Grok (xAI API)

This page is for developers building on the xAI API, not for the Grok consumer app on grok.com, X, or the mobile clients. Those don’t expose a way to add a custom MCP connector. xAI’s API does: you pass an MCP server config inside the tools array of a Chat, Responses, or Voice request, and xAI brokers the connection on the server side.

Protocol background lives at MCP. Full xAI reference: docs.x.ai/developers/tools/remote-mcp.

Prerequisites

Before you start, confirm:

You have an Engram account at app.engram.page.
At least one vault is synced. Open the Obsidian plugin or the web app and confirm notes have synced within the last day.
You can sign in via browser. The MCP auth flow opens a browser window.

Plus xAI-specific:

An xAI API key with model access (Grok 4 family or whichever model you target).
An Engram API key for the Bearer header. xAI’s Remote MCP Tools feature passes the authorization value straight through to the MCP server on every call. Generate one at app.engram.page/settings/api-keys.

Endpoint

https://mcp.engram.page/api/mcp

Native `xai_sdk`

from xai_sdk import Client

client = Client(api_key="YOUR_XAI_KEY")

response = client.chat.create(
    model="grok-4",
    messages=[{"role": "user", "content": "What did I write about Q3 planning?"}],
    tools=[
        {
            "type": "mcp",
            "server_url": "https://mcp.engram.page/api/mcp",
            "server_label": "engram",
            "authorization": "Bearer YOUR_ENGRAM_API_KEY",
        }
    ],
)

print(response.output_text)

OpenAI-compatible API

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_XAI_KEY",
    base_url="https://api.x.ai/v1",
)

response = client.responses.create(
    model="grok-4",
    input="What did I write about Q3 planning?",
    tools=[
        {
            "type": "mcp",
            "server_url": "https://mcp.engram.page/api/mcp",
            "server_label": "engram",
            "authorization": "Bearer YOUR_ENGRAM_API_KEY",
        }
    ],
)

print(response.output_text)

Optional knobs xAI exposes on the tool object: allowed_tools (list of MCP tool names to whitelist), headers (extra headers per call). See the xAI Remote MCP reference for the full schema.

Transports

xAI’s Remote MCP Tools supports Streamable HTTP and SSE. Engram’s endpoint speaks Streamable HTTP. Pass it directly, no adapter needed.

Why no OAuth flow

The xAI API is a server-to-server surface. There’s no browser to open and no end-user session to attach a token to. Pass an Engram API key in the authorization field instead. Treat it like any service credential: keep it out of source control and rotate it when teammates rotate off.

The grant is the full mcp scope today. Granular per-action scopes are on the roadmap.

Troubleshooting

401 from the MCP server. Your Engram API key is wrong or revoked. Generate a fresh key in Engram settings.
Tool calls never fire. Grok decided it didn’t need the tool. Make the system prompt explicit: “Use the engram tools to look up the user’s notes before answering.”
Invalid transport. Your endpoint URL is wrong or the tool block is malformed. Confirm the URL matches the endpoint above and the tool block has type: mcp plus the four fields shown above.

For cross-client failures, see Troubleshooting.

Revocation

Revoke the Engram API key under your account → API Keys & Sessions. Once revoked, xAI calls carrying that key return 401 immediately.

Next steps

MCP Protocol overview.

Scopes What the grant covers.

All integrations Pick a different client.