whichlib

Dependency picker for coding agents: recommends, compares and scores GitHub repos with a verdict.

CommunityOnlineAPI key requiredGlobalFreeRead-only

What it can do

What data it sees

Do you need an account

An API key from the service settings is required

Dependency picker for coding agents: recommends, compares and scores GitHub repos with a verdict.

How to connect

How to connect whichlib to Claude

The server address to paste into Claude settings:

https://whichlib.com/mcp

Open Claude (claude.ai or the desktop app).
Go to Settings → Connectors.
Click Add custom connector.
Paste the server address copied below into Remote MCP server URL and click Add.
In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect whichlib to ChatGPT

The server address to paste into ChatGPT settings:

https://whichlib.com/mcp

Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
Open Settings → Connectors and click Create.
Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect whichlib to Cursor

The server address to paste into Cursor settings:

https://whichlib.com/mcp

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (3)

Raw names from tools/list. Only developers need these.

recommend_repos	Find the best open-source library for a need before adding a dependency. Give the need in plain words and get up to `limit` GitHub repositories ranked by fit = score x relevance to the need. Each result has a 0-100 score (momentum 40% (stars gained per week; without history, lifetime stars per week scaled by the npm/PyPI download trend), maintenance 25%, adoption incl. npm/PyPI weekly downloads 25%, license 10%), a tier (Strong >=75, Solid >=50, Watch >=25, Avoid <25; New for repos under 30 days old, too new to judge), a one-line verdict and the full breakdown. Use this when you do not yet have candidates; use compare_repos when you already have names. Makes 3 GitHub searches plus npm/PyPI lookups for the shortlist. Hosted: 50 free tool calls per day per user; send header X-GitHub-Token with your own GitHub token for unlimited use, or run the npm package locally (npx -y whichlib).
compare_repos	Compare 2-10 known GitHub repositories side by side, best score first: score and tier, stars, forks, open issues, last push, license, npm/PyPI weekly downloads (only when the registry links back to the repository) and a verdict. Each result has a 0-100 score (momentum 40% (stars gained per week; without history, lifetime stars per week scaled by the npm/PyPI download trend), maintenance 25%, adoption incl. npm/PyPI weekly downloads 25%, license 10%), a tier (Strong >=75, Solid >=50, Watch >=25, Avoid <25; New for repos under 30 days old, too new to judge), a one-line verdict and the full breakdown. Use this to choose between candidates you already have (for example zod vs valibot) or to check a dependency the project already uses; use recommend_repos to find candidates. One GitHub API call per repository plus npm/PyPI lookups. A repository that does not exist is listed under notFound and the rest are still compared; the call fails only if none can be fetched, or when GitHub's rate limit is reached or the token is rejected. Hosted: 50 free tool calls per day per user; send header X-GitHub-Token with your own GitHub token for unlimited use, or run the npm package locally (npx -y whichlib).
trending_repos	Discover projects: the most-starred GitHub repositories created in the last day, week or month, or with period "rising" repositories of any age that gained the most stars this week (like GitHub Trending; risingRank keeps that order). Optionally one language; each scored and returned sorted by score (starsRank keeps the stars order). Each result has a 0-100 score (momentum 40% (stars gained per week; without history, lifetime stars per week scaled by the npm/PyPI download trend), maintenance 25%, adoption incl. npm/PyPI weekly downloads 25%, license 10%), a tier (Strong >=75, Solid >=50, Watch >=25, Avoid <25; New for repos under 30 days old, too new to judge), a one-line verdict and the full breakdown. Not the right tool for picking a dependency, since new repositories have little maintenance history; use recommend_repos for that. One GitHub search (rising: one download of the daily list from raw.githubusercontent.com instead), plus one npm/PyPI lookup per repository when withDownloads is true. Hosted: 50 free tool calls per day per user; send header X-GitHub-Token with your own GitHub token for unlimited use, or run the npm package locally (npx -y whichlib).