Skip to content
COHO
Atrium dev docs

COHO docs

Atrium

COHO

v1.1
App samples
AI Building

Build an Atrium app with AI

One minimised file with everything an AI tool needs: how to work, the hard rules, the full app contract and the design system. Upload it to any LLM, then describe your app.

ATRIUM-AI-BUILD.mdMarkdown
  1. Upload the file to ChatGPT, Claude, Cursor or any AI tool (or paste its contents).
  2. Describe the app you want in plain English.
  3. Let the AI ask you for the API key when it needs one.
View the file
Auto

App sample

hello-go

View .md

Minimal Atrium web app using Go stdlib (net/http, crypto/hmac).

Default port: 5102 (PORT env override).

Run

Section titled “Run”
Terminal window
go run .

Your process reads ATRIUM_SETUP_SECRET to verify the first lifecycle.setup call. That is your app’s own setup secret: COHO mints it when you register the app and shows it once in the create response (regenerate it from My apps if lost). On Atrium Hosting, COHO injects the env var for you; when self-hosting, set it yourself before connecting. Set ATRIUM_DATA_DIR to persist connection secrets and config across restarts. Set ATRIUM_FRAME_ANCESTORS and ATRIUM_PARENT_ORIGIN to the Store origin for the environment you embed from (same value for both). Playground and production values are in developer spec §6; when unset, these kits default to http://localhost:4200 for local ng serve.

Endpoints

Section titled “Endpoints”

Same runtime contract as the other hello samples:

  • /health
  • signed /webhooks/atrium/*
  • signed native config at /config/schema and /config
  • signed iframe quick view at /ui
  • external app-owned page at /configure

COHO opens /ui and /configure with a short-lived signed launch URL that includes connectionReference, atriumUsageToken (person + organisation + connection JWT), and atriumSignature. Prefer Authorization: Bearer <atriumUsageToken> for interactive Public API calls from the quick view; keep the connection apiKey from lifecycle.setup for background/webhooks. See developer spec §6 / §8.

For local Store registration, use manifest.example.json.

Signature verification is pinned to the published test vectors in the app developer spec.