contract-compliance-check skill

Dispatch Requirement

When invoked, dispatch to a polymorphic-agent:

Agent(
  subagent_type="onex:polymorphic-agent",
  description="Contract compliance check <ticket_id>",
  prompt="Run the contract-compliance-check skill for <ticket_id>. <full context>"
)

CRITICAL: subagent_type MUST be "onex:polymorphic-agent" (with the onex: prefix).

Skill ID: onex:contract-compliance-check
Version: 1.0.0
Owner: omniclaude
Ticket: OMN-2978
Depends on: OMN-2975 (generate-ticket-contract)

---

Purpose

Pre-merge seam validation. Reads a ModelTicketContract, diffs the branch against
origin/main to find changed files, runs targeted probes for each declared surface
in interfaces_touched, and returns PASS / WARN / BLOCK.

Respects emergency_bypass to downgrade BLOCK verdicts when a justification and
follow-up ticket are provided.

---

Usage

/contract-compliance-check OMN-1234

Or with an explicit contract path:

/contract-compliance-check OMN-1234 --contract-path /path/to/OMN-1234.yaml

---

Probe Surfaces

Surface	What is compared	BLOCK condition	WARN condition
topics	Producer constant vs consumer subscribe string	Producer != consumer (exact bytes)	New topic with no known consumer
events	Event model field set	Required field removed	New optional field added
protocols	Method signatures on changed Protocol classes	Method removed or signature changed	New method added
public_api	SHA-256 of openapi.json	(never BLOCK)	Hash changed without public_api in interfaces_touched
envelopes	Envelope model field set	Required field removed	New optional field added

---

Baseline Strategy

All probes compare branch state against git diff origin/main — not the PR diff:

git diff origin/main --name-only   # list of changed files relative to main
git show origin/main:{file}        # baseline version of a file

---

emergency_bypass Semantics

If emergency_bypass.enabled=true:
  - require justification non-empty AND follow_up_ticket_id non-empty
  - if both present: downgrade all BLOCK -> WARN
  - if either missing: BLOCK with "emergency_bypass enabled but incomplete"

---

Output Format

CONTRACT COMPLIANCE CHECK — OMN-XXXX
is_seam_ticket: true
interfaces_touched: [topics, events]

TOPICS probe ──────────
  ✅ PASS  onex.evt.omniclaude.prompt-submitted.v1

EVENTS probe ──────────
  ⚠️ WARN  ModelHookPromptSubmittedPayload: field added: intent_class: str | None = None

Overall: PASS (2 warnings, not blocking)

---

Architecture

prompt.md          → orchestrates probe dispatch, contract loading, output formatting
SKILL.md           → descriptive documentation (this file)

The skill is invoked as a pre-merge gate, typically from the ticket-pipeline
local_review phase or manually by a developer before creating a PR.

---

See Also

• generate-ticket-contract skill (OMN-2975) — produces the ModelTicketContract consumed here
• ModelTicketContract in onex_change_control repo
• ticket-pipeline Phase 2 (local_review) — primary trigger surface