verification-contract

verification-contract is a skill for Claude Code, Codex from gtrabanco/agentic-workflow. It costs 48 tokens per session (795 once invoked), scanned A, original, MIT.

An internal agreement that defines the exact finish line for each feature or fix. It records acceptance criteria, how each criterion will be checked, and a fingerprint that detects changes to the agreement.

In plain words
What is it for?
Use it to create and verify an ACCEPTANCE.md file beside a feature specification, record its validation commands, and confirm that the same requirements are used throughout delivery.
Why use it?
It prevents the definition of done from quietly changing during implementation or review. It also stops work when the agreed requirements file was altered or lost.

Skill for Claude CodeCodex

Part of the agentic-workflow plugin — 39 skills shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/gtrabanco/agentic-workflow/verification-contract
Any agent
npx skills add gtrabanco/agentic-workflow --skill verification-contract
Clone the repo
git clone --depth 1 https://github.com/gtrabanco/agentic-workflow

Made for: Claude Code, Codex.

Or install agentic-workflow, the plugin that ships this one along with the rest of its 39 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for verification-contract

README.md
[![agentmods](https://agentmods.dev/badge/skills/gtrabanco/agentic-workflow/verification-contract.svg)](https://agentmods.dev/skills/gtrabanco/agentic-workflow/verification-contract)
Your own site
<a href="https://agentmods.dev/skills/gtrabanco/agentic-workflow/verification-contract"><img src="https://agentmods.dev/badge/skills/gtrabanco/agentic-workflow/verification-contract.svg" alt="Measured on agentmods" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 795 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00048 $0.00795
Opus 5 $0.00024 $0.00398
Sonnet 5 $0.00010 $0.00159
Haiku 4.5 $0.00005 $0.00080

Measured today against content hash c4181892a695, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

verification-contract scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

packages/pi-agentic-workflow/skills/verification-contract/SKILL.md · 87 lines

How it starts

The opening of the file, as written. The whole thing — 87 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Verification Contract (internal)

Single owner of the delivery finish line. Planning freezes it; executors may strengthen coverage but cannot move it; review checks the same bytes.

Artifact

Every new feature/fix carries ACCEPTANCE.md beside its SPEC. Copy the matching repository template. Required parts: Status: frozen; one stable ID per SPEC criterion; Required outcome; named Validator; literal quality floor; project commands. Prefer commands, otherwise use read-verified: <evidence> or manual: <exact observation>. Unlabelled prose is invalid. A planned test may name its future project runner; it cannot substitute a narrower runner later.

Validator stability. A validator must never gate on a surface other workflow actors mutate — the branch diff as a whole, the session log, progress entries, review ledgers, or forge state — because any out-of-unit commit (a session-log append, another unit's fold) then re-fails a frozen criterion on a finished unit and re-opens its review loop. Grep the unit's own files and outputs; a diff-based validator enumerates the unit's paths or excludes the workflow-mutated surfaces explicitly (docs/LOGS.md, the unit's own docs directory, harness/toolstate).

Freeze and receipt

At first execution run git hash-object <unit>/ACCEPTANCE.md and append to the unit progress file:

## Acceptance receipt v1
- Manifest: <path> · Blob: <sha> · Status: frozen · Verified: <date>

Before every phase and final review, recompute it. Exact match continues; missing/mismatched evidence stops before edits:

ACCEPTANCE GATE — <unit> BLOCKED
Expected blob: <sha|missing> · Actual: <sha|missing>
Reason: the frozen finish line is missing or changed.

→ Next: restore the frozen manifest, or obtain explicit user approval for a
  SPEC amendment and replacement manifest; then write a fresh receipt
  · never edit tests, commands, or acceptance to make the current candidate pass

A legitimate change requires, in order: explicit user approval; dated SPEC ## Amendments row; replacement manifest; committed fresh receipt. The executor never self-authorizes it.

Read the full file on GitHub · 87 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. today Changed · +9 lines c4181892a695
  2. 4d ago First seen · 78 lines · 48 tokens per session scan A 02141fe84d20

Subscribe to this mod's changes

verification-contract is a skill published in the GitHub repository gtrabanco/agentic-workflow (20 stars, last pushed today), licensed MIT. It adds 48 tokens to every session and 795 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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