Setting up MCP in a Plugin

.mcp.json

.claude-plugin/

mcp.json

File location

plugins/<name>/
├── .claude-plugin/
│   └── plugin.json
├── .mcp.json        ← here
├── commands/
└── ...

Schema

{
  "<server-name>": {
    "type": "http",
    "url": "https://<endpoint>/mcp/",
    "headers": {
      "Authorization": "Bearer ${ENV_VAR}"
    }
  }
}

• Top-level keys are the server names (used as identifiers in Claude Code)

• type

  : transport type — use

  "http"

  for HTTP/SSE endpoints

• url

  : the MCP server endpoint URL

• headers

  : optional; use

  ${VAR}

  syntax for environment variable interpolation (e.g.,

  ${GITHUB_TOKEN}

  )

Example (github plugin)

{
  "github": {
    "type": "http",
    "url": "https://githubcopilot-api.gsmlg.dev/mcp/",
    "headers": {
      "Authorization": "Bearer ${GITHUB_TOKEN}"
    }
  }
}

Notes

• Multiple servers can be registered in the same

  .mcp.json

  by adding more top-level keys

• headers

  is only needed for authenticated endpoints

• plugin.json

  does not carry MCP config — keep them separate

• lspServers

  in

  plugin.json

  is for LSP (code intelligence), not MCP