diff --git a/docs_v1.0/API_WORKSPACE/modules/07_identity.md b/docs_v1.0/API_WORKSPACE/modules/07_identity.md
index 066428c..f662b2f 100644
--- a/docs_v1.0/API_WORKSPACE/modules/07_identity.md
+++ b/docs_v1.0/API_WORKSPACE/modules/07_identity.md
@@ -234,6 +234,11 @@ Bind a face detection to an identity. Associates the face trace with the identit
 | `file_uuid` | string | Yes | File where face is detected |
 | `face_id` | string | Yes | Face ID (format: `{frame}_{idx}`) |
 
+#### Side Effects
+
+- 清除該 face detection row 的 `stranger_id`（設為 NULL）
+- 不影響 `identities` 表中原有的 stranger auto-identity 記錄
+
 #### Example
 
 ```bash
@@ -259,6 +264,11 @@ Bind all face detections of a trace to an identity. Updates all rows in `face_de
 | `file_uuid` | string | Yes | File where trace exists |
 | `trace_id` | integer | Yes | Trace ID (from `face_detections.trace_id`) |
 
+#### Side Effects
+
+- 清除該 trace 所有 face detection rows 的 `stranger_id`（設為 NULL）
+- 不影響 `identities` 表中原有的 stranger auto-identity 記錄
+
 #### Example
 
 ```bash
@@ -287,6 +297,78 @@ curl -s -X POST "$API/api/v1/identity/$IDENTITY_UUID/bind/trace" \
 
 ---
 
+### `GET /api/v1/identity/:identity_uuid/traces`
+
+**Auth**: Required
+**Scope**: identity-level
+
+Get paginated face traces (continuous tracking segments) associated with this identity across all files.
+
+#### Query Parameters
+
+| Field | Type | Required | Default | Description |
+|-------|------|----------|---------|-------------|
+| `page` | integer | No | `1` | Page number |
+| `page_size` | integer | No | `20` | Items per page |
+
+#### Example
+
+```bash
+curl -s "$API/api/v1/identity/$IDENTITY_UUID/traces?page=1&page_size=3" \
+  -H "X-API-Key: $KEY" | jq '{total, total_faces, traces}'
+```
+
+#### Response (200)
+
+```json
+{
+  "success": true,
+  "identity_uuid": "a9a901056d6b46ff92da0c3c1a57dff4",
+  "name": "Cary Grant",
+  "total": 18,
+  "page": 1,
+  "page_size": 3,
+  "total_faces": 542,
+  "traces": [
+    {
+      "file_uuid": "aeed71342a899fe4b4c57b7d41bcb692",
+      "trace_id": 906,
+      "frame_count": 52,
+      "first_frame": 37974,
+      "last_frame": 38127,
+      "first_sec": 1519.0,
+      "last_sec": 1525.1,
+      "avg_confidence": 0.8254
+    }
+  ]
+}
+```
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `success` | bool | Always `true` |
+| `identity_uuid` | string | Identity UUID |
+| `name` | string | Identity display name |
+| `total` | integer | Total number of traces (across all pages) |
+| `total_faces` | integer | Sum of all face detections in returned traces |
+| `traces[].file_uuid` | string | File where trace exists |
+| `traces[].trace_id` | integer | Trace tracking ID |
+| `traces[].frame_count` | integer | Number of frames in this trace |
+| `traces[].first_frame` | integer | Start frame number |
+| `traces[].last_frame` | integer | End frame number |
+| `traces[].first_sec` | float | Start time in seconds |
+| `traces[].last_sec` | float | End time in seconds |
+| `traces[].avg_confidence` | float | Average detection confidence (0.0–1.0) |
+
+#### Error Responses
+
+| HTTP | When |
+|------|------|
+| `404` | Identity not found |
+| `500` | Database error |
+
+---
+
 ### `POST /api/v1/identity/:identity_uuid/unbind`
 
 **Auth**: Required
@@ -294,6 +376,61 @@ curl -s -X POST "$API/api/v1/identity/$IDENTITY_UUID/bind/trace" \
 
 Unbind a face detection from an identity. Removes the identity association from the face record.
 
