diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f44ebac..a1cd028b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- **Opt-in deep chat history (`deep=true`).** `GET /sessions/:id/messages/:chatId/history` was capped at
+  100 messages per request — OpenWA's own bound, not a WhatsApp limit, since whatsapp-web.js can load
+  earlier messages on demand. A new `deep=true` query raises the ceiling to 2000 so callers can reach
+  weeks/months back. Deep mode is metadata-only (it ignores `includeMedia`, since base64 for up to 2000
+  messages would be an enormous payload). The default path is unchanged (default 50, max 100). The Baileys
+  engine has no history sync, so the endpoint still returns `501` there regardless of `deep`. (#347)
+
 ### Fixed
 
 - **Baileys engine: inbound message ids are now engine-neutral (`@c.us`).** The Baileys adapter emitted
diff --git a/docs/examples/chat-history-limits.md b/docs/examples/chat-history-limits.md
index 635e4f56..91d5cfd6 100644
--- a/docs/examples/chat-history-limits.md
+++ b/docs/examples/chat-history-limits.md
@@ -23,17 +23,32 @@ This endpoint asks the active WhatsApp engine for recent messages in a chat. It
 The endpoint is intentionally bounded:
 
 - `limit` defaults to `50`.
-- `limit` is clamped to the range `1`–`100`.
+- `limit` is clamped to the range `1`–`100` (or `1`–`2000` with `deep=true`, see below).
 - Values such as `limit=999` do not request unbounded history; they are reduced to the maximum allowed limit.
 - `includeMedia=true` downloads media data and is slower than metadata-only history.
+- `deep=true` raises the ceiling to `2000` for reaching further back, and forces metadata-only.
 
 ## How Deep It Can Reach
 
-The live history endpoint returns at most the **100 most recent** messages per request (the `limit` clamp
-above). The `whatsapp-web.js` engine *can* load older messages on demand — internally it drives WhatsApp
-Web's "load earlier messages" mechanism — so reaching further back is bounded by **OpenWA's current cap**,
-not by what WhatsApp Web is willing to expose. To go back weeks or months you would need a much larger
-window than 100; a deeper-history mode is tracked in [#347](https://github.com/rmyndharis/OpenWA/issues/347).
+By default the live history endpoint returns at most the **100 most recent** messages per request (the
+`limit` clamp above). The `whatsapp-web.js` engine *can* load older messages on demand — internally it
+drives WhatsApp Web's "load earlier messages" mechanism — so reaching further back is bounded by
+**OpenWA's cap**, not by what WhatsApp Web is willing to expose.
+
+To go back weeks or months, set `deep=true`. This raises the ceiling to **2000** messages per request:
+
+```http
+GET /api/sessions/{sessionId}/messages/{chatId}/history?limit=2000&deep=true
+```
+
+Deep mode is **metadata-only** — `includeMedia` is ignored, because downloading base64 media for up to
+2000 messages would produce an enormous, slow response. Fetch media separately for the specific messages
+you need. Note that a very large, rapid history pull is heavier on the linked session and can increase the
+risk of WhatsApp rate-limiting; use the smallest window that meets your need.
+
+Deep mode applies to the `whatsapp-web.js` engine. The Baileys engine does not expose on-demand history
+(it has no message-history sync), so the history endpoint returns `501 Not Implemented` there regardless
+of `deep`; consume Baileys history through local storage / webhooks / WebSocket as it arrives instead.
 
 There is still an ultimate ceiling: once WhatsApp's servers stop returning older messages for the linked
 session, no further history is retrievable through the web engine, regardless of `limit`. So the endpoint
diff --git a/src/modules/message/message.controller.ts b/src/modules/message/message.controller.ts
index 4cf7fcb4..160adc4e 100644
--- a/src/modules/message/message.controller.ts
+++ b/src/modules/message/message.controller.ts
@@ -272,21 +272,32 @@ export class MessageController {
     type: Boolean,
     description: 'When true, downloads media (base64) for messages that have it. Slower; default false.',
   })
+  @ApiQuery({
+    name: 'deep',
+    required: false,
+    type: Boolean,
+    description:
+      'When true, raises the limit ceiling from 100 to 2000 for reaching further back in history ' +
+      '(whatsapp-web.js only; loads earlier messages on demand). Forces metadata-only (includeMedia ' +
+      'is ignored). Large/slow requests may increase WhatsApp rate-limiting risk; default false.',
+  })
   @ApiResponse({ status: 200, description: 'Chat history (most recent messages)' })
   async getChatHistory(
     @Param('sessionId') sessionId: string,
     @Param('chatId') chatId: string,
     @Query('limit') limit?: string,
     @Query('includeMedia') includeMedia?: string,
+    @Query('deep') deep?: string,
   ) {
     // Parse the limit defensively: a non-numeric query value (?limit=abc) yields NaN,
-    // so fall back to undefined and let the service apply its default + [1,100] clamp.
+    // so fall back to undefined and let the service apply its default + clamp.
     const parsedLimit = limit ? parseInt(limit, 10) : undefined;
     return this.messageService.getChatHistory(
       sessionId,
       chatId,
       parsedLimit !== undefined && !Number.isNaN(parsedLimit) ? parsedLimit : undefined,
       includeMedia === 'true' || includeMedia === '1',
+      deep === 'true' || deep === '1',
     );
   }
 
