fix(ai-obs): recognize legacy Gemini tool blocks in traces

products/ai_observability/frontend/utils.test.ts

@@ -1442,13 +1442,22 @@ describe.each(IMPLS)('AI observability utils [$name]', ({ normalizeMessage, norm
                 'custom {type:"function", tool_name, content}',
                 { type: 'function', tool_name: 'lookup', content: 'opaque' },
             ],
+            [
+                'legacy Gemini function_response (posthog-python 7.30.1-7.35.x)',
+                { type: 'function_response', function_response: { name: 'get_weather', response: { temp: '18C' } } },
+            ],
         ])('returns true for: %s', (_, item) => {
             expect(isToolResult(item)).toBe(true)
         })
 
         it.each<[name: string, item: unknown]>([
             ['plain text part', { type: 'text', text: 'hi' }],
             ['Anthropic tool_use (a tool CALL, not a result)', { type: 'tool_use', id: 't1', name: 'x', input: {} }],
+            [
+                'legacy Gemini function_call (a tool CALL, not a result)',
+                { type: 'function_call', function_call: { name: 'get_weather', args: {} } },
+            ],
+            ['function_response without the nested payload', { type: 'function_response' }],
             [
                 'OpenAI tool CALL with nested function object',
                 { type: 'function', function: { name: 'get_weather', arguments: '{}' } },
@@ -2582,6 +2591,16 @@ describe.each(IMPLS)('AI observability utils [$name]', ({ normalizeMessage, norm
                 { type: 'tool-result', toolCallId: 'a', toolName: 'search_docs', result: 'ok' },
                 true,
             ],
+            [
+                'accepts legacy Gemini `function_call`',
+                { type: 'function_call', function_call: { name: 'get_weather', args: { city: 'SF' } } },
+                true,
+            ],
+            [
+                'accepts legacy Gemini `function_response`',
+                { type: 'function_response', function_response: { name: 'get_weather', response: { temp: '18C' } } },
+                true,
+            ],
             ['rejects text content items', { type: 'text', text: 'hi' }, false],
             ['rejects image items', { type: 'image_url', image_url: { url: 'x' } }, false],
             ['rejects file items', { type: 'file', file: { filename: 'f', file_data: 'd' } }, false],

products/ai_observability/frontend/utils.ts

@@ -505,12 +505,28 @@ function isCustomFunctionToolResult(item: unknown): boolean {
     return isObject(item) && item.type === 'function' && isString(item.tool_name) && !isObject(item.function)
 }
 
+// Gemini function calls and their responses, in the raw form the google-genai
+// SDK emits. posthog-python 7.30.1 through 7.35.x copied that form into
+// `$ai_input` without converting it (PostHog/posthog-python#725), so traces from
+// that window still contain it.
+// `function_call` needs its nested object checked. The OpenAI Responses API uses
+// the same `type` with a top-level `name` and `call_id`, and
+// `isOpenAIResponsesFunctionCall` already owns that case.
+function isLegacyGeminiFunctionResponse(item: unknown): boolean {
+    return isObject(item) && item.type === 'function_response' && isObject(item.function_response)
+}
+
+function isLegacyGeminiFunctionCall(item: unknown): boolean {
+    return isObject(item) && item.type === 'function_call' && isObject(item.function_call)
+}
+
 export function isToolResult(item: unknown): boolean {
     return (
         isAnthropicToolResultMessage(item) ||
         isVercelSDKToolResultMessage(item) ||
         isOpenAIResponsesFunctionCallOutput(item) ||
-        isCustomFunctionToolResult(item)
+        isCustomFunctionToolResult(item) ||
+        isLegacyGeminiFunctionResponse(item)
     )
 }
 
@@ -535,7 +551,9 @@ export function isToolStepItem(item: unknown): boolean {
         isVercelSDKToolCallMessage(item) ||
         isVercelSDKToolResultMessage(item) ||
         isOpenAIResponsesFunctionCall(item) ||
-        isOpenAIResponsesBuiltinToolCall(item)
+        isOpenAIResponsesBuiltinToolCall(item) ||
+        isLegacyGeminiFunctionCall(item) ||
+        isLegacyGeminiFunctionResponse(item)
     ) {
         return true
     }