claude-code - 💡(How to fix) Fix [FEATURE] Add agent instance ID headers to API requests [2 comments, 2 participants]

TL;DR

Add x-claude-code-agent-id and x-claude-code-parent-agent-id headers to outgoing Anthropic API requests to enable deterministic agent identification.

Guidance

• Identify the createAgentId() function in AgentTool.tsx and verify it generates unique IDs for each agent instance.
• Modify the API client layer to include the x-claude-code-agent-id and x-claude-code-parent-agent-id headers in outgoing requests, using the agentId and parentSessionId values from the runWithAgentContext async local storage.
• Test the modified API client to ensure the new headers are correctly included in requests.
• Verify that proxies and observability tools can successfully distinguish subagent requests and group them by agent instance using the new headers.

Example

// Example of adding headers to an API request
const agentId = asyncLocalStorage.get('agentId');
const parentSessionId = asyncLocalStorage.get('parentSessionId');

const headers = {
  'x-claude-code-agent-id': agentId,
  'x-claude-code-parent-agent-id': parentSessionId || '', // empty string for main agent
};

// Include headers in API request
fetch(apiUrl, { headers });

Notes

This solution assumes that the createAgentId() function generates unique IDs for each agent instance and that the runWithAgentContext async local storage contains the necessary agentId and parentSessionId values.

Recommendation

Apply workaround: Add the proposed headers to outgoing API requests, as this will enable deterministic agent identification without requiring significant changes to the existing system.