> ## Documentation Index
> Fetch the complete documentation index at: https://docs.manthan.systems/llms.txt
> Use this file to discover all available pages before exploring further.

# Policy Evaluation

> Deterministic, first-match rule evaluation over runtime signals.

<Info>**\[AVAILABLE]** — `packages/policy`, 61 tests. CLAIMS.md 2.2/2.3.</Info>

## Deterministic policy selection

The runtime executes exactly one, explicitly-referenced business policy — identified by
`PolicyReference { name, version, schemaVersion }` on the Business Transaction. It does
not discover policies, negotiate them, auto-select "latest," or substitute an alternative.
`PolicyRouter` loads by exact name+version; `PolicyValidator` checks the loaded policy's
identity before evaluation.

## Real policy shape

From `policies/vendor-payment/2.0.0/policy.json` (a real policy in this repo):

```json theme={null}
{
  "policyId": "vendor-payment",
  "policyVersion": "2.0.0",
  "schemaVersion": "1.0.0",
  "signalsSchema": {
    "vendorVerified": "boolean",
    "invoiceVerified": "boolean",
    "paymentApproved": "boolean",
    "sufficientFunds": "boolean",
    "paymentAmount": "number",
    "riskScore": "number"
  },
  "rules": [
    {
      "id": "approve-payment",
      "condition": {
        "all": [
          { "fact": "vendorVerified", "operator": "eq", "value": true },
          { "fact": "invoiceVerified", "operator": "eq", "value": true },
          { "fact": "paymentApproved", "operator": "eq", "value": true },
          { "fact": "sufficientFunds", "operator": "eq", "value": true },
          { "fact": "paymentAmount", "operator": "gt", "value": 0 },
          { "fact": "riskScore", "operator": "lte", "value": 20 }
        ]
      },
      "outcome": { "action": "approve", "reason": "..." }
    }
  ]
}
```

Rules are evaluated **sequentially, first match wins**. A trailing default rule (`"always":
true`) typically covers the reject-by-default case.

## What a Decision records

```typescript theme={null}
// packages/shared/src/domain/decision.ts
export interface Decision {
  readonly decisionId: string;
  readonly intentId: string;
  readonly policy: PolicyReference;
  readonly signals: Record<string, JsonValue>;   // captured for deterministic replay
  readonly outcome: DecisionOutcome;              // APPROVED | REJECTED
  readonly reason?: string;
  readonly evaluatedAt: Date;
}
```

The signals evaluated are captured on the Decision itself — this is what
[Replay](/replay/overview) reconstructs from.

## Fail-closed on missing prerequisites

`TrustChainValidationComponent` and `RuntimeEngine` refuse to execute when required trust
artifacts are missing or the Decision is not `APPROVED` (CLAIMS.md 2.4). See
[The Execution Pipeline](/architecture/execution-pipeline) for where this sits relative to
authorization signing.