Our picks

AnswerDotAI/llms-txt

The llms.txt proposal and its site, with a small Python package that turns an llms.txt into context for a model.

Why we picked it: It's the source: what an llms.txt should hold, from the people who proposed it, before any tool's take on it.

Helps you pass:

• llms.txt: defines the format our llms.txt check reads
• Docs in Markdown: proposes a Markdown copy of each page at the same address with .md added

last commit 24 Sep 2026 · Apache-2.0 · read in full 11 Nov 2026 · source

okineadev/vitepress-plugin-llms

A VitePress plugin that builds llms.txt, llms-full.txt and a Markdown copy of every page.

Why we picked it: If your docs run on VitePress, two of our checks become one plugin in your config. VitePress only.

Helps you pass:

• llms.txt: generates llms.txt at build time, with each page's description as its link note
• Docs in Markdown: writes a .md copy next to each page

last commit 10 Nov 2026 · MIT · read in full 11 Nov 2026 · source

google/schema-dts

TypeScript types for Schema.org JSON-LD, and a tool that generates them.

Why we picked it: Structured data is easy to get subtly wrong by hand. Types catch the mistakes before the page ships.

Helps you pass:

• Structured data: type-checks the JSON-LD you write; you still put the script tag in the page's HTML yourself

last commit 1 Nov 2026 · Apache-2.0 · read in full 11 Nov 2026 · source

meta/docusaurus

A static site generator for docs, blogs and project sites.

Why we picked it: Static HTML by default, so agents that don't run JavaScript read every page. llms.txt isn't built in.

Helps you pass:

• Readable without JavaScript: builds static HTML for every page, so an agent reads it without running JavaScript
• Sitemap: its default preset includes a sitemap plugin
• Meta description: turns each page's description front matter into its meta description
• Docs page: gives you a docs site to link from your homepage

last commit 6 Nov 2026 · MIT · read in full 11 Nov 2026 · source

withastro/starlight

A documentation site framework built on Astro.

Why we picked it: Docs with no client-side JavaScript by default. llms.txt comes from a community plugin on its plugins page.

Helps you pass:

• Readable without JavaScript: sends pages with no client-side JavaScript by default
• Sitemap: builds a sitemap once your site's address is set
• Meta description: uses each page's description for its metadata
• Docs page: gives you a docs site to link from your homepage

last commit 10 Nov 2026 · MIT · read in full 11 Nov 2026 · source

mixmark-io/turndown

A JavaScript library that converts HTML into Markdown.

Why we picked it: For docs that aren't on a framework with Markdown output: a small building block, not a whole fix.

Helps you pass:

• Docs in Markdown: turns your HTML pages into .md copies in your own build step; set codeBlockStyle to fenced

last commit 4 Nov 2026 · MIT · read in full 11 Nov 2026 · source

Redocly/redocly-cli

A command-line tool that lints, bundles and builds reference docs for OpenAPI files.

Why we picked it: One free tool covers three of our API checks in CI. Its usage telemetry is on by default: set REDOCLY_TELEMETRY=off.

Helps you pass:

• OpenAPI spec: lint validates your spec, and bundle joins a split one into a single file
• Every operation has an operationId: its operation-operationId rule flags every operation without one
• Errors have a schema: its operation-4xx-problem-details-rfc7807 rule asks 4xx responses for a problem+json schema

last commit 10 Nov 2026 · MIT · read in full 11 Nov 2026 · source

stoplightio/spectral

A JSON and YAML linter with ready-made OpenAPI rulesets, and room for your own rules.

Why we picked it: Good when you want your own API style rules beside the standard ones. A rule for error schemas is one you write.

Helps you pass:

• OpenAPI spec: its OpenAPI ruleset validates the spec's structure
• Every operation has an operationId: its operation-operationId and operation-operationId-unique rules

last commit 6 Nov 2026 · Apache-2.0 · read in full 11 Nov 2026 · source

asteasolutions/zod-to-openapi

Generates OpenAPI documents from Zod schemas and the routes you register.

Why we picked it: For TypeScript teams on Zod: the spec comes from schemas you already have.

Helps you pass:

• OpenAPI spec: generates the spec from your code, so it stays in step with it
• Errors have a schema: each response by status code takes a Zod schema, so your errors can have one

last commit 2 Oct 2026 · MIT · read in full 11 Nov 2026 · source

modelcontextprotocol/typescript-sdk

The official TypeScript SDK for MCP servers and clients.

