     *
+     * @param string $collectionId
+     */
+    public function setCollectionId($collectionId)
+    {
+        $this->collectionId = $collectionId;
+    }
+
+    /**
+     * Get the owner third party access state of the tree.
+     *
+     * @return string
+     */
+    public function getOwnerAccess()
+    {
+        return $this->ownerAccess;
+    }
+
+    /**
+     * Set the owner third party access state of the tree.
+     *
+     * @param string $ownerAccess
+     */
+    public function setOwnerAccess($ownerAccess)
+    {
+        $this->ownerAccess = $ownerAccess;
+    }
+
+    /**
+     * Get the group third party access state of the tree.
+     *
+     * @return string
+     */
+    public function getGroupAccess()
+    {
+        return $this->groupAccess;
+    }
+
+    /**
+     * Set the group third party access state of the tree.
+     *
+     * @param string $groupAccess
+     */
+    public function setGroupAccess($groupAccess)
+    {
+        $this->groupAccess = $groupAccess;
+    }
+
+    /**
+     * Get the all third party access state of the tree.
+     *
+     * @return string
+     */
+    public function getAllAccess()
+    {
+        return $this->allAccess;
+    }
+
+    /**
+     * Set the all third party access state of the tree.
+     *
+     * @param string $allAccess
+     */
+    public function setAllAccess($allAccess)
+    {
+        $this->allAccess = $allAccess;
+    }
+
+    /**
+     * Returns the associative array for this Tree.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = array();
+        if ($this->id) {
+            $a["id"] = $this->id;
+        }
+        if ($this->groupIds) {
+            $a["groupIds"] = $this->groupIds;
+        }
+        if ($this->name) {
+            $a["name"] = $this->name;
+        }
+        if ($this->description) {
+            $a["description"] = $this->description;
+        }
+        if ($this->startingPersonId) {
+            $a["startingPersonId"] = $this->startingPersonId;
+        }
+        if ($this->hidden !== null) {
+            $a["hidden"] = $this->hidden;
+        }
+        if ($this->isPrivate !== null) {
+            $a["private"] = $this->isPrivate;
+        }
+        if ($this->collectionId) {
+            $a["collectionId"] = $this->collectionId;
+        }
+        if ($this->ownerAccess) {
+            $a["ownerAccess"] = $this->ownerAccess;
+        }
+        if ($this->groupAccess) {
+            $a["groupAccess"] = $this->groupAccess;
+        }
+        if ($this->allAccess) {
+            $a["allAccess"] = $this->allAccess;
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this Tree.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this Tree from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        if (isset($o['id'])) {
+            $this->id = $o["id"];
+        }
+        if (isset($o['groupIds'])) {
+            $this->groupIds = $o["groupIds"];
+        }
+        if (isset($o['name'])) {
+            $this->name = $o["name"];
+        }
+        if (isset($o['description'])) {
+            $this->description = $o["description"];
+        }
+        if (isset($o['startingPersonId'])) {
+            $this->startingPersonId = $o["startingPersonId"];
+        }
+        if (isset($o['hidden'])) {
+            $this->hidden = $o["hidden"];
+        }
+        if (isset($o['private'])) {
+            $this->isPrivate = $o["private"];
+        }
+        if (isset($o['collectionId'])) {
+            $this->collectionId = $o["collectionId"];
+        }
+        if (isset($o['ownerAccess'])) {
+            $this->ownerAccess = $o["ownerAccess"];
+        }
+        if (isset($o['groupAccess'])) {
+            $this->groupAccess = $o["groupAccess"];
+        }
+        if (isset($o['allAccess'])) {
+            $this->allAccess = $o["allAccess"];
+        }
+    }
+
+    /**
+     * Initializes this Tree from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        $empty = $xml->isEmptyElement;
+
+        if ($xml->hasAttributes) {
+            $moreAttributes = $xml->moveToFirstAttribute();
+            while ($moreAttributes) {
+                if (!$this->setKnownAttribute($xml)) {
+                    //skip unknown attributes...
+                }
+                $moreAttributes = $xml->moveToNextAttribute();
+            }
+        }
+
+        if (!$empty) {
+            $xml->read();
+            while ($xml->nodeType != \XMLReader::END_ELEMENT) {
+                if ($xml->nodeType != \XMLReader::ELEMENT) {
+                    //no-op: skip any insignificant whitespace, comments, etc.
+                }
+                else if (!$this->setKnownChildElement($xml)) {
+                    $n = $xml->localName;
+                    $ns = $xml->namespaceURI;
+                    //skip the unknown element
+                    while ($xml->nodeType != \XMLReader::END_ELEMENT && $xml->localName != $n && $xml->namespaceURI != $ns) {
+                        $xml->read();
+                    }
+                }
+                $xml->read(); //advance the reader.
+            }
+        }
+    }
+
+    /**
+     * Sets a known child element of Tree from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        $happened = false;
+        if (($xml->localName == 'groupId') && ($xml->namespaceURI == 'http://familysearch.org/v1/')) {
+            if ($this->groupIds === null) {
+                $this->groupIds = array();
+            }
+            $this->groupIds[] = $xml->readString();
+            $happened = true;
+        }
+        return $happened;
+    }
+
+    /**
+     * Sets a known attribute of Tree from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        return false;
+    }
+
+    /**
+     * Writes this Tree to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'tree', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this Tree to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        if ($this->id) {
+            $writer->writeElement('id', $this->id);
+        }
+        if ($this->groupIds) {
+            foreach ($this->groupIds as $groupId) {
+                $writer->writeElement('groupId', $groupId);
+            }
+        }
+        if ($this->name) {
+            $writer->writeElement('name', $this->name);
+        }
+        if ($this->description) {
+            $writer->writeElement('description', $this->description);
+        }
+        if ($this->startingPersonId) {
+            $writer->writeElement('startingPersonId', $this->startingPersonId);
+        }
+        if ($this->hidden !== null) {
+            $writer->writeElement('hidden', $this->hidden ? 'true' : 'false');
+        }
+        if ($this->isPrivate !== null) {
+            $writer->writeElement('private', $this->isPrivate ? 'true' : 'false');
+        }
+        if ($this->collectionId) {
+            $writer->writeElement('collectionId', $this->collectionId);
+        }
+        if ($this->ownerAccess) {
+            $writer->writeElement('ownerAccess', $this->ownerAccess);
+        }
+        if ($this->groupAccess) {
+            $writer->writeElement('groupAccess', $this->groupAccess);
+        }
+        if ($this->allAccess) {
+            $writer->writeElement('allAccess', $this->allAccess);
+        }
+    }
+}
diff --git a/src/Extensions/FamilySearch/Platform/Tree/TreePersonReference.php b/src/Extensions/FamilySearch/Platform/Tree/TreePersonReference.php
new file mode 100644
index 00000000..6eea9de2
--- /dev/null
+++ b/src/Extensions/FamilySearch/Platform/Tree/TreePersonReference.php
@@ -0,0 +1,286 @@
+<?php
+/**
+ * Copyright Intellectual Reserve, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Gedcomx\Extensions\FamilySearch\Platform\Tree;
+
+use Gedcomx\Common\Attribution;
+use Gedcomx\Common\ResourceReference;
+use Gedcomx\Links\HypermediaEnabledData;
+
+/**
+ * Class TreePersonReference
+ *
+ * A reference to another person in a different FamilySearch tree that may be
+ * a representation of the same individual.
