julianobarbosa/Context7

Context7

Query up-to-date, version-specific documentation and code examples directly from source libraries via Context7's documentation aggregation platform.

Why Context7

| Benefit | Description | |---------|-------------| | Current APIs | No hallucinated or outdated patterns - documentation comes from actual sources | | Version-Specific | Gets docs for exact library versions you're using | | Code Examples | Real, working code extracted from actual documentation | | Broad Coverage | 1000+ libraries including React, Next.js, Vue, Go, Python, Kubernetes, etc. |

Setup

# Navigate to tools directory and install dependencies
cd ~/.claude/skills/Context7/Tools
bun install

# Optional: Set API key for higher rate limits
export CONTEXT7_API_KEY="ctx7sk_your_key_here"  # Get at context7.com/dashboard

Available CLI Tools

| Tool | Purpose | Command | |------|---------|---------| | lookup | Full lookup (resolve + query) | bun src/cli/lookup.ts <library> <query> | | resolve | Find library ID | bun src/cli/resolve.ts <library> [query] | | query | Query docs by ID | bun src/cli/query.ts <library_id> <query> |

Quick Reference

Full Lookup (Recommended)

One command to resolve library and query documentation:

cd ~/.claude/skills/Context7/Tools
bun src/cli/lookup.ts react "useEffect cleanup function"
bun src/cli/lookup.ts next.js "app router middleware"
bun src/cli/lookup.ts kubernetes "deployment rolling update"

Step-by-Step (When Needed)

Step 1: Resolve Library ID

bun src/cli/resolve.ts react
bun src/cli/resolve.ts next.js "authentication"

Returns: Context7-compatible library ID like /facebook/react or /vercel/next.js

Step 2: Query Documentation

bun src/cli/query.ts /facebook/react "useEffect cleanup"
bun src/cli/query.ts /vercel/next.js "middleware configuration"

Returns: Relevant documentation snippets and code examples

Common Library IDs

| Library | Context7 ID | CLI Shortcut | |---------|-------------|--------------| | React | /facebook/react | react | | Next.js | /vercel/next.js | next.js, nextjs | | Vue | /vuejs/vue | vue | | Kubernetes | /kubernetes/kubernetes | kubernetes, k8s | | Go stdlib | /golang/go | go, golang | | Python | /python/cpython | python | | Node.js | /nodejs/node | node, nodejs | | TypeScript | /microsoft/typescript | typescript, ts | | Prisma | /prisma/prisma | prisma | | Tailwind | /tailwindlabs/tailwindcss | tailwind, tailwindcss |

Workflow Routing

| Workflow | Trigger | File | |----------|---------|------| | ResolveLibrary | "find library ID", "resolve library" | Workflows/ResolveLibrary.md | | QueryDocs | "lookup docs", "get documentation", "code examples" | Workflows/QueryDocs.md | | FullLookup | "help me with [library]", "how do I use [feature]" | Workflows/FullLookup.md |

Gotchas

These are real Context7 API behaviors that bite if you don't know about them. Add to this list whenever a query goes wrong in a way that wasn't already documented.

1. Library ID requires a leading slash. /facebook/react works; facebook/react fails with a cryptic "library not found." The error doesn't tell you the slash is missing.
2. The resolver is fuzzy and ranked, not deterministic. resolve.ts <name> returns multiple candidates ordered by an LLM-powered ranker that takes your optional context query into account. A narrow context can promote a less-canonical fork above the official repo. Always inspect the top match before passing the ID to query.ts.
3. Version pinning matters at major boundaries. Library IDs may include a version segment: /vercel/next.js/14.2.0. The bare ID resolves to whatever Context7 currently treats as "latest stable," which can lag behind real releases — asking about Next.js "app router" without a pin can return Next 13 docs. Pin the version when the framework changed shape across majors.
4. Public rate limits are tight. Without CONTEXT7_API_KEY, you'll hit limits in fewer queries than you expect. The "max 3 calls per question" tip in this skill is a defensive ceiling on Claude's behavior — it is not the real API budget. Set the API key from context7.com/dashboard for any sustained use.
5. Snippet truncation is silent. Long doc pages return excerpts, not full content. If a returned example references a function or symbol the snippet didn't define, do NOT guess what it does — re-query with a tighter, more specific question rather than fabricating the missing piece.
6. The known-IDs cache can go stale. Common libraries (react, next.js, kubernetes, etc.) shortcut to hardcoded IDs in Tools/src/lib/context7.ts and skip the resolver entirely. If an upstream project renames its repo or moves orgs, the cached ID becomes wrong and queries silently miss. To force a fresh resolve, use an alias the cache doesn't know.

Examples

Example 1: React Hooks Documentation

cd ~/.claude/skills/Context7/Tools
bun src/cli/lookup.ts react "useEffect cleanup function"

Output includes current React docs with cleanup pattern examples.

Example 2: Kubernetes Deployment Spec

bun src/cli/lookup.ts kubernetes "deployment spec rolling update strategy"

Output includes current K8s API reference for Deployment.

Example 3: Next.js App Router

bun src/cli/lookup.ts next.js "middleware authentication app router"

Output includes latest Next.js middleware documentation.

Example 4: Using in Claude Code Session

When you need documentation during a coding session:

User: "How do I implement server-side data fetching in Next.js 14?"

Claude runs:
  cd ~/.claude/skills/Context7/Tools && bun src/cli/lookup.ts next.js "server components data fetching"

Then synthesizes response with current patterns (Server Components, not old getServerSideProps)

Environment Variables

| Variable | Description | Default | |----------|-------------|---------| | CONTEXT7_API_KEY | API key for higher rate limits | None (uses public rate limits) |

Get your API key at context7.com/dashboard

Tips

• Be specific in your query for better results
• Max 3 calls per question - if you can't find it after 3 tries, use best available info
• Include version in query if you need specific version docs (e.g., "React 18 concurrent features")
• Combine with local context - use Context7 to verify APIs, then apply to your codebase
• Known IDs skip API - common libraries like react, next.js use cached IDs to skip the resolve step

Project Structure

Tools/
├── package.json          # Dependencies and scripts
├── tsconfig.json         # TypeScript configuration
└── src/
    ├── index.ts          # Library exports
    ├── lib/
    │   └── context7.ts   # Core API client
    └── cli/
        ├── lookup.ts     # Full lookup command
        ├── resolve.ts    # Library ID resolver
        └── query.ts      # Documentation query

API Reference

The TypeScript client can also be imported programmatically:

import { Context7Client, getKnownLibraryId } from "./src/index.js";

const client = new Context7Client({ apiKey: process.env.CONTEXT7_API_KEY });

// Full lookup
const result = await client.lookup("react", "useEffect hooks");
console.log(result.rawContent);

// Or step by step
const { bestMatch } = await client.resolveLibrary("react");
const docs = await client.queryDocs(bestMatch.id, "useEffect cleanup");