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 brcampidelli/chimera-agent --skill chimera-write-the-check-before-the-codegit clone --depth 1 https://github.com/brcampidelli/chimera-agentWrote 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/brcampidelli/chimera-agent/chimera-write-the-check-before-the-code)<a href="https://agentmods.dev/skills/brcampidelli/chimera-agent/chimera-write-the-check-before-the-code"><img src="https://agentmods.dev/badge/skills/brcampidelli/chimera-agent/chimera-write-the-check-before-the-code/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/brcampidelli/chimera-agent/chimera-write-the-check-before-the-code"><img src="https://agentmods.dev/badge/skills/brcampidelli/chimera-agent/chimera-write-the-check-before-the-code.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00032 | $0.00986 |
| Opus 5 | $0.00016 | $0.00493 |
| Sonnet 5 | $0.00006 | $0.00197 |
| Haiku 4.5 | $0.00003 | $0.00099 |
Grade A, and why
chimera-write-the-check-before-the-code 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 9d 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 — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Trigger
You are about to implement something whose "done" is not yet observable — a feature, a bug fix, a refactor that claims to preserve behaviour. It bites hardest when the author and the only reviewer are the same process: an agent working alone, or a solo commit nobody else will read.
It does not apply to a spike. Exploration whose purpose is to find out what is even possible has no acceptance criterion yet, and inventing one upfront just anchors you to the first idea. Write the check when the spike ends and the real work begins.
This card is about the check that does not exist yet. Its sibling, chimera-prove-the-test- discriminates, is about a check that already exists and may be empty — you reach for that one after
a fix, to show the test fails without it. Same instinct, opposite ends of the work.
Do
- Before touching the implementation, write the criterion as something that can fail: a test, an assertion, a command whose exit code flips, a query with an expected row. Prose is not a check — "the endpoint should be faster" is not; "p95 under 200 ms on the fixture set, measured by the existing bench command" is.
- Say where the observation comes from. The machine, not your reading of the diff.
- Run the check now, against unmodified code. It must fail. If it passes, either the behaviour already exists — in which case stop, there is nothing to build — or the check does not test what you think.
- Read the failure message. It must fail for the intended reason, not on an import error, a missing fixture, or a typo in the test name. A red that comes from the wrong cause is a green in disguise.
- Land the check before the implementation, in its own commit. Once the implementation exists, the check becomes editable to match it, and it will be.
- Implement. Done is when the check passes — not when the code looks finished.
Avoid
Writing the assertion afterwards, from the output:
# implementation already written; you run it once to see what it does
normalize(" Foo ") # -> "foo"
# test transcribed from that observation
assert normalize(" Foo ") == "foo"
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.
- 9d ago First seen · 92 lines · 32 tokens per session scan A 95d0a1b750e2
chimera-write-the-check-before-the-code is a skill published in the GitHub repository brcampidelli/chimera-agent (22 stars, last pushed today), licensed Apache-2.0. It adds 32 tokens to every session and 986 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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