Comet ML MCP Server

A comprehensive Model Context Protocol (MCP) server that provides tools for interacting with Comet ML API. This server enables seamless integration with Comet ML's experiment tracking platform through a standardized protocol.

Features

• 🔧 MCP Server: Full Model Context Protocol implementation for tool integration

• 📊 Experiment Management: List, search, and analyze experiments with detailed metrics

• 📁 Project Management: Organize and explore projects across workspaces

• 🔍 Advanced Search: Search experiments by name, description, and project

• 📈 Session Management: Singleton comet_ml.API() instance with robust error handling

Installation

Prerequisites

• Python 3.8 or higher

• Comet ML account and API key

Install from Source

pip install comet-mcp --upgrade

Docker Installation (Alternative)

You can run the Comet MCP server using Docker to avoid installing Python dependencies on your system.

1. Build the Docker image:

   docker build -t comet-mcp .

2. Configure your MCP client (see Usage section below for configuration examples)

Configuration

The server uses standard comet_ml configuration:

1. Using comet init; or

2. Using environment variables

Example:

export COMET_API_KEY=your_comet_api_key_here

# Optional: Set default workspace (if not provided, uses your default)
export COMET_WORKSPACE=your_workspace_name

Available Tools

Core Comet ML Tools

• list_experiments(workspace, project_name) - List recent experiments with optional filtering

• get_experiment_details(experiment_id) - Get comprehensive experiment information including metrics and parameters

• get_experiment_code(experiment_id) - Retrieve source code from experiments

• get_experiment_output(experiment_id) - Get raw training logs (stdout/stderr) from experiments

• get_experiment_metric_data(experiment_ids, metric_names, x_axis) - Get metric data for multiple experiments

• get_default_workspace() - Get the default workspace name for the current user

• list_projects(workspace) - List all projects in a workspace

• list_project_experiments(project_name, workspace) - List experiments within a specific project

• count_project_experiments(project_name, workspace) - Count and analyze experiments in a project

• get_session_info() - Get current session status and connection information

Tool Features

• Structured Data: All tools return properly typed data structures

• Error Handling: Graceful handling of API failures and missing data

• Flexible Filtering: Filter by workspace, project, or search terms

• Rich Metadata: Includes timestamps, descriptions, and status information

• File Resources: Some tools (like experiment_spreadsheet) create CSV files that are available as MCP resources

MCP Resources

The server provides access to generated files (like CSV exports) through the MCP resources API. When a tool creates a file, it returns a resource URI that can be accessed using the MCP read_resource method.

Accessing Resources:

• Tools that create files will return a resource_uri in their response

• Use the MCP read_resource method with the URI to read the file content

• Resources are stored on the server and can be accessed without processing all content through the LLM

Example:

# After calling experiment_spreadsheet, you'll get a resource_uri
# Access it using:
read_resource(uri="file://comet-mcp/experiment_spreadsheet_20251206_103508.csv")

Most MCP clients (like Claude Desktop, Cursor, etc.) will automatically handle resource access when you reference the resource URI in your conversation.

Usage

1. MCP Server Mode

Run the server to provide tools to MCP clients:

# Start the MCP server
comet-mcp

The server will:

• Initialize Comet ML session

• Register all available tools

• Listen for MCP client connections via stdio

2. Configuration File

Create a configuration for your AI system. For example:

Local Installation:

{
  "servers": [
    {
      "name": "comet-mcp",
      "description": "Comet ML MCP server for experiment management",
      "command": "comet-mcp",
      "env": {
        "COMET_API_KEY": "${COMET_API_KEY}"
      }
    }
  ]
}

Docker Installation (Alternative):

{
  "mcpServers": {
    "comet-mcp": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "COMET_API_KEY",
        "-e",
        "COMET_WORKSPACE",
        "comet-mcp",
        "comet-mcp",
        "--transport",
        "stdio"
      ],
      "env": {
        "COMET_API_KEY": "your_api_key_here",
        "COMET_WORKSPACE": "your_workspace_name"
      }
    }
  }
}

comet-mcp supports "stdio" and "sse" transport modes.

4. Command line options

usage: comet-mcp [-h] [--transport {stdio,sse}] [--host HOST] [--port PORT]

Comet ML MCP Server

options:
  -h, --help            show this help message and exit
  --transport {stdio,sse}
                        Transport method to use (default: stdio)
  --host HOST           Host for SSE transport (default: localhost)
  --port PORT           Port for SSE transport (default: 8000)

5. OpenTelemetry Observability

The Comet MCP server includes built-in OpenTelemetry instrumentation for distributed tracing and structured logging. This provides visibility into server operations, tool calls, and Comet ML API interactions.

Features

• Distributed Tracing: Track requests across server operations, tool calls, and API interactions

• Structured Logging: Capture detailed log events with context

• Dual Export: Export telemetry data to both files and Opik (Comet's observability platform)

• Low Overhead: Minimal performance impact with async-friendly instrumentation

Configuration

Telemetry is enabled by default but can be configured via environment variables.

