diff --git a/docs/architecture/core-decomposition.md b/docs/architecture/core-decomposition.md
index 03621004e..abc225c3d 100644
--- a/docs/architecture/core-decomposition.md
+++ b/docs/architecture/core-decomposition.md
@@ -189,7 +189,7 @@ owner 边界，否则不要把一个 feature group 继续拆成更小的 crate
   - 当前 `product-domains` 可继续承载 MiniApp runtime search plan、worker install 命令选择、
     package.json storage-shape helper、lifecycle / revision helper、host routing / allowlist helper、
     customization metadata / permission diff、built-in MiniApp bundle/hash/marker/source payload
-    seed-decision contract 等纯决策 / 解析逻辑；实际 runtime detection、worker pool、
+    seed-decision contract、seed plan / marker wire helper 等纯决策 / 解析逻辑；实际 runtime detection、worker pool、
     storage IO、PathManager、进程执行、host dispatch 执行、customization draft 存储 / 应用与 builtin
     asset include / seeding / marker IO / recompile 仍留在 core product runtime。最新内置 PR Review
     MiniApp 依赖 core asset include、user-data seed、customized update runtime 与 source-hash input
@@ -210,7 +210,8 @@ owner 边界，否则不要把一个 feature group 继续拆成更小的 crate
     built-in asset seeding/source-hash input lookup, host-dispatch execution,
     `PathManager` integration, function-agent Git/AI calls, prompt templates,
     JSON extraction, and error mapping. The built-in MiniApp bundle/hash/marker/source payload
-    seed-decision contract can live in `bitfun-product-domains`, but bundled
+    seed-decision contract plus seed plan / marker wire helper can live in
+    `bitfun-product-domains`, but bundled
     asset includes, marker IO, customized update runtime, and recompile
     orchestration remain core-owned.
   - 高风险：`ToolUseContext`、product tool registry / runtime manifest assembly / `GetToolSpec` 执行 owner 化、
@@ -269,7 +270,8 @@ owner 边界，否则不要把一个 feature group 继续拆成更小的 crate
   `analyze_git=false` time-info 与 `analyzed_at` 时序。
   core 仍持有 MiniApp filesystem IO、compiler 调度、worker process、host dispatch、
   built-in asset include / seed / marker IO / recompile，以及 function-agent Git/AI service adapter、prompt template、
-  JSON extraction 和 error mapping。
+  JSON extraction 和 error mapping；`product-domains` 仅承接 extracted JSON string
+  到 domain DTO 的解析 helper，不承接 extraction 或错误映射 owner。
 
 ## 产品表面边界（Product Surface Boundary）
 
diff --git a/docs/plans/core-decomposition-plan.md b/docs/plans/core-decomposition-plan.md
index 093c5a549..b83b6e96b 100644
--- a/docs/plans/core-decomposition-plan.md
+++ b/docs/plans/core-decomposition-plan.md
@@ -1131,7 +1131,9 @@ product-full = ["miniapp", "function-agents"]
 - 2026-05-18 update: Git function-agent diff truncation and commit prompt preparation are now owner-crate helpers used by core; AI client calls, prompt template ownership, JSON extraction, error mapping, and runtime analysis execution remain core-owned. The current PR adds focused core snapshots for staged-only Git commit diff collection and AI response JSON extraction / error mapping before any Git/AI runtime migration.
 - 2026-05-19 update: `bitfun-product-domains` now owns port-backed MiniApp runtime-state and function-agent runtime facades. Core delegates only MiniApp storage-backed lifecycle persistence through the MiniApp facade; compilation, source reads, storage IO adapter, worker process execution, host dispatch, built-in asset include / seed / marker IO / recompile, prompt templates, JSON extraction, and concrete error mapping remain core-owned. The Git commit-message and Startchat work-state product paths now route through the function-agent facade using core-owned Git/AI adapters; Startchat wiring is guarded by focused tests for legacy git-state, no-HEAD git-diff fallback, and `analyze_git=false` time-info, while core keeps the previous post-analysis `analyzed_at` assignment.
 - 2026-05-19 built-in MiniApp contract update: built-in bundle shape, install marker DTO, content-hash helper, source/placeholder/package payload helpers, and seed-decision policy now live in `bitfun-product-domains::miniapp::builtin`; core still owns the bundled asset includes, user-data filesystem IO, marker read/write, customization metadata IO, source-hash input lookup, and recompile orchestration.
-- boundary check 已补充 product-domain owner anchor：`MiniAppStoragePort` / `MiniAppRuntimePort` 的 core adapter、MiniApp host/customization/builtin 纯 contract、MiniApp manager preflight tests、function-agent Git adapter 与 AI response parsing helper 必须存在，防止把 port contract 或 pure parser 误读成 storage IO、worker process、host dispatch、customization draft runtime、builtin asset seeding runtime、Git/AI service runtime 已完成迁移。
+- 2026-05-19 follow-up: MiniApp built-in seed artifact / action resolution and install-marker serialize/parse helpers have also moved to `bitfun-product-domains::miniapp::builtin`; core still owns bundled asset includes, user-data filesystem reads/writes, marker read/write calls, local customization metadata IO, source-hash input lookup, timestamp source, and recompile orchestration.
+- 2026-05-19 function-agent parser update: Git commit-message and Startchat complete-analysis JSON-string parsers now live in `bitfun-product-domains::function_agents`; core still owns AI service calls, prompt templates, `extract_json_from_ai_response`, log/error mapping, and runtime analysis orchestration.
+- boundary check 已补充 product-domain owner anchor：`MiniAppStoragePort` / `MiniAppRuntimePort` 的 core adapter、MiniApp host/customization/builtin 纯 contract、MiniApp manager preflight tests、function-agent Git adapter 与 AI response parsing helper 必须存在，防止把 port contract 或 pure parser 误读成 storage IO、worker process、host dispatch、customization draft runtime、builtin asset seeding runtime、Git/AI service runtime、JSON extraction 或错误映射已完成迁移。
 - miniapp runtime/storage/manager/host dispatch/exporter/builtin 与 function-agent 运行逻辑继续迁移前，需要先确认 agent/tool/provider port 和 Git/AI service 边界。
 
