Briven/examples/counter

counter

the smallest possible briven app — one table, two functions, demonstrates the reactive query pipeline end-to-end without any UI complexity.

what's in here

counter/
├─ briven.json              project descriptor (filled by `briven link`)
├─ briven/
│  ├─ schema.ts             one table: counters (id, count)
│  └─ functions/
│     ├─ getCount.ts        reactive query · returns {id, count}
│     └─ increment.ts       mutation · upserts +1, returns new count
└─ README.md                you are here

try it in 30 seconds

# 1. authenticate (skip if you already have credentials stored)
briven login --project p_<id> --key brk_<...>

# 2. copy, link, deploy
cp -r examples/counter my-counter
cd my-counter
briven link
briven deploy

# 3. exercise the api
briven invoke getCount
briven invoke increment
briven invoke increment --body '{"by":5}'
briven invoke getCount

react client

import { BrivenProvider, useMutation, useQuery } from '@briven/react';

function App() {
  return (
    <BrivenProvider config={{ projectId: 'p_<id>', apiKey: 'brk_<...>' }}>
      <Counter />
    </BrivenProvider>
  );
}

function Counter() {
  const { data } = useQuery('getCount', {});
  const inc = useMutation('increment');
  return (
    <button onClick={() => inc({})}>
      count: {data?.count ?? '…'}
    </button>
  );
}

useQuery('getCount') subscribes to the counters table. When increment commits its UPDATE, postgres NOTIFY fires, the realtime service re-invokes the query, and every subscribed button re-renders with the new count.

Two browser windows side by side make the reactive nature obvious — increment in one, watch the other refresh in real time.

next steps

• per-user counters: extend increment to read ctx.auth.userId and use that as the counter id, so each signed-in user has their own row
• rate limit: the existing project rate-limit middleware already caps invokes per-tier; for stricter per-user limits, gate inside the mutation handler