Logfire MCP Server

A Model Context Protocol server that provides access to OpenTelemetry traces and metrics through Logfire. This server enables LLMs to query your application's telemetry data, analyze distributed traces, and perform custom queries using Logfire's OpenTelemetry-native API, with automatic token-based authentication.

Available Tools

• find_exceptions - Get exception counts from traces grouped by file

  • Required arguments:
    • age (int): Number of minutes to look back (e.g., 30 for last 30 minutes, max 7 days)

• find_exceptions_in_file - Get detailed trace information about exceptions in a specific file

  • Required arguments:
    • filepath (string): Path to the file to analyze
    • age (int): Number of minutes to look back (max 7 days)

• arbitrary_query - Run custom SQL queries on your OpenTelemetry traces and metrics

  • Required arguments:
    • query (string): SQL query to execute
    • age (int): Number of minutes to look back (max 7 days)

• get_logfire_records_schema - Get the OpenTelemetry schema to help with custom queries

  • No required arguments

Usage

First, you need a Logfire read token. You can create one at: https://logfire.pydantic.dev/-/redirect/latest-project/settings/read-tokens

Then you can run the MCP server using uvx:

LOGFIRE_READ_TOKEN=YOUR_TOKEN uvx logfire-mcp

Or using the --read-token flag:

uvx logfire-mcp --read-token=YOUR_TOKEN

Configuration

Configure for Cursor

Create a .cursor/mcp.json file in your project root:

{
  "mcpServers": {
    "logfire": {
      "command": "uvx",
      "args": ["logfire-mcp", "--read-token=YOUR-TOKEN"]
    }
  }
}

The Cursor doesn't accept the env field, so you need to use the --read-token flag instead.

Configure for Claude Desktop

Add to your Claude settings:

{
  "command": ["uvx"],
  "args": ["logfire-mcp"],
  "type": "stdio",
  "env": {
    "LOGFIRE_READ_TOKEN": "YOUR_TOKEN"
  }
}

Configure for Cline

Add to your Cline settings in cline_mcp_settings.json:

{
  "mcpServers": {
    "logfire": {
      "command": "uvx",
      "args": ["logfire-mcp"],
      "env": {
        "LOGFIRE_READ_TOKEN": "YOUR_TOKEN"
      },
      "disabled": false,
      "autoApprove": []
    }
  }
}

Customization - Base URL

By default, the server connects to the Logfire API at https://logfire-api.pydantic.dev. You can override this by:

1. Using the --base-url argument:

uvx logfire-mcp --base-url=https://your-logfire-instance.com

2. Setting the environment variable:

LOGFIRE_BASE_URL=https://your-logfire-instance.com uvx logfire-mcp

Example Interactions

1. Find all exceptions in traces from the last hour:

{
  "name": "find_exceptions",
  "arguments": {
    "age": 60
  }
}

Response:

[
  {
    "filepath": "app/api.py",
    "count": 12
  },
  {
    "filepath": "app/models.py",
    "count": 5
  }
]

2. Get details about exceptions from traces in a specific file:

{
  "name": "find_exceptions_in_file",
  "arguments": {
    "filepath": "app/api.py",
    "age": 1440
  }
}

Response:

[
  {
    "created_at": "2024-03-20T10:30:00Z",
    "message": "Failed to process request",
    "exception_type": "ValueError",
    "exception_message": "Invalid input format",
    "function_name": "process_request",
    "line_number": "42",
    "attributes": {
      "service.name": "api-service",
      "code.filepath": "app/api.py"
    },
    "trace_id": "1234567890abcdef"
  }
]

3. Run a custom query on traces:

{
  "name": "arbitrary_query",
  "arguments": {
    "query": "SELECT trace_id, message, created_at, attributes->>'service.name' as service FROM records WHERE severity_text = 'ERROR' ORDER BY created_at DESC LIMIT 10",
    "age": 1440
  }
}

Examples of Questions for Claude

1. "What exceptions occurred in traces from the last hour across all services?"
2. "Show me the recent errors in the file 'app/api.py' with their trace context"
3. "How many errors were there in the last 24 hours per service?"
4. "What are the most common exception types in my traces, grouped by service name?"
5. "Get me the OpenTelemetry schema for traces and metrics"
6. "Find all errors from yesterday and show their trace contexts"

Getting Started

1. First, obtain a Logfire read token from: https://logfire.pydantic.dev/-/redirect/latest-project/settings/read-tokens

2. Run the MCP server:

   uvx logfire-mcp --read-token=YOUR_TOKEN

3. Configure your preferred client (Cursor, Claude Desktop, or Cline) using the configuration examples above

4. Start using the MCP server to analyze your OpenTelemetry traces and metrics!

Contributing

We welcome contributions to help improve the Logfire MCP server. Whether you want to add new trace analysis tools, enhance metrics querying functionality, or improve documentation, your input is valuable.

For examples of other MCP servers and implementation patterns, see the Model Context Protocol servers repository.

License

Logfire MCP is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License.