fix(agent-core-v2): make Gemini tool call ids unique across turns

.changeset/fix-gemini-tool-call-id-collision.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix tool call id collisions across turns for Gemini-protocol models, which merged separate swarm runs into a single card in the web UI.

packages/agent-core-v2/src/app/llmProtocol/providers/google-genai.ts

@@ -141,8 +141,9 @@ interface GooglePart {
 function toolCallIdToName(toolCallId: string, toolNameById: Map<string, string>): string {
   const name = toolNameById.get(toolCallId);
   if (name !== undefined) return name;
-  const match = /^(.+)_[^_]+$/.exec(toolCallId);
-  return match?.[1] ?? toolCallId;
+  const withoutEntropy = toolCallId.replace(/_[0-9a-f]{8}$/, '');
+  const match = /^(.+)_[^_]+$/.exec(withoutEntropy);
+  return match?.[1] ?? withoutEntropy;
 }
 
 function convertMediaUrl(
@@ -510,7 +511,7 @@ export class GoogleGenAIStreamedMessage implements StreamedMessage {
           const name = fc['name'] as string;
           if (!name) continue;
           const id_ = (fc['id'] as string) ?? crypto.randomUUID();
-          const toolCallId = `${name}_${id_}`;
+          const toolCallId = `${name}_${id_}_${crypto.randomUUID().replaceAll('-', '').slice(0, 8)}`;
           const thoughtSigB64 = p['thoughtSignature'] ?? p['thought_signature'];
           const toolCall: ToolCall = {
             type: 'function',

packages/kosong/src/providers/google-genai.ts

@@ -163,14 +163,18 @@ function toolCallIdToName(toolCallId: string, toolNameById: Map<string, string>)
   const name = toolNameById.get(toolCallId);
   if (name !== undefined) return name;
   // Fallback: ids produced by this provider follow the format
-  // "{tool_name}_{id_suffix}" where `tool_name` may itself contain
-  // underscores (e.g. `fetch_image`) and `id_suffix` is a single trailing
-  // token without underscores (e.g. a random hex / UUID fragment). We strip
-  // the last "_<suffix>" segment by matching it explicitly — splitting on
-  // the first underscore would truncate multi-word tool names like
-  // `fetch_image_<id>` to just `fetch`.
-  const match = /^(.+)_[^_]+$/.exec(toolCallId);
-  return match?.[1] ?? toolCallId;
+  // "{tool_name}_{upstream_id}_{entropy}" where `tool_name` may itself
+  // contain underscores (e.g. `fetch_image`) and `entropy` is the fixed
+  // 8-hex-char suffix this provider appends for cross-turn uniqueness. Strip
+  // the entropy suffix first, then the trailing "_<upstream_id>" segment by
+  // matching it explicitly — splitting on the first underscore would truncate
+  // multi-word tool names like `fetch_image_<id>` to just `fetch`. (Pre-entropy
+  // ids of the form "{tool_name}_{id_suffix}" still parse: a trailing 8-hex
+  // segment is indistinguishable from the entropy suffix, and stripping it
+  // recovers the same name the old single-suffix shape did.)
+  const withoutEntropy = toolCallId.replace(/_[0-9a-f]{8}$/, '');
+  const match = /^(.+)_[^_]+$/.exec(withoutEntropy);
+  return match?.[1] ?? withoutEntropy;
 }
 
