sxsphinxstack

Skills / Starter / Compare two api responses

Starter Code skill

Compare two api responses

Compare two API responses across status, headers, schema, values, ordering, timing, and side effects.

Normalize noise without erasing meaningful differences.

When to use

  • Use for regression, migration, contract, environment, or retry comparisons.
  • Redact credentials, tokens, cookies, personal data, and sensitive identifiers.

Preconditions

  • Preserve exact requests, endpoints, versions, time, identity, environment, and response captures.

Procedure

  1. Confirm the requests are equivalent or list every intentional difference.
  2. Compare transport, status, headers, content type, caching, and timing.
  3. Parse bodies with the correct schema and preserve raw captures.
  4. Normalize only documented volatile fields such as generated IDs or timestamps.
  5. Compare missing, extra, type, value, precision, null, ordering, pagination, and error differences.
  6. Check observable side effects and idempotency, not only response bodies.
  7. Classify each difference as expected, compatible, breaking, data-dependent, or unresolved.

Failure plan

  • If requests or identity differ, do not call the response difference a regression.

Worked example

Two checkout responses share a status but one omits a required currency and creates a duplicate order on retry, revealing both contract and side-effect regressions.

Related skills

  • Check an api pagination loop — Check an API pagination loop for cursor handling, termination, duplicates, omissions, mutation, rate limits, retries, and bounded memory.
  • Compare two container manifests — Compare two container workload manifests across image identity, command, resources, security, network, storage, configuration, rollout, and metadata.
  • Check a database index — Check whether a database index supports a real query using definition, selectivity, plan, statistics, write cost, and production-safe evidence.