Artifact Lifecycle
MPCP artifacts flow through a defined lifecycle from policy evaluation to settlement verification.
Pipeline
Fleet Policy
↓
PolicyGrant
↓
SignedBudgetAuthorization
↓
SignedPaymentAuthorization
↓
SettlementIntent
↓
Settlement
Each artifact constrains the next. Downstream artifacts must be subsets of upstream constraints.
Artifact Roles
| Artifact | Issued By | Purpose |
|---|---|---|
| PolicyGrant | Fleet/service policy | Initial permission envelope; rails, assets, caps |
| SBA | Vehicle wallet | Session-level spending envelope |
| SPA | Vehicle wallet | Binds specific payment to quote and policy |
| SettlementIntent | Vehicle wallet | Canonical settlement description (optional hash in SPA) |
| Settlement Result | Settlement rail | Confirms execution |
Typical Lifecycle
- Pre-session — PolicyGrant issued and stored (fleet backend, vehicle wallet)
- Session entry — Vehicle loads PolicyGrant, may issue SBA
- Payment request — Service requests payment; vehicle validates policy and budget
- Authorization — Vehicle creates SettlementIntent, signs SPA
- Verification — Service verifies MPCP chain
- Settlement — Payment executes on rail
- Reconciliation — Settlement verified against authorization
Storage
Artifacts may be stored in:
- Fleet backend — Authoritative PolicyGrant; audit logs
- Vehicle wallet — Operational PolicyGrant, SBA, SPA, receipts
- Service provider — Received authorizations, verification results, receipts
- Settlement rail — Transaction record (authoritative)
See Also
- Reference Flow — End-to-end EV charging scenario with timeline
- Protocol specs — Full artifact specifications