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MPCP Authorization Chain

The authorization chain is the core visual model for MPCP. Each step produces a verifiable artifact that constrains the next. PolicyGrant, SignedBudgetAuthorization, and SignedPaymentAuthorization are cryptographically signed; verifiers validate all three signatures before accepting settlement. Machines spend within bounds established upstream—no per-transaction approval required.

PolicyGrant
↓
SignedBudgetAuthorization
↓
SignedPaymentAuthorization
↓
SettlementIntent
↓
Settlement

In fleet deployments, an optional FleetPolicyAuthorization (FPA) layer may sit above PolicyGrant.

Fleet Policy
↓
PolicyGrant
↓
SignedBudgetAuthorization
↓
SignedPaymentAuthorization
↓
SettlementIntent
↓
Settlement

What Each Step Does

Step Artifact Purpose
Fleet Policy Policy definition Rules: rails, assets, vendors, caps
PolicyGrant Session entry "This machine may initiate payment under these constraints"
SignedBudgetAuthorization Spending envelope "Up to X, on these rails, to these destinations"
SignedPaymentAuthorization Payment binding "This exact payment was authorized"
SettlementIntent Canonical description Deterministic settlement parameters (optional hash binding)
Settlement Executed transaction Rail executes payment; verifier checks chain

Key Idea

Approval moves upstream. The human or policy administrator grants a session and budget. The machine spends within that budget using pre-authorized intents. Settlement becomes a background operation.

See Also