# CAGE-Compatible Governed Execution

URL: https://docs.nexart.io/docs/governed-execution/cage

Integrate a CAGE governance producer with NexArt: verified baseline, routes, accepted and rejected graph cases, and how to verify Node evidence independently.

NexArt Node0.30.1@nexart/governed-execution0.4.2

CAGE emits a `provider_02` `AttestationBundle`. NexArt seals it as `cer.governed.execution.v1` under the `cage-governance-v1` profile. CAGE is described here as a reference producer. The NexArt package is not endorsed by, sponsored by or affiliated with Google or CAGE.

## Verified interoperability baseline

| Item | Value |
| --- | --- |
| Node | 0.30.1 |
| Governed SDK | 0.4.2 |
| Authenticated submission | POST /api/attest |
| Stateless verification | POST /v1/cer/verify |
| Key discovery | GET /.well-known/nexart-node.json |
| Cyclic static topology | Accepted |
| Acyclic concrete lineage | Required |
| HITL parent subset | Accepted |
| Omitted-node ancestor contraction | Accepted |
| Illegal concrete edge | Rejected: TOPOLOGY_ERROR / ILLEGAL_EXECUTED_EDGE |
| Dangling parent reference | Rejected: CAUSAL_ERROR |
| Malformed stateHash | Rejected: SCHEMA_ERROR |

## Validation layers for a successful CER

```
certificateIntegrity: valid
cageSchemaValidity:   valid
causalGraphValidity:  valid
topologyValidation:   valid | not-supplied
resourceSafety:       valid
```

## Independent verification by the producer

- Recompute the certificate hash using RFC 8785 JCS and SHA-256.
- Verify the receipt signature over canonical `JCS(receipt)`, the whole receipt.
- Verify the verification-envelope signature over the canonical `{ attestation, bundle }` projection, using your own expected whitelist.
- Select the signing key by `receipt.attestorKeyId` from `GET /.well-known/nexart-node.json`.

## Runtime interoperability evidence

Production interoperability validation reported by the CAGE project: 19/19 over-the-wire checks passed against NexArt Node 0.30.1 and `@nexart/governed-execution` 0.4.2.

- This confirms observed interoperability.
- It does not prove deployed Git commit provenance.
- It is not a general security audit.
- It does not prove automatic public discoverability.

The request and response contract is documented separately from the inspected release source in the Governed Attestation Contract.

## Boundaries

- `stateHash` is an opaque producer commitment; NexArt does not receive the private AgentState preimage.
- `signals.governanceSignature` is not interpreted as a provider signature. Producer authentication is not claimed.
- Attestation does not publish the record. Default visibility is `hidden` and there is no governed public-reseal workflow.

See Topology and Concrete Lineage and Errors and Troubleshooting.