fix(antigravity): bypass gemini mapping for claude models on vertex ai

open-sse/executors/antigravity.ts

@@ -295,66 +295,72 @@ export class AntigravityExecutor extends BaseExecutor {
     }
 
     const upstreamModel = cleanModelName(model);
+    const isClaude = upstreamModel.toLowerCase().includes("claude");
     const baseBody = body && typeof body === "object" ? body : {};
     const normalizedBody = shouldStripCloudCodeThinking(this.provider, upstreamModel)
       ? stripCloudCodeThinkingConfig(baseBody)
       : baseBody;
 
-    // Fix contents for Claude models via Antigravity
-    const normalizedContents =
-      normalizedBody.request?.contents?.map((c) => {
-        let role = c.role;
-        // functionResponse must be role "user" for Claude models
-        if (c.parts?.some((p) => p.functionResponse)) {
-          role = "user";
+    let transformedRequest;
+
+    if (isClaude) {
+      // Claude models on Vertex AI Cloud Code expect the native Anthropic payload
+      // exactly as generated by openaiToClaudeRequestForAntigravity, without Gemini mappings.
+      transformedRequest = {
+        ...normalizedBody.request,
+        sessionId: normalizedBody.request?.sessionId || this.generateSessionId(),
+      };
+    } else {
+      // Fix contents for Gemini models via Antigravity
+      const normalizedContents =
+        normalizedBody.request?.contents?.map((c) => {
+          let role = c.role;
+          if (c.parts?.some((p) => p.functionResponse)) {
+            role = "user";
+          }
+
+          const hasFunctionCall = c.parts?.some((p) => p.functionCall) || false;
+
+          const parts =
+            c.parts?.filter((p) => {
+              if (typeof p.text === "string" && p.text === "") return false;
+              if (p.functionCall && !p.functionCall.name) return false;
+
+              return !p.thought && (hasFunctionCall || !p.thoughtSignature);
+            }) || [];
+          return { ...c, role, parts };
+        }) || [];
+
+      const contents = [];
+      for (const c of normalizedContents) {
+        if (!Array.isArray(c.parts) || c.parts.length === 0) continue;
+        if (contents.length > 0 && contents[contents.length - 1].role === c.role) {
+          contents[contents.length - 1].parts.push(...c.parts);
+        } else {
+          contents.push(c);
         }
-
-        const hasFunctionCall = c.parts?.some((p) => p.functionCall) || false;
-
-        // Antigravity rejects synthetic thought text, but Gemini 3+ requires any
-        // returned thoughtSignature metadata to survive model tool-call turns.
-        const parts =
-          c.parts?.filter((p) => {
-            // Drop empty text parts
-            if (typeof p.text === "string" && p.text === "") return false;
-            // Drop empty functionCalls
-            if (p.functionCall && !p.functionCall.name) return false;
-
-            return !p.thought && (hasFunctionCall || !p.thoughtSignature);
-          }) || [];
-        return { ...c, role, parts };
-      }) || [];
-
-    // Merge consecutive same-role entries and filter out empty sequences
-    const contents = [];
-    for (const c of normalizedContents) {
-      if (!Array.isArray(c.parts) || c.parts.length === 0) continue;
-      if (contents.length > 0 && contents[contents.length - 1].role === c.role) {
-        contents[contents.length - 1].parts.push(...c.parts);
-      } else {
-        contents.push(c);
       }
-    }
 
-    const transformedRequest = {
-      ...normalizedBody.request,
-      ...(contents.length > 0 && { contents }),
-      sessionId: normalizedBody.request?.sessionId || this.generateSessionId(),
-      safetySettings: undefined,
-      toolConfig:
-        normalizedBody.request?.tools?.length > 0
-          ? { functionCallingConfig: { mode: "VALIDATED" } }
-          : normalizedBody.request?.toolConfig,
-    };
+      transformedRequest = {
+        ...normalizedBody.request,
+        ...(contents.length > 0 && { contents }),
+        sessionId: normalizedBody.request?.sessionId || this.generateSessionId(),
+        safetySettings: undefined,
+        toolConfig:
+          normalizedBody.request?.tools?.length > 0
+            ? { functionCallingConfig: { mode: "VALIDATED" } }
+            : normalizedBody.request?.toolConfig,
+      };
 