 **验证：**
@@ -1545,7 +1547,7 @@ cargo check --workspace
 - 未声明完成的 P2/后续剩余部分：remote-ssh runtime、remote-connect 等重 service 迁移、`ToolUseContext` 外移、runtime manifest assembly / `GetToolSpec` 执行 owner 化、concrete tool implementation 迁移、product registry / provider assembly、miniapp/function-agent 运行逻辑迁移。这些会触碰 `PathManager`、`ToolUseContext`、workspace service、snapshot wrapper、prompt-visible tool catalog、`AgentSubmissionPort` 或 AI service 边界，需要在继续前显式确认。
 - 本次 rebase 后重新核对最新主干 Deep Review capacity/cost/queue、context profile、evidence ledger 与 session manifest 变更：当前 PR 已完成 Git feature group 的 owner crate 归属迁移，但未改动这些 Deep Review 行为路径；后续迁移必须补端口设计和等价测试后再推进。
 - 本次 rebase 后重新核对最新主干 tool 变更：on-demand tool spec discovery 新增 collapsed/expanded manifest、`GetToolSpec`、context-aware schema/description 与 unlock state。这不要求回退当前 P2 已完成内容，但要求后续 tool/provider 迁移先补 manifest / catalog / unlock 等价保护，且不得和 PR5 product-domain runtime 收口混合。
-- PR5 已先推进低风险 product-domain slice：MiniApp 纯 compiler、export/runtime/worker DTO、runtime search plan、worker install 命令选择、package.json storage-shape helper、import layout / fallback payload contract、lifecycle / revision helper、manager 纯状态转换 helper、host routing string / allowlist policy helper、customization metadata / permission diff、built-in bundle/hash/marker/source payload seed-decision contract、runtime/storage port contract，以及 git/startchat function-agent 纯 utils / commit summary / message assembly / prompt format / commit prompt preparation / AI response parsing policy / action normalization / git porcelain / diff combine / time-of-day / Git/AI port contract / project context analyzer 已移入 `bitfun-product-domains`，core 保留原路径兼容 wrapper；core 只保留 AI client 调用、JSON 提取、错误映射、Git service adapter 和原路径 facade。已新增 core-owned Git snapshot、MiniApp storage/runtime port adapter 等价测试，并补齐 MiniApp manager import/sync/recompile/rollback/deps state、built-in asset seeding decision 等价测试与 function-agent staged diff / AI response error mapping 的迁移前快照。PathManager、Git/AI service、prompt template、builtin asset includes / seed / marker IO / recompile、host dispatch 执行、customization draft 存储 / 应用、worker pool / storage IO 执行逻辑和任何 tool runtime 仍未迁移。
+- PR5 已先推进低风险 product-domain slice：MiniApp 纯 compiler、export/runtime/worker DTO、runtime search plan、worker install 命令选择、package.json storage-shape helper、import layout / fallback payload contract、lifecycle / revision helper、manager 纯状态转换 helper、host routing string / allowlist policy helper、customization metadata / permission diff、built-in bundle/hash/marker/source payload seed-decision contract、built-in seed plan / marker wire helper、runtime/storage port contract，以及 git/startchat function-agent 纯 utils / commit summary / message assembly / prompt format / commit prompt preparation / AI response parsing policy / JSON-string parsing helper / action normalization / git porcelain / diff combine / time-of-day / Git/AI port contract / project context analyzer 已移入 `bitfun-product-domains`，core 保留原路径兼容 wrapper；core 只保留 AI client 调用、JSON 提取、错误映射、Git service adapter 和原路径 facade。已新增 core-owned Git snapshot、MiniApp storage/runtime port adapter 等价测试，并补齐 MiniApp manager import/sync/recompile/rollback/deps state、built-in asset seeding decision 等价测试与 function-agent staged diff / AI response error mapping 的迁移前快照。PathManager、Git/AI service、prompt template、builtin asset includes / seed / marker IO / recompile、host dispatch 执行、customization draft 存储 / 应用、worker pool / storage IO 执行逻辑和任何 tool runtime 仍未迁移。
 - 本次 P2 后续复核结论：上述高耦合剩余项不是纯文件搬迁；若继续迁移会改变依赖方向或需要新增 port/provider 行为合约。因此当前 PR 将它们显式保留为 core-owned runtime，只完成低风险 owner container 化，并通过 boundary check 防止已拆 owner crate 回流依赖 core。
 
 **后续风险重排（2026-05-13）：**
@@ -1743,7 +1745,7 @@ git diff -- package.json scripts/dev.cjs scripts/desktop-tauri-build.mjs scripts
 15. 已完成：agent tools + `tool-packs` owner 化低风险闭环；tool contract / DTO、runtime restriction、path resolution、portable context facts/provider、generic registry / static provider installation / dynamic provider container 已归属 `bitfun-agent-tools`，`tool-packs` 只提供计划内 feature-group scaffold，core 保留 core-owned product provider groups、snapshot decorator、`ToolUseContext` 和 concrete tool implementation，后续外移需单独 service port/provider 设计。
 16. 已完成：关键语义回归 baseline，不移动 runtime owner。覆盖 MCP config failure / catalog invalidation / 既有 list-changed helper / dynamic manifest、tool manifest / `GetToolSpec`、product-domains adapter equivalence、remote workspace search fallback 的 focused tests 或 snapshots。
 17. 已完成：remote-connect runtime 当前批次收口。已基于当前 port baseline 记录 remote command/response、remote model catalog、poll response、model catalog delta、session restore、active turn、cancel、image context、tracker event、queue/event fanout 的输入输出和验证命令；tracker state / registry lifecycle、legacy image context fallback / preference、restore target decision、cancel decision 与 remote file transfer size/chunk/name policy 已迁入 `bitfun-services-integrations`。dispatcher / product execution、`ImageContextData` adapter、file IO/path resolution、terminal pre-warm 与 workspace/session restore 执行显式保留在 core-owned runtime；后续只有在另起 port/provider 设计且 focused regression 继续通过时才允许继续移动这些 runtime owner，不能把 generic attachment guard 当作已接入多模态行为。
-18. 当前阶段：`product-domains` runtime port/facade closure。已迁入 MiniApp storage-backed runtime-state facade 与 function-agent Git/AI port-backed runtime facade，并补充 focused contract tests；core 只对 MiniApp deps/restart/recompile/sync/rollback 的状态持久化委托 facade，仍保留 `PathManager` 注入、filesystem IO、worker process execution、host dispatch 执行、built-in asset seeding/source-hash lookup、prompt template、JSON extraction 和 error mapping adapter。Git commit-message 与 Startchat work-state 产品路径已通过 core-owned Git/AI adapter 接入 function-agent facade；Startchat 接线已用 no-HEAD diff fallback、非 Git 目录空状态和 `analyze_git=false` time-info 保护旧行为，`analyzed_at` 仍由 core 在 AI 分析完成后赋值。
+18. 当前阶段：`product-domains` runtime port/facade closure。已迁入 MiniApp storage-backed runtime-state facade、built-in seed plan / marker wire helper 与 function-agent Git/AI port-backed runtime facade，并补充 focused contract tests；core 只对 MiniApp deps/restart/recompile/sync/rollback 的状态持久化委托 facade，仍保留 `PathManager` 注入、filesystem IO、worker process execution、host dispatch 执行、built-in asset seeding/source-hash lookup、prompt template、JSON extraction 和 error mapping adapter。Git commit-message 与 Startchat work-state 产品路径已通过 core-owned Git/AI adapter 接入 function-agent facade；extracted JSON string 可委托 product-domain parser，但 JSON 提取、日志与错误映射仍在 core。Startchat 接线已用 no-HEAD diff fallback、非 Git 目录空状态和 `analyze_git=false` time-info 保护旧行为，`analyzed_at` 仍由 core 在 AI 分析完成后赋值。
 19. 后续独立评估：`bitfun-core default = []`、per-product feature set、依赖版本收敛或构建收益优化；任何收益声明都需要记录 `cargo check -p bitfun-core`、workspace check 和目标 crate check 的前后数据。
 
