context7

name	context7
description	Use before writing or referencing any stack library — fetches version-accurate docs via the context7 MCP server so call signatures, hooks, and APIs match what is installed. Invoke on first usage of any non-none slot library, on any non-trivial Next.js API, or when uncertain whether an API is current.

context7 — fetch version-current docs before writing stack-library code

Purpose

The context7 MCP server provides version-accurate library documentation on demand. Before writing code that uses a stack library, resolve the library ID and fetch targeted docs to ensure your call signatures, hooks, and API surface match the version installed in this project.

When to invoke

• First usage of any non-none library from auth, state, http, data-fetching, forms, validation, i18n, or testing slots in a new file
• Any non-trivial Next.js API usage (app router, server actions, middleware, metadata)
• When uncertain whether an API signature is current
• When a type error or runtime error suggests an API mismatch

How to invoke

1. mcp__context7__resolve-library-id — resolve the canonical library ID from the package name
2. mcp__context7__get-library-docs — fetch targeted docs using the resolved ID and a specific topic

Always resolve first. Never call get-library-docs with a guessed ID.

Stack

Slot	Package	Suggested topics
state	zustand	create, slices, persist, selectors
http	ky	instance, hooks, retry, timeout
data-fetching	@tanstack/react-query	useQuery, useMutation, queryClient, ssr hydration
forms	react-hook-form	useForm, Controller, resolver, zodResolver
validation	zod	schema, refine, transform, discriminated union
i18n	next-intl	useTranslations, getTranslations, routing, middleware
testing	vitest	mock, spy, setup, coverage
next	next	app router, server actions, middleware, metadata

Anti-patterns

• Don't call get-library-docs without first resolving the ID via resolve-library-id.
• Don't fetch the entire library doc when a topic will do.
• Don't cache mentally across sessions — re-fetch when uncertain.