# Product Requirements — Flamethrower v0.1.0
## Goal
Provide a deterministic cognition ledger that uses `power_house` for verification and optionally `pent_house` for resonance behavior. Keep the code standard-library only beyond those two crates.
## Success metrics
- Same `(label, seed)` yields identical shard bytes.
- Core tests cover ≥80% of the engine and ledger logic.
- Quickstart works copy‑paste with no external services.
## Functional scope
1. Mint shard from `(label, seed)` → checksum and energy.
2. Verify shard by recomputing and comparing checksums.
3. Append-only ledger with a cumulative digest.
4. Minimal operations endpoints: `/healthz` and `/metrics`.
## Non-functional
- Input validation on labels and seeds.
- No secrets in the repository.
- Basic logging as line‑delimited JSON to stdout.
- Rollback by restoring a previous ledger file.