---
id: review-002-projection-truthfulness
name: Projection doc truthfulness — dangling CallError ref, status clobber/drifts, OAS-invalid extension (PRJ-16b/17/18/19/20/21/23/24)
status: completed
depends_on: []
scope: moderate
risk: low
impact: component
level: implementation
tags: [adapters, review-002, to-openapi]
---

## Description

Eight review-002 findings in `to_openapi.rs` (+ one in `to_mcp.rs`),
all "the generated document must be runtime-truthful and
OAS-valid" — the PRJ-01..15 remediation's remaining tail:

- **PRJ-16b [major]**: `BatchResultEntry.error` refs
  `#/components/schemas/CallError` which does not exist
  (to_openapi.rs:602 vs components at :387-413 defines `CallFailure` +
  per-code variants). The openapiv3 parse test runs on an **empty
  registry** so nothing trips. Generated clients/validators fail to
  resolve.
- **PRJ-17**: an op declaring `HTTP_404@404` clobbers the shared
  NotFound response on `/call` (:694/:237-239/:295-300) — losing
  `NOT_FOUND` which the runtime still emits; every real 404 then
  violates the documented schema. Merge op codes into the shared
  response (oneOf append) instead of overwriting.
- **PRJ-18**: `/publish` 400 over-declares `INVALID_OPERATION_TYPE`;
  runtime maps that condition to 401 without a token (the 401 entry in
  the same doc is the true one) (:268-277).
- **PRJ-19**: extractor plain-text 415 (missing content-type) and
  data-error 422 (JsonDataError) undocumented on `/call`, `/batch`,
  `/subscribe` (axum 0.8 emits them; the module doc admits
  "plain-text 400/415/422") (:673-682).
- **PRJ-20**: `/call` 401 under-declares — unauthenticated Sub/Pub
  call → 401 with `INVALID_OPERATION_TYPE`, absent from the enum
  (:218-219 vs error.rs:67-73; `/publish` got this split right).
- **PRJ-21**: `/batch` documents a 500 the runtime never emits (all
  dispatch failures are in-band entries) (:329-334).
- **PRJ-23**: `x-operation-error-statuses` is emitted *inside*
  `components.schemas` (:414-417) — extension keys are legal on
  `components`, not as a schema name; OAS-invalid on any registry with
  op errors. Move to `components` level or delete (nothing consumes
  it).
- **PRJ-24**: dead `search_filter` parameter in `to_mcp::handle_batch`
  (computed then `let _ =` discarded) — remove.

## Acceptance Criteria

- [ ] PRJ-16b: `CallError` defined (generic code/message/retryable/
      details) OR `error` points at existing per-code components via
      oneOf; the openapiv3 parse test runs on a **populated** registry
      (with op errors — exercising PRJ-23's key too)
- [ ] PRJ-17: protocol-status op errors merge into the shared response
      (oneOf append); test with `HTTP_404@404` asserting `NOT_FOUND`
      survives alongside
- [ ] PRJ-18/20: 400 and 401 oneOf lists match error.rs's actual
      mapping (drop IOT from publish-400; add IOT to call-401) —
      conformance tests for both bodies
- [ ] PRJ-19: 415 + plain-text 422 slots documented (extend
      `plain_text_extractor_rejection` or an equivalent shared
      component)
- [ ] PRJ-21: unreachable /batch 500 removed or marked reserved
- [ ] PRJ-23: extension key legal placement (or deleted); parse test
      covers the with-errors path
- [ ] PRJ-24: dead parameter removed from `handle_batch`
- [ ] Golden-doc tests updated (byte-identical assertion refreshed);
      `cargo test --all-features`, `cargo clippy --all-features
      --all-targets -- -D warnings`, `cargo fmt --check` pass

## References

- docs/reviews/002-post-remediation-review.md (Part F', PRJ-16b/17/18/19/20/21/23/24; Test-gaps 5/6)
- src/adapters/to_openapi.rs:387-433 (components), :602 (dangling ref), :218-300 (status oneOfs), :414-417 (extension), :673-682 (extractor text)
- src/gateway/error.rs:57-81 (the runtime mapping these must match), routes.rs (the runtime truth)
- tasks/adapters/review-001-openapi-projection-fidelity.md (the PRJ-01..15 work this completes)

## Notes

The review-001 lesson applies again: every fix here needs its test to
run against a populated registry (the empty-registry parse test is how
PRJ-16b and PRJ-23 escaped). Consider one shared
`golden_doc_with_ops()` fixture replacing per-test registry setup.
ADR-045's version bump: these are doc-contract corrections — bump
`info.version` per ADR-045's tracking rule (gateway endpoint contract
itself unchanged).

## Summary

PRJ-16b BatchError component oneOf; PRJ-17 op-declared errors merge into protocol responses; PRJ-18 /publish 400 narrowed; PRJ-19 415/422 slots via shared builders; PRJ-20 /call 401 identity split; PRJ-21 unreachable /batch 500 removed; PRJ-23 invalid extension deleted; PRJ-24 dead search_filter removed. gateway-spec 1.2.0 -> 1.3.0 (minor per ADR-045). GW-15 413 context folded into 400-slot docs.