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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

Build with AI

Build your first app

View .md

This walkthrough builds a private app that COHO hosts for you. Copy each prompt into your AI tool, adding your own details where it says so. Each prompt block has a copy button in its top-right corner.

  1. Check you’re connected

    Make sure your AI tool is connected to COHO and is working on the right organisation.

  2. Give your AI the Atrium ADK

    The ADK is the rulebook for Atrium apps: the spec, the rules and the design system in one file. Your AI needs it to build an app COHO will accept. You can also download it as ADK.md.

    Prompt
    Read the COHO Atrium ADK in full:
    https://docs.coho.life/atrium-developer/llms-full.txt
    For any screens, use the Atrium design system:
    https://docs.coho.life/atrium-design/llms-full.txt
    

    We'll build an Atrium app together. Start from the hello-go sample in
    https://github.com/CompanyForLife/atrium-app-samples/tree/main/samples/hello-go
    (it already has the Dockerfile COHO Hosting needs) and keep to the ADK exactly,
    especially signature verification (section 3). Don't do anything yet; tell me when you've read it.

  3. Describe your app

    Say what it should do in plain words: when it runs, what it does, and whether managers need a screen or settings.

    Prompt
    Here's the app I want: [describe it, for example: "when a tenancy starts,
    send the tenant a welcome message", "a panel that lists tenancies that
    started this week"].
    

    Before writing any code, explain in plain English:
    - which COHO events or schedules it will use
    - what it will read or change in COHO, and which capabilities that needs
    - whether it needs a panel inside COHO or a settings form
    Then wait for me to agree.

  4. Let your AI build it

    Prompt
    Go ahead and build it from the hello-go sample. Keep the health check,
    setup, disconnect and signature code from the sample. Check the signature
    code against the test vectors in section 3.1.1 of the spec and show me the result.

  5. Ask your AI to host it on COHO

    Your AI packages the app and asks COHO to build and run it. COHO’s tools make it show you a preview first: once for the permissions your app asks for, then for the app itself. It should only go ahead after you say yes each time.

    Prompt
    Package the app as a zip for COHO Hosting: include the Dockerfile, leave out
    anything that isn't source (dependencies folders, .git), and make the app listen
    on the port in the PORT environment variable.
    Then use the COHO MCP tools to create it as a PRIVATE hosted app
    (requestPublicListing: false). Follow the tools' own instructions: show me the
    permissions preview and the registration preview, and wait for my yes before
    confirming each one.

  6. Wait until it’s ready

    COHO builds your app. The stages are queued → fetching → building → pushing image → deploying → ready.

    Prompt
    Using the COHO MCP tools, check my app's provisioning state every minute or so
    until it's ready or failed. If it fails, tell me why in plain English.

  7. Connect it in the COHO Store

    Your AI can’t do this step for you yet. In COHO, open the Store, go to My apps, find your app and choose Connect.

    If connecting fails, COHO rolls it back. See Get help for what to try.

  8. Try it out

    • Use Run test in the Store to send your app a test event.
    • Check your app’s logs in the Store. Warnings and errors show as needing attention.
    • If your app has a panel, open it from the Store.

Changing your app later

Section titled “Changing your app later”
Prompt
I want to change my Atrium app: [describe the change].
Make the change, package a new zip, and use the COHO MCP tools to update the hosted
app (this rebuilds it). If only the name or description changes, update the listing
instead, which doesn't need a rebuild. Show me the preview and wait for my yes.

More ready-made prompts: Prompts to copy.