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.
npx skills add codebygarv/Ai-skills --skill contract-testing-designergit clone --depth 1 https://github.com/codebygarv/Ai-skillsWrote 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.
[](https://agentmods.dev/skills/codebygarv/ai-skills/contract-testing-designer)<a href="https://agentmods.dev/skills/codebygarv/ai-skills/contract-testing-designer"><img src="https://agentmods.dev/badge/skills/codebygarv/ai-skills/contract-testing-designer.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00024 | $0.00300 |
| Opus 5 | $0.00012 | $0.00150 |
| Sonnet 5 | $0.00005 | $0.00060 |
| Haiku 4.5 | $0.00002 | $0.00030 |
Grade A, and why
contract-testing-designer 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 3d ago.
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.
What it actually says
Purpose
Design consumer-driven contract testing suites (Pact, OpenAPI contract validators) to ensure microservices and frontend/backend interfaces stay compatible without requiring expensive, brittle end-to-end test environments.
When to Use
- Microservices that communicate over HTTP REST, gRPC, or message queues.
- Preventing frontend outages caused by uncoordinated backend API payload changes.
- Replacing flaky end-to-end staging environments with fast, isolated CI contract verification.
What to Analyze
- Consumer Expectations: What fields does the client actually read and rely on?
- Provider State Definitions: Setting up backend database fixtures to satisfy contract scenarios.
- Contract Serialization (Pact JSON / OpenAPI Schema): Contract artifact published to a central broker.
- CI Verification Gate: Provider builds verifying against all active consumer contracts before deploying (
can-i-deploy).
Output Format
- Consumer Contract Test: Pact consumer test asserting request shape and response mock.
- Provider Verification Test: Provider test running against the contract with state handlers.
- CI Pipeline Workflow: Integration with Pact Broker or schema registry.
Avoid
- Writing contracts that assert on every unused field in the response (violates consumer-driven principle).
- Relying on manual human reviews to detect breaking JSON changes.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 3d ago First seen · 33 lines · 24 tokens per session scan A a168ae381b2b
contract-testing-designer is a skill published in the GitHub repository codebygarv/Ai-skills (25 stars, last pushed 18d ago), licensed MIT. It adds 24 tokens to every session and 300 once invoked, about $0.0001 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 2026-09-03.
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