+ *
+ * In FamilySearch, different trees (such as private user trees, group trees,
+ * and the public tree) may contain representations of the same person. This
+ * class provides a way to link between these representations, facilitating
+ * data sharing and duplicate detection across tree boundaries.
+ *
+ * @package Gedcomx\Extensions\FamilySearch\Platform\Tree
+ */
+class TreePersonReference extends HypermediaEnabledData
+{
+    /**
+     * The person referenced in another tree.
+     *
+     * A ResourceReference pointing to the person record in the other tree
+     * that represents the same individual.
+     *
+     * @var ResourceReference
+     */
+    private $treePerson;
+
+    /**
+     * The tree containing the person referenced.
+     *
+     * A ResourceReference identifying which tree contains the referenced
+     * person record.
+     *
+     * @var ResourceReference
+     */
+    private $tree;
+
+    /**
+     * The attribution metadata for this tree person reference.
+     *
+     * Information about who created this reference link and when, useful
+     * for tracking the history of cross-tree connections.
+     *
+     * @var Attribution
+     */
+    private $attribution;
+
+    /**
+     * Constructs a TreePersonReference from a (parsed) JSON hash or XML reader.
+     *
+     * @param mixed $o Either an array (JSON) or an XMLReader.
+     *
+     * @throws \Exception
+     */
+    public function __construct($o = null)
+    {
+        parent::__construct($o);
+    }
+
+    /**
+     * Gets the reference to the person in the tree.
+     *
+     * @return ResourceReference
+     */
+    public function getTreePerson()
+    {
+        return $this->treePerson;
+    }
+
+    /**
+     * Sets the reference to the person in the tree.
+     *
+     * @param ResourceReference $treePerson
+     */
+    public function setTreePerson($treePerson)
+    {
+        $this->treePerson = $treePerson;
+    }
+
+    /**
+     * Gets the reference to the tree containing the person.
+     *
+     * @return ResourceReference
+     */
+    public function getTree()
+    {
+        return $this->tree;
+    }
+
+    /**
+     * Sets the reference to the tree containing the person.
+     *
+     * @param ResourceReference $tree
+     */
+    public function setTree($tree)
+    {
+        $this->tree = $tree;
+    }
+
+    /**
+     * Gets the attribution metadata for this tree person reference.
+     *
+     * @return Attribution
+     */
+    public function getAttribution()
+    {
+        return $this->attribution;
+    }
+
+    /**
+     * Sets the attribution metadata for this tree person reference.
+     *
+     * @param Attribution $attribution
+     */
+    public function setAttribution($attribution)
+    {
+        $this->attribution = $attribution;
+    }
+
+    /**
+     * Returns the associative array for this TreePersonReference.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        $a = parent::toArray();
+        if ($this->treePerson) {
+            $a["treePerson"] = $this->treePerson->toArray();
+        }
+        if ($this->tree) {
+            $a["tree"] = $this->tree->toArray();
+        }
+        if ($this->attribution) {
+            $a["attribution"] = $this->attribution->toArray();
+        }
+        return $a;
+    }
+
+    /**
+     * Returns the JSON string for this TreePersonReference.
+     *
+     * @return string
+     */
+    public function toJson()
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Initializes this TreePersonReference from an associative array.
+     *
+     * @param array $o
+     */
+    public function initFromArray($o)
+    {
+        parent::initFromArray($o);
+        if (isset($o['treePerson'])) {
+            $this->treePerson = new ResourceReference($o["treePerson"]);
+        }
+        if (isset($o['tree'])) {
+            $this->tree = new ResourceReference($o["tree"]);
+        }
+        if (isset($o['attribution'])) {
+            $this->attribution = new Attribution($o["attribution"]);
+        }
+    }
+
+    /**
+     * Initializes this TreePersonReference from an XML reader.
+     *
+     * @param \XMLReader $xml The reader to use to initialize this object.
+     */
+    public function initFromReader($xml)
+    {
+        parent::initFromReader($xml);
+    }
+
+    /**
+     * Sets a known child element of TreePersonReference from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether a child element was set.
+     */
+    protected function setKnownChildElement($xml)
+    {
+        $happened = parent::setKnownChildElement($xml);
+        if ($happened) {
+            return true;
+        }
+
+        if (($xml->localName == 'treePerson') && ($xml->namespaceURI == 'http://familysearch.org/v1/')) {
+            $child = new ResourceReference($xml);
+            $this->treePerson = $child;
+            return true;
+        }
+        else if (($xml->localName == 'tree') && ($xml->namespaceURI == 'http://familysearch.org/v1/')) {
+            $child = new ResourceReference($xml);
+            $this->tree = $child;
+            return true;
+        }
+        else if (($xml->localName == 'attribution') && ($xml->namespaceURI == 'http://gedcomx.org/v1/')) {
+            $child = new Attribution($xml);
+            $this->attribution = $child;
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Sets a known attribute of TreePersonReference from an XML reader.
+     *
+     * @param \XMLReader $xml The reader.
+     *
+     * @return bool Whether an attribute was set.