 /**
@@ -588,8 +592,14 @@ export class GoogleGenAIStreamedMessage implements StreamedMessage {
           const fc = (p['functionCall'] ?? p['function_call']) as Record<string, unknown>;
           const name = fc['name'] as string;
           if (!name) continue;
+          // The upstream function-call id is only unique within its own
+          // response (some backends re-issue small ids like "0" every turn),
+          // so `${name}_${id}` collided across turns — two AgentSwarm calls in
+          // different turns both became `AgentSwarm_0` and the web client
+          // merged their member lists into one card. Append entropy so ids
+          // stay unique across the whole session.
           const id_ = (fc['id'] as string) ?? crypto.randomUUID();
-          const toolCallId = `${name}_${id_}`;
+          const toolCallId = `${name}_${id_}_${crypto.randomUUID().replaceAll('-', '').slice(0, 8)}`;
           const thoughtSigB64 = p['thoughtSignature'] ?? p['thought_signature'];
           const toolCall: ToolCall = {
             type: 'function',

packages/kosong/test/e2e/google-genai-adapter.test.ts

@@ -210,7 +210,7 @@ describe('e2e: Google GenAI adapter bridge', () => {
         { type: 'text', text: 'Done.' },
         {
           type: 'function',
-          id: 'notify_call-1',
+          id: expect.stringMatching(/^notify_call-1_[0-9a-f]{8}$/),
           name: 'notify', arguments: '{"ok":true}',
           extras: { thought_signature_b64: 'sig-1' },
         } satisfies ToolCall,

packages/kosong/test/google-genai.test.ts

@@ -753,10 +753,10 @@ describe('GoogleGenAIChatProvider', () => {
     // When a tool message arrives without a preceding assistant message
     // carrying the tool_call (e.g. after history compaction), the provider
     // falls back to parsing the name out of the tool_call_id. Google IDs
-    // produced by this provider have the shape "{tool_name}_{id_suffix}"
-    // where the suffix is a single non-underscored token, so stripping the
-    // first underscore truncates multi-word tool names such as
-    // `fetch_image_<id>` down to `fetch`.
+    // produced by this provider have the shape "{tool_name}_{upstream_id}_{entropy}"
+    // where `entropy` is a fixed 8-hex-char suffix and the upstream id is a
+    // non-underscored token, so stripping the first underscore would truncate
+    // multi-word tool names such as `fetch_image_<id>` down to `fetch`.
     function firstFunctionResponseName(history: Message[]): string | undefined {
       const contents = messagesToGoogleGenAIContents(history);
       for (const content of contents) {
@@ -814,6 +814,30 @@ describe('GoogleGenAIChatProvider', () => {
       ];
       expect(firstFunctionResponseName(history)).toBe('bareid');
     });
+
+    it('strips both the entropy suffix and the upstream id', () => {
+      const history: Message[] = [
+        {
+          role: 'tool',
+          content: [{ type: 'text', text: 'ok' }],
+          toolCallId: 'AgentSwarm_0_ab12cd34',
+          toolCalls: [],
+        },
+      ];
+      expect(firstFunctionResponseName(history)).toBe('AgentSwarm');
+    });
+
+    it('strips entropy and upstream id from multi-word tool names', () => {
+      const history: Message[] = [
+        {
+          role: 'tool',
+          content: [{ type: 'text', text: 'ok' }],
+          toolCallId: 'fetch_image_abc123_a1b2c3d4',
+          toolCalls: [],
+        },
+      ];
+      expect(firstFunctionResponseName(history)).toBe('fetch_image');
+    });
   });
 
   describe('no id in functionCall or functionResponse', () => {
@@ -1224,7 +1248,7 @@ describe('GoogleGenAIChatProvider', () => {
       expect(parts).toEqual([
         {
           type: 'function',
-          id: 'add_call_1',
+          id: expect.stringMatching(/^add_call_1_[0-9a-f]{8}$/),
           name: 'add', arguments: '{"a":2,"b":3}',
         },
       ]);
@@ -1254,7 +1278,7 @@ describe('GoogleGenAIChatProvider', () => {
       expect(parts).toEqual([
         {
           type: 'function',
-          id: 'search_fc_1',
+          id: expect.stringMatching(/^search_fc_1_[0-9a-f]{8}$/),
           name: 'search', arguments: '{"q":"test"}',
           extras: { thought_signature_b64: 'sig_abc123' },
         },