Grok Build: add Sume's hosted MCP server with grok mcp add

Add Sume to Grok Build with grok mcp add --transport http sume https://mcp.sume.com/mcp, optionally with --header to send an API key, then run grok mcp doctor to check the connection. xAI's Grok Build page documents that command shape for HTTP servers.

xAI's announcement says Grok 4.7 is available in Grok Build, Cursor and the Grok API. The commands and file paths below come from xAI's Grok Build MCP page, read 2026-09-29. This site has not tested Sume's OAuth sign-in with Grok Build's client, so the API-key route is the one shown first.

What are the two ways to authenticate?

xAI's page describes static headers and an automatic OAuth flow that opens a browser on first use. Sume supports both a key and OAuth on the hosted endpoint.

What is the command?

xAI's page says ${VAR} and ${VAR:-default} are expanded in the config, so the key can stay in your environment. Quote the header so your shell leaves the variable for Grok to expand.

grok mcp add --transport http sume https://mcp.sume.com/mcp \
  --header 'Authorization: Bearer ${SUME_API_KEY}'
grok mcp doctor

Where does the config live?

User level is ~/.grok/config.toml and project level is .grok/config.toml. Grok Build also reads compatibility files: ~/.claude.json, .cursor/mcp.json and .mcp.json. To keep a server in a project, grok mcp add --scope project writes .grok/config.toml. A server you already added for Claude Code or Cursor may therefore show up without a second setup step.

What should I call first?

Ask the agent to run mcp_health, then tools_list. Both are read-only. Before any paid generate_video call, have it send dry_run=true with an idempotency_key to preview the cost, and add max_spend_usd if you want a hard cap.

grok mcp doctor accepts --json for machine-readable output, which is useful in a setup script.