Context7

Overview

Context7 eliminates the most frustrating part of AI coding: when the AI confidently writes code using APIs that don’t exist anymore. By injecting up-to-date documentation directly into the LLM’s context, Context7 ensures your AI always uses the current API. With 51k+ stars, it’s become an essential tool for AI-assisted development.

How It Works

1. Install as MCP server — Add to your MCP client config
2. Use use context7 — Add this phrase to your prompt
3. Fresh docs injected — Context7 fetches current documentation
4. Accurate code — AI uses the real, current API

Use Cases

• Framework migration — Upgrading to React 19? Get correct API usage
• New library adoption — Learn libraries with zero hallucination
• Version-specific code — Work with specific library versions
• API exploration — Discover what’s available in the current version

Getting Started

{
  "mcpServers": {
    "context7": {
      "command": "npx",
      "args": ["-y", "@upstash/context7-mcp@latest"]
    }
  }
}

Example

User: "use context7 — How do I create a streaming response in FastAPI 0.115?"

Agent → Context7: resolve_library("fastapi", version: "0.115")
Returns: Current StreamingResponse docs with correct imports

Agent generates code using the real, current API — not outdated training data.

Alternatives

• RAG systems — Custom documentation retrieval (requires setup)
• Cursor docs — Built-in docs for some frameworks
• Manual context — Copy-paste docs into prompts (tedious)