 冗余清理 PR 不进入上述主线序号。只有在满足 `0A.6` 的绝对等价要求时，才可以插入到相邻里程碑之间，并且不得与主线拆分 PR 混合。
diff --git a/scripts/check-core-boundaries.mjs b/scripts/check-core-boundaries.mjs
index a247305b9..c2969477e 100644
--- a/scripts/check-core-boundaries.mjs
+++ b/scripts/check-core-boundaries.mjs
@@ -1919,6 +1919,14 @@ const requiredContentRules = [
         regex: /\bshould_seed_builtin_app\b/,
         message: 'missing product-domain built-in MiniApp seed decision use',
       },
+      {
+        regex: /\bresolve_builtin_seed_check\b/,
+        message: 'missing product-domain built-in MiniApp seed check use',
+      },
+      {
+        regex: /\bresolve_builtin_seed_action\b/,
+        message: 'missing product-domain built-in MiniApp seed action use',
+      },
       {
         regex: /\bbuiltin_source_files\b/,
         message: 'missing product-domain built-in MiniApp source payload use',
@@ -1931,10 +1939,18 @@ const requiredContentRules = [
         regex: /\bread_builtin_install_marker\b/,
         message: 'missing core-owned built-in MiniApp marker read IO',
       },
+      {
+        regex: /\bparse_builtin_install_marker\b/,
+        message: 'missing product-domain built-in MiniApp marker parse helper use',
+      },
       {
         regex: /\bwrite_builtin_install_marker\b/,
         message: 'missing core-owned built-in MiniApp marker write IO',
       },
+      {
+        regex: /\bserialize_builtin_install_marker\b/,
+        message: 'missing product-domain built-in MiniApp marker serialization helper use',
+      },
       {
         regex: /\brecompile\b/,
         message: 'missing core-owned built-in MiniApp recompile orchestration',
@@ -2288,6 +2304,10 @@ const requiredContentRules = [
         regex: /\bextract_json_from_ai_response\b/,
         message: 'missing core-owned AI response JSON extraction',
       },
+      {
+        regex: /\bparse_commit_analysis_json\b/,
+        message: 'missing product-domain Git function-agent JSON parser use',
+      },
       {
         regex: /\bAgentError::analysis_error\b/,
         message: 'missing core-owned AI response error mapping',
@@ -2298,6 +2318,37 @@ const requiredContentRules = [
       },
     ],
   },
+  {
+    path: 'src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs',
+    reason:
+      'core must continue owning Startchat prompt template, AI call, JSON extraction, and error mapping until AI runtime migration is reviewed',
+    patterns: [
+      {
+        regex: /\bconst WORK_STATE_ANALYSIS_PROMPT\b/,
+        message: 'missing core-owned Startchat prompt template',
+      },
+      {
+        regex: /\bai_client\s*\.\s*send_message\b/,
+        message: 'missing core-owned Startchat AI call',
+      },
+      {
+        regex: /\bextract_json_from_ai_response\b/,
+        message: 'missing core-owned Startchat JSON extraction',
+      },
+      {
+        regex: /\bparse_complete_analysis_json\b/,
+        message: 'missing product-domain Startchat JSON parser use',
+      },
+      {
+        regex: /\bAgentError::internal_error\b/,
+        message: 'missing core-owned Startchat error mapping',
+      },
+      {
+        regex: /\bparse_complete_analysis_preserves_core_json_extraction_and_error_mapping\b/,
+        message: 'missing Startchat AI response boundary regression test',
+      },
+    ],
+  },
   {
     path: 'src/crates/core/src/function_agents/git-func-agent/commit_generator.rs',
     reason:
@@ -2342,6 +2393,34 @@ const requiredContentRules = [
         regex: /\bpub fn should_seed_builtin_app\b/,
         message: 'missing built-in MiniApp seed decision helper',
       },
+      {
+        regex: /\bpub struct BuiltinSeedArtifacts\b/,
+        message: 'missing built-in MiniApp seed artifacts contract',
+      },
+      {
+        regex: /\bpub enum BuiltinSeedCheck\b/,
+        message: 'missing built-in MiniApp seed check contract',
+      },
+      {
+        regex: /\bpub enum BuiltinSeedAction\b/,
+        message: 'missing built-in MiniApp seed action contract',
+      },
+      {
+        regex: /\bpub fn resolve_builtin_seed_check\b/,
+        message: 'missing built-in MiniApp seed check helper',
+      },
+      {
+        regex: /\bpub fn resolve_builtin_seed_action\b/,
+        message: 'missing built-in MiniApp seed action helper',
+      },
+      {
+        regex: /\bpub fn serialize_builtin_install_marker\b/,
+        message: 'missing built-in MiniApp marker serialization helper',
+      },
+      {
+        regex: /\bpub fn parse_builtin_install_marker\b/,
+        message: 'missing built-in MiniApp marker parse helper',
+      },
       {
         regex: /\bpub fn builtin_source_files\b/,
         message: 'missing built-in MiniApp source payload helper',
@@ -2419,6 +2498,10 @@ const requiredContentRules = [
         regex: /\bpub fn parse_complete_analysis_value\b/,
         message: 'missing Startchat complete-analysis value parser',
       },
+      {
+        regex: /\bpub fn parse_complete_analysis_json\b/,
+        message: 'missing Startchat complete-analysis JSON parser',
+      },
     ],
   },
   {
@@ -2430,6 +2513,10 @@ const requiredContentRules = [
         regex: /\bpub fn parse_commit_analysis_value\b/,
         message: 'missing Git function-agent commit analysis value parser',
       },
+      {
+        regex: /\bpub fn parse_commit_analysis_json\b/,
+        message: 'missing Git function-agent commit analysis JSON parser',
+      },
       {
         regex: /\bpub fn truncate_diff_for_commit_prompt\b/,
         message: 'missing Git function-agent diff truncation helper',
@@ -3177,10 +3264,14 @@ function runManifestParserSelfTest() {
         'BUILTIN_APPS',
         'builtin_content_hash',
         'should_seed_builtin_app',
+        'resolve_builtin_seed_check',
+        'resolve_builtin_seed_action',
         'builtin_source_files',
         'BUILTIN_PLACEHOLDER_COMPILED_HTML',
         'read_builtin_install_marker',
+        'parse_builtin_install_marker',
         'write_builtin_install_marker',
+        'serialize_builtin_install_marker',
         'recompile',
         'load_customization_metadata',
         'available_builtin_update',
@@ -3194,6 +3285,13 @@ function runManifestParserSelfTest() {
         'BUILTIN_INSTALL_MARKER',
         'builtin_content_hash',
         'should_seed_builtin_app',
+        'BuiltinSeedArtifacts',
+        'BuiltinSeedCheck',
+        'BuiltinSeedAction',
+        'resolve_builtin_seed_check',
+        'resolve_builtin_seed_action',
+        'serialize_builtin_install_marker',
+        'parse_builtin_install_marker',
         'builtin_source_files',
         'BUILTIN_PLACEHOLDER_COMPILED_HTML',
         'build_builtin_package_json',
@@ -3323,10 +3421,22 @@ function runManifestParserSelfTest() {
         'prepare_commit_prompt',
         'send_message',
         'extract_json_from_ai_response',
+        'parse_commit_analysis_json',
         'AgentError::analysis_error',
         'parse_commit_response_preserves_core_json_extraction_and_error_mapping',
       ],
     },
+    {
+      path: 'src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs',
+      contracts: [
+        'WORK_STATE_ANALYSIS_PROMPT',
+        'send_message',
+        'extract_json_from_ai_response',
+        'parse_complete_analysis_json',
+        'AgentError::internal_error',
+        'parse_complete_analysis_preserves_core_json_extraction_and_error_mapping',
+      ],
+    },
     {
       path: 'src/crates/core/src/function_agents/git-func-agent/commit_generator.rs',
       contracts: [
@@ -3348,11 +3458,16 @@ function runManifestParserSelfTest() {
     },
     {
       path: 'src/crates/product-domains/src/function_agents/startchat_func_agent/utils.rs',
-      contracts: ['ParsedCompleteAnalysis', 'parse_complete_analysis_value'],
+      contracts: ['ParsedCompleteAnalysis', 'parse_complete_analysis_value', 'parse_complete_analysis_json'],
     },
     {
       path: 'src/crates/product-domains/src/function_agents/git_func_agent/utils.rs',
-      contracts: ['parse_commit_analysis_value', 'truncate_diff_for_commit_prompt', 'prepare_commit_prompt'],
+      contracts: [
+        'parse_commit_analysis_value',
+        'parse_commit_analysis_json',
+        'truncate_diff_for_commit_prompt',
+        'prepare_commit_prompt',
+      ],
     },
     {
       path: 'src/crates/core/src/miniapp/runtime_detect.rs',
diff --git a/src/crates/core/AGENTS-CN.md b/src/crates/core/AGENTS-CN.md
index e54ac7a7f..cbde21600 100644
--- a/src/crates/core/AGENTS-CN.md
+++ b/src/crates/core/AGENTS-CN.md
@@ -34,6 +34,14 @@ SessionManager → Session → DialogTurn → ModelRound
 - Tool 迁移必须保持 expanded/collapsed exposure、prompt 可见 manifest、`ToolUseContext.unlocked_collapsed_tools`，以及 desktop/MCP/ACP tool catalog 行为等价。
 - 不要把 OpenAI Responses / Codex ChatGPT flat tool schema 等 provider-specific 序列化行为写进 core tool contract；AI adapter 负责 provider 序列化，core 保持 provider-neutral manifest。
 - 调整 session/token usage 路径时，`cached_content_token_count` 必须继续表示 cache reads/hits，`cache_creation_token_count` 必须作为独立 provider fact 保留。
+- Function-agent commit-message 与 Startchat work-state orchestration 可以经由
+  `bitfun-product-domains`；Git/AI service adapter、prompt template、JSON
+  extraction 和 error mapping 仍由 core 拥有。JSON extraction 之后的 JSON string
+  parser 可以放在 `bitfun-product-domains`。
+- MiniApp built-in bundle/hash/marker seed plan 与 marker wire helper 可以放在
+  `bitfun-product-domains`；bundled asset include、filesystem writes、marker IO、
+  customization metadata IO、recompile orchestration、worker process runtime 和
+  host dispatch execution 仍由 core 拥有，直到有评审过的迁移和等价测试。
 - 不要在没有小型 port/interface 边界的情况下新增 `service` 到 `agentic` 的跨层引用。
 - 不要在 core 拆解中把平台专属逻辑、构建脚本行为或产品能力选择下沉到 shared core。
 
