Grafana-Loki MCP Server

A FastMCP server that allows querying Loki logs from Grafana.

MCP Server Settings

{
  "mcpServers": {
    "loki": {
      "command": "uvx",
      "args": [
        "grafana-loki-mcp",
        "-u",
        "GRAFANA_URL",
        "-k",
        "GRAFANA_API_KEY"
      ]
    }
  }
}

• GRAFANA_URL: URL of your Grafana instance
• GRAFANA_API_KEY: Grafana API key with appropriate permissions

Features

• Query Loki logs through Grafana API
• Get Loki labels and label values
• Format query results in different formats (text, JSON, markdown)
• Support for both stdio and SSE transport protocols

Requirements

• Python 3.10+
• FastMCP
• Requests

Installation

Using pip

pip install grafana-loki-mcp

Development Setup

1. Clone this repository

2. Install dependencies using uv:

# Install uv
pip install uv

# Create and activate virtual environment
uv venv
source .venv/bin/activate  # On Windows: .venv\Scripts\activate

# Install dependencies
uv pip install -e ".[dev]"

Usage

Environment Variables

Set the following environment variables:

• GRAFANA_URL: URL of your Grafana instance
• GRAFANA_API_KEY: Grafana API key with appropriate permissions

Command Line Arguments

You can also provide these values as command line arguments:

grafana-loki-mcp -u https://your-grafana-instance.com -k your-api-key

Additional options:

• --transport: Transport protocol to use (stdio or sse, default: stdio)

Running the Server

# Using environment variables
export GRAFANA_URL=https://your-grafana-instance.com
export GRAFANA_API_KEY=your-api-key
grafana-loki-mcp

# Using command line arguments
grafana-loki-mcp -u https://your-grafana-instance.com -k your-api-key

# Using SSE transport
grafana-loki-mcp --transport sse

Development

Testing

Run the test suite:

pytest

Run with coverage:

pytest --cov=. --cov-report=term

Linting and Formatting

# Run ruff linter
ruff check .

# Run black formatter
black .

# Run type checking
mypy .

Available Tools

query_loki

Query Loki logs through Grafana.

Parameters:

• query: Loki query string
• start: Start time (ISO format, Unix timestamp, or Grafana-style relative time like 'now-1h', default: 1 hour ago)
• end: End time (ISO format, Unix timestamp, or Grafana-style relative time like 'now', default: now)
• limit: Maximum number of log lines to return (default: 100)
• direction: Query direction ('forward' or 'backward', default: 'backward')
• max_per_line: Maximum characters per log line (0 for unlimited, default: 100)

get_loki_labels

Get all label names from Loki.

get_loki_label_values

Get values for a specific label from Loki.

Parameters:

• label: Label name

format_loki_results

Format Loki query results in a more readable format.

Parameters:

• results: Loki query results from query_loki
• format_type: Output format ('text', 'json', or 'markdown', default: 'text')
• max_per_line: Maximum characters per log line (0 for unlimited, default: 0)

Example Usage

# Example client code
from mcp.client import Client

async with Client() as client:
    # Query Loki logs with max_per_line limit
    results = await client.call_tool(
        "query_loki",
        {
            "query": '{app="my-app"} |= "error"',
            "limit": 50,
            "max_per_line": 100,  # Limit log lines to 100 characters
            "start": "now-6h",    # Grafana-style relative time: 6 hours ago
            "end": "now"          # Current time
        }
    )

    # Format the results
    formatted = await client.call_tool(
        "format_loki_results",
        {
            "results": results,
            "format_type": "markdown",
            "max_per_line": 100  # Can also limit at formatting time
        }
    )

    print(formatted)

License

This project is licensed under the MIT License - see the LICENSE file for details.