Prometheus MCP Server

A minimal Model Context Protocol (MCP) server focused on reading from Prometheus. It exposes Prometheus discovery and query tools to MCP-compatible apps and includes a convenient CLI for local queries.

Highlights

Instant and range queries via Prometheus HTTP API
Discovery helpers: list metrics, get metadata, series selectors, label values
Optional internal metrics exporter at /metrics (disabled by default)
Works as a stdio MCP server or a one-off CLI

Installation

Build from source (Rust):

cargo build --release
# binary at ./target/release/prometheus-mcp

Or build a Docker image:

docker build -t prometheus-mcp:latest .

Usage (CLI)

The CLI mirrors the tools exposed over MCP.

Instant query

prometheus-mcp query --query 'up' --prometheus-url http://localhost:9090
# optionally set an evaluation time
prometheus-mcp query --query 'up' --time '2025-09-27T12:00:00Z'

Range query

prometheus-mcp range --query 'rate(http_requests_total[5m])' \
  --start '2025-09-27T12:00:00Z' --end '2025-09-27T13:00:00Z' --step '30s'

List metric names

prometheus-mcp list-metrics

Metric metadata

prometheus-mcp metadata --metric 'up'

Series selectors (repeat --selector)

prometheus-mcp series --selector 'up' --selector 'node_cpu_seconds_total{mode="idle"}'

Label values

prometheus-mcp label-values --label 'job'

MCP server (stdio)

Start the MCP server over stdio:

prometheus-mcp --mcp --prometheus-url http://localhost:9090

Optional: enable internal metrics at /metrics (default off):

prometheus-mcp --mcp --metrics-exporter --metrics-port 9091

Running in Docker

Build the image:

docker build -t prometheus-mcp:latest .

Run the MCP server:

# Linux: easiest if Prometheus is on the host at :9090
docker run --rm -it --network host prometheus-mcp:latest --mcp \
  --prometheus-url http://localhost:9090

# macOS/Windows: use host.docker.internal
docker run --rm -it prometheus-mcp:latest --mcp \
  --prometheus-url http://host.docker.internal:9090

# Linux without host network: map host gateway
docker run --rm -it --add-host=host.docker.internal:host-gateway \
  prometheus-mcp:latest --mcp \
  --prometheus-url http://host.docker.internal:9090

One-off CLI in the container:

# Instant query
docker run --rm prometheus-mcp:latest query --query 'up' \
  --prometheus-url http://host.docker.internal:9090

# Range query
docker run --rm prometheus-mcp:latest range --query 'rate(http_requests_total[5m])' \
  --start '2025-09-27T12:00:00Z' --end '2025-09-27T13:00:00Z' --step '30s' \
  --prometheus-url http://host.docker.internal:9090

Basic Auth

Pass credentials via environment variables or CLI flags.

Environment variables:

export PROMETHEUS_URL=https://prom.example.com
export PROMETHEUS_USERNAME=api
export PROMETHEUS_PASSWORD=secret
prometheus-mcp --mcp

CLI flags:

prometheus-mcp --mcp \
  --prometheus-url https://prom.example.com \
  --prometheus-username api \
  --prometheus-password secret

Docker with env vars:

docker run --rm -it \
  -e PROMETHEUS_URL=https://prom.example.com \
  -e PROMETHEUS_USERNAME=api \
  -e PROMETHEUS_PASSWORD=secret \
  prometheus-mcp:latest --mcp

Configuration

All settings can be provided via environment variables; some also via flags.

Name	Type	Default	CLI flag	Description
PROMETHEUS_URL	string (URL)	http://localhost:9090	--prometheus-url	Base URL of your Prometheus server
PROMETHEUS_TIMEOUT	integer (seconds)	10	—	HTTP request timeout
PROMETHEUS_RETRIES	integer	3	—	Number of retries for Prometheus API calls
PROMETHEUS_RETRY_BACKOFF_MS	integer (ms)	500	—	Time to wait between retries
PROMETHEUS_MIN_INTERVAL_MS	integer (ms)	—	—	Minimum interval between query requests (basic rate limit)
PROMETHEUS_CACHE_TTL_SECS	integer (seconds)	—	—	TTL for simple in-process caches (list metrics and label values)
PROMETHEUS_USERNAME	string	—	--prometheus-username	Basic auth username
PROMETHEUS_PASSWORD	string	—	--prometheus-password	Basic auth password
—	boolean	false	--mcp	Start MCP server over stdio
—	boolean	false	--metrics-exporter	Enable internal Prometheus metrics at /metrics
—	integer (port)	9091	--metrics-port	Port for /metrics when exporter is enabled

See docs/configuration.md for notes and examples.

Accessing from Claude Desktop

Follow the official guide to locate claude_desktop_config.json: https://modelcontextprotocol.io/quickstart/user#for-claude-desktop-users

Minimal Docker-based entry:

{
  "mcpServers": {
    "prometheus": {
      "command": "docker",
      "args": ["run", "--rm", "-i", "prometheus-mcp:latest"]
    }
  }
}

With host Prometheus and exporter (macOS/Windows):

{
  "mcpServers": {
    "prometheus": {
      "command": "docker",
      "args": [
        "run", "--rm", "-i",
        "-p", "9091:9091",
        "prometheus-mcp:latest",
        "--mcp",
        "--prometheus-url", "http://host.docker.internal:9090",
        "--metrics-exporter",
        "--metrics-port", "9091"
      ]
    }
  }
}

With Basic Auth via environment variables:

{
  "mcpServers": {
    "prometheus": {
      "command": "docker",
      "args": [
        "run", "--rm", "-i",
        "-e", "PROMETHEUS_URL=https://prom.example.com",
        "-e", "PROMETHEUS_USERNAME=api",
        "-e", "PROMETHEUS_PASSWORD=secret",
        "prometheus-mcp:latest", "--mcp"
      ]
    }
  }
}

More examples: see docs/claude-desktop.md.

Debugging

Use the MCP Inspector to exercise the server interactively:

npx @modelcontextprotocol/inspector

Connect with transport "STDIO", command prometheus-mcp, and optional args --mcp --prometheus-url http://localhost:9090.

Logs are appended to /tmp/mcp.jsonl; tail it with:

tail -f /tmp/mcp.jsonl

Security Considerations

The server does not provide authentication itself; when running outside stdio, keep it on localhost.
Handle credentials via environment variables or your secret manager. Avoid committing secrets.

License

Apache-2.0

prometheus-mcp 0.0.1