rm caller field from Anthropic tool_use blocks

.changeset/certain-nice-caracara.md

@@ -0,0 +1,5 @@
+---
+"stagehand": patch
+---
+
+fix: invalid_request_error when using anthropic cua client

examples/agent_example_local.py

@@ -26,12 +26,34 @@
 
 load_dotenv()
 
+ANTHROPIC_MODEL = "claude-sonnet-4-20250514"
+REPRO_INSTRUCTION = (
+    "Step 1: Use the goto tool to open https://example.com/.\n"
+    "Step 2: After it loads, scroll down and click the 'More information...' link "
+    "to open the iana.org page, then report the heading text you see."
+)
+ERROR_SIGNATURES = [
+    "messages.1.content.1.tool_use.caller",
+    "Extra inputs are not permitted",
+]
+
 # Configure logging with the utility function
 configure_logging(
     level=logging.INFO,  # Set to INFO for regular logs, DEBUG for detailed
     quiet_dependencies=True,  # Reduce noise from dependencies
 )
 
+
+def require_env_var(var_name: str) -> str:
+    """Fetch a required env var with a helpful error for local runs."""
+    value = os.getenv(var_name)
+    if not value:
+        raise RuntimeError(
+            f"{var_name} is not set. Add it to your .env before running this example."
+        )
+    return value
+
+
 async def main():
     # Build a unified configuration object for Stagehand
     config = StagehandConfig(
@@ -53,19 +75,37 @@ async def main():
     await stagehand.page.goto("https://google.com/")
     console.print("✅ [success]Navigated to Google[/]")
 
-    console.print("\n▶️ [highlight] Using Agent to perform a task[/]: playing a game of 2048")
+    console.print(
+        "\n▶️ [highlight]Using Anthropic CUA agent[/]: reproducing the tool_use caller bug"
+    )
+    anthropic_api_key = require_env_var("ANTHROPIC_API_KEY")
     agent = stagehand.agent(
-        model="gemini-2.5-computer-use-preview-10-2025",
-        instructions="You are a helpful web navigation assistant that helps users find information. You are currently on the following page: google.com. Do not ask follow up questions, the user will trust your judgement.",
-        options={"apiKey": os.getenv("GEMINI_API_KEY")}
+        model=ANTHROPIC_MODEL,
+        instructions=(
+            "You are controlling a fullscreen local browser with the Anthropic computer-use tools. "
+            "Read the current page carefully, decide on your next action, and avoid asking follow-up questions."
+        ),
+        options={"apiKey": anthropic_api_key}
     )
     agent_result = await agent.execute(
-        instruction="Play a game of 2048",
-        max_steps=20,
+        instruction=REPRO_INSTRUCTION,
+        max_steps=5,
         auto_screenshot=True,
     )
 
     console.print(agent_result)
+    if agent_result.message and any(
+        signature in agent_result.message for signature in ERROR_SIGNATURES
+    ):
+        console.print(
+            "🐛 [error]Reproduced the Anthropic `tool_use.caller` validation error.[/]\n"
+            "    Check the logs above for 'Extra inputs are not permitted' to link back to the GitHub issue."
+        )
+    else:
+        console.print(
+            "⚠️ [warning]Bug signature not detected in this run. "
+            "Re-run the example or tweak the instructions if you need the failing payload."
+        )
 
     console.print("📊 [info]Agent execution result:[/]")
     console.print(f"🎯 Completed: [bold]{'Yes' if agent_result.completed else 'No'}[/]")
@@ -100,4 +140,4 @@ async def main():
             padding=(1, 10),
         ),
     )
-    asyncio.run(main()) 
+    asyncio.run(main())

stagehand/agent/anthropic_cua.py

@@ -295,9 +295,13 @@ def _process_provider_response(
         if hasattr(response, "content") and isinstance(response.content, list):
             # Serialize Pydantic models from response.content for history
             try:
-                raw_assistant_content_blocks = [
-                    block.model_dump() for block in response.content
-                ]
+                for block in response.content:
+                    block_dict = block.model_dump()
+                    if isinstance(block_dict, dict):
+                        # Anthropic beta responses include a `caller` field on tool_use blocks
+                        # but the API rejects that key on subsequent requests.
+                        block_dict.pop("caller", None)
+                    raw_assistant_content_blocks.append(block_dict)
             except Exception as e:
                 self.logger.error(
                     f"Could not model_dump response.content blocks: {e}",