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

# Credit Rollout and Acceptance

> Validate, canary, monitor, and roll back product-credit integrations

Roll out product credits in stages: configure, shadow, test, canary, monitor, and expand. Use separate sandbox customers and deterministic identifiers so every result is reproducible.

## 1. Validate configuration

Before mutation traffic:

* confirm the Feature is classified for credit consumption;
* verify one effective conversion rate for the intended Credit System;
* verify plan grants and paid top-ups create separate balance sources;
* verify Entity pool policy where Entity attribution is used; and
* confirm the backend key has only the required permissions.

## 2. Shadow with advisory checks

Call `usage.check()` using representative production-shaped properties. Compare the exact-decimal metric amount, credits required, total availability, and projected source deductions with your expected fixtures.

Advisory checks do not mutate balances and are safe for shadow evaluation.

## 3. Test idempotency and concurrency

In a sandbox customer, confirm:

* same-key retries return one logical result;
* the same key with a different payload is rejected;
* concurrent requests cannot overdraw a source;
* denied operations create no allocations or billing-event outbox row;
* successful operations reconcile to one billing event; and
* source expiry, top-ups, and subscription grants retain expected priority.

Use fixed timestamps and deterministic keys in repeatable test fixtures.

## 4. Canary one workflow

Enable one application workflow for a small set of non-production or internal customers. Monitor:

* allow and denial rates;
* request latency;
* balance and operation history;
* outbox publication delay and failures;
* reconciliation status; and
* support or application errors caused by changed denial behavior.

## 5. Audit acceptance

Use Nozle's read-only credit audit tooling when available. At minimum, verify:

* source balances equal initial amounts plus immutable allocations;
* successful consumes have exact deductions and one durable outbox event;
* denied consumes have no side effects;
* paid top-ups and subscription grants materialize once; and
* customer and organization ownership remain consistent.

Retain the audit output with release evidence.

## 6. Expand gradually

Expand by workflow, metric, or customer cohort only after the canary window is clean. Keep a dashboard for denial changes, reconciliation lag, and publication failures.

## Rollback

Stop sending new `usage.track()` requests for the affected workflow and fall back to your previous authorization path. Do not delete ledger rows. If a committed operation must be reversed, use an explicit compensating operation so financial history remains auditable.