Weights & Biases

Weights & Biases' official MCP server provides AI agents with direct access to W&B's machine learning platform, enabling querying of Weave traces and evaluations, GraphQL-based experiment data retrieval, trace counting, report creation with visualizations, and access to wandbot support. Built with FastMCP and supporting both STDIO and HTTP transports, it features multi-tenant session management with API key isolation, comprehensive authentication middleware, and optional Weave tracing for observability of MCP operations. The implementation is particularly valuable for ML practitioners and teams who want to integrate W&B's experiment tracking, model evaluation, and collaboration features directly into AI-assisted workflows for model development, performance analysis, and automated reporting.