diff --git a/src/crates/core/AGENTS.md b/src/crates/core/AGENTS.md
index 620148fc9..9a2a39611 100644
--- a/src/crates/core/AGENTS.md
+++ b/src/crates/core/AGENTS.md
@@ -55,11 +55,11 @@ SessionManager → Session → DialogTurn → ModelRound
   fact.
 - Function-agent commit-message and Startchat work-state orchestration may
   route through `bitfun-product-domains`; keep Git/AI service adapters, prompt
-  templates, JSON extraction, and error mapping core-owned until a reviewed
-  migration proves equivalence.
-- MiniApp built-in bundle/hash/marker seed-decision contracts may live in
-  `bitfun-product-domains`; keep bundled asset includes, filesystem writes,
-  marker IO, customization metadata IO, recompile orchestration, worker
+  templates, JSON extraction, and error mapping core-owned. JSON-string parsing
+  helpers may live in `bitfun-product-domains` after extraction has happened.
+- MiniApp built-in bundle/hash/marker seed-plan and marker wire helpers may
+  live in `bitfun-product-domains`; keep bundled asset includes, filesystem
+  writes, marker IO, customization metadata IO, recompile orchestration, worker
   process runtime, and host dispatch execution core-owned until a reviewed
   migration proves equivalence.
 - Do not add new cross-layer references from `service` to `agentic` without a
diff --git a/src/crates/core/src/function_agents/git-func-agent/ai_service.rs b/src/crates/core/src/function_agents/git-func-agent/ai_service.rs
index 3e801af11..45e044641 100644
--- a/src/crates/core/src/function_agents/git-func-agent/ai_service.rs
+++ b/src/crates/core/src/function_agents/git-func-agent/ai_service.rs
@@ -7,7 +7,9 @@ use crate::util::types::Message;
  *
  * Handles AI client interaction and provides intelligent analysis for commit message generation
  */
-use bitfun_product_domains::function_agents::git_func_agent::prepare_commit_prompt;
+use bitfun_product_domains::function_agents::git_func_agent::{
+    parse_commit_analysis_json, prepare_commit_prompt,
+};
 use log::{debug, error, warn};
 use std::sync::Arc;
 
@@ -99,11 +101,7 @@ impl AIAnalysisService {
         let json_str = crate::util::extract_json_from_ai_response(response)
             .ok_or_else(|| AgentError::analysis_error("Cannot extract JSON from response"))?;
 
-        let value: serde_json::Value = serde_json::from_str(&json_str).map_err(|e| {
-            AgentError::analysis_error(format!("Failed to parse AI response: {}", e))
-        })?;
-
-        super::utils::parse_commit_analysis_value(&value).map_err(AgentError::analysis_error)
+        parse_commit_analysis_json(&json_str).map_err(AgentError::analysis_error)
     }
 }
 
diff --git a/src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs b/src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs
index 096caa65a..e57828f21 100644
--- a/src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs
+++ b/src/crates/core/src/function_agents/startchat-func-agent/ai_service.rs
@@ -2,6 +2,7 @@ use super::types::*;
 use crate::function_agents::common::{AgentError, AgentResult, Language};
 use crate::infrastructure::ai::AIClient;
 use crate::util::types::Message;
+use bitfun_product_domains::function_agents::startchat_func_agent::parse_complete_analysis_json;
 /**
  * AI analysis service
  *
@@ -107,16 +108,11 @@ impl AIWorkStateService {
 
         debug!("Parsing JSON response: length={}", json_str.len());
 
