diff --git a/rayyan/reviews/customizations.py b/rayyan/reviews/customizations.py
index a274e58..4b4ab04 100644
--- a/rayyan/reviews/customizations.py
+++ b/rayyan/reviews/customizations.py
@@ -1,18 +1,174 @@
-from typing import Any, Dict
+import json
+from typing import Any, Dict, List, Optional, Union
 from rayyan.paths import REVIEWS_ROUTE
 
+# Customization keys for exclusion reasons are namespaced with this prefix.
+EXCLUSION_REASON_PREFIX = "__EXR__"
+
+# Value used to remove a customization (label/reason) from an article.
+REMOVE_VALUE = -1
+
+# Template for a stage-level customization "scope", built from a stage ID.
+STAGE_SCOPE_TEMPLATE = "__SYSTEM__STAGE__{stage_id}"
+
+
+def stage_scope(stage_id: Any) -> str:
+    """Build a stage-level customization scope from its stage ID."""
+    return STAGE_SCOPE_TEMPLATE.format(stage_id=stage_id)
+
+
+def stage_question_answer_key(stage_id: Any, question_id: Any) -> str:
+    """Build a data-extraction question's answer_key (scope) from its IDs."""
+    return f"{stage_scope(stage_id)}__QUESTION__{question_id}"
+
+
+def _to_article_ids_list(article_ids: Union[str, List[Any]]) -> List[Any]:
+    """Normalize article IDs (list/tuple or comma-separated string) to a list."""
+    if isinstance(article_ids, (list, tuple)):
+        return list(article_ids)
+    return [part.strip() for part in str(article_ids).split(",") if part.strip()]
+
 
 class ReviewCustomizations:
-    def customize(self, id: int, article_id: int, plan: Dict[str, Any]) -> Dict[str, Any]:
+    def customize(
+        self,
+        id: int,
+        article_id: int,
+        plan: Dict[str, Any],
+        scope: Optional[str] = None,
+        allow_string_value: Optional[bool] = None,
+    ) -> Dict[str, Any]:
+        payload: Dict[str, Any] = {"article_id": article_id, "plan": plan}
+        if scope is not None:
+            payload["scope"] = scope
+        if allow_string_value is not None:
+            payload["allow_string_value"] = allow_string_value
         return self._request(
             "POST",
             f"{REVIEWS_ROUTE}/{id}/customize",
-            payload={"article_id": article_id, "plan": plan},
+            payload=payload,
+        )
+
+    def answer_question(
+        self,
+        id: int,
+        article_id: int,
+        stage_id: Any,
+        question_id: Any,
+        answer: Union[str, List[str]],
+        key: str = "included",
+        allow_string_value: bool = True,
+    ) -> Dict[str, Any]:
+        """Answer a data-extraction question for a single article.
+
+        The question is identified by its ``stage_id`` and ``question_id``, from
+        which the customization ``scope`` (the question's answer_key) is built.
+        ``answer`` is the value (or list of values) to record; it is encoded into
+        the ``plan`` payload the API expects, i.e.
+        ``{key: '[{"text": <value>}, ...]'}``.
+        """
+        answers = [answer] if isinstance(answer, str) else list(answer)
+        plan = {key: json.dumps([{"text": a} for a in answers])}
+        return self.customize(
+            id=id,
+            article_id=article_id,
+            plan=plan,
+            scope=stage_question_answer_key(stage_id, question_id),
+            allow_string_value=allow_string_value,
         )
 