-    // Obfuscate sensitive client names in user content (e.g. "OpenCode", "Cursor")
-    const requestContents = transformedRequest.contents;
-    if (Array.isArray(requestContents)) {
-      for (const msg of requestContents) {
-        if (Array.isArray(msg.parts)) {
-          for (const part of msg.parts) {
-            if (typeof part.text === "string") {
-              part.text = obfuscateSensitiveWords(part.text);
+      // Obfuscate sensitive client names in user content (e.g. "OpenCode", "Cursor")
+      const requestContents = transformedRequest.contents;
+      if (Array.isArray(requestContents)) {
+        for (const msg of requestContents) {
+          if (Array.isArray(msg.parts)) {
+            for (const part of msg.parts) {
+              if (typeof part.text === "string") {
+                part.text = obfuscateSensitiveWords(part.text);
+              }
             }
           }
         }

open-sse/translator/request/openai-to-gemini.ts

@@ -57,7 +57,8 @@ type GeminiFunctionDeclaration = {
 
 type GeminiRequest = {
   model: string;
-  contents: GeminiContent[];
+  contents?: GeminiContent[];
+  [key: string]: any;
   generationConfig: GeminiGenerationConfig;
   safetySettings: unknown;
   systemInstruction?: GeminiContent;
@@ -79,7 +80,8 @@ type CloudCodeEnvelope = {
   request: {
     session_id?: string;
     sessionId?: string;
-    contents: GeminiContent[];
+    contents?: GeminiContent[];
+    [key: string]: any;
     systemInstruction?: GeminiContent;
     generationConfig: GeminiGenerationConfig;
     tools?: Array<{
@@ -475,12 +477,6 @@ function wrapInCloudCodeEnvelopeForClaude(
   credentials = null,
   sourceBody = {}
 ) {
-  const toolNameMap = new Map<string, string>();
-  const sanitizeToolName = (name: string) =>
-    sanitizeGeminiToolName(name, {
-      stripNamespace: true,
-      toolNameMap,
-    });
   let projectId = credentials?.projectId;
 
   if (!projectId) {
@@ -493,11 +489,6 @@ function wrapInCloudCodeEnvelopeForClaude(
 
   const cleanModel = model.includes("/") ? model.split("/").pop()! : model;
 
-  const generationConfig: GeminiGenerationConfig = {
-    temperature: claudeRequest.temperature || 1,
-    maxOutputTokens: getAntigravityClaudeOutputTokens(sourceBody),
-  };
-
   const envelope: CloudCodeEnvelope = {
     project: projectId,
     model: cleanModel,
@@ -505,109 +496,11 @@ function wrapInCloudCodeEnvelopeForClaude(
     requestId: `agent-${generateUUID()}`,
     requestType: "agent",
     request: {
+      ...claudeRequest,
       sessionId: generateSessionId(),
-      contents: [],
-      generationConfig,
     },
   };
 
