Context7

Skill alebgl77/claude-inc/skills/context7

Anti-hallucination protocol for library APIs — resolves the exact installed version from the lockfile, fetches current official docs (Context7 MCP if installed, web fetch otherwise), quotes the doc before writing any code, and pins the version in output. Use when code touches a fast-moving library (Next.js, React, LangChain, Prisma, Tailwind), when the user says "check the actual docs" or "what's the current API for X", or after any deprecation or breaking-change error.From its SKILL.md

Install

npx -y skills add alebgl77/claude-inc --skill context7

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

8 stars8 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

SKILL.md

3.7 KB, 782 tokens by cl100k_base, as published. Nobody here has run it

Context7 — Docs Fetcher

"Live library docs"

Trained knowledge ages; your dependencies don't wait. The docs are the source of truth — memory is only a hint.

When to use

Writing code against fast movers — Next.js, React, LangChain, Prisma, Tailwind — where trained knowledge is stale by default
"Check the actual docs before you write this" / "is this still the right API in v15?"
"This worked in v4 but breaks in v5" — any deprecation warning or breaking-change error
Choosing between API generations — "app router or pages router way?"
Before adding a dependency — verify the current install command and quickstart, not remembered ones

Workflow

List the libraries the task touches and flag fast movers (any project with major releases in the past year).
Resolve the exact installed version from the lockfile — package-lock.json, pnpm-lock.yaml, yarn.lock, poetry.lock, uv.lock, Cargo.lock, go.sum. Grep the lockfile itself; never trust manifest ranges or memory.
Fetch current docs for that version. Optional upgrade: with the Context7 MCP server installed, call resolve-library-id then get-library-docs. Otherwise WebFetch/WebSearch the official docs, changelog, and migration guide — official sources only.
Quote the relevant passage verbatim — signature, options, gotchas — before writing a single line of code.
Write the code against the quoted signature, exactly; no extra parameters from memory.
Pin the library and version in the output header; note any deprecations between installed and latest.
If lockfile and docs disagree (docs describe a newer API), surface it: ship code for the installed version plus the upgrade path.
If the doc page covers multiple versions, confirm the version selector matches the installed one before quoting.
No network at all? Say so loudly, mark the code UNVERIFIED, and list exactly which signatures must be checked before merge.

Output format

Library: <name>@<exact version>   (source: <lockfile>)
Docs: <official URL or Context7 library ID>   (fetched <date>)

Doc quote:
> <verbatim excerpt covering every API surface used below>

Code:
<snippet that matches the quote>

Version notes: <deprecations, breaking changes, upgrade advice — or "none">

Quality bar

Version came from a lockfile, not a guess or a ^range
Doc passage quoted verbatim before code was written
Code uses only the quoted, verified surface — zero from-memory APIs
Library and version pinned in the output header
Source is official (docs, changelog, repo) with fetch date recorded
Docs-vs-lockfile disagreements surfaced with an upgrade path

Example

Ask: "Add streaming to our LangChain chat endpoint."

Run: lockfile shows langchain==0.3.14; 0.3 docs fetched; quoted the astream_events signature and event schema; wrote the endpoint against it; flagged the deprecated alternative and the migration notes.

Library: langchain==0.3.14   (source: uv.lock)
Docs: python.langchain.com/docs/how_to/streaming   (fetched 2026-07-11)
Doc quote: > "astream_events(version='v2') yields event dicts with event, name, data"
Version notes: astream_log deprecated in 0.3; event payload keys renamed in 0.4

Credits

Inspired by Upstash Context7.

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.

Gives 0 of the 12 instructions most docs writing skills give in 782 tokens

Counted across 1,951 of the 3,904 authors here whose files we hold, read 2026-09-06

Use third-person for skill descriptionsin 54 of 1951, across 35 files
Start descriptions with Use whenin 43 of 1951, across 29 files
Run baseline scenarios before writing any skillin 40 of 1951, across 26 files
Use active voicein 40 of 1951, across 36 files
Map file responsibilities before defining tasksin 36 of 1951, across 29 files
Use checkbox syntax for tracking stepsin 35 of 1951, across 27 files
Ask one question at a timein 35 of 1951
Offer execution options after saving the planin 33 of 1951, across 24 files
Include complete code in every stepin 33 of 1951, across 27 files
Design units with clear boundaries and interfacesin 31 of 1951, across 23 files
Announce the skill usage at the startin 30 of 1951
Verify agent compliance after adding the skillin 29 of 1951, across 17 files

Said here and by no other author read

Identify fast-moving libraries in the task
Resolve exact library versions from lockfiles
Quote relevant documentation passages verbatim
Pin library and version in output header
Surface disagreements between lockfile and documentation
Mark code as unverified if network is unavailable

Grouped from the skills themselves: near-identical wordings counted once, and counted by distinct author, so one author publishing three of these counts once. Length counted with cl100k_base; the agent that loads this file may tokenize it differently.