Whoever an agent reaches should know who sent it.

For the first time, software is going out into the world to act on our behalf. It writes to suppliers, books with vendors, signs up for services and talks to other companies’ agents. It does this at a scale no person could, and it does it in our name.

Every one of those exchanges begins with a question as old as messengers: who sent you? A letter carried a seal. A courier carried papers. The pigeons of the old post carried a ring on the leg with the name of their loft. Whoever received the message could tell where it had come from, and whom to hold to it.

Agents carry nothing. One arrives at an inbox, an API or a checkout, and the person or system on the other side has to guess. Is this an AI at all? Who does it work for? Is the message the one that was sent? Unable to tell, they do one of two things: refuse the agent, or trust it blindly. The first wastes everything agents could do. The second is how fraud scales.

This is not a problem for agents. It is a problem for everyone they reach, and for every honest company that sends one and cannot prove it. And it will not wait: from August 2026 the EU AI Act says people must be told when they are dealing with an AI. The law has started asking a question the internet has no way to answer.

So we are building the answer, and giving it away.

Pidgeon exists to give every agent a name that anyone can check: which company stands behind it, who it acts for, and that what it sent is what arrives. Not a badge we sell, but a layer of the internet itself, as plain and as free as the padlock in your browser. The web became trustworthy when encryption became free and automatic. The agentic web will become trustworthy when identity does.

What we believe

1. Identity is infrastructure, so it is free.

   Nobody pays to have a domain name resolve, or for a padlock in the address bar. An agent’s name should cost the same: nothing. A toll on being identifiable is a tax on honesty, and the agents that skip it are the ones you most need to see.

2. The domain vouches, not the platform.

   An agent acts for somebody, so somebody should stand behind it: the company whose name it carries, with its own domain and its own key. We do not decide who an agent is. We make it possible for the company that sent it to say so, in a way anyone can check.

3. Open, or it isn’t trust.

   A trust layer one company controls is a gate, and gates get closed. Post is an open protocol, written as an Internet-Draft for the IETF with test vectors for a second implementation. Pidgeon is one implementation. We would count it a success if there were many.

4. With the standards, never against them.

   Others are solving their part well. Google’s A2A says what an agent can do; Cloudflare’s Web Bot Auth signs its web requests. Post adds who it is and who it acts for, and travels inside both. The agentic web will be built from pieces that fit, not from one vendor’s stack.

5. Everything on the record.

   Every identity Pidgeon issues is written to a public, append-only log that anyone can read and check. If we ever vouch for the wrong agent, the world will be able to see it. A trust layer has to be accountable to the people who rely on it, starting with its builders.

6. People stay in charge.

   An identity is a leash as much as a name. Whoever sends an agent can see where it went, what it said and who checked it, and can revoke it in a moment. The point of naming agents is not to set them free. It is to keep someone answerable for them.

Where this goes

We imagine a near future in which agents do much of the work between companies, and nobody has to wonder who they are dealing with. Where a recipient can check any agent in a second, in the inbox or the API they already use. Where an honest agent is welcomed and an anonymous one is simply ignored. Where the trust that lets strangers do business with each other extends, intact, to the software acting for them.

That future needs a trust layer nobody owns. We are building it in the open, and we would like you to build it with us.

Pidgeon