-        let parsed: serde_json::Value = serde_json::from_str(&json_str).map_err(|e| {
-            error!(
-                "Failed to parse complete analysis response: {}, response: {}",
-                e, response
-            );
-            AgentError::internal_error(format!("Failed to parse complete analysis response: {}", e))
+        let parsed_analysis = parse_complete_analysis_json(&json_str).map_err(|message| {
+            error!("{}, response: {}", message, response);
+            AgentError::internal_error(message)
         })?;
 
-        let parsed_analysis = super::utils::parse_complete_analysis_value(&parsed);
-
         if parsed_analysis.predicted_actions_count < 3 {
             warn!(
                 "AI generated insufficient predicted actions ({}), adding defaults",
@@ -151,3 +147,83 @@ impl AIWorkStateService {
         Ok(parsed_analysis.analysis)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::function_agents::common::AgentErrorType;
+    use crate::util::types::AIConfig;
+    use bitfun_ai_adapters::types::ReasoningMode;
+
+    fn test_service() -> AIWorkStateService {
+        AIWorkStateService {
+            ai_client: Arc::new(AIClient::new(AIConfig {
+                name: "test".to_string(),
+                base_url: "http://127.0.0.1".to_string(),
+                request_url: "http://127.0.0.1".to_string(),
+                api_key: "test".to_string(),
+                model: "test-model".to_string(),
+                format: "openai".to_string(),
+                context_window: 8192,
+                max_tokens: None,
+                temperature: None,
+                top_p: None,
+                reasoning_mode: ReasoningMode::Default,
+                inline_think_in_text: false,
+                custom_headers: None,
+                custom_headers_mode: None,
+                skip_ssl_verify: false,
+                reasoning_effort: None,
+                thinking_budget_tokens: None,
+                custom_request_body: None,
+                custom_request_body_mode: None,
+            })),
+        }
+    }
+
+    #[test]
+    fn parse_complete_analysis_preserves_core_json_extraction_and_error_mapping() {
+        let service = test_service();
+        let analysis = service
+            .parse_complete_analysis(
+                r#"The answer is:
+```json
+{
+  "summary": "Working on product-domain owner closure.",
+  "predicted_actions": [
+    {"description": "Run checks", "priority": "High", "icon": "check", "is_reminder": false}
+  ],
+  "quick_actions": [
+    {"title": "Status", "command": "git status", "icon": "git", "action_type": "ViewStatus"}
+  ]
+}
+```
+"#,
+            )
+            .unwrap();
+
+        assert_eq!(analysis.summary, "Working on product-domain owner closure.");
+        assert_eq!(analysis.predicted_actions.len(), 3);
+        assert_eq!(analysis.quick_actions.len(), 1);
+
+        let missing_json = service.parse_complete_analysis("no json here").unwrap_err();
+        assert_eq!(missing_json.error_type, AgentErrorType::InternalError);
+        assert_eq!(
+            missing_json.message,
+            "Failed to extract JSON from analysis response"
+        );
+
+        let invalid_json = service
+            .parse_complete_analysis(
+                r#"```json
+not json
+```"#,
+            )
+            .unwrap_err();
+        assert_eq!(invalid_json.error_type, AgentErrorType::InternalError);
+        assert_eq!(
+            invalid_json.message,
+            "Failed to extract JSON from analysis response"
+        );
+    }
+}
diff --git a/src/crates/core/src/miniapp/builtin/mod.rs b/src/crates/core/src/miniapp/builtin/mod.rs
index e4ca41946..b640204b8 100644
--- a/src/crates/core/src/miniapp/builtin/mod.rs
+++ b/src/crates/core/src/miniapp/builtin/mod.rs
@@ -9,9 +9,10 @@ use crate::miniapp::manager::MiniAppManager;
 use crate::miniapp::types::MiniAppMeta;
 use crate::util::errors::{BitFunError, BitFunResult};
 use bitfun_product_domains::miniapp::builtin::{
-    build_builtin_package_json, builtin_content_hash, builtin_source_files,
-    should_seed_builtin_app, BuiltinInstallMarker, BuiltinMiniAppBundle, BUILTIN_INSTALL_MARKER,
-    BUILTIN_PLACEHOLDER_COMPILED_HTML, LEGACY_BUILTIN_VERSION_MARKER,
+    build_builtin_package_json, builtin_source_files, parse_builtin_install_marker,
+    resolve_builtin_seed_action, resolve_builtin_seed_check, serialize_builtin_install_marker,
+    BuiltinInstallMarker, BuiltinMiniAppBundle, BuiltinSeedAction, BuiltinSeedCheck,
+    BUILTIN_INSTALL_MARKER, BUILTIN_PLACEHOLDER_COMPILED_HTML, LEGACY_BUILTIN_VERSION_MARKER,
 };
 use chrono::Utc;
 use std::path::Path;
@@ -90,28 +91,35 @@ pub async fn seed_builtin_miniapps(manager: &Arc<MiniAppManager>) -> BitFunResul
 async fn seed_one(manager: &Arc<MiniAppManager>, app: &BuiltinApp) -> BitFunResult<()> {
     let app_dir = manager.path_manager().miniapp_dir(app.id);
     let marker_path = app_dir.join(BUILTIN_INSTALL_MARKER);
-    let content_hash = builtin_content_hash(app);
+    let installed_marker = read_builtin_install_marker(&marker_path).await?;
+    let seed_artifacts = match resolve_builtin_seed_check(app, installed_marker.as_ref()) {
+        BuiltinSeedCheck::Skip => return Ok(()),
+        BuiltinSeedCheck::NeedsSeed(artifacts) => artifacts,
+    };
 
-    if let Some(marker) = read_builtin_install_marker(&marker_path).await? {
-        if !should_seed_builtin_app(app, &content_hash, Some(&marker)) {
-            return Ok(());
+    let now = Utc::now().timestamp_millis();
+    let has_local_override = match manager.load_customization_metadata(app.id).await {
+        Ok(Some(metadata)) => metadata.local_override,
+        Ok(None) => false,
+        Err(e) => {
+            log::warn!(
+                "read customization metadata for builtin miniapp '{}' failed: {}",
+                app.id,
+                e
+            );
+            false
         }
-    }
+    };
 
-    let now = Utc::now().timestamp_millis();
-    match manager.load_customization_metadata(app.id).await {
-        Ok(Some(metadata)) if metadata.local_override => {
+    match resolve_builtin_seed_action(seed_artifacts, has_local_override) {
+        BuiltinSeedAction::PreserveLocalOverride(artifacts) => {
             let recorded = manager
-                .mark_builtin_update_available(app.id, app.version, &content_hash, now)
+                .mark_builtin_update_available(app.id, app.version, &artifacts.content_hash, now)
                 .await?;
-            let marker = BuiltinInstallMarker {
-                version: app.version,
-                hash: content_hash,
-            };
-            write_builtin_install_marker(&marker_path, &marker).await?;
+            write_builtin_install_marker(&marker_path, &artifacts.marker).await?;
             write_file(
                 app_dir.join(LEGACY_BUILTIN_VERSION_MARKER),
-                &app.version.to_string(),
+                &artifacts.legacy_version,
             )
             .await?;
             if recorded {
@@ -129,16 +137,19 @@ async fn seed_one(manager: &Arc<MiniAppManager>, app: &BuiltinApp) -> BitFunResu
             }
             return Ok(());
         }
-        Ok(_) => {}
-        Err(e) => {
-            log::warn!(
-                "read customization metadata for builtin miniapp '{}' failed: {}",
-                app.id,
-                e
-            );
+        BuiltinSeedAction::SeedBundle(artifacts) => {
+            seed_builtin_bundle(manager, app, artifacts, now).await
         }
     }
+}
 
