Simple Loki MCP Server

Loki MCP Server is a Model Context Protocol (MCP) interface for querying Grafana Loki logs using logcli. The server enables AI assistants to access and analyze log data from Loki directly.

Features

• Query Loki logs with full LogQL support
• Get label values and metadata
• Authentication and configuration support via environment variables or config files
• Provides formatted results in different output formats (default, raw, JSON lines)

Prerequisites

• Node.js v16 or higher
• TypeScript
• Grafana Loki logcli installed and accessible in your PATH
• Access to a Loki server instance

Installation

for MCP

{
  "mcpServers": {
    "simple-loki": {
      "command": "npx",
      "args": ["-y", "simple-loki-mcp"],
      "env": {
        "LOKI_ADDR": "https://loki.sup.band"
      }
    }
  }
}

npm

1. Clone the repository:

git clone https://github.com/ghrud92/loki-mcp.git
cd loki-mcp

2. Install dependencies:

npm install

3. Build the project:

npm run build

Available MCP Tools

query-loki

Query logs from Loki with filtering options.

Parameters:

• query (required): Loki query string (LogQL)
• from: Start timestamp (e.g. "2023-01-01T12:00:00Z")
• to: End timestamp (e.g. "2023-01-01T13:00:00Z")
• limit: Maximum number of logs to return
• batch: Batch size for query results
• output: Output format ("default", "raw", or "jsonl")
• quiet: Suppress query metadata
• forward: Display results in chronological order

get-label-values

Retrieve all values for a specific label.

Parameters:

• label (required): Label name to get values for

get-labels

Retrieve all available labels.

No parameters required.

Configuration

You can configure Loki access using:

Environment Variables

• LOKI_ADDR: Loki server address (URL)
• LOKI_USERNAME: Username for basic auth
• LOKI_PASSWORD: Password for basic auth
• LOKI_TENANT_ID: Tenant ID for multi-tenant Loki
• LOKI_BEARER_TOKEN: Bearer token for authentication
• LOKI_BEARER_TOKEN_FILE: File containing bearer token
• LOKI_CA_FILE: Custom CA file for TLS
• LOKI_CERT_FILE: Client certificate file for TLS
• LOKI_KEY_FILE: Client key file for TLS
• LOKI_ORG_ID: Organization ID for multi-org setups
• LOKI_TLS_SKIP_VERIFY: Skip TLS verification ("true" or "false")
• LOKI_CONFIG_PATH: Custom path to config file
• DEBUG: Enable debug logging

Config Files

Alternatively, create a logcli-config.yaml file in one of these locations:

• Custom path specified by LOKI_CONFIG_PATH
• Current working directory
• Your home directory (~/.logcli-config.yaml)

Example config file:

addr: https://loki.example.com
username: user
password: pass
tenant_id: mytenant

Usage

Start the server:

npm start

For development:

npm run dev

Development

# Run linter
npm run lint

# Fix linting issues
npm run lint:fix

# Run tests
npm run test

License

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