+     */
+    protected function setKnownAttribute($xml)
+    {
+        return parent::setKnownAttribute($xml);
+    }
+
+    /**
+     * Writes this TreePersonReference to an XML writer.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     * @param bool $includeNamespaces Whether to write out the namespaces in the element.
+     */
+    public function toXml($writer, $includeNamespaces = true)
+    {
+        $writer->startElementNS('fs', 'tree-person-reference', null);
+        if ($includeNamespaces) {
+            $writer->writeAttributeNs('xmlns', 'fs', null, 'http://familysearch.org/v1/');
+            $writer->writeAttributeNs('xmlns', 'gx', null, 'http://gedcomx.org/v1/');
+        }
+        $this->writeXmlContents($writer);
+        $writer->endElement();
+    }
+
+    /**
+     * Writes the contents of this TreePersonReference to an XML writer.
+     * The startElement is expected to be already provided.
+     *
+     * @param \XMLWriter $writer The XML writer.
+     */
+    public function writeXmlContents($writer)
+    {
+        parent::writeXmlContents($writer);
+        if ($this->treePerson) {
+            $writer->startElementNS('fs', 'treePerson', null);
+            $this->treePerson->writeXmlContents($writer);
+            $writer->endElement();
+        }
+        if ($this->tree) {
+            $writer->startElementNS('fs', 'tree', null);
+            $this->tree->writeXmlContents($writer);
+            $writer->endElement();
+        }
+        if ($this->attribution) {
+            $writer->startElementNS('gx', 'attribution', null);
+            $this->attribution->writeXmlContents($writer);
+            $writer->endElement();
+        }
+    }
+}
diff --git a/tests/fixtures/familysearch-api-examples.json b/tests/fixtures/familysearch-api-examples.json
new file mode 100644
index 00000000..8c3fec4b
--- /dev/null
+++ b/tests/fixtures/familysearch-api-examples.json
@@ -0,0 +1,168 @@
+{
+  "description": "Realistic FamilySearch API response examples for testing new extension classes",
+
+  "tree": {
+    "id": "TREE-12345",
+    "groupIds": ["GROUP-001", "GROUP-002", "GROUP-003"],
+    "name": "Smith Family Tree",
+    "description": "Collaborative research on the Smith family lineage from England to America",
+    "startingPersonId": "KWQS-BBQ",
+    "hidden": false,
+    "private": true,
+    "collectionId": "TREE-COLLECTION-1",
+    "ownerAccess": "http://familysearch.org/v1/AnyApps",
+    "groupAccess": "http://familysearch.org/v1/CompanyApps",
+    "allAccess": "http://familysearch.org/v1/None"
+  },
+
+  "group": {
+    "id": "GROUP-001",
+    "name": "Smith Family Researchers",
+    "description": "Group dedicated to researching the Smith family line",
+    "codeOfConduct": "Be respectful, collaborative, and cite your sources",
+    "treeIds": ["TREE-12345", "TREE-67890"],
+    "members": [
+      {
+        "groupId": "GROUP-001",
+        "cisId": "cis-user-12345",
+        "contactName": "John Smith",
+        "status": "active"
+      },
+      {
+        "groupId": "GROUP-001",
+        "cisId": "cis-user-67890",
+        "contactName": "Jane Doe",
+        "status": "active"
+      },
+      {
+        "groupId": "GROUP-001",
+        "cisId": "cis-user-11111",
+        "contactName": "Robert Johnson",
+        "status": "invited"
+      }
+    ]
+  },
+
+  "personInfo": {
+    "canUserEdit": true,
+    "visibleToAll": true,
+    "visibleToAllWhenUsingFamilySearchApps": true,
+    "treeId": "TREE-12345"
+  },
+
+  "searchInfo": {
+    "totalHits": 1543,
+    "closeHits": 127
+  },
+
+  "nameFormInfo": {
+    "order": "http://familysearch.org/v1/Eurotypic"
+  },
+
+  "nameFormInfoSinotypic": {
+    "order": "http://familysearch.org/v1/Sinotypic"
+  },
+
+  "additionalAttribution": {
+    "contributor": {
+      "resource": "https://familysearch.org/platform/users/cis-user-12345",
+      "resourceId": "cis-user-12345"
+    },
+    "modified": 1625097600000,
+    "changeMessage": "Added birth date from 1850 census record"
+  },
+
+  "treePersonReference": {
+    "treePerson": {
+      "resource": "https://familysearch.org/platform/tree/persons/KWQS-BBQ",
+      "resourceId": "KWQS-BBQ"
+    },
+    "tree": {
+      "resource": "https://familysearch.org/platform/tree/trees/TREE-12345",
+      "resourceId": "TREE-12345"
+    },
+    "attribution": {
+      "contributor": {
+        "resource": "https://familysearch.org/platform/users/cis-user-12345",
+        "resourceId": "cis-user-12345"
+      },
+      "modified": 1625097600000,
+      "changeMessage": "Linked from alternate tree for comparison"
+    }
+  },
+
+  "changeTypes": {
+    "personChanges": [
+      "http://familysearch.org/v1/CreatePerson",
+      "http://familysearch.org/v1/UpdatePerson",
+      "http://familysearch.org/v1/DeletePerson",
+      "http://familysearch.org/v1/RestorePerson",
+      "http://familysearch.org/v1/MergePerson",
+      "http://familysearch.org/v1/UnmergePerson"
+    ],
+    "factChanges": [
+      "http://familysearch.org/v1/AddBirth",
+      "http://familysearch.org/v1/UpdateBirth",
+      "http://familysearch.org/v1/DeleteBirth",
+      "http://familysearch.org/v1/AddDeath",
+      "http://familysearch.org/v1/UpdateDeath",
+      "http://familysearch.org/v1/DeleteDeath"
+    ],
+    "relationshipChanges": [
+      "http://familysearch.org/v1/CreateCoupleRelationship",
+      "http://familysearch.org/v1/DeleteCoupleRelationship",
+      "http://familysearch.org/v1/CreateChildAndParentsRelationship",
+      "http://familysearch.org/v1/DeleteChildAndParentsRelationship"
+    ]
+  },
+
+  "familySearchFactTypes": [
+    "http://familysearch.org/v1/Affiliation",
+    "http://familysearch.org/v1/LifeSketch",
+    "http://familysearch.org/v1/TribeName",
+    "http://familysearch.org/v1/TitleOfNobility"
+  ],
+
+  "familySearchIdentifierTypes": [
+    "http://familysearch.org/v1/ChildAndParentsRelationship",
+    "http://familysearch.org/v1/MemoryPerson",
+    "http://familysearch.org/v1/FamilyTreePerson"