-  const toolUseNames: Record<string, string> = {};
-  if (claudeRequest.messages && Array.isArray(claudeRequest.messages)) {
-    for (const msg of claudeRequest.messages) {
-      if (!Array.isArray(msg.content)) continue;
-      for (const block of msg.content) {
-        if (block.type === "tool_use" && block.id && typeof block.name === "string") {
-          toolUseNames[block.id] = sanitizeToolName(block.name);
-        }
-      }
-    }
-  }
-
-  // Convert Claude messages to Gemini contents
-  if (claudeRequest.messages && Array.isArray(claudeRequest.messages)) {
-    for (const msg of claudeRequest.messages) {
-      const parts = [];
-
-      if (Array.isArray(msg.content)) {
-        for (const block of msg.content) {
-          if (block.type === "text") {
-            parts.push({ text: block.text });
-          } else if (block.type === "image" && block.source) {
-            parts.push({
-              inlineData: {
-                mimeType: block.source.media_type,
-                data: block.source.data,
-              },
-            });
-          } else if (block.type === "tool_use") {
-            parts.push({
-              functionCall: {
-                id: block.id,
-                name: sanitizeToolName(block.name),
-                args: block.input || {},
-              },
-            });
-          } else if (block.type === "tool_result") {
-            let content = block.content;
-            if (Array.isArray(content)) {
-              content = content
-                .map((c) => (c.type === "text" ? c.text : JSON.stringify(c)))
-                .join("\n");
-            }
-            parts.push({
-              functionResponse: {
-                id: block.tool_use_id,
-                name: toolUseNames[block.tool_use_id] || "unknown",
-                response: { result: tryParseJSON(content) || content },
-              },
-            });
-          }
-        }
-      } else if (typeof msg.content === "string") {
-        parts.push({ text: msg.content });
-      }
-
-      if (parts.length > 0) {
-        envelope.request.contents.push({
-          role: msg.role === "assistant" ? "model" : "user",
-          parts,
-        });
-      }
-    }
-  }
-
-  // Convert Claude tools to Gemini functionDeclarations
-  if (claudeRequest.tools && Array.isArray(claudeRequest.tools)) {
-    const geminiTools = buildGeminiTools(claudeRequest.tools, {
-      stripNamespace: true,
-      toolNameMap,
-    });
-    if (geminiTools) {
-      envelope.request.tools = geminiTools;
-    }
-  }
-
-  // Keep Antigravity's default and caller-provided system rules as distinct parts,
-  // matching the Gemini bridge and avoiding accidental prompt concatenation.
-  const systemParts: GeminiPart[] = [{ text: ANTIGRAVITY_DEFAULT_SYSTEM }];
-
-  if (claudeRequest.system) {
-    if (Array.isArray(claudeRequest.system)) {
-      for (const block of claudeRequest.system) {
-        if (block.text) systemParts.push({ text: block.text });
-      }
-    } else if (typeof claudeRequest.system === "string") {
-      systemParts.push({ text: claudeRequest.system });
-    }
-  }
-
-  envelope.request.systemInstruction = { role: "system", parts: systemParts };
-
-  const changedToolNameMap = buildChangedToolNameMap(toolNameMap);
-  if (changedToolNameMap) {
-    envelope._toolNameMap = changedToolNameMap;
-  }
-
   return envelope;
 }
 

tests/unit/executor-antigravity.test.ts

@@ -503,3 +503,37 @@ test("AntigravityExecutor.execute applies CLI fingerprint when enabled", async (
     globalThis.fetch = originalFetch;
   }
 });
+
+test("AntigravityExecutor.transformRequest bypasses Gemini contents mapping for claude models", async () => {
+  const executor = new AntigravityExecutor();
+  const body = {
+    project: "project-1",
+    model: "claude-sonnet-4-6",
+    userAgent: "antigravity",
+    requestId: "agent-123",
+    requestType: "agent",
+    request: {
+      messages: [{ role: "user", content: [{ type: "text", text: "Hello" }] }],
+      system: [{ type: "text", text: "System prompt" }],
+      generationConfig: {
+        temperature: 1,
+        maxOutputTokens: 16384,
+      },
+    },
+  };
+
+  const result = (await executor.transformRequest("antigravity/claude-sonnet-4-6", body, true, {
+    projectId: "project-1",
+  })) as any;
+
+  assert.equal(result.project, "project-1");
+  assert.equal(result.model, "claude-sonnet-4-6");
+  assert.equal(result.requestType, "agent");
+  assert.ok(result.request.sessionId);
+  assert.deepEqual(result.request.messages, [
+    { role: "user", content: [{ type: "text", text: "Hello" }] },
+  ]);
+  assert.deepEqual(result.request.system, [{ type: "text", text: "System prompt" }]);
+  assert.equal(result.request.contents, undefined);
+  assert.equal(result.request.toolConfig, undefined);
+});