Context7
title: context7 MCP radar_quadrant: Tools radar_ring: Assess radar_position: inner created: 2026-05-26 last_updated: 2026-05-26 tags: [mcp, llm, coding-assistant, documentation, context-injection] source_url: https://github.com/upstash/context7
An MCP server from Upstash that resolves stale training data in coding assistants by injecting current, version-matched library documentation into LLM context at request time. When a coding assistant queries a library, context7 fetches the live official docs for that specific version and prepends them to the prompt before the model answers.
LLM training data has a cutoff. A coding assistant asked about FastAPI lifespan events, Pydantic v2 validators, or any rapidly-evolving library will confidently answer based on a version that may be 12–18 months old. Context7 intercepts that query, resolves the library and version, and provides the current documentation — eliminating hallucinations caused by API drift.
Configured as an MCP server in the coding assistant (Cursor, Claude Code, VS Code Copilot, etc.). The tool resolve-library-id maps a library name to context7's index; get-library-docs fetches the relevant documentation slice. The assistant calls these tools transparently during code generation or Q&A.
Complements Cline and OpenHands (coding agents that benefit from accurate library docs). Addresses a failure mode implicit in BuildingEffectiveAgents and LLMSystemPatterns — agent tool calls return stale answers when the model's knowledge of an API is outdated. Works alongside McpKnowledgeGraph in the MCP server ecosystem.
Placed in Tools / Assess / inner. Solves a concrete, widely-felt problem (stale-docs hallucinations in coding assistants) with a clean MCP integration requiring no workflow changes from the developer. Inner position reflects immediate applicability to any team using MCP-compatible coding assistants with rapidly-evolving dependencies. Trial gate: configured in an active coding assistant with at least one instance of a library-version hallucination confirmed absent after installation.