+  ],
+
+  "relationshipRoles": [
+    "http://familysearch.org/v1/Parent1",
+    "http://familysearch.org/v1/Parent2",
+    "http://familysearch.org/v1/Child",
+    "http://familysearch.org/v1/Spouse1",
+    "http://familysearch.org/v1/Spouse2"
+  ],
+
+  "thirdPartyAccessLevels": {
+    "mostPermissive": "http://familysearch.org/v1/AnyApps",
+    "restricted": "http://familysearch.org/v1/CompanyApps",
+    "blocked": "http://familysearch.org/v1/None"
+  },
+
+  "matchCollections": [
+    "https://familysearch.org/platform/collections/tree",
+    "https://familysearch.org/platform/collections/records",
+    "https://familysearch.org/platform/collections/trees",
+    "https://familysearch.org/platform/collections/user_trees"
+  ],
+
+  "searchCollections": {
+    "tree": {
+      "uri": "https://familysearch.org/platform/collections/tree",
+      "id": "0"
+    },
+    "userTrees": {
+      "uri": "https://familysearch.org/platform/collections/user_trees",
+      "id": "10"
+    }
+  },
+
+  "sourceReferenceTagTypes": [
+    "http://gedcomx.org/Name",
+    "http://gedcomx.org/Gender"
+  ]
+}
diff --git a/tests/unit/NewFamilySearchExtensionsTests.php b/tests/unit/NewFamilySearchExtensionsTests.php
new file mode 100644
index 00000000..991a1662
--- /dev/null
+++ b/tests/unit/NewFamilySearchExtensionsTests.php
@@ -0,0 +1,779 @@
+<?php
+
+namespace Gedcomx\Tests\Unit;
+
+use Gedcomx\Common\Attribution;
+use Gedcomx\Common\ResourceReference;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\AdditionalAttribution;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\ChangeType;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\FamilySearchFactType;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\FamilySearchIdentifierType;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\FamilyTreeFactQualifierType;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\Group;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\GroupMember;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\MatchCollection;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\NameFormInfo;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\NameFormOrder;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\PersonInfo;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\RelationshipRole;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\SearchCollection;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\SearchInfo;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\SourceReferenceTagType;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\ThirdPartyAccess;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\Tree;
+use Gedcomx\Extensions\FamilySearch\Platform\Tree\TreePersonReference;
+use Gedcomx\Tests\ApiTestCase;
+
+/**
+ * Comprehensive tests for 18 newly implemented FamilySearch extension classes
+ * Tests construction, getters/setters, and serialization/deserialization
+ */
+class NewFamilySearchExtensionsTests extends ApiTestCase
+{
+    // ========== ENUM TESTS ==========
+
+    /**
+     * Test ChangeType enum constants
+     */
+    public function testChangeTypeConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/CreatePerson', ChangeType::CREATE_PERSON);
+        $this->assertEquals('http://familysearch.org/v1/DeletePerson', ChangeType::DELETE_PERSON);
+        $this->assertEquals('http://familysearch.org/v1/AddBirth', ChangeType::ADD_BIRTH);
+        $this->assertEquals('http://familysearch.org/v1/MergePerson', ChangeType::MERGE_PERSON);
+        $this->assertEquals('http://familysearch.org/v1/CreateCoupleRelationship', ChangeType::CREATE_COUPLE_RELATIONSHIP);
+        $this->assertEquals('http://familysearch.org/v1/CreateChildAndParentsRelationship', ChangeType::CREATE_CHILD_AND_PARENTS_RELATIONSHIP);
+    }
+
+    /**
+     * Test FamilySearchFactType enum constants
+     */
+    public function testFamilySearchFactTypeConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/Affiliation', FamilySearchFactType::AFFILIATION);
+        $this->assertEquals('http://familysearch.org/v1/LifeSketch', FamilySearchFactType::LIFE_SKETCH);
+        $this->assertEquals('http://familysearch.org/v1/TribeName', FamilySearchFactType::TRIBE_NAME);
+        $this->assertEquals('http://familysearch.org/v1/TitleOfNobility', FamilySearchFactType::TITLE_OF_NOBILITY);
+    }
+
+    /**
+     * Test FamilySearchIdentifierType enum constants
+     */
+    public function testFamilySearchIdentifierTypeConstants()
+    {
+        $this->assertEquals(
+            'http://familysearch.org/v1/ChildAndParentsRelationship',
+            FamilySearchIdentifierType::CHILD_AND_PARENTS_RELATIONSHIP
+        );
+        $this->assertEquals(
+            'http://familysearch.org/v1/MemoryPerson',
+            FamilySearchIdentifierType::MEMORY_PERSON
+        );
+        $this->assertEquals(
+            'http://familysearch.org/v1/FamilyTreePerson',
+            FamilySearchIdentifierType::FAMILY_TREE_PERSON
+        );
+    }
+
+    /**
+     * Test FamilyTreeFactQualifierType enum constants
+     */
+    public function testFamilyTreeFactQualifierTypeConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/Event', FamilyTreeFactQualifierType::EVENT);
+    }
+
+    /**
+     * Test SourceReferenceTagType enum constants
+     */
+    public function testSourceReferenceTagTypeConstants()
+    {
+        $this->assertEquals('http://gedcomx.org/Name', SourceReferenceTagType::NAME);
+        $this->assertEquals('http://gedcomx.org/Gender', SourceReferenceTagType::GENDER);
+    }
+
+    /**
+     * Test RelationshipRole enum constants
+     */
+    public function testRelationshipRoleConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/Parent1', RelationshipRole::PARENT1);
+        $this->assertEquals('http://familysearch.org/v1/Parent2', RelationshipRole::PARENT2);
+        $this->assertEquals('http://familysearch.org/v1/Child', RelationshipRole::CHILD);
+        $this->assertEquals('http://familysearch.org/v1/Spouse1', RelationshipRole::SPOUSE1);
