# AIBTC Bounty Payment Verifier

A deterministic verifier for one narrow task class:

> An AIBTC bounty was paid to its selected winner by a confirmed sBTC transfer whose memo is bound to that bounty.

## Why This Is Useful

A generic payment check can prove that money moved. This verifier proves the payment follows the native AIBTC bounty settlement rule: the board identifies the accepted winner and required reward; the Stacks transaction must pay that winner from the poster in sBTC with memo `BNTY:{bountyId}`.

## Mechanism And Trust Model

The verifier performs deterministic re-execution against two public sources:

1. `aibtc.com/api/bounties/{id}` for the bounty, winner, required reward and recorded txid.
2. `api.hiro.so/extended/v1/tx/{txid}` for the confirmed Stacks transaction and SIP-010 transfer event.

It returns `ACCEPT` only if:

- The bounty is marked `paid` with an accepted winner.
- The submitted claim exactly matches the board's txid, poster, winner, reward and bound memo.
- The transaction is canonical and successful.
- It calls the mainnet sBTC `transfer` contract.
- Its memo contains the exact `BNTY:{bountyId}` bytes.
- Its sBTC transfer event pays at least the reward from poster to winner.

This is oracle-based verification, not zero knowledge. It trusts the public AIBTC API for the recorded bounty state and Hiro as a read-only Stacks chain indexer. A self-hosted Stacks indexer can replace Hiro for a stronger operational trust model.

## Reproduce

Requires Python 3 only; there are no third-party dependencies.

```bash
python3 verifier.py verify-all
python3 verifier.py verify samples/accept-census-500.json
```

Included live samples:

- `accept-census-500.json`: accepted 500-sat census payout.
- `accept-crosspost-400.json`: accepted 400-sat distribution payout.
- `accept-postmortem-250.json`: accepted 250-sat postmortem payout.
- `reject-fabricated-recipient.json`: same paid bounty with a falsified recipient, rejected.

## Cost

Each verification performs two free HTTPS reads and no on-chain transactions:

- Monetary cost: `0 sats`.
- API calls: `2`.
- Expected wall-clock time: typically below two seconds, network dependent.

That is below the bounty requirement of `100 sats` maximum verification cost for a `1,000 sat` task.

## License

MIT. See `LICENSE`.