From 922bcf76602f729cc96dc832628515223c8e05e9 Mon Sep 17 00:00:00 2001
From: DoSun <dosun9588@gmail.com>
Date: Mon, 11 May 2026 15:30:37 +0800
Subject: [PATCH] fix(server): accept client messageID to enable optimistic
 message dedup

---
 src/server/routes/session.ts | 10 +++++++---
 src/server/sessionHandle.ts  |  7 +++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/server/routes/session.ts b/src/server/routes/session.ts
index ff7a231fa..5577281bf 100644
--- a/src/server/routes/session.ts
+++ b/src/server/routes/session.ts
@@ -27,6 +27,7 @@ function ssePrompt(
   content: string,
   c: import('hono').Context,
   parts?: Array<Record<string, unknown>>,
+  messageID?: string,
 ) {
   return streamSSE(c, async stream => {
     const startTime = Date.now()
@@ -82,7 +83,7 @@ function ssePrompt(
     })
 
     try {
-      await handle.prompt(content, { parts })
+      await handle.prompt(content, { parts, messageID })
     } catch {
       if (!resultWritten) {
         pendingWrite = pendingWrite.then(() =>
@@ -374,6 +375,7 @@ export function createSessionRoutes(
         images?: unknown[]
         model?: { providerID?: string; modelID?: string }
         agent?: string
+        messageID?: string
       }>()
 
       const textContent = body.content ?? body.parts
@@ -396,7 +398,7 @@ export function createSessionRoutes(
         try { await handle.setAgent(effectiveAgent) } catch {}
       }
 
-      return ssePrompt(handle, id, content, c, body.parts)
+      return ssePrompt(handle, id, content, c, body.parts, body.messageID)
     })
     .post('/session/:sessionID/prompt_async', async c => {
       const id = c.req.param('sessionID')
@@ -427,6 +429,7 @@ export function createSessionRoutes(
         images?: unknown[]
         model?: { providerID?: string; modelID?: string }
         agent?: string
+        messageID?: string
       }>()
 
       const textContent = body.content ?? body.parts
@@ -457,7 +460,8 @@ export function createSessionRoutes(
           if (effectiveAgent && effectiveAgent !== handle.agent) {
             try { await handle.setAgent(effectiveAgent) } catch {}
           }
-          handle.prompt(content, { parts: body.parts }).catch(() => {})
+          handle.prompt(content, { parts: body.parts, messageID: body.messageID }).catch(() => {})
+
         } catch {}
       })()
 
diff --git a/src/server/sessionHandle.ts b/src/server/sessionHandle.ts
index f49d62759..bb30301a3 100644
--- a/src/server/sessionHandle.ts
+++ b/src/server/sessionHandle.ts
@@ -468,7 +468,7 @@ export class SessionHandle {
     return (response.mcpServers as unknown[]) ?? []
   }
 
-  async prompt(content: string, _opts?: { parts?: Array<Record<string, unknown>> }): Promise<{ done: boolean; error?: string }> {
+  async prompt(content: string, opts?: { parts?: Array<Record<string, unknown>>; messageID?: string }): Promise<{ done: boolean; error?: string }> {
     if (this._status === 'stopped') {
       throw new Error(
         `Session ${this.sessionId} is stopped`,
@@ -487,10 +487,12 @@ export class SessionHandle {
     this.emitBusyStatus()
     this.lastActiveAt = Date.now()
 
+    const uuid = opts?.messageID ?? crypto.randomUUID()
+
     const userMsg = jsonStringify({
       type: 'user',
       content,
-      uuid: crypto.randomUUID(),
+      uuid,
       session_id: this.sessionId,
       message: { role: 'user', content },
       parent_tool_use_id: null,
@@ -499,6 +501,7 @@ export class SessionHandle {
     this.emitEvent('message', {
       type: 'user',
       content,
+      uuid,
       session_id: this.sessionId,
       model: this._model ?? '',
       provider_id: this._providerId ?? '',