+        $this->assertEquals('http://familysearch.org/v1/Spouse2', RelationshipRole::SPOUSE2);
+    }
+
+    /**
+     * Test ThirdPartyAccess enum constants
+     */
+    public function testThirdPartyAccessConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/AnyApps', ThirdPartyAccess::ANY_APPS);
+        $this->assertEquals('http://familysearch.org/v1/CompanyApps', ThirdPartyAccess::COMPANY_APPS);
+        $this->assertEquals('http://familysearch.org/v1/None', ThirdPartyAccess::NONE);
+        $this->assertEquals('http://familysearch.org/v1/OTHER', ThirdPartyAccess::OTHER);
+    }
+
+    /**
+     * Test MatchCollection enum constants
+     */
+    public function testMatchCollectionConstants()
+    {
+        $this->assertEquals('https://familysearch.org/platform/collections/tree', MatchCollection::TREE);
+        $this->assertEquals('https://familysearch.org/platform/collections/records', MatchCollection::RECORDS);
+        $this->assertEquals('https://familysearch.org/platform/collections/trees', MatchCollection::LLS);
+        $this->assertEquals('https://familysearch.org/platform/collections/user_trees', MatchCollection::USER_TREES);
+    }
+
+    /**
+     * Test SearchCollection enum constants and getId method
+     */
+    public function testSearchCollectionConstants()
+    {
+        $this->assertEquals('https://familysearch.org/platform/collections/tree', SearchCollection::TREE);
+        $this->assertEquals('0', SearchCollection::TREE_ID);
+        $this->assertEquals('https://familysearch.org/platform/collections/user_trees', SearchCollection::USER_TREES);
+        $this->assertEquals('10', SearchCollection::USER_TREES_ID);
+
+        // Test static getId method
+        $this->assertEquals('0', SearchCollection::getId(SearchCollection::TREE));
+        $this->assertEquals('10', SearchCollection::getId(SearchCollection::USER_TREES));
+    }
+
+    /**
+     * Test NameFormOrder enum constants
+     */
+    public function testNameFormOrderConstants()
+    {
+        $this->assertEquals('http://familysearch.org/v1/Eurotypic', NameFormOrder::EUROTYPIC);
+        $this->assertEquals('http://familysearch.org/v1/Sinotypic', NameFormOrder::SINOTYPIC);
+    }
+
+    // ========== DATA CLASS TESTS ==========
+
+    /**
+     * Test AdditionalAttribution construction
+     */
+    public function testAdditionalAttributionConstruction()
+    {
+        $additionalAttr = new AdditionalAttribution();
+
+        $contributor = new ResourceReference();
+        $contributor->setResource('https://familysearch.org/platform/users/USER123');
+        $additionalAttr->setContributor($contributor);
+
+        $additionalAttr->setModified(1625097600000);
+        $additionalAttr->setChangeMessage('Added birth date from parish records');
+
+        $this->assertNotNull($additionalAttr->getContributor());
+        $this->assertEquals('https://familysearch.org/platform/users/USER123', $additionalAttr->getContributor()->getResource());
+        $this->assertEquals(1625097600000, $additionalAttr->getModified());
+        $this->assertEquals('Added birth date from parish records', $additionalAttr->getChangeMessage());
+    }
+
+    /**
+     * Test AdditionalAttribution from array
+     */
+    public function testAdditionalAttributionFromArray()
+    {
+        $additionalAttr = new AdditionalAttribution([
+            'contributor' => [
+                'resource' => 'https://familysearch.org/platform/users/USER456'
+            ],
+            'modified' => 1625097600000,
+            'changeMessage' => 'Verified with census record'
+        ]);
+
+        $this->assertNotNull($additionalAttr->getContributor());
+        $this->assertEquals(1625097600000, $additionalAttr->getModified());
+        $this->assertEquals('Verified with census record', $additionalAttr->getChangeMessage());
+    }
+
+    /**
+     * Test AdditionalAttribution JSON round-trip
+     */
+    public function testAdditionalAttributionJsonRoundTrip()
+    {
+        $additionalAttr = new AdditionalAttribution([
+            'contributor' => ['resource' => '#USER1'],
+            'modified' => 1625097600000,
+            'changeMessage' => 'Test change'
+        ]);
+
+        $json = $additionalAttr->toJson();
+        $this->assertStringContainsString('USER1', $json);
+        $this->assertStringContainsString('Test change', $json);
+
+        $decoded = json_decode($json, true);
+        $additionalAttr2 = new AdditionalAttribution($decoded);
+        $this->assertEquals('Test change', $additionalAttr2->getChangeMessage());
+    }
+
+    /**
+     * Test NameFormInfo construction
+     */
+    public function testNameFormInfoConstruction()
+    {
+        $nameInfo = new NameFormInfo();
+        $nameInfo->setOrder(NameFormOrder::SINOTYPIC);
+
+        $this->assertEquals(NameFormOrder::SINOTYPIC, $nameInfo->getOrder());
+    }
+
+    /**
+     * Test NameFormInfo from array
+     */
+    public function testNameFormInfoFromArray()
+    {
+        $nameInfo = new NameFormInfo([
+            'order' => NameFormOrder::EUROTYPIC
+        ]);
+
+        $this->assertEquals(NameFormOrder::EUROTYPIC, $nameInfo->getOrder());
+    }
+
+    /**
+     * Test NameFormInfo JSON round-trip
+     */
+    public function testNameFormInfoJsonRoundTrip()
+    {
+        $nameInfo = new NameFormInfo(['order' => NameFormOrder::SINOTYPIC]);
+
+        $json = $nameInfo->toJson();
+        $this->assertStringContainsString('Sinotypic', $json);
+
+        $decoded = json_decode($json, true);
+        $nameInfo2 = new NameFormInfo($decoded);
+        $this->assertEquals(NameFormOrder::SINOTYPIC, $nameInfo2->getOrder());
+    }
+
+    /**
+     * Test SearchInfo construction
+     */
+    public function testSearchInfoConstruction()
+    {
+        $searchInfo = new SearchInfo();
+        $searchInfo->setTotalHits(150);
+        $searchInfo->setCloseHits(25);
+
+        $this->assertEquals(150, $searchInfo->getTotalHits());
