Step 1: name → Context7 library ID

Pre-computed context

Installed CLI version: !ctx7 --version 2>/dev/null || echo "not installed (run: npm install -g ctx7@latest)"

MCP availability: check your own tool list — if mcp__context7__resolve-library-id / mcp__context7__query-docs are present, the MCP path is configured.

Purpose

A primary source of up-to-date library documentation. Two equivalent interfaces: CLI (ctx7) via npm, and the Context7 HTTP MCP server (mcp__context7__*) when the consuming project has it configured. Both read the same backend. Pick by workflow (see When to use CLI vs MCP).

Philosophy: training data is stale by the time you use it. Library APIs, framework defaults, best practices change. Before claiming how a library works, verify against Context7 — even for libraries you "know."

Actions

Action	When	Loads
lookup <library> <query> (default)	User asks about a library	context/lookup.md
update	Drift check + CLI upgrade + upstream skill changes	context/update.md

If the argument is bare (no action keyword), treat as lookup.

First-time setup — CLI install, CONTEXT7_API_KEY auth, optional MCP server wiring, and the Windows Git Bash gotcha — lives in its own skill: run /context7:setup.

Lookup (happy path)

Two-step: resolve library name → fetch docs with resolved ID.

# Step 1: name → Context7 library ID
ctx7 library "<name>" "<question>"
# Step 2: ID → docs (Windows Git Bash: prefix with MSYS_NO_PATHCONV=1 — see context/cli.md)
MSYS_NO_PATHCONV=1 ctx7 docs "<libraryId>" "<question>"

Equivalent via MCP when the consuming project has the Context7 MCP server configured (no Windows gotcha, cleaner output, returns ~1.5-2× more content):

mcp__context7__resolve-library-id(libraryName: "...", query: "...")
mcp__context7__query-docs(libraryId: "/org/project", query: "...")

You MUST call library / resolve-library-id first to get a valid ID, UNLESS the user provides one in /org/project format. One concept per query — when a question spans several independent topics, run a separate lookup per topic. Do not run more than 3 lookup commands per topic — if you cannot find what you need, fall back to training knowledge and tell the user Context7 didn't cover it.

Do not include sensitive information (API keys, passwords, credentials) in queries — sent to the Context7 backend.

Details: query-writing, result selection, version-specific IDs, common mistakes → context/lookup.md

When to use CLI vs MCP

Both read the same backend — results equivalent in substance. Pick by workflow.

Use the CLI (ctx7) when	Use the MCP (mcp__context7__*) when
Piping into grep, jq, head, a file	Conversational lookup where the model picks the tool naturally
Dumping large docs to disk (> docs.md) instead of context	Default docs depth matters (MCP returns ~1.8× more content per call)
Scripting, loops, Bash one-liners	Clean markdown output (no ANSI codes)
No MCP server configured, or mcp.context7.com blocked	Zero Windows Git Bash ceremony (no MSYS_NO_PATHCONV=1)
Structured extraction (--json)	Auto-discoverable from the model's tool list

More: context/cli.md, context/mcp.md

Update

Two upstream dependencies can drift: the ctx7 npm package, and Upstash's reference skill content. Aggregate-level stale-tracking via metadata.upstream-version + metadata.synced in the frontmatter above; the verbatim upstream baselines under vendor/ refresh together.

When CLI or upstream skill content drifts:

bash "${CLAUDE_PLUGIN_ROOT}/skills/lookup/scripts/update.sh"        # check only
bash "${CLAUDE_PLUGIN_ROOT}/skills/lookup/scripts/update.sh" --fix  # apply CLI upgrade

Script (a) reports installed vs latest ctx7 version, (b) fetches latest upstream find-docs/SKILL.md and context7-cli/SKILL.md from upstash/context7, (c) diffs against the vendor/ baselines, (d) if different, reports NEW upstream guidance for manual integration into this skill. The script does NOT auto-overwrite this SKILL.md — customizations (Windows gotcha, CLI-vs-MCP guidance, action dispatch) must be preserved.

Full protocol (merge strategy, what to preserve, maintainer-only baseline refresh) → context/update.md

What this skill does NOT do

• Does not replace multi-source research — use your research workflow for architecture decisions or anything needing cross-referenced sources. This skill is library-doc retrieval only
• Does not refactor code — retrieves docs. User's question shapes what comes back
• Does not cache content locally — docs fetched fresh each call. vendor/ baseline is verbatim upstream for skill-content drift detection only, not doc retrieval (do NOT read vendor/ for normal lookup invocations; only when running the update action)
• Does not auto-overwrite on update — update is advisory. User approves any merge before changes land

Gotchas

• Windows Git Bash: ctx7 docs /org/project "..." gets path-mangled to C:/Program Files/Git/org/project. Always prefix with MSYS_NO_PATHCONV=1. ctx7 library is unaffected. Full detail: context/cli.md
• Prefer the CONTEXT7_API_KEY env var over ctx7 login: ctx7 login triggers browser OAuth and writes a token to ~/.ctx7/ — the env var is simpler and portable across machines. See context/cli.md
• No content tuning: CLI has no --tokens / --limit flag. Default depth is server-controlled. For more content per call, prefer MCP (returns ~1.8× more by default)
• Don't run ctx7 skills install into .claude/skills/: this plugin owns the Context7 lookup surface. Installing Upstash's find-docs skill alongside creates a parallel surface that fragments lookups and drifts independently