# Who Builds Agents

A free directory of the companies building AI-agent and MCP tooling: one page per company, keyed by its domain, listing every MCP server it publishes to the Official MCP Registry. Companies only, never people.

Status: Live since 2026-10-31.

## What it is

whobuildsagents.com reads the Official MCP Registry every day and rolls each server up to the company that publishes it, mapping the server's registry name to the company's domain. Each company gets one page with its servers, whether each one answers when called, and its latest releases, sorted into categories by a keyword classifier rather than a model. A company can claim its page with a code sent to an address on its own domain, or remove it for good. It lists companies only: no founder, staff or personal profiles are collected.

## Why we built it

The registry is organised by server, not by company, so there was no page that answered the plain questions: who builds these, how many do they ship, and do they answer when called. The registry data is public under CC0, so we built that page. Our own listing sits in it under the same rules as everyone else's.

## What it proves

That we run a data product end to end: a daily ingest of the full registry, an identity rule with tests behind it, an hourly check that only counts a server as live when it answers like one and never calls it down on a timeout, and a claim and removal flow that keeps the privacy lines we hold ourselves to.

## Facts

- **Companies listed: 17,789** — As of 2026-11-03. The live count is on the site and in its llms.txt. (source: whobuildsagents.com/llms.txt (read 2026-11-03))
- **MCP servers: 22,906** — Published by those companies to the Official MCP Registry; 21,098 of them run remotely. As of 2026-11-03. (source: whobuildsagents.com/llms.txt (read 2026-11-03))
- **Categories: 22** — Assigned by a tested keyword classifier, recomputed after each daily ingest. No model, no per-company cost. (source: whobuildsagents.com/llms.txt (§Categories), whobuildsagents/src/lib/categories.ts)
- **People listed: 0** — Companies only, never people. (source: whobuildsagents/README.md)

## Links

- [Site](https://whobuildsagents.com)
- [How it is built](https://runs-on.dev/blog/2026-11-01-who-builds-agents-a-directory-of-mcp-companies)
- [Our own listing](https://whobuildsagents.com/advancelabs.dev)

License: Registry data CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0/)
Platforms: Web

— An Advance Labs instrument. https://advancelabs.dev/lab/whobuildsagents