+        $this->assertEquals(25, $searchInfo->getCloseHits());
+    }
+
+    /**
+     * Test SearchInfo from array
+     */
+    public function testSearchInfoFromArray()
+    {
+        $searchInfo = new SearchInfo([
+            'totalHits' => 200,
+            'closeHits' => 30
+        ]);
+
+        $this->assertEquals(200, $searchInfo->getTotalHits());
+        $this->assertEquals(30, $searchInfo->getCloseHits());
+    }
+
+    /**
+     * Test SearchInfo JSON round-trip
+     */
+    public function testSearchInfoJsonRoundTrip()
+    {
+        $searchInfo = new SearchInfo(['totalHits' => 100, 'closeHits' => 15]);
+
+        $json = $searchInfo->toJson();
+        $this->assertStringContainsString('100', $json);
+        $this->assertStringContainsString('15', $json);
+
+        $decoded = json_decode($json, true);
+        $searchInfo2 = new SearchInfo($decoded);
+        $this->assertEquals(100, $searchInfo2->getTotalHits());
+        $this->assertEquals(15, $searchInfo2->getCloseHits());
+    }
+
+    /**
+     * Test PersonInfo construction
+     */
+    public function testPersonInfoConstruction()
+    {
+        $personInfo = new PersonInfo();
+        $personInfo->setCanUserEdit(true);
+        $personInfo->setVisibleToAll(false);
+        $personInfo->setVisibleToAllWhenUsingFamilySearchApps(true);
+        $personInfo->setTreeId('TREE123');
+
+        $this->assertTrue($personInfo->getCanUserEdit());
+        $this->assertFalse($personInfo->getVisibleToAll());
+        $this->assertTrue($personInfo->getVisibleToAllWhenUsingFamilySearchApps());
+        $this->assertEquals('TREE123', $personInfo->getTreeId());
+    }
+
+    /**
+     * Test PersonInfo from array
+     */
+    public function testPersonInfoFromArray()
+    {
+        $personInfo = new PersonInfo([
+            'canUserEdit' => true,
+            'visibleToAll' => true,
+            'treeId' => 'TREE456'
+        ]);
+
+        $this->assertTrue($personInfo->getCanUserEdit());
+        $this->assertTrue($personInfo->getVisibleToAll());
+        $this->assertEquals('TREE456', $personInfo->getTreeId());
+    }
+
+    /**
+     * Test PersonInfo JSON round-trip
+     */
+    public function testPersonInfoJsonRoundTrip()
+    {
+        $personInfo = new PersonInfo([
+            'canUserEdit' => true,
+            'visibleToAll' => false,
+            'treeId' => 'TREE789'
+        ]);
+
+        $json = $personInfo->toJson();
+        $this->assertStringContainsString('TREE789', $json);
+
+        $decoded = json_decode($json, true);
+        $personInfo2 = new PersonInfo($decoded);
+        $this->assertTrue($personInfo2->getCanUserEdit());
+        $this->assertEquals('TREE789', $personInfo2->getTreeId());
+    }
+
+    /**
+     * Test GroupMember construction
+     */
+    public function testGroupMemberConstruction()
+    {
+        $member = new GroupMember();
+        $member->setGroupId('GROUP1');
+        $member->setCisId('USER001');
+        $member->setContactName('John Smith');
+        $member->setStatus('active');
+
+        $this->assertEquals('GROUP1', $member->getGroupId());
+        $this->assertEquals('USER001', $member->getCisId());
+        $this->assertEquals('John Smith', $member->getContactName());
+        $this->assertEquals('active', $member->getStatus());
+    }
+
+    /**
+     * Test GroupMember from array
+     */
+    public function testGroupMemberFromArray()
+    {
+        $member = new GroupMember([
+            'groupId' => 'GROUP2',
+            'cisId' => 'USER002',
+            'contactName' => 'Jane Doe',
+            'status' => 'invited'
+        ]);
+
+        $this->assertEquals('GROUP2', $member->getGroupId());
+        $this->assertEquals('USER002', $member->getCisId());
+        $this->assertEquals('Jane Doe', $member->getContactName());
+        $this->assertEquals('invited', $member->getStatus());
+    }
+
+    /**
+     * Test GroupMember JSON round-trip
+     */
+    public function testGroupMemberJsonRoundTrip()
+    {
+        $member = new GroupMember([
+            'cisId' => 'USER999',
+            'contactName' => 'Test User',
+            'status' => 'active'
+        ]);
+
+        $json = $member->toJson();
+        $this->assertStringContainsString('USER999', $json);
+        $this->assertStringContainsString('Test User', $json);
+
+        $decoded = json_decode($json, true);
+        $member2 = new GroupMember($decoded);
+        $this->assertEquals('USER999', $member2->getCisId());
+        $this->assertEquals('Test User', $member2->getContactName());
+    }
+
+    // ========== CONTAINER/COLLECTION TESTS ==========
+
+    /**
+     * Test Group construction with arrays
+     */
+    public function testGroupConstruction()
+    {
+        $group = new Group();
+        $group->setId('GROUP123');
+        $group->setName('Smith Family Research');
+        $group->setDescription('Collaborative research on Smith family');
+        $group->setTreeIds(['TREE1', 'TREE2', 'TREE3']);
+
+        $member1 = new GroupMember();
+        $member1->setCisId('USER001');
+        $member1->setContactName('John Smith');
+        $group->addMember($member1);
+
+        $member2 = new GroupMember();
+        $member2->setCisId('USER002');
+        $member2->setContactName('Jane Doe');
+        $group->addMember($member2);
+
+        $this->assertEquals('GROUP123', $group->getId());
+        $this->assertEquals('Smith Family Research', $group->getName());
+        $this->assertCount(3, $group->getTreeIds());
+        $this->assertCount(2, $group->getMembers());
+        $this->assertEquals('USER001', $group->getMembers()[0]->getCisId());
+    }
+
+    /**
+     * Test Group from array
+     */
+    public function testGroupFromArray()
+    {
+        $group = new Group([
+            'id' => 'GROUP456',
+            'name' => 'Research Group',
+            'treeIds' => ['TREE1', 'TREE2'],
+            'members' => [
+                ['cisId' => 'USER1', 'contactName' => 'User One'],
