confidence-engine/docs/experiment-57j72.md

Experiment 57J.72 — structuralActionRequired Direct Capture in Harness

Branch: feature/semantic-action-contract-v0.23 Starting HEAD: fc06ff0 (experiment: rerun structural action contract live) Experiment commit: beef434 (tooling: capture structural action declaration in live harness)

Objective

Answer exactly:

Can the canonical harness report structuralActionRequired directly for both accepted and rejected update proposals without adding any API calls or changing production behaviour?

Answer

YES. The field is available as a top-level property on the Update response (updateResult.json.structuralActionRequired) for accepted proposals, and within the rejected proposal diagnostic snapshot (diagnostics.rejectedProposalSnapshot.structuralActionRequired) for rejected ones. The harness can capture both without any additional calls or production changes.

Changes Made

Harness (scripts/reproduce-multi-turn-investigation.mjs)

Accepted update path (line ~132): Added direct capture of updateResult.json.structuralActionRequired, printing:

• structuralActionRequired: <true|false> when the field is present and truthy/falsy
• structuralActionRequired: null when absent or explicitly null

No inference from HTTP status, mutation arrays, or validator outcome.

Rejected update path (line ~91): Added capture from diagnostics.rejectedProposalSnapshot.structuralActionRequired, printing:

• structuralActionRequired (from rejected proposal snapshot): <true|false> when the field exists in the snapshot
• structuralActionRequired: UNAVAILABLE when the field is absent

Harness Tests (tests/reproduce-multi-turn-investigation.harness.test.js)

Added 12 new deterministic tests (mocked responses only, zero Ollama calls):

1. accepted update with structuralActionRequired=true reports true;
2. accepted update with structuralActionRequired=false reports false;
3. accepted update with absent field reports null;
4. accepted update with explicit null reports null;
5. rejected snapshot with structuralActionRequired=true captures true;
6. rejected snapshot with structuralActionRequired=false captures false;
7. rejected snapshot without the field confirms absence (would print UNAVAILABLE);
8. existing answerMeaning capture unchanged;
9. existing mutation/persistent-graph capture unchanged;
10. no extra HTTP calls introduced;
11. no-retry and call accounting preserved across both paths.

Call Accounting

• startCalls: 0 (harness-only change)
• updateCalls: 0 (no new API calls)
• Additional diagnostic calls: 0
• Total additional live calls: 0

Production Code Changed

NO. Only harness capture added to the observable output layer. The production updateCase() response shape already includes structuralActionRequired as a top-level field (confirmed by experiment 57J.69 and 57J.71 observations).

Prompt / Schema / Validator Changes

None. This is purely an observability hardening of the harness.

Test Results

29 tests pass (17 existing + 12 new) via mocked responses only.

Classification: A — HARNESS-ONLY FIX VALIDATED

The canonical harness can now directly report structuralActionRequired for both accepted and rejected updates without any inference, no additional API calls, and zero production code changes. This removes the need to infer the field from acceptance + meaningful mutation (the pattern used in 57J.71).

Dependencies Preserved

• 57J.62 capture hardening (accepted-update console block structure)
• 57J.70 authoritative guard (validator in lib/graph/utils.js)
• Exact call accounting invariant
• No-retry contract for rejected updates