@observer-protocol/wdk-op-policy

Enforce a signed Observer Protocol delegation credential on a Tether WDK account — at the signer boundary, fail-closed — via the WDK transaction policy engine (tetherto/wdk #55).

The third Observer Protocol enforcement engine. Same credential, same mandate vocabulary, same vendored core as the OWS verifier and the mppx account — here as a pair of WDK policy rules. The API always registers an ALLOW + DENY pair together: the DENY companion is the mandatory fail-closed backbone (DENY-wins + fail-closed-on-throw), so it holds regardless of what else the consumer registered.

Install

npm install @observer-protocol/wdk-op-policy @tetherto/wdk

Requires @tetherto/wdk >= 1.0.0-beta.11 — the first published release carrying the transaction policy engine (PR #55). Verified against 1.0.0-beta.11 (see docs/CONFORMANCE.md).

Use

import { registerObserverPolicy } from '@observer-protocol/wdk-op-policy';

registerObserverPolicy(wdk, {
  policy: {
    credentialPath: '~/.op/agent-delegation.json',     // the signed ObserverDelegationCredential
    issuerDid: 'did:web:observerprotocol.org',
    schemaAllowlist: ['https://observerprotocol.org/schemas/delegation/v2.1.json'],
    agentDid: 'did:web:observerprotocol.org:agents:my-agent',
    revocation: { maxStalenessHours: 24, onUnreachable: 'cache-then-deny', fetchTimeoutMs: 1500 },
    auditLog: '~/.op/decisions.jsonl',
    // evmTokens / rails as needed; defaults cover mainnet USDC/USDT
  },
  wallets: { ethereum: 'eip155:1' },                   // wallet label -> CAIP-2 (MUST resolve to a rail)
}, { wallet: 'ethereum' });

// Every write op on the governed account now verifies the mandate before signing.
// Out-of-mandate / unverifiable -> PolicyViolationError; the key never signs.

registerObserverPolicy emits two rules — an ALLOW (in-mandate) and a DENY (violation/uncertainty). Do not hand-author a lone ALLOW, and never pair OP with a broad permissive wildcard ALLOW on the same operations without the DENY — that reopens a fail-open hole (proven; see SUPPORT-MATRIX).

What it enforces

Gates sendTransaction, signTransaction, transfer, approve, signTypedData against per-rail ceiling, counterparty, temporal window, and cross-tx velocity. Exact decode per operation, the fail-closed construction, rail resolution, and limitations are in docs/SUPPORT-MATRIX.md; scope/non-goals in docs/SCOPE.md.

Security model

• Fail-closed: uncertainty (DID/status outage, thrown verification, timeout) blocks — the DENY condition never resolves uncertainty to a silent allow.
• Default-deny aware: OP relies on the engine's default-deny on governed accounts, and the DENY backbone holds even alongside a permissive baseline.
• Enforcement locus: the signer boundary, from the actual operation params — portable across OWS, mppx, and WDK. The binding layer is contested; the enforcement locus is not.
• Validated against the published engine (@tetherto/wdk@1.0.0-beta.11), 26 conformance cases.

Develop

npm test                  # typecheck + build + fixtures + 26 conformance cases (real engine)
npm run check:core-sync   # vendored core must match ows-op-verify byte-for-byte

MIT.