General Configuration

# Enable/disable telemetry (default: true)
export OTEL_ENABLED=true

# Service name (default: comet-mcp)
export OTEL_SERVICE_NAME=comet-mcp

# Service version (default: 1.2.0)
export OTEL_SERVICE_VERSION=1.2.0

File Export Configuration

Export traces and logs to local files in JSON Lines format:

# Path for trace export file (default: traces.jsonl, empty to disable)
export OTEL_TRACES_FILE=traces.jsonl

# Path for log export file (default: logs.jsonl, empty to disable)
export OTEL_LOGS_FILE=logs.jsonl

File Format:

• Traces: OTLP JSON format, one span per line

• Logs: Structured JSON format, one log record per line

• Files are append-only and can be rotated externally

Example: Reading trace files:

import json

with open("traces.jsonl", "r") as f:
    for line in f:
        span = json.loads(line)
        print(f"Span: {span['name']}, Duration: {span['end_time_unix_nano'] - span['start_time_unix_nano']}")

Opik Export Configuration

Export traces and logs to Opik (Comet's observability platform) for cloud-based observability.

Option 1: Using OTLP Environment Variables

# Opik endpoint
export OTEL_EXPORTER_OTLP_ENDPOINT="https://www.comet.com/opik/api/v1/private/otel"

# Headers (comma-separated key=value pairs)
export OTEL_EXPORTER_OTLP_HEADERS="Authorization=your-api-key,projectName=your-project,Comet-Workspace=your-workspace"

Option 2: Using Individual Variables

# Opik endpoint (defaults to Comet Cloud if not set)
export OPIK_ENDPOINT="https://www.comet.com/opik/api/v1/private/otel"

# Opik API key
export OPIK_API_KEY=your-api-key

# Opik project name
export OPIK_PROJECT_NAME=your-project

# Comet workspace name
export OPIK_WORKSPACE=your-workspace

For Self-Hosted Opik:

export OTEL_EXPORTER_OTLP_ENDPOINT="http://localhost:5173/api/v1/private/otel"

For Enterprise Deployment:

export OTEL_EXPORTER_OTLP_ENDPOINT="https://<comet-deployment-url>/opik/api/v1/private/otel"
export OTEL_EXPORTER_OTLP_HEADERS="Authorization=your-api-key,projectName=your-project,Comet-Workspace=your-workspace"

Configuration Examples

File-only export:

export OTEL_TRACES_FILE=traces.jsonl
export OTEL_LOGS_FILE=logs.jsonl
# Opik export disabled (no endpoint configured)

Opik-only export:

export OTEL_EXPORTER_OTLP_ENDPOINT="https://www.comet.com/opik/api/v1/private/otel"
export OPIK_API_KEY=your-api-key
export OPIK_PROJECT_NAME=your-project
export OPIK_WORKSPACE=your-workspace
# File export disabled (empty file paths)
export OTEL_TRACES_FILE=""
export OTEL_LOGS_FILE=""

Both file and Opik export:

# File export
export OTEL_TRACES_FILE=traces.jsonl
export OTEL_LOGS_FILE=logs.jsonl

# Opik export
export OTEL_EXPORTER_OTLP_ENDPOINT="https://www.comet.com/opik/api/v1/private/otel"
export OPIK_API_KEY=your-api-key
export OPIK_PROJECT_NAME=your-project
export OPIK_WORKSPACE=your-workspace

What Gets Instrumented

The following operations are automatically instrumented:

• Server Lifecycle: Startup, shutdown, session initialization

• Tool Operations: All MCP tool calls (list_tools, call_tool, list_resources, read_resource)

• Comet ML API Calls: All tool functions that interact with Comet ML API

• Cache Operations: Cache hits, misses, and writes

• Session Management: Session initialization and API access

Viewing Traces

In Opik:

1. Navigate to your Opik project

2. Open the Traces view

3. Filter by service name: comet-mcp

4. Explore trace spans and their relationships

From Files:

• Use tools like jq to parse JSON Lines files:

  cat traces.jsonl | jq '.name, .attributes'

• Import into analysis tools that support OTLP JSON format

• Use log aggregation tools for log files

Troubleshooting

Telemetry not appearing:

• Check that OTEL_ENABLED=true (or not set, defaults to true)

• Verify file paths are writable (for file export)

• Check network connectivity (for Opik export)

• Review server logs for telemetry initialization messages

Opik export errors:

• Verify API key and endpoint are correct

• Check that project name and workspace match your Opik configuration

• Ensure you're using HTTP endpoint (not gRPC)

• Network errors are logged but don't crash the server

For more information about Opik, see the Opik OpenTelemetry documentation.

6. Integration with Opik for use, testing, and optimization

For complete details on testing this (or any MCP server) see examples/README.

License

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

Support

• Documentation: GitHub Repository

• Issues: GitHub Issues

• Comet ML: Comet ML Documentation