+async fn seed_builtin_bundle(
+    manager: &Arc<MiniAppManager>,
+    app: &BuiltinApp,
+    artifacts: bitfun_product_domains::miniapp::builtin::BuiltinSeedArtifacts,
+    now: i64,
+) -> BitFunResult<()> {
+    let app_dir = manager.path_manager().miniapp_dir(app.id);
     let source_dir = app_dir.join("source");
     tokio::fs::create_dir_all(&source_dir)
         .await
@@ -191,21 +202,18 @@ async fn seed_one(manager: &Arc<MiniAppManager>, app: &BuiltinApp) -> BitFunResu
     // Recompile to assemble the final compiled.html with bridge + theme + import map.
     manager.recompile(app.id, "dark", None).await?;
 
-    let marker = BuiltinInstallMarker {
-        version: app.version,
-        hash: content_hash,
-    };
-    write_builtin_install_marker(&marker_path, &marker).await?;
+    let marker_path = app_dir.join(BUILTIN_INSTALL_MARKER);
+    write_builtin_install_marker(&marker_path, &artifacts.marker).await?;
     write_file(
         app_dir.join(LEGACY_BUILTIN_VERSION_MARKER),
-        &app.version.to_string(),
+        &artifacts.legacy_version,
     )
     .await?;
     log::info!(
         "seeded builtin miniapp '{}' (v{}, {})",
         app.id,
         app.version,
-        marker.hash
+        artifacts.marker.hash
     );
     Ok(())
 }
@@ -223,7 +231,7 @@ async fn read_builtin_install_marker(path: &Path) -> BitFunResult<Option<Builtin
         }
     };
 
-    match serde_json::from_str::<BuiltinInstallMarker>(&content) {
+    match parse_builtin_install_marker(&content) {
         Ok(marker) => Ok(Some(marker)),
         Err(error) => {
             log::warn!(
@@ -240,7 +248,7 @@ async fn write_builtin_install_marker(
     path: &Path,
     marker: &BuiltinInstallMarker,
 ) -> BitFunResult<()> {
-    let content = serde_json::to_string_pretty(marker).map_err(BitFunError::from)?;
+    let content = serialize_builtin_install_marker(marker).map_err(BitFunError::from)?;
     write_file(path, &content).await
 }
 
@@ -253,6 +261,7 @@ async fn write_file<P: AsRef<std::path::Path>>(path: P, content: &str) -> BitFun
 #[cfg(test)]
 mod tests {
     use super::*;
+    use bitfun_product_domains::miniapp::builtin::{builtin_content_hash, should_seed_builtin_app};
     use bitfun_product_domains::miniapp::customization::{
         MiniAppCustomizationMetadata, MiniAppCustomizationOrigin, MiniAppCustomizationOriginKind,
     };
diff --git a/src/crates/product-domains/AGENTS-CN.md b/src/crates/product-domains/AGENTS-CN.md
index cfd91ca1c..75d24987a 100644
--- a/src/crates/product-domains/AGENTS-CN.md
+++ b/src/crates/product-domains/AGENTS-CN.md
@@ -33,15 +33,18 @@
 - `miniapp` 拥有 MiniApp DTO、compiler/bridge helper、storage/draft/import
   文件形态、fallback payload、runtime search plan、worker install 命令选择、
   lifecycle/revision 与 manager state-transition helper、host-routing string
-  policy、customization metadata policy、port trait，以及 storage-backed runtime
+  policy、customization metadata policy、built-in update/decline 决策、
+  built-in bundle/hash/marker seed plan 与 marker wire helper、built-in
+  source/placeholder payload contract、port trait，以及 storage-backed runtime
   state facade。
 - `function-agents` 拥有纯 DTO、prompt assembly、commit prompt preparation、
-  AI response parsing policy、diff truncation policy、本地文件形态分析、
-  Git/AI port trait，以及 port-backed runtime facade orchestration。
+  AI response parsing policy、diff truncation policy、JSON string 到领域 DTO 的
+  解析 helper、本地文件形态分析、Git/AI port trait，以及 port-backed runtime
+  facade orchestration。
 - Core 仍拥有 MiniApp filesystem IO、worker process、host dispatch、built-in
-  asset seeding/source-hash lookup、`PathManager` 集成、function-agent Git/AI
-  调用、prompt template、JSON extraction、error mapping，以及尚未被等价测试覆盖的
-  产品调用路径切换。
+  asset include/seeding、marker IO、recompile orchestration、source-hash lookup、
+  `PathManager` 集成、function-agent Git/AI service adapter、prompt template、
+  JSON extraction 和 error mapping。
 
 ## 验证
 
diff --git a/src/crates/product-domains/AGENTS.md b/src/crates/product-domains/AGENTS.md
index 593795cd0..7c114f3fe 100644
--- a/src/crates/product-domains/AGENTS.md
+++ b/src/crates/product-domains/AGENTS.md
@@ -37,14 +37,14 @@ moves here gradually.
   file shapes, import fallback payloads, runtime search-plan helpers, worker
   install command selection, lifecycle/revision and manager state-transition
   helpers, host-routing string policy, customization metadata policy including
-  built-in update/decline decisions, built-in bundle/hash/marker seed-decision
-  contracts, built-in source/placeholder payload contracts, port traits, and
-  storage-backed runtime state facade logic.
+  built-in update/decline decisions, built-in bundle/hash/marker seed plan and
+  marker wire helpers, built-in source/placeholder payload contracts, port
+  traits, and storage-backed runtime state facade logic.
 - `function-agents` owns pure function-agent DTOs, prompt assembly helpers,
   commit prompt preparation, AI-response parsing policy, diff truncation policy,
-  local file-shape analysis, Git/AI port traits, and port-backed runtime facade
-  orchestration, including the commit-message and Startchat work-state facades
-  used by core adapters.
+  JSON-string-to-domain parsing helpers, local file-shape analysis, Git/AI port
+  traits, and port-backed runtime facade orchestration, including the
+  commit-message and Startchat work-state facades used by core adapters.
 - Core still owns MiniApp filesystem IO, worker process execution, host dispatch
   execution, built-in asset includes/seeding, marker IO, recompile orchestration,
   source-hash input lookup, `PathManager` integration, function-agent Git/AI
diff --git a/src/crates/product-domains/src/function_agents/git_func_agent/utils.rs b/src/crates/product-domains/src/function_agents/git_func_agent/utils.rs
index 8d8241b43..37e44252a 100644
--- a/src/crates/product-domains/src/function_agents/git_func_agent/utils.rs
+++ b/src/crates/product-domains/src/function_agents/git_func_agent/utils.rs
@@ -294,3 +294,9 @@ pub fn parse_commit_analysis_value(value: &serde_json::Value) -> Result<AICommit
         confidence: value["confidence"].as_f64().unwrap_or(0.8) as f32,
     })
 }
+
+pub fn parse_commit_analysis_json(json: &str) -> Result<AICommitAnalysis, String> {
+    let value = serde_json::from_str::<serde_json::Value>(json)
+        .map_err(|error| format!("Failed to parse AI response: {}", error))?;
+    parse_commit_analysis_value(&value)
+}
diff --git a/src/crates/product-domains/src/function_agents/startchat_func_agent/utils.rs b/src/crates/product-domains/src/function_agents/startchat_func_agent/utils.rs
index fb56fee5f..ea54d72e8 100644
--- a/src/crates/product-domains/src/function_agents/startchat_func_agent/utils.rs
+++ b/src/crates/product-domains/src/function_agents/startchat_func_agent/utils.rs
@@ -137,6 +137,7 @@ pub fn limit_quick_actions(mut actions: Vec<QuickAction>) -> Vec<QuickAction> {
     actions
 }
 