+                ['cisId' => 'USER2', 'contactName' => 'User Two']
+            ]
+        ]);
+
+        $this->assertEquals('GROUP456', $group->getId());
+        $this->assertCount(2, $group->getTreeIds());
+        $this->assertCount(2, $group->getMembers());
+        $this->assertEquals('USER1', $group->getMembers()[0]->getCisId());
+    }
+
+    /**
+     * Test Group JSON round-trip
+     */
+    public function testGroupJsonRoundTrip()
+    {
+        $group = new Group([
+            'id' => 'GROUP789',
+            'name' => 'Test Group',
+            'treeIds' => ['TREE1'],
+            'members' => [
+                ['cisId' => 'USER123', 'contactName' => 'Test User']
+            ]
+        ]);
+
+        $json = $group->toJson();
+        $this->assertStringContainsString('GROUP789', $json);
+        $this->assertStringContainsString('Test Group', $json);
+
+        $decoded = json_decode($json, true);
+        $group2 = new Group($decoded);
+        $this->assertEquals('GROUP789', $group2->getId());
+        $this->assertCount(1, $group2->getMembers());
+    }
+
+    /**
+     * Test Tree construction with access controls
+     */
+    public function testTreeConstruction()
+    {
+        $tree = new Tree();
+        $tree->setId('TREE123');
+        $tree->setName('Smith Family Tree');
+        $tree->setDescription('Main family tree');
+        $tree->setGroupIds(['GROUP1', 'GROUP2']);
+        $tree->setOwnerAccess(ThirdPartyAccess::ANY_APPS);
+        $tree->setGroupAccess(ThirdPartyAccess::COMPANY_APPS);
+        $tree->setAllAccess(ThirdPartyAccess::NONE);
+        $tree->setHidden(false);
+        $tree->setPrivate(true);
+
+        $this->assertEquals('TREE123', $tree->getId());
+        $this->assertEquals('Smith Family Tree', $tree->getName());
+        $this->assertCount(2, $tree->getGroupIds());
+        $this->assertEquals(ThirdPartyAccess::ANY_APPS, $tree->getOwnerAccess());
+        $this->assertFalse($tree->getHidden());
+        $this->assertTrue($tree->getPrivate());
+    }
+
+    /**
+     * Test Tree from array
+     */
+    public function testTreeFromArray()
+    {
+        $tree = new Tree([
+            'id' => 'TREE456',
+            'name' => 'Test Tree',
+            'groupIds' => ['GROUP1'],
+            'ownerAccess' => ThirdPartyAccess::ANY_APPS,
+            'hidden' => false,
+            'private' => true
+        ]);
+
+        $this->assertEquals('TREE456', $tree->getId());
+        $this->assertEquals('Test Tree', $tree->getName());
+        $this->assertCount(1, $tree->getGroupIds());
+        $this->assertEquals(ThirdPartyAccess::ANY_APPS, $tree->getOwnerAccess());
+    }
+
+    /**
+     * Test Tree JSON round-trip
+     */
+    public function testTreeJsonRoundTrip()
+    {
+        $tree = new Tree([
+            'id' => 'TREE789',
+            'name' => 'Round Trip Tree',
+            'groupIds' => ['G1', 'G2'],
+            'ownerAccess' => ThirdPartyAccess::COMPANY_APPS
+        ]);
+
+        $json = $tree->toJson();
+        $this->assertStringContainsString('TREE789', $json);
+        $this->assertStringContainsString('Round Trip Tree', $json);
+
+        $decoded = json_decode($json, true);
+        $tree2 = new Tree($decoded);
+        $this->assertEquals('TREE789', $tree2->getId());
+        $this->assertCount(2, $tree2->getGroupIds());
+    }
+
+    /**
+     * Test TreePersonReference construction (inheritance test)
+     */
+    public function testTreePersonReferenceConstruction()
+    {
+        $ref = new TreePersonReference();
+
+        $personRef = new ResourceReference();
+        $personRef->setResource('https://familysearch.org/platform/tree/persons/PERSON123');
+        $ref->setTreePerson($personRef);
+
+        $treeRef = new ResourceReference();
+        $treeRef->setResource('https://familysearch.org/platform/tree/trees/TREE456');
+        $ref->setTree($treeRef);
+
+        $attribution = new Attribution();
+        $contributor = new ResourceReference();
+        $contributor->setResource('#USER1');
+        $attribution->setContributor($contributor);
+        $ref->setAttribution($attribution);
+
+        $this->assertNotNull($ref->getTreePerson());
+        $this->assertNotNull($ref->getTree());
+        $this->assertNotNull($ref->getAttribution());
+        $this->assertEquals('https://familysearch.org/platform/tree/persons/PERSON123', $ref->getTreePerson()->getResource());
+    }
+
+    /**
+     * Test TreePersonReference from array
+     */
+    public function testTreePersonReferenceFromArray()
+    {
+        $ref = new TreePersonReference([
+            'treePerson' => ['resource' => '#PERSON1'],
+            'tree' => ['resource' => '#TREE1'],
+            'attribution' => [
+                'contributor' => ['resource' => '#USER1']
+            ]
+        ]);
+
+        $this->assertNotNull($ref->getTreePerson());
+        $this->assertNotNull($ref->getTree());
+        $this->assertNotNull($ref->getAttribution());
+    }
+
+    /**
+     * Test TreePersonReference JSON round-trip
+     */
+    public function testTreePersonReferenceJsonRoundTrip()
+    {
+        $ref = new TreePersonReference([
+            'treePerson' => ['resource' => '#PERSON999'],
+            'tree' => ['resource' => '#TREE999']
+        ]);
+
+        $json = $ref->toJson();
+        $this->assertStringContainsString('PERSON999', $json);
+        $this->assertStringContainsString('TREE999', $json);
+
+        $decoded = json_decode($json, true);
+        $ref2 = new TreePersonReference($decoded);
+        $this->assertNotNull($ref2->getTreePerson());
+        $this->assertNotNull($ref2->getTree());
+    }
+
+    // ========== NULL/EMPTY TESTS ==========
+
+    /**
+     * Test classes handle null values gracefully
+     */
+    public function testNullValues()
+    {
+        // Test empty construction
+        $searchInfo = new SearchInfo();
+        $this->assertNull($searchInfo->getTotalHits());
+        $this->assertNull($searchInfo->getCloseHits());
