mcp

CLI that turns MCP servers into terminal commands.

mcp sentry search_issues '{"query": "is:unresolved level:error"}'

No SDKs. No wrapper code. One binary, any MCP server.

What it does

MCP (Model Context Protocol) servers expose tools — search issues, query logs, send messages, read files. This CLI lets you call those tools directly from your terminal. You configure a server once, then use it like any other command.

$ mcp slack list_channels
$ mcp grafana search_dashboards '{"query": "api-latency"}'
$ mcp sentry get_issue_details '{"issue_id": "12345"}'

Output is always JSON. Pipe it, jq it, script it.

Quick start

Install:

# Homebrew (macOS and Linux)
brew install avelino/mcp/mcp

# Pre-built binary from GitHub Releases
# Download the latest from https://github.com/avelino/mcp/releases

# From source (requires Rust)
cargo install --path .

Add a server from the registry:

mcp add filesystem

Or add an HTTP server manually:

mcp add --url https://mcp.sentry.dev/sse sentry

See what tools are available:

mcp sentry --list

Call a tool:

mcp sentry search_issues '{"query": "is:unresolved"}'

That's it. You're using MCP.

How it works

You  -->  mcp CLI  -->  MCP Server  -->  Service API
              |
         servers.json

The CLI reads your config (~/.config/mcp/servers.json), connects to the server using stdio or HTTP, and speaks JSON-RPC 2.0 to call tools. Authentication (OAuth 2.0, API tokens) is handled automatically.

Configuration

Servers live in ~/.config/mcp/servers.json:

{
  "mcpServers": {
    "slack": {
      "command": "npx",
      "args": ["-y", "slack-mcp-server@latest", "--transport", "stdio"],
      "env": {
        "SLACK_MCP_XOXP_TOKEN": "${SLACK_TOKEN}",
        "SLACK_MCP_TEAM_ID": "${SLACK_TEAM_ID}"
      }
    },
    "sentry": {
      "url": "https://mcp.sentry.dev/sse"
    }
  }
}

Two types of servers:

• Stdio — the CLI spawns a local process (command + args)
• HTTP — the CLI connects to a remote URL (url + optional headers)

Environment variables use ${VAR_NAME} syntax and are resolved at runtime.

Authentication

For HTTP servers that require auth, mcp handles it automatically:

1. OAuth 2.0 — If the server supports it, mcp opens your browser, completes the flow, and saves the token
2. Manual token — If OAuth isn't available, it guides you to get a token with service-specific instructions
3. Config headers — You can set Authorization headers directly in config

Tokens are saved in ~/.config/mcp/auth.json and refreshed automatically.

Commands

| Command | Description | |---|---| | mcp --list | List configured servers | | mcp <server> --list | List available tools | | mcp <server> --info | List tools with input schemas | | mcp <server> <tool> [json] | Call a tool | | mcp search <query> | Search the MCP server registry | | mcp add <name> | Add a server from registry | | mcp add --url <url> <name> | Add an HTTP server | | mcp remove <name> | Remove a server |

Piping JSON from stdin

If you don't pass JSON arguments on the command line, mcp reads from stdin:

echo '{"query": "is:unresolved"}' | mcp sentry search_issues

Environment variables

| Variable | Description | |---|---| | MCP_CONFIG_PATH | Override config file location | | MCP_TIMEOUT | Timeout in seconds for stdio servers (default: 60) |

Documentation

Full documentation: docs/

Development

cargo build
cargo test

Contributing

1. Fork the repo
2. Create your branch (git checkout -b my-feature)
3. Make your changes
4. Run tests (cargo test)
5. Submit a pull request

License

MIT