Official (Vendor)Active· 6d★ 4.3by Upstash

Context7

Upstash's Context7 MCP. Pulls version-specific library docs into your agent so it stops hallucinating outdated APIs.

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Safety & Trust

Delv Safety Grade: A

Score 84/100 · assessed 2026-04-28

Maintainer85

Permissions95

Supply chain70

Transparency88

Incidents100

Context7 is Upstash's documentation fetcher that pulls version-specific library docs into Claude's context window. The permissions model is excellent: read-only network requests to fetch documentation, no filesystem writes, no shell access, no secrets required. Upstash is a credible mid-tier vendor (serverless Redis/Kafka) with active maintenance. The supply chain is slightly weaker because installation uses npx without a traditional npm package, relying on their setup script. Transparency is strong with open source code, clear docs, and active GitHub presence. No known security incidents. The tool solves a real problem (API version hallucination) with minimal attack surface. Main risk is the npx-based install pattern and network dependency on Upstash's documentation service, but both are reasonable for this use case.

Lethal Trifecta (prompt-injection exposure)

TWO OF THREE

Private dataNo

Reads secrets, credentials, private files

Untrusted inputYes

Ingests web pages, PRs, issues, emails

External commsYes

Can send data outbound

Pulls library docs from registered sources. Generally curated; small input-axis risk in the long tail.

Green flags

Read-only network access, no filesystem or shell permissions
No environment variables or secrets required
Upstash is established vendor with active GitHub presence
Solves real problem (version-specific docs) with narrow scope
Open source with clear documentation and examples

Red flags

npx-based install without traditional npm package versioning
Network dependency on Upstash's external documentation service
No explicit rate limiting or quota documentation visible

Permissions requested

Outbound network

Assessed by Delv Editorial using public metadata. Grades are advisory and update as the ecosystem changes. They do not replace your own review of permissions and code before granting an agent access to sensitive systems.

Install

npx ctx7 setup

Review

Context7 solves a problem every agent user has hit: Claude confidently citing a deprecated API or mixing up versions of the same library. You ask for Next.js 15 code, it gives you 14 patterns. You want Postgres 16 syntax, it hallucinates 13. Context7 pulls version-pinned documentation into the agent's context window on demand, so it stops guessing. The workflow is clean. You run `npx ctx7 setup`, it drops a config into your MCP settings, and from then on you can ask Claude to fetch docs for a specific library and version mid-conversation. "Get me the Prisma 5.8 migration docs" becomes a tool call, not a web search. The agent gets the actual reference material, not a stale training snapshot from 2023. I've used it most when prototyping with fast-moving frameworks. Next.js 15 shipped with breaking changes to server actions, and Context7 let me pull the current docs without leaving the editor. Same for Drizzle ORM when I needed to check if a new adapter had landed. It's faster than tabbing out to read the docs yourself, and it keeps the agent honest. Quirks: it's only as good as the upstream docs it indexes. If a library has poor or incomplete documentation, Context7 won't magically fix that. It also adds latency to the first query while it fetches and chunks the docs, though subsequent calls are cached. The setup is trivial for Claude Desktop, but if you're running it in Cursor or Windsurf, you'll need to manually wire the MCP config. Who shouldn't bother: if you're working with stable, well-known libraries where the APIs haven't changed in years, this is overkill. If you're already copy-pasting docs into prompts manually, Context7 just automates that. But if you're building with anything that ships breaking changes quarterly, or you're tired of agents confidently lying about method signatures, this is worth the 30 seconds to install.

Verdict

Install it if you work with fast-moving libraries or need version-specific API references on tap. Skip it if you're only using mature, stable dependencies where the agent already knows the APIs cold. The setup is trivial, the upside is real, and it costs you nothing but a config line.

Good at

Stops agents hallucinating outdated or wrong API signatures by pulling current, version-pinned docs on demand.
Setup is one command and a config line, no API keys or external dependencies.
Caches fetched docs so repeat queries are fast.
Works across multiple MCP hosts, not just Claude Desktop.
Particularly useful for fast-moving frameworks like Next.js, Drizzle, or Prisma where breaking changes land often.

Watch out

Only as good as the upstream documentation it indexes, so poorly documented libraries stay poorly documented.
First fetch for a new library adds noticeable latency while it pulls and chunks the docs.
Manual config required for hosts beyond Claude Desktop, though it's still straightforward.
No offline mode, so you need a network connection for fresh doc pulls.

Use cases

Fetching the right Next.js 16 docs in-flow
Looking up a Postgres extension API on demand
Avoiding deprecated method names in generated code
Pinning a library version per project

Getting started

1. Run `npx ctx7 setup` in your terminal. It will guide you through adding the MCP server to your Claude Desktop or other host config. 2. Restart your MCP host (Claude Desktop, Cursor, etc.) so it picks up the new server. 3. In a conversation, ask Claude to fetch docs for a specific library and version, like "Get the Prisma 5.8 schema reference." You'll see a tool call to Context7. 4. The first fetch for a given library takes a few seconds while it pulls and indexes the docs. Subsequent queries are faster. 5. Watch out: if the library's docs are poorly structured or missing, Context7 can't invent better ones. Garbage in, garbage out.

Works with

Claude DesktopClaude CodeCursorWindsurfVS Code