+#### Side Effects
+
+- 只清除 `identity_id`（設為 NULL），**不會恢復 `stranger_id`**
+- 被 unbind 的 face 不會自動成為 stranger
+- 要重新標記為 stranger 需重新跑 Agent API（`identity/analyze`）
+
+---
+
+### `POST /api/v1/identity/:identity_uuid/mergeinto`
+
+**Auth**: Required
+**Scope**: identity-level
+
+Transfer all face bindings from this identity to another identity, then optionally delete or mark the source as merged.
+
+#### Request Parameters
+
+| Field | Type | Required | Default | Description |
+|-------|------|----------|---------|-------------|
+| `into_uuid` | string | Yes | — | Target identity UUID to merge into |
+| `keep_history` | bool | No | `true` | Keep source identity record with `status='merged'` (`true`) or delete it (`false`) |
+
+#### Side Effects
+
+- 轉移所有 `face_detections.identity_id` 到目標 identity
+- 同時清除所有被轉移 rows 的 `stranger_id`
+- `keep_history: true`（預設）：source identity 設為 `status='merged'`，保留記錄
+- `keep_history: false`：**刪除** source identity 及其 identity JSON 檔案
+
+#### Example
+
+```bash
+curl -s -X POST "$API/api/v1/identity/$SOURCE_UUID/mergeinto" \
+  -H "X-API-Key: $KEY" \
+  -H "Content-Type: application/json" \
+  -d '{"into_uuid": "'"$TARGET_UUID"'", "keep_history": false}'
+```
+
+#### Response (200)
+
+```json
+{
+  "success": true,
+  "message": "Merged 'stranger_13894' into 'Louis Viret' (52 faces transferred, source deleted)",
+  "data": { "faces_transferred": 52 }
+}
+```
+
+#### Error Responses
+
+| HTTP | When |
+|------|------|
+| `404` | Source or target identity not found |
+| `500` | Database error |
+
 ---
 
 ### `GET /api/v1/identities/search`
@@ -491,4 +628,4 @@ PATCH /api/v1/identity/:identity_uuid
 This **replaces** the entire `aliases` array. To add to existing aliases, include all existing entries in the request.
 
 ---
-*Updated: 2026-05-22
+*Updated: 2026-05-25
diff --git a/docs_v1.0/doc_wasm/modules/07_identity.md b/docs_v1.0/doc_wasm/modules/07_identity.md
index 066428c..f662b2f 100644
--- a/docs_v1.0/doc_wasm/modules/07_identity.md
+++ b/docs_v1.0/doc_wasm/modules/07_identity.md
@@ -234,6 +234,11 @@ Bind a face detection to an identity. Associates the face trace with the identit
 | `file_uuid` | string | Yes | File where face is detected |
 | `face_id` | string | Yes | Face ID (format: `{frame}_{idx}`) |
 
+#### Side Effects
+
+- 清除該 face detection row 的 `stranger_id`（設為 NULL）
+- 不影響 `identities` 表中原有的 stranger auto-identity 記錄
+
 #### Example
 
 ```bash
@@ -259,6 +264,11 @@ Bind all face detections of a trace to an identity. Updates all rows in `face_de
 | `file_uuid` | string | Yes | File where trace exists |
 | `trace_id` | integer | Yes | Trace ID (from `face_detections.trace_id`) |
 
+#### Side Effects
+
+- 清除該 trace 所有 face detection rows 的 `stranger_id`（設為 NULL）
+- 不影響 `identities` 表中原有的 stranger auto-identity 記錄
+
 #### Example
 
 ```bash
@@ -287,6 +297,78 @@ curl -s -X POST "$API/api/v1/identity/$IDENTITY_UUID/bind/trace" \
 
 ---
 
+### `GET /api/v1/identity/:identity_uuid/traces`
+
+**Auth**: Required
+**Scope**: identity-level
+
+Get paginated face traces (continuous tracking segments) associated with this identity across all files.
+
+#### Query Parameters
+
+| Field | Type | Required | Default | Description |
+|-------|------|----------|---------|-------------|
+| `page` | integer | No | `1` | Page number |
+| `page_size` | integer | No | `20` | Items per page |
+
+#### Example
+
+```bash
+curl -s "$API/api/v1/identity/$IDENTITY_UUID/traces?page=1&page_size=3" \
+  -H "X-API-Key: $KEY" | jq '{total, total_faces, traces}'
+```
+
+#### Response (200)
+
+```json
+{
+  "success": true,
+  "identity_uuid": "a9a901056d6b46ff92da0c3c1a57dff4",
+  "name": "Cary Grant",
+  "total": 18,
+  "page": 1,
+  "page_size": 3,
+  "total_faces": 542,
+  "traces": [
+    {
+      "file_uuid": "aeed71342a899fe4b4c57b7d41bcb692",
+      "trace_id": 906,
+      "frame_count": 52,
+      "first_frame": 37974,
+      "last_frame": 38127,
+      "first_sec": 1519.0,
+      "last_sec": 1525.1,
+      "avg_confidence": 0.8254
+    }
+  ]
+}
+```
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `success` | bool | Always `true` |
+| `identity_uuid` | string | Identity UUID |
+| `name` | string | Identity display name |
+| `total` | integer | Total number of traces (across all pages) |
+| `total_faces` | integer | Sum of all face detections in returned traces |
+| `traces[].file_uuid` | string | File where trace exists |
+| `traces[].trace_id` | integer | Trace tracking ID |
+| `traces[].frame_count` | integer | Number of frames in this trace |
+| `traces[].first_frame` | integer | Start frame number |
+| `traces[].last_frame` | integer | End frame number |
+| `traces[].first_sec` | float | Start time in seconds |
+| `traces[].last_sec` | float | End time in seconds |
+| `traces[].avg_confidence` | float | Average detection confidence (0.0–1.0) |
+
+#### Error Responses
+
+| HTTP | When |
+|------|------|
+| `404` | Identity not found |
+| `500` | Database error |
+
+---
+
 ### `POST /api/v1/identity/:identity_uuid/unbind`
 
