How do I install the Contract Check skill?

Run npx skillmds@latest add onedro1d/contract-check in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Contract Check safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Contract Check?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Contract Check free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Contract Check?

OneDro1d (@onedro1d) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Contract Check by onedro1d — Agent Skill

Name: Contract Check
Author: OneDro1d

Contract Check

Validate an agent hand-off (Evidence Bundle, Root Cause, Design Spec, Implementation Report, Validation Report, Knowledge Entry) against its data contract before consuming it. Use at any pipeline seam to enforce LOCAL-reject ("escalate, don't guess") and the unforgeable-evidence rule (a PASS must carry test counts) instead of trusting prose. Triggers on "check the handoff", "is this evidence bundle complete", "verify the validation report", "contract check".

OneDro1d 0930e86 4 files · 14.4 KB Updated Sep 17, 2026

File contents

contract-check — reject incomplete hand-offs before you act on them

Goal: stop a malformed or under-evidenced hand-off from flowing downstream where the next agent quietly copes — or guesses. This is the data-transform lens' LOCAL reject rule and the promise-theory unforgeable-evidence rule, made runnable. The contracts are defined in .claude/context/AGENT-CONTRACTS.md; this skill runs the checker that mirrors them.

When to run it

A consuming agent receives an upstream artifact → check it before consuming. REJECT ⇒ kick back to the producer with the listed gaps; do not proceed.
The orchestrator / a human reviews a Validation Report claiming PASS → confirm it carries test-count evidence (not "looks green").
CI or a pre-commit hook wants a cheap structural gate on agent outputs.

How to run it

# from repo root; reads a file or stdin
python3 .claude/skills/contract-check/check_contract.py <contract> path/to/artifact.txt

# contracts: evidence_bundle | root_cause | design_spec |
#            implementation_report | validation_report | knowledge_entry

Exit 0 + OK → consume. Exit 1 + REJECT → kick back; the output lists each missing section and rule violation. Exit 2 → usage error.

What each contract requires

See the table in .claude/context/AGENT-CONTRACTS.md. The rules with teeth:

evidence_bundle / root_cause — must carry a real file:line citation.
validation_report — VERDICT ∈ PASS|CONDITIONAL|FAIL, and a PASS must carry test counts (a bare "PASS" is UNVERIFIED → REJECT).
knowledge_entry — must have an F-###/D-### id and a source.

Maintaining it (the checker is itself test-first)

The checker is built RED→GREEN and guarded by tests:

python3 .claude/skills/contract-check/check_contract_test.py            # author suite
python3 .claude/skills/contract-check/check_contract_adversary_test.py  # blind adversary suite

If you add or change a contract: update AGENT-CONTRACTS.md (the source of truth) and check_contract.py (its mirror), add a RED test first, keep both suites green. No secrets/PII in fixtures.

---name: contract-checkdescription: Validate an agent hand-off (Evidence Bundle, Root Cause, Design Spec, Implementation Report, Validation Report, Knowledge Entry) against its data contract before consuming it. Use at any pipeline seam to enforce LOCAL-reject ("escalate, don't guess") and the unforgeable-evidence rule (a PASS must carry test counts) instead of trusting prose. Triggers on "check the handoff", "is this evidence bundle complete", "verify the validation report", "contract check".---# contract-check — reject incomplete hand-offs before you act on themGoal: stop a malformed or under-evidenced hand-off from flowing downstream wherethe next agent quietly copes — or guesses. This is the data-transform lens'**LOCAL reject** rule and the promise-theory **unforgeable-evidence** rule, maderunnable. The contracts are defined in `.claude/context/AGENT-CONTRACTS.md`; thisskill runs the checker that mirrors them.## When to run it- A consuming agent receives an upstream artifact → check it **before** consuming. `REJECT` ⇒ kick back to the producer with the listed gaps; do not proceed.- The orchestrator / a human reviews a `Validation Report` claiming PASS → confirm it carries test-count evidence (not "looks green").- CI or a pre-commit hook wants a cheap structural gate on agent outputs.## How to run it```bash# from repo root; reads a file or stdinpython3 .claude/skills/contract-check/check_contract.py <contract> path/to/artifact.txt# contracts: evidence_bundle | root_cause | design_spec |# implementation_report | validation_report | knowledge_entry```Exit `0` + `OK` → consume. Exit `1` + `REJECT` → kick back; the output lists eachmissing section and rule violation. Exit `2` → usage error.## What each contract requiresSee the table in `.claude/context/AGENT-CONTRACTS.md`. The rules with teeth:- `evidence_bundle` / `root_cause` — must carry a real `file:line` citation.- `validation_report` — `VERDICT` ∈ PASS|CONDITIONAL|FAIL, and a **PASS must carry test counts** (a bare "PASS" is UNVERIFIED → REJECT).- `knowledge_entry` — must have an `F-###`/`D-###` id **and** a source.## Maintaining it (the checker is itself test-first)The checker is built RED→GREEN and guarded by tests:```bashpython3 .claude/skills/contract-check/check_contract_test.py # author suitepython3 .claude/skills/contract-check/check_contract_adversary_test.py # blind adversary suite```If you add or change a contract: update `AGENT-CONTRACTS.md` (the source oftruth) **and** `check_contract.py` (its mirror), add a RED test first, keep bothsuites green. No secrets/PII in fixtures.

Frequently asked questions