Grok
Use Thirdfy MCP from xAI Grok with remote MCP tools in the xAI Responses API and the xai-sdk.
xAI's API connects Grok to remote MCP servers. You add Thirdfy to the tools of a request, and xAI handles the connection. See xAI's Remote MCP tools docs.
You need a Thirdfy agent API key (agent-...) for any tool that acts for your agent. Get one with email onboarding: run it once through any MCP client or with the Agent CLI.
Request
authorization is sent to Thirdfy in the Authorization header.
Keep writes under control
xAI runs MCP tool calls without an approval step: it does not support require_approval. Limit what Grok can do in two places:
allowed_tools(allowed_tool_namesin the xai-sdk). List only the tools the task needs. Without it, every Thirdfy tool is loaded, which also adds context.- Your agent's policy in Thirdfy. The key's action allowlist and daily limit bind every call, whatever the model asks for. See Delegation & protection.
For a research agent, allow only getActionsCatalog, getProviderActions and agentRun, and ask it to run read actions such as the get_openmarket_* and get_cmc_* reads.
Troubleshooting
| Issue | Fix |
|---|---|
401 Authentication required | Pass the agent key in authorization |
| Grok calls a tool you didn't expect | Narrow allowed_tools, and the key's action allowlist |
AGENT_IDENTITY_MISMATCH | The model passed a different key in arguments. The bearer key is used |