Duplicacy

Duplicacy MCP

A tiny bridge that reads Duplicacy backup metrics from a Prometheus exporter and exposes them as an MCP server, enabling LLMs to monitor backup status, progress, and health.

Features

• Reads the metrics of duplicacy-exporter and serves them over MCP.
• One call answers "are my backups OK?": get_backup_overview gives every backup a verdict (ok, running, stale, never, failed) with a reason.
• Speaks MCP 2026-07-28 (server/discover, stateless requests) and every earlier revision down to 2024-11-05 (the initialize handshake) from the same binary, over stdio and Streamable HTTP. Clients that still use the old handshake keep working.
• Read-only by design: every tool and resource only reads the exporter, so there is no read-only flag to set. Every tool carries readOnlyHint, a title, an output schema and structured results.
• HTTP listens on 127.0.0.1:8080 by default. On any other address it refuses to start without a bearer token, rejects cross-origin browser requests and caps request bodies.
• Ships as Go binaries for several platforms (GoReleaser), a Docker image and an npm wrapper.

Tools and resources

Resources: duplicacy://status, duplicacy://progress and duplicacy://health. Parameters and output fields are on Usage.

Install

The npm package runs the server over stdio; set DUPLICACY_EXPORTER_URL to your exporter.

Claude Code

claude mcp add --transport stdio --env DUPLICACY_EXPORTER_URL=http://localhost:9750 duplicacy -- npx -y duplicacy-mcp

Claude Desktop (claude_desktop_config.json) and Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "duplicacy": {
      "command": "npx",
      "args": ["-y", "duplicacy-mcp"],
      "env": { "DUPLICACY_EXPORTER_URL": "http://localhost:9750" }
    }
  }
}

VS Code (.vscode/mcp.json)

{
  "servers": {
    "duplicacy": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "duplicacy-mcp"],
      "env": { "DUPLICACY_EXPORTER_URL": "http://localhost:9750" }
    }
  }
}

Codex (~/.codex/config.toml)

[mcp_servers.duplicacy]
command = "npx"
args = ["-y", "duplicacy-mcp"]
env = { DUPLICACY_EXPORTER_URL = "http://localhost:9750" }

npm 12, pnpm and Bun skip install scripts, so the wrapper downloads and verifies the binary on first start. Versions up to 0.1.2 relied on the install script alone; with npm 12 run them as npx -y --allow-scripts=duplicacy-mcp duplicacy-mcp.

Docker (Streamable HTTP)

export MCP_AUTH_TOKEN=$(openssl rand -hex 32)
docker run -d -p 127.0.0.1:8080:8080 -e MCP_AUTH_TOKEN \
  -e DUPLICACY_EXPORTER_URL=http://duplicacy-exporter:9750 drumsergio/duplicacy-mcp:v0.2.0
claude mcp add --transport http duplicacy http://127.0.0.1:8080/mcp --header "Authorization: Bearer $MCP_AUTH_TOKEN"

The image listens on 0.0.0.0:8080 inside the container, so it will not start without MCP_AUTH_TOKEN (or MCP_ALLOW_UNAUTHENTICATED=true behind a reverse proxy that authenticates). Compose, a global npm install and a local build are in Getting started; every variable is in Configuration.

Documentation

• Getting started: Docker Compose, npm, local build, first run
• Configuration: environment variables, HTTP security, client config for stdio and HTTP
• Usage: tools, parameters, output fields and resources
• Development: testing with Inspector, credits, contributing
• Related projects: the Duplicacy family, other MCP servers, registry listings

Related projects

Part of the Duplicacy family: duplicacy-exporter, duplicacy-cli-cron, duplicacy-ha, duplicacy-container.

License

GPL-3.0-or-later