-    def bulk_customizations(self, id: int, key: str, value: int, article_ids: str) -> Dict[str, Any]:
-        params = {"key": key, "value": value, "article_ids": article_ids}
+    def bulk_customizations(
+        self,
+        id: int,
+        key: str,
+        value: int,
+        article_ids: Union[str, List[Any]],
+        stage_id: Optional[Any] = None,
+    ) -> Dict[str, Any]:
+        """Apply a customization (e.g. a screening decision) to many articles at once.
+
+        ``article_ids`` may be a list/tuple of IDs or an already comma-separated
+        string; it is normalized to the comma-separated string the API expects.
+        For screening decisions, ``key`` is typically ``"included"`` and ``value``
+        is ``1`` (include), ``0`` (maybe) or ``-1`` (exclude).
+
+        When ``stage_id`` is given, the customization is scoped to that stage (so
+        the decision is recorded for the stage rather than at the review level).
+        """
+        if isinstance(article_ids, (list, tuple)):
+            article_ids = ", ".join(str(article_id) for article_id in article_ids)
+        params: Dict[str, Any] = {"key": key, "value": value, "article_ids": article_ids}
+        if stage_id is not None:
+            params["scope"] = stage_scope(stage_id)
         return self._request("POST", f"{REVIEWS_ROUTE}/{id}/customize", params=params)
 
+    def _set_customization(
+        self,
+        id: int,
+        article_ids: Union[str, List[Any]],
+        key: str,
+        value: int,
+    ) -> Union[Dict[str, Any], List[Dict[str, Any]]]:
+        """Add or remove a keyed customization (label/reason) on articles.
+
+        This sets the given ``key`` to ``value``.
+        Adding uses the bulk endpoint (``{article_ids, key, value}``) in a single
+        request. Removing uses the per-article ``plan`` form
+        (``{article_id, plan: {key: value}}``) applied to each article, since the
+        remove flow is not a bulk operation on the API.
+        """
+        if value > REMOVE_VALUE:
+            return self.bulk_customizations(
+                id=id,
+                key=key,
+                value=value,
+                article_ids=article_ids,
+            )
+        return [
+            self.customize(id=id, article_id=article_id, plan={key: value})
+            for article_id in _to_article_ids_list(article_ids)
+        ]
+
+    def set_label(
+        self,
+        id: int,
+        article_ids: Union[str, List[Any]],
+        label: str,
+        value: int = 1,
+    ) -> Union[Dict[str, Any], List[Dict[str, Any]]]:
+        """Add or remove a label on one or more articles.
+
+        ``label`` is the label name, used as the customization ``key``. ``value``
+        is ``1`` to add the label and ``-1`` to remove it. ``article_ids`` may be
+        a list/tuple of IDs or an already comma-separated string.
+        """
+        return self._set_customization(
+            id=id,
+            article_ids=article_ids,
+            key=label,
+            value=value,
+        )
+
+    def set_reason(
+        self,
+        id: int,
+        article_ids: Union[str, List[Any]],
+        reason: str,
+        value: int = 1,
+    ) -> Union[Dict[str, Any], List[Dict[str, Any]]]:
+        """Add or remove an exclusion reason on one or more articles.
+
+        ``reason`` is the reason text; it is namespaced with
+        ``EXCLUSION_REASON_PREFIX`` to form the customization ``key``. ``value``
+        is ``1`` to add the reason and ``-1`` to remove it. ``article_ids`` may be
+        a list/tuple of IDs or an already comma-separated string.
+        """
+        return self._set_customization(
+            id=id,
+            article_ids=article_ids,
+            key=f"{EXCLUSION_REASON_PREFIX}{reason}",
+            value=value,
+        )
+
     def get_customizations(self, id: int, params: Dict[str, Any]) -> Dict[str, Any]:
-        return self._request("GET", f"{REVIEWS_ROUTE}/{id}/customizations", params=params)
\ No newline at end of file
+        return self._request("GET", f"{REVIEWS_ROUTE}/{id}/customizations", params=params)
diff --git a/setup.cfg b/setup.cfg
index 726f675..14c1544 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = rayyan_sdk
-version = 1.0rc16
+version = 1.0rc17
 description = A Python SDK for Rayyan APIs
 long_description = file: README.md
 long_description_content_type = text/markdown