a2a-market-compute-ledger

# a2a-Market Compute Ledger Build and operate the compute ledger module for RealMarket A2A runtime. Current status: scaffold-first skill for early registration. Keep APIs stable, add production logic incrementally. ## Scope - Own `ComputeAccount` domain object, balance snapshots, and immutable transaction journal. - Support reserve/freeze before negotiation and final debit after order confirmation. - Emit billing events to event bus for reputation, websocket push, and finance logs. ## Suggested Project Layout - `app/domain/entities/compute_account.py` - `app/application/services/billing_service.py` - `app/infrastructure/db/ledger_repository.py` - `app/infrastructure/tasks/reconcile_ledger.py` ## Minimum Contracts (MVP P0) 1. `freeze(account_id, amount, reason)` returns hold id and expiry. 2. `capture_hold(hold_id, order_id)` converts hold to settled charge. 3. `release_hold(hold_id)` unlocks unused balance. 4. `list_ledger_entries(account_id, from_ts, to_ts)` returns ordered journal records. ## Event Mapping - On hold created: emit `INTENT_CREATED` + billing extension payload. - On charge captured: emit `ORDER_CREATED` and settlement payload. - On charge finalized: emit `PAYMENT_SUCCEEDED`. ## Guardrails - Use integer minor units for money; avoid float math. - Enforce idempotency key on every mutating operation. - Keep journal append-only; never rewrite posted entries. ## Implementation Backlog - Add double-entry validation rules. - Add monthly statement export and audit tooling. ## Runtime Implementation - Status: implemented in local runtime package. - Primary code paths: - `runtime/src/domain/compute-ledger.js` - Validation: covered by `runtime/tests` and `npm test` in `runtime/`.