+#[derive(Debug, Clone)]
 pub struct ParsedCompleteAnalysis {
     pub analysis: AIGeneratedAnalysis,
     pub predicted_actions_count: usize,
@@ -175,6 +176,12 @@ pub fn parse_complete_analysis_value(parsed: &serde_json::Value) -> ParsedComple
     }
 }
 
+pub fn parse_complete_analysis_json(json: &str) -> Result<ParsedCompleteAnalysis, String> {
+    let parsed = serde_json::from_str::<serde_json::Value>(json)
+        .map_err(|error| format!("Failed to parse complete analysis response: {}", error))?;
+    Ok(parse_complete_analysis_value(&parsed))
+}
+
 pub fn parse_action_priority_label(label: &str) -> ActionPriority {
     match label {
         "High" => ActionPriority::High,
diff --git a/src/crates/product-domains/src/miniapp/builtin.rs b/src/crates/product-domains/src/miniapp/builtin.rs
index 3b8ac7ccc..6c20b6b0e 100644
--- a/src/crates/product-domains/src/miniapp/builtin.rs
+++ b/src/crates/product-domains/src/miniapp/builtin.rs
@@ -17,6 +17,25 @@ pub struct BuiltinInstallMarker {
     pub hash: String,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct BuiltinSeedArtifacts {
+    pub content_hash: String,
+    pub marker: BuiltinInstallMarker,
+    pub legacy_version: String,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum BuiltinSeedCheck {
+    Skip,
+    NeedsSeed(BuiltinSeedArtifacts),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum BuiltinSeedAction {
+    PreserveLocalOverride(BuiltinSeedArtifacts),
+    SeedBundle(BuiltinSeedArtifacts),
+}
+
 /// Pure built-in MiniApp asset bundle shape. The owning runtime still decides
 /// how assets are embedded, seeded, compiled, and persisted.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -46,6 +65,62 @@ pub fn builtin_content_hash(app: &BuiltinMiniAppBundle) -> String {
     format!("sha256:{}", hex_encode(&hasher.finalize()))
 }
 
+pub fn build_builtin_install_marker(
+    app: &BuiltinMiniAppBundle,
+    content_hash: &str,
+) -> BuiltinInstallMarker {
+    BuiltinInstallMarker {
+        version: app.version,
+        hash: content_hash.to_string(),
+    }
+}
+
+pub fn legacy_builtin_version_marker_content(app: &BuiltinMiniAppBundle) -> String {
+    app.version.to_string()
+}
+
+pub fn build_builtin_seed_artifacts(app: &BuiltinMiniAppBundle) -> BuiltinSeedArtifacts {
+    let content_hash = builtin_content_hash(app);
+    BuiltinSeedArtifacts {
+        marker: build_builtin_install_marker(app, &content_hash),
+        legacy_version: legacy_builtin_version_marker_content(app),
+        content_hash,
+    }
+}
+
+pub fn resolve_builtin_seed_check(
+    app: &BuiltinMiniAppBundle,
+    installed: Option<&BuiltinInstallMarker>,
+) -> BuiltinSeedCheck {
+    let artifacts = build_builtin_seed_artifacts(app);
+    if should_seed_builtin_app(app, &artifacts.content_hash, installed) {
+        BuiltinSeedCheck::NeedsSeed(artifacts)
+    } else {
+        BuiltinSeedCheck::Skip
+    }
+}
+
+pub fn resolve_builtin_seed_action(
+    artifacts: BuiltinSeedArtifacts,
+    has_local_override: bool,
+) -> BuiltinSeedAction {
+    if has_local_override {
+        BuiltinSeedAction::PreserveLocalOverride(artifacts)
+    } else {
+        BuiltinSeedAction::SeedBundle(artifacts)
+    }
+}
+
+pub fn serialize_builtin_install_marker(
+    marker: &BuiltinInstallMarker,
+) -> serde_json::Result<String> {
+    serde_json::to_string_pretty(marker)
+}
+
+pub fn parse_builtin_install_marker(content: &str) -> serde_json::Result<BuiltinInstallMarker> {
+    serde_json::from_str(content)
+}
+
 pub fn should_seed_builtin_app(
     app: &BuiltinMiniAppBundle,
     content_hash: &str,
diff --git a/src/crates/product-domains/tests/function_agent_contracts.rs b/src/crates/product-domains/tests/function_agent_contracts.rs
index 146c02969..f9974a8f5 100644
--- a/src/crates/product-domains/tests/function_agent_contracts.rs
+++ b/src/crates/product-domains/tests/function_agent_contracts.rs
@@ -3,10 +3,10 @@
 use bitfun_product_domains::function_agents::{
     git_func_agent::{
         assemble_commit_message, build_changes_summary_from_paths, build_commit_prompt,
-        detect_change_patterns, extract_module_name, infer_file_type, parse_commit_analysis_value,
-        parse_commit_type_label, prepare_commit_prompt, truncate_diff_for_commit_prompt,
-        ChangePattern, CommitFormat, CommitMessageOptions, CommitType, FileChange, FileChangeType,
-        ProjectContext,
+        detect_change_patterns, extract_module_name, infer_file_type, parse_commit_analysis_json,
+        parse_commit_analysis_value, parse_commit_type_label, prepare_commit_prompt,
+        truncate_diff_for_commit_prompt, ChangePattern, CommitFormat, CommitMessageOptions,
+        CommitType, FileChange, FileChangeType, ProjectContext,
     },
     ports::{
         CommitAiAnalysisRequest, FunctionAgentAiPort, FunctionAgentFuture, FunctionAgentGitPort,
@@ -15,9 +15,10 @@ use bitfun_product_domains::function_agents::{
     },
     startchat_func_agent::{
         build_complete_analysis_prompt, combine_git_diffs, limit_quick_actions,
-        normalize_predicted_actions, parse_complete_analysis_value, parse_git_status_porcelain,
-        parse_predicted_actions_from_values, parse_quick_actions_from_values, time_of_day_for_hour,
-        ActionPriority, AheadBehind, GitWorkState, QuickActionType, TimeOfDay, WorkStateOptions,
+        normalize_predicted_actions, parse_complete_analysis_json, parse_complete_analysis_value,
+        parse_git_status_porcelain, parse_predicted_actions_from_values,
+        parse_quick_actions_from_values, time_of_day_for_hour, ActionPriority, AheadBehind,
+        GitWorkState, QuickActionType, TimeOfDay, WorkStateOptions,
     },
     AgentErrorType, Language,
 };
@@ -645,3 +646,56 @@ fn git_function_agent_utils_preserve_change_classification() {
     assert!(patterns.contains(&ChangePattern::BugFix));
     assert!(patterns.contains(&ChangePattern::DocumentationUpdate));
 }
+
+#[test]
+fn function_agent_json_helpers_parse_ai_payloads_without_core_runtime() {
+    let commit = parse_commit_analysis_json(
+        r#"{
+            "type": "refactor",
+            "title": "refactor(product-domains): move parse helpers",
+            "body": "Keep runtime adapters in core.",
+            "confidence": 0.92
+        }"#,
+    )
+    .unwrap();
+    assert_eq!(commit.commit_type, CommitType::Refactor);
+    assert_eq!(
+        commit.title,
+        "refactor(product-domains): move parse helpers"
+    );
+    assert_eq!(
+        commit.body.as_deref(),
+        Some("Keep runtime adapters in core.")
+    );
+    assert_eq!(commit.confidence, 0.92);
+
+    let missing_title = parse_commit_analysis_json(r#"{"type":"fix"}"#).unwrap_err();
+    assert_eq!(missing_title, "Missing title field");
+
+    let invalid_commit = parse_commit_analysis_json("not json").unwrap_err();
+    assert!(invalid_commit.starts_with("Failed to parse AI response:"));
+
+    let work_state = parse_complete_analysis_json(
+        r#"{
+            "summary": "Working on product-domain owner closure.",
+            "predicted_actions": [
+                {"description": "Run checks", "priority": "High", "icon": "check", "is_reminder": false}
+            ],
+            "quick_actions": [
+                {"title": "Status", "command": "git status", "icon": "git", "action_type": "ViewStatus"}
+            ]
+        }"#,
+    )
+    .unwrap();
+    assert_eq!(
+        work_state.analysis.summary,
+        "Working on product-domain owner closure."
+    );
+    assert_eq!(work_state.predicted_actions_count, 1);
+    assert_eq!(work_state.quick_actions_count, 1);
+    assert_eq!(work_state.analysis.predicted_actions.len(), 3);
+    assert_eq!(work_state.analysis.quick_actions.len(), 1);
+
+    let invalid_work_state = parse_complete_analysis_json("not json").unwrap_err();
+    assert!(invalid_work_state.starts_with("Failed to parse complete analysis response:"));
+}
diff --git a/src/crates/product-domains/tests/miniapp_contracts.rs b/src/crates/product-domains/tests/miniapp_contracts.rs
index 81e91717c..8f962c12e 100644
--- a/src/crates/product-domains/tests/miniapp_contracts.rs
+++ b/src/crates/product-domains/tests/miniapp_contracts.rs
@@ -2,9 +2,12 @@
 