Why we picked it: The reference implementation, from the protocol's own maintainers.

Helps you pass:

• MCP server: server libraries for local and Streamable HTTP servers
• Sign-in an MCP client can use: serves protected-resource metadata and answers with the challenge an MCP client follows to sign in

last commit 10 Nov 2026 · Apache-2.0 (code moving from MIT), CC-BY-4.0 for docs · read in full 11 Nov 2026 · source

modelcontextprotocol/python-sdk

The official Python SDK for MCP servers and clients, with an mcp command-line tool.

Why we picked it: The reference implementation for Python, from the protocol's own maintainers.

Helps you pass:

• MCP server: builds servers that offer tools, resources and prompts
• Sign-in an MCP client can use: serves the protected-resource metadata from its auth settings; you bring the token check and the sign-in provider

last commit 5 Nov 2026 · MIT · read in full 11 Nov 2026 · source

modelcontextprotocol/inspector

Tools for testing MCP servers: a web interface, a command-line client and a terminal interface.

Why we picked it: Test your server the way a client meets it, before an agent does.

Helps you pass:

• MCP server: connects to your server, lists and calls its tools, with exit codes for CI
• Sign-in an MCP client can use: its command-line client runs a real sign-in, so you see what an MCP client sees

last commit 5 Nov 2026 · Apache-2.0 (code moving from MIT), CC-BY-4.0 for docs · read in full 11 Nov 2026 · source

PrefectHQ/fastmcp

A Python framework for MCP servers, clients and interactive apps.

Why we picked it: A higher-level way to a Python server with sign-in. It works without the paid gateway its README mentions.

Helps you pass:

• MCP server: a server with its tools in a few lines of Python
• Sign-in an MCP client can use: an OAuth proxy for sign-in providers without dynamic client registration, like GitHub and Google

last commit 11 Nov 2026 · Apache-2.0 · read in full 11 Nov 2026 · source

vercel-labs/mcp-handler

Turns an MCP server into a web handler for Next.js, Nuxt, SvelteKit, Hono and more.

Why we picked it: If your site runs on one of these frameworks, an MCP server is a route, not a new service.

Helps you pass:

• MCP server: an MCP endpoint as a route in the web app you already run
• Sign-in an MCP client can use: protectedResourceHandler serves the RFC 9728 metadata, and withMcpAuth answers 401s the way clients expect
• Tools for browser agents: an experimental bridge offers allowlisted tools to in-page agents through WebMCP

last commit 5 Nov 2026 · Apache-2.0, per its package.json (no licence file in the repo) · read in full 11 Nov 2026 · source

webmachinelearning/webmcp

A W3C community group's draft for web pages to offer tools to browser AI agents.

Why we picked it: A draft that may still change. Read it before building, alongside our call on that check.

Helps you pass:

• Tools for browser agents: defines the document.modelContext API our check looks for, with guidance

last commit 11 Nov 2026 · W3C Software and Document License · read in full 11 Nov 2026 · source

anthropics/skills

Example Agent Skills, a template, and a skill for building and testing skills.

Why we picked it: See what a good SKILL.md looks like before you publish yours. Its examples are for learning from.

Helps you pass:

• An agent skill is published: the format, a template and worked examples, for publishing your own

last commit 6 Nov 2026 · Apache-2.0 for each skill but one, which has no licence file · read in full 11 Nov 2026 · source

astral-sh/uv

A fast Python package and project manager.

Why we picked it: One tool to build and publish a Python package, and a one-line install for your CLI.

Helps you pass:

• npm and PyPI packages: uv build and uv publish put your package on PyPI
• MCP server or CLI: your docs can show uv tool install for your CLI, a line our check counts

last commit 11 Nov 2026 · Apache-2.0 or MIT · read in full 11 Nov 2026 · source

OpenAPITools/openapi-generator

Generates client libraries, server stubs and docs from an OpenAPI spec.

Why we picked it: From a spec you have to SDKs in many languages. It needs Java, and don't feed it a spec you don't trust.

Helps you pass:

• npm and PyPI packages: generates TypeScript and Python clients from your spec, for you to publish

last commit 11 Nov 2026 · Apache-2.0 · read in full 11 Nov 2026 · source