Build apps for Banga

Apps add slash commands, native forms, interactive cards and full web pages to Banga chats. You host the app. The platform takes care of installing, permissions, drawing forms and cards, signing and delivery.

What you can build

Webhook apps

A user types a command such as /temp. The phone shows your form and the platform sends the answers to your HTTPS webhook. You reply with a card the user keeps to themselves or posts into the room.

Web apps

A page you host opens inside the app, full screen or as a sheet. The window.banga bridge gives it the user's per-app identity, a signed session token for your backend, a native main button and a way to post cards.

Room bots

A room's admin adds your app to a room. Your server then posts cards into it on its own, such as news, alerts or reminders, with a bot token.

One app can be all three. A manifest may declare a webhook, a web page and roomBot together.

How a command works

  1. The user types your command in a room and fills in the form your manifest declares. The phone draws the form natively.
  2. The platform checks the answers against your manifest again, so your webhook never receives values that break your own rules.
  3. The platform sends a signed POST to your webhook with the values and whatever the user allowed you to know.
  4. Your webhook answers within the time budget with a card, a short message, an error for the user, or the next step of a form.
  5. The platform checks the card against the contract, signs it and hands it to the phone. The user sees it privately, or confirms and posts it into the room.

What an app can know

  • Every user has a per-app id. It stays the same for your app, differs for every other app, and cannot be linked to the person's account, phone number or other apps.
  • Anything more needs a scope the user accepts when installing: name, language, a per-room reference, approximate location (only when the user chooses to share it for one use), and permission to offer cards to rooms.
  • No scope reveals the phone number, the real user id, room ids, room members or messages. Apps never read a room.
  • Room bots cannot be added to end-to-end encrypted rooms.

Where to go next

  • Getting started: build, publish and test a complete app in a few minutes.
  • Manifest: every field of the JSON document that describes your app.
  • Cards: blocks, actions, templates and who sees what.
  • Webhooks: requests, signatures, replies, multi-step forms and sealed answers.
  • Web apps: the JavaScript bridge and verifying session tokens.
  • Room bots: posting cards into rooms from your server.
  • Payments: the app wallet, the platform fee, and how apps will charge and pay users.
  • Limits and errors: rate limits, time budgets and what users see when something fails.