@zanii/sla

Machine-verifiable service agreements between agents. Provider and client co-sign terms — what service (a target scope), over what window, how much (min/max actions), how continuously (max_gap_ms, an uptime proxy) — and then compliance is computed from receipts, not argued about. Same terms + same receipts → same verdict for everyone, and every breach cites its evidence. Pair with @zanii/escrow: a breach verdict is refund evidence.

npm install @zanii/sla @zanii/core @zanii/payments

import { buildSlaBody, signSla, assembleSla, assessCompliance } from '@zanii/sla';

const body = buildSlaBody({
  provider: worker.did, client: buyer.did, scope: 'feed.*',
  window: { start, end },
  commitments: { min_actions: 100, max_gap_ms: 15 * 60_000 },
  price: { amount: '499.00', currency: 'USD' },   // informational — ties to an escrow
  createdAt: now,
});
const sla = assembleSla(body, [signSla(body, worker.did, workerKey), signSla(body, buyer.did, buyerKey)]);

// hand in the provider's CONSECUTIVE chain segment covering the window:
const report = assessCompliance(sla, receipts, { asOf: now }); // asOf: fair mid-window checks
report.ok;        // no breaches
report.breaches;  // [{ kind, detail, receipt? }] — each cites the evidence
report.metrics;   // { actions, max_gap_ms }

Python: from zanii.sla import build_sla_body, assess_compliance, ... — byte-identical JCS objects and hashes.

The property that makes the metrics honest

Counting receipts is worthless if the provider can omit the bad hour. Zanii receipts form a per-agent hash chain (prev links), so completeness is provable: assessCompliance verifies the slice is consecutive in the provider's chain — a broken link is an INCOMPLETE_RECORD breach, not a silently wrong count. Trimming the ends doesn't help either: it shows as fewer actions and bigger edge gaps (gaps are measured to the window boundaries, not just between receipts).

Breach kinds: INVALID_RECEIPT · INCOMPLETE_RECORD · TOO_FEW_ACTIONS · TOO_MANY_ACTIONS · MAX_GAP_EXCEEDED.

The limit, stated up front

Receipts prove what was recorded — an action taken entirely off the rails is the credential-custody problem, not an SLA one. A gap breach proves silence on the ledger, which the SLA defines as breach; that definition is the parties' agreement, not a law of nature.