+
+        $personInfo = new PersonInfo();
+        // PersonInfo has default values, not null
+        $this->assertFalse($personInfo->getCanUserEdit());
+        $this->assertTrue($personInfo->getVisibleToAll());
+        $this->assertNull($personInfo->getTreeId());
+
+        $group = new Group();
+        $this->assertNull($group->getId());
+        $this->assertNull($group->getMembers());
+
+        $tree = new Tree();
+        $this->assertNull($tree->getId());
+        $this->assertNull($tree->getGroupIds());
+    }
+
+    /**
+     * Test empty arrays
+     */
+    public function testEmptyArrays()
+    {
+        $group = new Group();
+        $group->setTreeIds([]);
+        $group->setMembers([]);
+
+        $this->assertIsArray($group->getTreeIds());
+        $this->assertIsArray($group->getMembers());
+        $this->assertCount(0, $group->getTreeIds());
+        $this->assertCount(0, $group->getMembers());
+    }
+
+    // ========== COMPLEX NESTED OBJECT TESTS ==========
+
+    /**
+     * Test complex nested group structure
+     */
+    public function testComplexGroupStructure()
+    {
+        $group = new Group([
+            'id' => 'COMPLEX-GROUP',
+            'name' => 'Complex Research Group',
+            'description' => 'A group with multiple members and trees',
+            'codeOfConduct' => 'Be respectful and collaborative',
+            'treeIds' => ['TREE1', 'TREE2', 'TREE3', 'TREE4'],
+            'members' => [
+                [
+                    'groupId' => 'COMPLEX-GROUP',
+                    'cisId' => 'USER001',
+                    'contactName' => 'Alice Johnson',
+                    'status' => 'active'
+                ],
+                [
+                    'groupId' => 'COMPLEX-GROUP',
+                    'cisId' => 'USER002',
+                    'contactName' => 'Bob Smith',
+                    'status' => 'active'
+                ],
+                [
+                    'groupId' => 'COMPLEX-GROUP',
+                    'cisId' => 'USER003',
+                    'contactName' => 'Carol Williams',
+                    'status' => 'invited'
+                ]
+            ]
+        ]);
+
+        // Verify structure
+        $this->assertEquals('COMPLEX-GROUP', $group->getId());
+        $this->assertCount(4, $group->getTreeIds());
+        $this->assertCount(3, $group->getMembers());
+        $this->assertEquals('Alice Johnson', $group->getMembers()[0]->getContactName());
+        $this->assertEquals('invited', $group->getMembers()[2]->getStatus());
+
+        // Test JSON round-trip
+        $json = $group->toJson();
+        $decoded = json_decode($json, true);
+        $group2 = new Group($decoded);
+
+        $this->assertEquals('COMPLEX-GROUP', $group2->getId());
+        $this->assertCount(4, $group2->getTreeIds());
+        $this->assertCount(3, $group2->getMembers());
+    }
+
+    /**
+     * Test complex tree with all properties
+     */
+    public function testComplexTreeStructure()
+    {
+        $tree = new Tree([
+            'id' => 'COMPLEX-TREE',
+            'groupIds' => ['GROUP1', 'GROUP2', 'GROUP3'],
+            'name' => 'Complex Family Tree',
+            'description' => 'A comprehensive family tree',
+            'startingPersonId' => 'PERSON-ROOT',
+            'hidden' => false,
+            'private' => true,
+            'collectionId' => 'COLLECTION-1',
+            'ownerAccess' => ThirdPartyAccess::ANY_APPS,
+            'groupAccess' => ThirdPartyAccess::COMPANY_APPS,
+            'allAccess' => ThirdPartyAccess::NONE
+        ]);
+
+        $this->assertEquals('COMPLEX-TREE', $tree->getId());
+        $this->assertCount(3, $tree->getGroupIds());
+        $this->assertEquals('PERSON-ROOT', $tree->getStartingPersonId());
+        $this->assertFalse($tree->getHidden());
+        $this->assertTrue($tree->getPrivate());
+        $this->assertEquals(ThirdPartyAccess::ANY_APPS, $tree->getOwnerAccess());
+        $this->assertEquals(ThirdPartyAccess::COMPANY_APPS, $tree->getGroupAccess());
+        $this->assertEquals(ThirdPartyAccess::NONE, $tree->getAllAccess());
+
+        // Test JSON round-trip
+        $json = $tree->toJson();
+        $decoded = json_decode($json, true);
+        $tree2 = new Tree($decoded);
+
+        $this->assertEquals('COMPLEX-TREE', $tree2->getId());
+        $this->assertCount(3, $tree2->getGroupIds());
+    }
+
+    /**
+     * Test TreePersonReference with full attribution
+     */
+    public function testComplexTreePersonReference()
+    {
+        $ref = new TreePersonReference([
+            'treePerson' => [
+                'resource' => 'https://familysearch.org/platform/tree/persons/PERSON-123',
+                'resourceId' => 'PERSON-123'
+            ],
+            'tree' => [
+                'resource' => 'https://familysearch.org/platform/tree/trees/TREE-456',
+                'resourceId' => 'TREE-456'
+            ],
+            'attribution' => [
+                'contributor' => [
+                    'resource' => 'https://familysearch.org/platform/users/USER-789',
+                    'resourceId' => 'USER-789'
+                ],
+                'modified' => 1625097600000,
+                'changeMessage' => 'Linked from alternate tree'
+            ]
+        ]);
+
+        $this->assertNotNull($ref->getTreePerson());
+        $this->assertNotNull($ref->getTree());
+        $this->assertNotNull($ref->getAttribution());
+        $this->assertEquals(1625097600000, $ref->getAttribution()->getModified());
+        $this->assertEquals('Linked from alternate tree', $ref->getAttribution()->getChangeMessage());
+
+        // Test JSON round-trip
+        $json = $ref->toJson();
+        $decoded = json_decode($json, true);
+        $ref2 = new TreePersonReference($decoded);
+
+        $this->assertNotNull($ref2->getAttribution());
+        $this->assertEquals('Linked from alternate tree', $ref2->getAttribution()->getChangeMessage());
+    }
+}