context7-docs

Context7 Documentation Lookup

When you need documentation for a library, framework, or API - fetch it instead of relying on training data. This prevents hallucinated function signatures and outdated API patterns.

When to Use

• Implementing with a library you're not 100% sure about
• User asks to use a specific library version
• You're about to write code using an API and want to verify it exists
• Error suggests an API has changed since your training data

Workflow

1. Resolve library ID: Use mcp__context7__resolve-library-id with the library name
2. Fetch docs: Use mcp__context7__get-library-docs with the resolved ID
3. Apply: Use the fetched documentation to write correct code

Example

# Step 1: Resolve
mcp__context7__resolve-library-id("fastapi")

# Step 2: Fetch relevant docs
mcp__context7__get-library-docs(library_id="...", topic="dependency injection")

# Step 3: Write code using real API signatures

Rules

• Fetch docs BEFORE writing code for unfamiliar APIs
• Don't fetch docs for standard library or well-known stable APIs
• Keep fetched content focused (specify topic) to minimize context usage
• Always specify a focused topic parameter in query-docs — prefer specific queries (e.g., "dependency injection") over broad library-wide fetches
• If Context7 is unavailable, note the uncertainty in your response

MCP Configuration

Add to .mcp.json or settings.json if not already configured:

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