P8-A3 — reproduce Probity interoperability gap before any schema change #145

Status

OPEN — P8_A3_EXTERNAL_INTEROP_GAP_REPRODUCTION_GATE

Parent external-validation program: #114
Protocol: docs/development/P8_A3_INTEROPERABILITY_REVIEW_PROTOCOL.md
External source: probityai/agent-evidence-observer#41 (merged 2026-10-02)
External integration path: interop/execsurface-state-2026-10-02/
Public ExecSurface target used externally: v0.1.0-alpha.5

Why this gate exists

An external project integrated the published Alpha.5 native ptrace binary and built a substantial companion layer around the retained raw trace.

The external integration makes concrete technical claims that qualify for P8-A3 processing:

1. raw observation schema v2 carries global complete / warnings but no typed collection-health envelope;
2. file_descriptor_access write evidence carries operation/fd/path but not the successful byte count or syscall result;
3. state before/after bytes and state-root binding therefore had to be captured separately;
4. the integration preserves the original ExecSurface trace and explicitly refuses to inflate producer PASS into authority, complete custody, or production adoption;
5. the external project reports the resulting collection health as unknown-no-typed-envelope.

This is a concrete interoperability/evidence-expressivity finding, not generic praise.

Important internal observation

ExecSurface already contains a research-only Semantics v3 prototype with proposition-scoped guarantees and typed completeness dimensions, including observer-health semantics.

That prototype is deliberately disconnected from the public Alpha.5 learn/check path.

The external finding therefore does not authorize immediate schema promotion. It provides external evidence that the research direction addresses a real integration problem.

Gate question

What is the minimum semantics-preserving change, if any, required to let an external evidence consumer determine observation health and successful file-write semantics without rebuilding a bespoke trust layer around raw schema v2?

Required reproduction

G1 — Freeze and reproduce the exact Alpha.5 limitation

Using the immutable published Alpha.5 binary/source:

• reproduce one successful file write;
• prove the retained raw v2 event lacks transferred-byte/result information;
• prove current global complete + warnings cannot express the typed health state selected by the external consumer;
• retain the raw trace unchanged.

G2 — Map the finding to current Semantics v3

For each external gap, classify it as:

• already represented exactly by the research v3 model;
• represented only partially;
• not represented;
• intentionally out of ExecSurface scope.

Do not change v3 merely to match the external implementation.

G3 — Failure-first adversarial matrix

At minimum:

• zero-byte write / failed write;
• short write;
• repeated writes to the same fd/path;
• observer warning with successful target exit;
• incomplete/truncated observation;
• path/process mismatch;
• shared-fd ambiguity;
• binary/source identity mismatch;
• external before/after snapshot substitution.

G4 — Scope decision

Choose exactly one evidence-backed outcome:

• NO_PRODUCT_CHANGE_EXTERNAL_ADAPTER_SUFFICIENT
• REPORT_LAYER_TYPED_HEALTH_BRIDGE
• RAW_SCHEMA_NEXT_CANDIDATE
• SEMANTICS_V3_PUBLIC_PROMOTION_CANDIDATE
• INCONCLUSIVE_MORE_EXTERNAL_EVIDENCE_REQUIRED

G5 — Compatibility / anti-drift review

Any candidate change must preserve the P9.3 compatibility contract and must not silently reinterpret Alpha.5 baseline-v2 or verdict semantics.

Non-goals

This gate does not authorize:

• capturing file contents by default;
• building a general filesystem state/Merkle system into ExecSurface;
• turning ExecSurface into a general attestation/custody product;
• claiming external production adoption;
• claiming independent authority from same-operator signatures/timestamps;
• replacing ReproCert or other provenance/attestation layers;
• changing public v1 commitments before an executable proof gate passes.

Current decision

EXTERNAL_GAP_ACCEPTED_FOR_REPRODUCTION_ONLY

No product/schema change is authorized until the exact external finding is reproduced and the bounded decision above is closed.