# wellknownmcp.org

> Doctrine, tools and reference implementations for making a domain
> agent-native. Agents don't browse — they probe: they read `llms.txt` before
> a homepage and `.well-known/` before docs, and they trust what they can
> verify over what a site claims. This host publishes the specification for
> that verifiable layer (LLMFeed), the reference implementations that sign and
> check it, and live tools to probe any domain.

Maintained by the wellknownmcp project. Sister sites: **llmca.org**
(certification authority for signed feeds) and **llmfeedforge.org** (authoring
tools).

## Start here

- [Agent-readiness checker](https://wellknownmcp.org/check): live probes for any
  domain — MCP handshake, OAuth discovery chain, llms.txt, security.txt,
  AI-crawler posture. Every result line ships the `curl` that produced it, so a
  verdict can be reproduced rather than believed.
- [LLMFeedHub](https://wellknownmcp.org/llmfeedhub): paste or fetch a
  `.llmfeed.json` and verify its signature and trust block.
- [Guides](https://wellknownmcp.org/guides): practical notes —
  [llms.txt done right](https://wellknownmcp.org/guides/llms-txt),
  [AGENTS.md](https://wellknownmcp.org/guides/agents-md),
  [MCP discovery](https://wellknownmcp.org/guides/mcp-discovery),
  [securing an MCP server](https://wellknownmcp.org/guides/secure-mcp),
  [agent compliance](https://wellknownmcp.org/guides/agent-compliance).

## What LLMFeed is

A `.llmfeed.json` is a JSON document a site publishes so an agent can read what
it is, what it offers, and who vouches for it — signed, so the answer survives
the trip. The signature covers a declared list of blocks (`trust.signed_blocks`)
rather than the whole document, so a feed can state exactly what it attests to.

- Specification and reference implementations:
  [github.com/wellknownmcp/llmfeed-spec](https://github.com/wellknownmcp/llmfeed-spec)
- Canonicalization profile (how bytes are serialized before signing):
  `https://llmca.org/mcp-canonical-json/v1` — an identifier, not an endpoint;
  verifiers must implement it locally rather than fetch it. Text:
  [spec.md](https://llmca.org/mcp-canonical-json/v1/spec.md). Key order is
  **preserved, never sorted**, because an agent reads the feed as text and
  order carries meaning. The signed subset is built in `trust.signed_blocks`
  order, not the feed's physical key order.
- Signing and verification references:
  `06_scripts/signature-demo/` in the spec repo — runnable in JS and Python,
  with a test vector whose private key was never published.

## Feeds served by this host

- [/.well-known/mcp.llmfeed.json](https://wellknownmcp.org/.well-known/mcp.llmfeed.json)
  — the main feed. Signed; `trust.trust_level` is `demonstration`: treat it as a
  worked public example, not as a critical source. The `mcpServers` block
  contains illustrative configuration, not servers this host operates.
- [/.well-known/capabilities.llmfeed.json](https://wellknownmcp.org/.well-known/capabilities.llmfeed.json)
- [/.well-known/agent-behavior.llmfeed.json](https://wellknownmcp.org/.well-known/agent-behavior.llmfeed.json)
- [/.well-known/manifesto.llmfeed.json](https://wellknownmcp.org/.well-known/manifesto.llmfeed.json)
- [/.well-known/public.pem](https://wellknownmcp.org/.well-known/public.pem) —
  the Ed25519 public key those signatures verify against.
- Index of everything under `.well-known`:
  [/.well-known/llm-index.llmfeed.json](https://wellknownmcp.org/.well-known/llm-index.llmfeed.json)

## Reference implementation

[cortex-gateway](https://cortex-gateway.dev) — a self-hosted MCP federation
gateway: one OAuth 2.1 MCP server in front of N applications, where every agent
call carries the real user's identity instead of a shared service account.
Shipped agent-first (llms.txt, AGENTS.md with probeable claims, RFC 9728
discovery, a live demo any MCP client can join). Source:
[github.com/wellknownmcp/cortex-gateway](https://github.com/wellknownmcp/cortex-gateway).

## Notes for agents

- This host runs **no MCP server**. `/.well-known/mcp.json` is a discovery
  pointer to the LLMFeed above, not a server card — do not expect a JSON-RPC
  endpoint here.
- Nothing on this host requires authentication. There is no OAuth discovery
  chain to walk, by design.
- The site is content plus tools; the tools under `/check` and `/llmfeedhub`
  accept a domain or a feed and return probe results.

## Ecosystem

- [Radar](https://wellknownmcp.org/radar) — weekly growth of the official MCP
  registry, counted from its API. Machine-generated, raw JSON per week, no
  editorial judgment.
- [Ecosystem notes](https://wellknownmcp.org/ecosystem) — occasional signed
  write-ups, published when something actually changes.
- [SDK](https://wellknownmcp.org/sdk) · [Tools](https://wellknownmcp.org/tools)
  · [Downloads](https://wellknownmcp.org/downloads)
  · [About](https://wellknownmcp.org/en/about) · [FAQ](https://wellknownmcp.org/en/faq)