diff --git a/src/modules/message/message.service.spec.ts b/src/modules/message/message.service.spec.ts
index 9fade9d2..f1e01d53 100644
--- a/src/modules/message/message.service.spec.ts
+++ b/src/modules/message/message.service.spec.ts
@@ -555,6 +555,28 @@ describe('MessageService', () => {
       const result = await service.getChatHistory('sess-1', 'test@c.us');
       expect(result).toBe(fake);
     });
+
+    describe('deep mode (#347)', () => {
+      it('allows a limit above the standard 100 cap when deep=true', async () => {
+        await service.getChatHistory('sess-1', 'test@c.us', 500, false, true);
+        expect(mockEngine.getChatHistory).toHaveBeenLastCalledWith('test@c.us', 500, false);
+      });
+
+      it('clamps a deep limit to the 2000 ceiling', async () => {
+        await service.getChatHistory('sess-1', 'test@c.us', 5000, false, true);
+        expect(mockEngine.getChatHistory).toHaveBeenLastCalledWith('test@c.us', 2000, false);
+      });
+
+      it('forces includeMedia off in deep mode (metadata-only)', async () => {
+        await service.getChatHistory('sess-1', 'test@c.us', 300, true, true);
+        expect(mockEngine.getChatHistory).toHaveBeenLastCalledWith('test@c.us', 300, false);
+      });
+
+      it('still clamps to 100 when deep is not set (regression guard)', async () => {
+        await service.getChatHistory('sess-1', 'test@c.us', 500, false, false);
+        expect(mockEngine.getChatHistory).toHaveBeenLastCalledWith('test@c.us', 100, false);
+      });
+    });
   });
 
   describe('deleteMessage', () => {
diff --git a/src/modules/message/message.service.ts b/src/modules/message/message.service.ts
index e69072e2..5a1e4705 100644
--- a/src/modules/message/message.service.ts
+++ b/src/modules/message/message.service.ts
@@ -530,20 +530,24 @@ export class MessageService {
   /** Maximum messages a single getChatHistory call may request from the engine. */
   private static readonly MAX_CHAT_HISTORY_LIMIT = 100;
 
+  /** Higher ceiling for opt-in deep history (`deep=true`). Bounded so a caller still can't ask unbounded. */
+  private static readonly MAX_DEEP_CHAT_HISTORY_LIMIT = 2000;
+
   /**
    * Fetch chat history live from WhatsApp (bypasses local DB).
    * Returns the most recent `limit` messages for the given chat.
    * When `includeMedia` is true, downloads media (base64) for messages that have it.
    *
-   * `limit` is clamped to [1, 100] (and falls back to 50 for non-finite input) so a
-   * caller cannot ask the engine to fetch an unbounded number of messages.
+   * `limit` is clamped to [1, 100] (and falls back to 50 for non-finite input) so a caller cannot ask the
+   * engine to fetch an unbounded number of messages. When `deep` is true the ceiling is raised to 2000
+   * (for reaching weeks/months back on whatsapp-web.js, which can load earlier messages on demand) and
+   * media is forced off — downloading base64 for up to 2000 messages would be an enormous, slow payload.
    */
-  async getChatHistory(sessionId: string, chatId: string, limit = 50, includeMedia = false) {
+  async getChatHistory(sessionId: string, chatId: string, limit = 50, includeMedia = false, deep = false) {
     const engine = this.getEngine(sessionId);
-    const safeLimit = Number.isFinite(limit)
-      ? Math.min(Math.max(Math.trunc(limit), 1), MessageService.MAX_CHAT_HISTORY_LIMIT)
-      : 50;
-    return engine.getChatHistory(chatId, safeLimit, includeMedia);
+    const ceiling = deep ? MessageService.MAX_DEEP_CHAT_HISTORY_LIMIT : MessageService.MAX_CHAT_HISTORY_LIMIT;
+    const safeLimit = Number.isFinite(limit) ? Math.min(Math.max(Math.trunc(limit), 1), ceiling) : 50;
+    return engine.getChatHistory(chatId, safeLimit, deep ? false : includeMedia);
   }
 
   // ========== Delete Message ==========