Drone CI/CD MCP Server

Drone MCP Server

A Model Context Protocol (MCP) server for interacting with Drone CI/CD. This server provides tools and resources to query build information, repositories, and more from your Drone instance.

Features

• 45 tools covering repositories, builds, cron jobs, secrets, users and templates
• Read-only by default: the 27 write and destructive tools are only registered with --enable-write-tools
• Streamable HTTP transport with mandatory bearer authentication, DNS rebinding protection and cross-origin protection
• Validated inputs: repository identifiers, names, branches and build numbers are checked before they reach the Drone API
• Resource access: build details via drone://builds/{owner}/{repo}/{build}

Installation

go mod tidy
go build -o drone-mcp-server .

Configuration

Environment variables

export DRONE_SERVER=https://drone.example.com
export DRONE_TOKEN=your_drone_token
export MCP_AUTH_TOKEN="$(openssl rand -base64 32)"   # HTTP mode only

Grant the smallest Drone permission set that covers the tools you expose. The read-only tool set only needs read access to repositories and builds, while write tools such as deleteuser, createorgsecret or chownrepo require administrator permissions.

Security

This server is a privileged proxy: whatever it can reach, anyone who can talk to it can reach too. The defaults reflect that.

• HTTP mode fails closed. Without MCPAUTHTOKEN (or MCPAUTHTOKEN_FILE) the server refuses to start in HTTP mode. --insecure-allow-anonymous overrides this and logs a warning.
• Read-only by default. Only the 18 read-only tools are registered unless write access is requested explicitly. Every tool is annotated with the MCP hints readOnlyHint, destructiveHint and idempotentHint so clients can gate writes themselves.
• Streamable HTTP transport. The legacy SSE transport was removed from the MCP specification and shipped without DNS rebinding or cross-origin protection. This server uses the Go SDK's StreamableHTTPHandler, which rejects requests that arrive on a loopback address with a non-loopback Host header and rejects cross-site browser requests.
• Optional allowlists. --allowed-hosts and --allowed-origins add explicit Host and Origin allowlists on top of the transport defaults.
• Bearer token handling. Tokens are compared in constant time over SHA-256 digests, and repeated failures from one address are throttled (10 per minute, then 429).
• Input validation. Repository identifiers, secret and template names, branches and build numbers are validated before reaching the Drone API client, because drone-go assembles request paths by string formatting.
• Log hygiene. X-Forwarded-For / X-Real-IP are ignored unless --trust-proxy is set, and control characters are stripped from logged values so request data cannot forge log lines.
• Bounded requests. Request bodies are capped (1 MiB by default), idle sessions expire, and header read timeouts plus silent-connection timeouts limit slow-client abuse.

Deployment checklist

Shortened. The full README is on GitHub.