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 agentmods add skills/int2t05/engineering-skills/implementnpx skills add int2t05/engineering-skills --skill implementgit clone --depth 1 https://github.com/int2t05/engineering-skillsWhat 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 | $0.00126 | $0.01170 |
| Opus 5 | $0.00063 | $0.00585 |
| Sonnet 5 | $0.00025 | $0.00234 |
| Haiku 4.5 | $0.00013 | $0.00117 |
Grade A, and why
implement 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 2d 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 — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Implement
Execute the work described by a spec or tickets in thin vertical slices. Each slice cuts a complete path through every layer (schema, API, UI, tests) and lands green. Drive TDD within each slice; verify framework-specific patterns against official docs; subject non-trivial decisions to a fresh-context doubt cycle before they stand.
When to use
- Implementing work described by a spec, plan, or set of tickets.
- Multi-file changes that should land one vertical slice at a time.
- Framework-specific code where current docs determine correct patterns.
- High-stakes or unfamiliar code where correctness matters more than speed.
- Lightweight changes that don't need a spec — small config edits, mechanical renames/moves, project scaffolding (see
references/lightweight-changes.md).
Not for: changes needing design decisions (use spec); system architecture (use architecture); pure test-driven exploration or bugfix-via-test with no spec — red-green-refactor as the whole task (use tdd). Have a spec and want slice-by-slice implementation? That stays here, with TDD driven within each slice.
Steps
-
Read the spec or tickets. Orient on what "done" means. Note any pre-agreed TDD seams — integration points where tests must exist before code lands. If versions are missing or ambiguous, ask; the version determines which patterns are correct.
-
Slice the work vertically. One demoable end-to-end path per slice, sized to a single fresh context. Keep it compilable between slices. Wide refactors (one mechanical change fanning across the codebase) are the exception — sequence them as expand–contract, never force them into a tracer bullet.
-
For each slice, implement via TDD at the seams:
- Write the failing test first (red), then the code (green), then refactor.
- For framework-specific code: detect the stack and exact versions from the
dependency file; fetch the relevant official docs page (not the homepage);
follow the documented pattern and cite the source URL in a code comment.
Flag anything you cannot verify as
UNVERIFIED. When docs conflict with existing code, surface the conflict — don't silently pick one. See references/source-verification.md. - Run the typecheck and the affected test file(s) after each slice. Don't repeat a command on unchanged code — it adds no information.
What ships with it
4 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.
- 2d ago First seen · 86 lines · 126 tokens per session scan A dcaf5464ee68
implement is a skill published in the GitHub repository int2t05/engineering-skills (3 stars, last pushed 14d ago), licensed MIT. It adds 126 tokens to every session and 1,170 once invoked, about $0.0006 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 2026-08-31.
Other skills, from other repositories
test-driven-development
Use when implementing any feature or bugfix, before writing implementation code.
absolute-work
End-to-end, phase-gated SDLC for AI coding agents: relentless design interview → reviewed spec → dependency-graphed task board → safe-wave TDD execution → verification → converge. Handles features, bugs, refactors, greenfield projects, planning breakdowns, and migrations. Triggers on "absolute work", "build this…
implementer
Write minimal production-quality code to make failing tests pass. This is the GREEN phase of TDD.
tdd-cycle
Execute a complete Test-Driven Development cycle for a feature from the specification through production-quality code.
test-writer
Generate comprehensive failing tests from a feature specification. This is the RED phase of TDD — write tests before implementation.
tdd
Test-driven development discipline: the red-green-refactor cycle, the testing pyramid's proportion of unit/integration/e2e, Fowler's test-double taxonomy, and the FIRST properties of a test worth keeping. Use when building a feature or fixing a bug test-first, mentions "TDD" or "red-green-refactor", or when deciding…