agent-mcp

name	agent-mcp
description	Configure MCP servers for Antigravity, OpenCode, and Claude — stdio or remote transport, workspace or user scope. Use when adding, connecting, or troubleshooting an MCP server.
metadata	{"author":"Médéric HURIER (Fmind)","source":"github.com/fmind/dotfiles/tree/main/skills/agent-mcp","created":"2026-06-23T00:00:00.000Z","updated":"2026-07-06T00:00:00.000Z"}

Configure Agent MCP Servers

Configure Model Context Protocol (MCP) servers for Antigravity, OpenCode, and Claude — stdio runners, remote HTTP endpoints, and Google Cloud managed MCP.

Workflow

1. Locate Config:
   • Antigravity: Workspace .agents/mcp_config.json (default) or global ~/.gemini/antigravity-cli/mcp_config.json. Add servers under the "mcpServers" object.
   • OpenCode: Workspace opencode.json (default) or global ~/.config/opencode/opencode.json. Add servers under the "mcp" object.
   • Claude: Workspace .mcp.json (default) or global ~/.claude.json. Add servers under the "mcpServers" object.
2. Pick the Server: Find the server, transport, and auth from an authoritative catalog (see Catalogs) rather than a local snapshot — upstream docs stay current.
3. Write Configuration: Choose the transport (stdio for local runners, remote HTTP for hosted endpoints) and use the matching schema below.
4. Verify: Run /mcp inside the Antigravity or Claude session, opencode mcp list, or claude mcp list to check server status.

Schemas

Stdio (local runner)

Antigravity:

"server-name": {
  "command": "npx",
  "args": ["-y", "@modelcontextprotocol/server-everything"],
  "env": { "ENV_VAR": "value" }
}

OpenCode:

"server-name": {
  "type": "local",
  "command": ["npx", "-y", "@modelcontextprotocol/server-everything"],
  "environment": { "ENV_VAR": "value" },
  "enabled": true
}

Claude:

"server-name": {
  "type": "stdio",
  "command": "npx",
  "args": ["-y", "@modelcontextprotocol/server-everything"],
  "env": { "ENV_VAR": "value" }
}

Remote (HTTP endpoint)

Antigravity (use serverUrl; httpUrl is the legacy Gemini-CLI alias):

"server-name": {
  "serverUrl": "https://run.googleapis.com/mcp",
  "authProviderType": "google_credentials",
  "oauth": { "scopes": ["https://www.googleapis.com/auth/cloud-platform"] },
  "headers": { "x-goog-user-project": "PROJECT_ID" }
}

OpenCode:

"server-name": {
  "type": "remote",
  "url": "https://run.googleapis.com/mcp",
  "headers": { "x-goog-user-project": "PROJECT_ID" },
  "enabled": true
}

Claude:

"server-name": {
  "type": "http",
  "url": "https://run.googleapis.com/mcp",
  "headers": { "x-goog-user-project": "PROJECT_ID" }
}

Google Cloud Managed MCP

Most Google Cloud products expose a managed MCP server behind a common pattern:

1. Enable the API and its MCP endpoint:

   gcloud services enable <service>.googleapis.com
   gcloud beta services mcp enable <service>.googleapis.com
   gcloud auth application-default login
   

2. Configure the remote server (Antigravity example above), pointing serverUrl at https://<service>.googleapis.com/mcp and setting the x-goog-user-project billing/quota header.
3. Grant IAM: the principal needs roles/mcp.toolUser plus a product role (e.g. roles/bigquery.user for BigQuery reads, roles/run.developer for Cloud Run).

The current list of managed products, endpoints, and required roles is maintained upstream — see Catalogs. Prefer it over hardcoding a per-service copy here.

Catalogs

• Google Cloud managed MCP: Supported products · MCP overview
• Official & community servers: MCP registry
• Vendor servers (GitHub, Atlassian, Firebase, Terraform, Databricks, Airtable, …): consult each vendor's current MCP docs for the endpoint, transport, and auth.

Gotchas

1. Authentication Errors (401/403): Ensure Google Application Default Credentials (ADC) are configured (gcloud auth application-default login) or OAuth tokens are authorized.
2. Stdio Executables: Verify the required runner/binary (npx, uv, docker, etc.) is on your system PATH.
3. Remote Key: Antigravity expects serverUrl for remote HTTP servers; Claude expects type: "http" and url; httpUrl still works as a legacy alias in Antigravity but is deprecated.