# Release check APIs

## Migration History Integrity API

Compare an ordered release migration manifest with an ordered applied history. Provide up to 128 entries per list with unique case-sensitive IDs and caller-supplied lowercase SHA-256 digests. The result lists digest mismatches, unexpected applied IDs, order violations and missing entries before the last known applied position. Unapplied entries after that position are reported separately as pending. A consistent history can still have pending migrations. An order violation identifies an applied ID that appears after an entry later in the manifest. This checks the supplied records. It does not read scripts or databases, confirm digest authenticity or run migrations. Use authorized, non-sensitive data. The report describes supplied records and does not change external systems.

[Request example](migration-history-integrity.request.example.json) · [Input schema](migration-history-integrity.input.schema.json) · [Result schema](migration-history-integrity.result.schema.json)

## Canary Error-Rate Guardrail API

Compare canary and control error rates using caller-supplied counts from a comparable observation window. Set a minimum request count for each group and a maximum allowed increase in whole basis points, where 100 basis points equal one percentage point. The result is insufficient evidence when either group is below the minimum. Otherwise the exact increase is compared with the threshold, with equality passing. Positive differences mean the canary had a higher error rate. The difference is returned as a signed fraction of basis points, with no rounding in the decision. The check uses only the supplied counts. It does not establish statistical confidence, monitor traffic or promote a release. Use authorized, non-sensitive data. The report describes supplied records and does not change external systems.

[Request example](canary-error-rate-guardrail.request.example.json) · [Input schema](canary-error-rate-guardrail.input.schema.json) · [Result schema](canary-error-rate-guardrail.result.schema.json)

Per job, USD 9.00 once. Save your private JSON result within its 30-day access period.
Requests accept at most 36,000 UTF-8 input bytes. Send only authorized, non-sensitive records.

Use the existing [agent checkout guide](https://gatewayinformationgroup.com/developers) to prepare a quote, pay and retrieve the private result.