Borrowing it
Nothing to install: this file belongs to marcoemrich/EXACT-Coding-Exercises. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/marcoemrich/EXACT-Coding-Exercises/main/.claude/skills/exact-coding/SKILL.mdgit clone --depth 1 https://github.com/marcoemrich/EXACT-Coding-ExercisesWrote 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/marcoemrich/exact-coding-exercises/exact-coding)<a href="https://agentmods.dev/skills/marcoemrich/exact-coding-exercises/exact-coding"><img src="https://agentmods.dev/badge/skills/marcoemrich/exact-coding-exercises/exact-coding/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/marcoemrich/exact-coding-exercises/exact-coding"><img src="https://agentmods.dev/badge/skills/marcoemrich/exact-coding-exercises/exact-coding.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00075 | $0.00709 |
| Opus 5.5 | $0.00030 | $0.00284 |
| Sonnet 5.5 | $0.00015 | $0.00142 |
| Haiku 4.5 | $0.00007 | $0.00071 |
Grade A, and why
exact-coding 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- exact-coding-isolated-refactor — 89% identical, 12 lines differ
How it starts
The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.
EXACT Coding — Predictive TDD v1
This is the consumer form of the universal EXACT Coding Predictive-TDD line. It runs in one shared context: Test List once, then one-test Red-Green-Refactor cycles. Refactoring uses the Four Rules of Simple Design inline. Refactoring also applies a domain-responsibility review and a mandatory concrete boundary trial whenever it finds a credible semantic seam. This line deliberately has no APP calculation, metric-driven end pass, or refactor subagent.
Preparation
- Read
.claude/skills/test-list/SKILL.md. - Read
.claude/skills/predictive-tdd/SKILL.md. - Determine the project's language and test framework. Read the matching file
under
.claude/skills/predictive-tdd/stacks/before changing code. - Read the complete specification and establish the applicable baseline gates.
Do not assume TypeScript or Vitest from this orchestration file. Concrete inactive-test syntax, examples, paths, commands, compiler behavior, and quality tools belong only to the selected stack profile.
Sequence
- Create the complete ordered test list with every future behavior inactive, then predict and verify that the inactive list leaves the full suite green.
- Apply the Test-List checkpoint from
.claude/skills/exact-coding-shared/human-in-the-loop.md. - For exactly one behavior at a time, follow the Predictive TDD skill:
- activate one behavior and reach behavioral Red,
- state falsifiable predictions before deterministic checks and compare them explicitly with reality,
- apply the Red checkpoint,
- reach Green with the smallest production change,
- review and refactor inline under the Four Rules,
- perform the mandatory domain-boundary trial and retain or narrowly undo it based on semantic and test evidence,
- apply the Refactor checkpoint.
- Continue until every listed behavior is executable and all applicable gates from the active stack profile pass.
A test already satisfied by an earlier generalization is legitimate evidence. Confirm it and do not manufacture a failure or production change.
What ships with it
1 file 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.
- 1mo ago Changed 419e8da0601a
- 1mo ago First seen · 64 lines · 75 tokens per session scan A 1ba45bbea8d7
exact-coding is a skill published in the GitHub repository marcoemrich/EXACT-Coding-Exercises (18 stars, last pushed 1mo ago), licensed MIT. It adds 75 tokens to every session and 709 once invoked, about $0.0003 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 2026-09-17.
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