 **Auth**: Required
@@ -294,6 +376,61 @@ curl -s -X POST "$API/api/v1/identity/$IDENTITY_UUID/bind/trace" \
 
 Unbind a face detection from an identity. Removes the identity association from the face record.
 
+#### Side Effects
+
+- 只清除 `identity_id`（設為 NULL），**不會恢復 `stranger_id`**
+- 被 unbind 的 face 不會自動成為 stranger
+- 要重新標記為 stranger 需重新跑 Agent API（`identity/analyze`）
+
+---
+
+### `POST /api/v1/identity/:identity_uuid/mergeinto`
+
+**Auth**: Required
+**Scope**: identity-level
+
+Transfer all face bindings from this identity to another identity, then optionally delete or mark the source as merged.
+
+#### Request Parameters
+
+| Field | Type | Required | Default | Description |
+|-------|------|----------|---------|-------------|
+| `into_uuid` | string | Yes | — | Target identity UUID to merge into |
+| `keep_history` | bool | No | `true` | Keep source identity record with `status='merged'` (`true`) or delete it (`false`) |
+
+#### Side Effects
+
+- 轉移所有 `face_detections.identity_id` 到目標 identity
+- 同時清除所有被轉移 rows 的 `stranger_id`
+- `keep_history: true`（預設）：source identity 設為 `status='merged'`，保留記錄
+- `keep_history: false`：**刪除** source identity 及其 identity JSON 檔案
+
+#### Example
+
+```bash
+curl -s -X POST "$API/api/v1/identity/$SOURCE_UUID/mergeinto" \
+  -H "X-API-Key: $KEY" \
+  -H "Content-Type: application/json" \
+  -d '{"into_uuid": "'"$TARGET_UUID"'", "keep_history": false}'
+```
+
+#### Response (200)
+
+```json
+{
+  "success": true,
+  "message": "Merged 'stranger_13894' into 'Louis Viret' (52 faces transferred, source deleted)",
+  "data": { "faces_transferred": 52 }
+}
+```
+
+#### Error Responses
+
+| HTTP | When |
+|------|------|
+| `404` | Source or target identity not found |
+| `500` | Database error |
+
 ---
 
 ### `GET /api/v1/identities/search`
@@ -491,4 +628,4 @@ PATCH /api/v1/identity/:identity_uuid
 This **replaces** the entire `aliases` array. To add to existing aliases, include all existing entries in the request.
 
 ---
-*Updated: 2026-05-22
+*Updated: 2026-05-25
diff --git a/src/api/identity_binding.rs b/src/api/identity_binding.rs
index a2c0861..e08ba9d 100644
--- a/src/api/identity_binding.rs
+++ b/src/api/identity_binding.rs
@@ -100,7 +100,7 @@ pub async fn bind_identity(
 
     // Direct UPDATE face_detections.identity_id
     let result = sqlx::query(&format!(
-        "UPDATE {} SET identity_id = $1 WHERE file_uuid = $2 AND face_id = $3",
+        "UPDATE {} SET identity_id = $1, stranger_id = NULL WHERE file_uuid = $2 AND face_id = $3",
         table
     ))
     .bind(identity_id)
@@ -272,7 +272,7 @@ pub async fn merge_identities(
 
     // Transfer all face bindings from source → target
     let updated = sqlx::query(&format!(
-        "UPDATE {} SET identity_id = $1 WHERE identity_id = $2",
+        "UPDATE {} SET identity_id = $1, stranger_id = NULL WHERE identity_id = $2",
         face_table
     ))
     .bind(into_id)
@@ -427,7 +427,7 @@ pub async fn bind_identity_trace(
     })?;
 
     let result = sqlx::query(&format!(
-        "UPDATE {} SET identity_id = $1 WHERE file_uuid = $2 AND trace_id = $3",
+        "UPDATE {} SET identity_id = $1, stranger_id = NULL WHERE file_uuid = $2 AND trace_id = $3",
         fd_table
     ))
     .bind(identity_id)