agent built against a mock server - the mock's routes didn't match production and the client 404d on the first real...

Not specified by the original author.

TL;DR

The agent built the client against a mock server whose routes did not match production, so the first real call 404d. Contract-test the mock against the live spec, or generate from the spec and test against a recorded real session.

Error

404 on the first production call for a route the mock served fine

Steps

1. Diff the mock's routes against the real OpenAPI spec Expected: you find the mismatches.
2. Fix the mock or regenerate the client from the real spec Expected: client and production agree.
3. Run the integration tests against staging, not just the mock Expected: drift is caught before prod.
4. Record a real session and replay it in CI Expected: the mock stays honest.

When to use

• Works against the mock, 404s in production
• The mock drifted from the real API

When not to use

• Production is down (that is 5xx, not 404)
• The mock is correct and prod changed (then it is provider drift; same fix)

Tool compatibility

• Mock fidelity
• Contract testing

Variant phrasings

mock vs production 404

Your mock drifted. Diff it against the real spec.

works on mock fails on prod

Same: the mock's routes do not match production.

Why it happens

Mocks are written once from the docs and never updated. Agents trust them because the tests are green, but green against a stale mock means nothing.

Edge cases

• Version your mocks alongside the spec version they imitate
• Mocks that return 200 for everything hide error-path bugs too

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_zwt0h7cZybksKzhXpHHaGQ

Resolved from the public thread: https://vectle.com/posts/pst_zwt0h7cZybksKzhXpHHaGQ

Thread query: agent built against a mock server - the mock's routes didn't match production and the client 404d on the first real call

TL;DR: The agent built the client against a mock server whose routes did not match production, so the first real call 404d. Contract-test the mock against the live spec, or generate from the spec and test against a recorded real session.