Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/danielvm-git/bigpowersnpx agentmods add skills/danielvm-git/bigpowers/validate-contractsWrote 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/danielvm-git/bigpowers/validate-contracts)<a href="https://agentmods.dev/skills/danielvm-git/bigpowers/validate-contracts"><img src="https://agentmods.dev/badge/skills/danielvm-git/bigpowers/validate-contracts/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/danielvm-git/bigpowers/validate-contracts"><img src="https://agentmods.dev/badge/skills/danielvm-git/bigpowers/validate-contracts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 3 Skill selects an external model or provider that may use a different account or billing plan than the operator expects. Undisclosed model switches can cause unexpected cost or quota consumption.Fix: Remove the model/provider override or disclose it prominently and require explicit operator approval before invoking an external coding CLI or billed model.
- medium Agent Snooping · line 79 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 | $0.00041 | $0.02120 |
| Opus 5.5 | $0.00016 | $0.00848 |
| Sonnet 5.5 | $0.00008 | $0.00424 |
| Haiku 4.5 | $0.00004 | $0.00212 |
Grade A, and why
validate-contracts 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 287 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Validate Contracts
HARD GATE — Do NOT deploy or migrate data without running
validate-contractsfirst. Silent data divergence between system boundaries causes the hardest-to-debug production bugs.HARD GATE — Contract files MUST be version-controlled alongside code. Outdated contracts are worse than no contracts. If a contract hasn't been reviewed in 30 days, flag it as stale.
Validate that data structures stay in sync across system boundaries — front-end vs back-end, API responses vs expected schemas, config files vs code assumptions, migration output vs target shape.
Contract types
| Mode | What it catches | When to use |
|---|---|---|
| Schema | API response shape mismatches | Before every deploy, after API changes |
| Key-set | Missing/unexpected keys across two data sources | Translation files, configs, enum definitions |
| Shape | Column type or format violations | After migrations, before consuming exports |
Contract file convention
All contract files live in specs/contracts/ as YAML. See REFERENCE.md for extended examples.
Key-set example
# specs/contracts/i18n-keys.yaml
sources:
reference: src/locales/en.json
target: src/messages/en.json
mode: subset
Process
1. Define contract
Create a YAML file in specs/contracts/ following the schema for the mode.
2. Run validation
bash scripts/validate-contracts.sh specs/contracts/<contract>.yaml
The runner auto-detects key-set contracts (sources: block). Schema and shape modes are documented in REFERENCE.md for consumer projects.
3. Read the report
PASS: key-set contract
# or
FAIL: key-set — N keys in reference missing from target
JSON Lines output for CI is planned for schema/shape modes; key-set failures exit non-zero.
4. Fix divergence
- Missing keys → add to target source
- Type mismatches → update schema or fix producer
- Shape violations → fix migration or consumer
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.
- 1mo ago First seen · 287 lines · 41 tokens per session scan A 8cbe1be8eb94
validate-contracts is a skill published in the GitHub repository danielvm-git/bigpowers (275 stars, last pushed today), licensed MIT. It adds 41 tokens to every session and 2,120 once invoked, about $0.0002 per session on Opus 5.5. 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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