 use bitfun_product_domains::miniapp::bridge_builder::{build_bridge_script, build_csp_content};
 use bitfun_product_domains::miniapp::builtin::{
-    build_builtin_package_json, builtin_content_hash, builtin_source_files,
-    should_seed_builtin_app, BuiltinInstallMarker, BuiltinMiniAppBundle, BUILTIN_INSTALL_MARKER,
-    BUILTIN_PLACEHOLDER_COMPILED_HTML, LEGACY_BUILTIN_VERSION_MARKER,
+    build_builtin_install_marker, build_builtin_package_json, builtin_content_hash,
+    builtin_source_files, legacy_builtin_version_marker_content, parse_builtin_install_marker,
+    resolve_builtin_seed_action, resolve_builtin_seed_check, serialize_builtin_install_marker,
+    should_seed_builtin_app, BuiltinInstallMarker, BuiltinMiniAppBundle, BuiltinSeedAction,
+    BuiltinSeedCheck, BUILTIN_INSTALL_MARKER, BUILTIN_PLACEHOLDER_COMPILED_HTML,
+    LEGACY_BUILTIN_VERSION_MARKER,
 };
 use bitfun_product_domains::miniapp::compiler::compile;
 use bitfun_product_domains::miniapp::customization::{
@@ -784,6 +787,61 @@ fn miniapp_builtin_contract_preserves_seed_marker_and_hash_policy() {
     );
 }
 
+#[test]
+fn miniapp_builtin_contract_owns_seed_plan_and_marker_wire_shape() {
+    let app = BuiltinMiniAppBundle {
+        id: "builtin-demo",
+        version: 7,
+        meta_json: r#"{"id":"builtin-demo"}"#,
+        html: "<!doctype html><html></html>",
+        css: "body { color: red; }",
+        ui_js: r#"console.log("ui");"#,
+        worker_js: r#"console.log("worker");"#,
+        esm_dependencies_json: "[]",
+    };
+    let artifacts = bitfun_product_domains::miniapp::builtin::build_builtin_seed_artifacts(&app);
+    let marker = build_builtin_install_marker(&app, &artifacts.content_hash);
+
+    assert_eq!(artifacts.marker, marker);
+    assert_eq!(artifacts.legacy_version, "7");
+    assert_eq!(legacy_builtin_version_marker_content(&app), "7");
+    assert_eq!(
+        resolve_builtin_seed_check(&app, Some(&marker)),
+        BuiltinSeedCheck::Skip
+    );
+
+    let stale_marker = BuiltinInstallMarker {
+        version: 7,
+        hash: "sha256:stale".to_string(),
+    };
+    assert_eq!(
+        resolve_builtin_seed_check(&app, Some(&stale_marker)),
+        BuiltinSeedCheck::NeedsSeed(artifacts.clone())
+    );
+    assert_eq!(
+        resolve_builtin_seed_check(&app, None),
+        BuiltinSeedCheck::NeedsSeed(artifacts.clone())
+    );
+    assert_eq!(
+        resolve_builtin_seed_action(artifacts.clone(), true),
+        BuiltinSeedAction::PreserveLocalOverride(artifacts.clone())
+    );
+    assert_eq!(
+        resolve_builtin_seed_action(artifacts.clone(), false),
+        BuiltinSeedAction::SeedBundle(artifacts.clone())
+    );
+
+    let serialized = serialize_builtin_install_marker(&marker).unwrap();
+    assert_eq!(
+        serialized,
+        format!(
+            "{{\n  \"version\": 7,\n  \"hash\": \"{}\"\n}}",
+            artifacts.content_hash
+        )
+    );
+    assert_eq!(parse_builtin_install_marker(&serialized).unwrap(), marker);
+}
+
 #[test]
 fn miniapp_ports_keep_runtime_boundary_lightweight() {
     let decoded: MiniAppInstallDepsRequest = serde_json::from_value(serde_json::json!({