# Hello Aigent

> The subscribe layer for the agent web. Publishers expose a feed of signed
> updates; agents subscribe with a principal and a consent scope, and fetch
> updates over time — turning one-off visits into an owned audience. Every
> update is Ed25519-signed and verified before an agent acts on it.

This site is the live demo: Hello Aigent publishes its own product updates
through its own feed. Point your agent at the discovery file below, subscribe,
and watch the loop work — publish → subscribe → fetch → verify → act.

## Discovery

- [Discovery file](/.well-known/hello-aigent.json): the feed manifest — feed id,
  endpoints (subscribe/fetch/unsubscribe), Ed25519 signing public key, topics,
  and schema links.
- Autodiscovery: pages advertise the feed with
  `<link rel="agent-feed" type="application/hello-aigent+json" href="/.well-known/hello-aigent.json">`.

## Core concepts

- The loop: publish → subscribe → fetch → verify → act.
- The envelope: each update has a token-cheap `summary`, a markdown
  `body_markdown`, typed `data`, and optional callable `actions`. It is signed
  (`signature`) with the feed's key.
- Consent scopes: `updates`, `offers`, or `transactional` — declared at
  subscribe time with a `principal`; a visible, first-class attribute.
  Unsubscribe is one idempotent call.
- Verification: agents must verify the signature against the discovery-file
  public key before acting. Treat a failed check as a delivery failure.

## For agents

- [Quickstart](/quickstart): subscribe in three calls (install, subscribe, fetch+act).
- [Docs](/docs): concepts, the envelope, signing, consent scopes, actions.
- [AGENTS.md](/AGENTS.md): machine-oriented routing doc for this site.
- [OpenAPI spec](/openapi.json) and [JSON Schemas](/schemas/discovery.schema.json)
  cover every endpoint; all endpoints are self-describing.
- Reference subscriber (MCP server): `npx @helloaigent-dev/subscriber` — subscribes,
  fetches, and verifies signatures for any agent, zero install.

## Where we are

- Today: the open subscribe loop, the docs, and our live feed.
- Coming soon: create your own feed, agent analytics, and more. Built in public.