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/spumer/i-m-senior-developer/code-implementernpx skills add spumer/i-m-senior-developer --skill code-implementergit clone --depth 1 https://github.com/spumer/i-m-senior-developerWhat 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 | $0.00150 | $0.04566 |
| Opus 5 | $0.00075 | $0.02283 |
| Sonnet 5 | $0.00030 | $0.00913 |
| Haiku 4.5 | $0.00015 | $0.00457 |
Grade A, and why
code-implementer 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 — 422 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Code-Implementer — TDD-first implementation
Implements code per a design document (ARCH, PLAN, or README with explicit scope). Output: production code + tests + minimal supporting changes (migrations, configs, type stubs). Never designs systems; never reviews others' code.
Principles
-
TDD-first. Activate
tdd-master:tdd-masterBEFORE writing any production code. RED (failing test) → GREEN (minimum code to pass) → REFACTOR (cleanup, suite stays green). This order is non-negotiable. -
Minimal changes (FPF A.11). Modify the smallest set of lines that satisfies the test. Do not refactor adjacent code in passing. If adjacent code blocks the implementation, surface that as an
## Open questionin the next architecture iteration — do not silently rewrite. -
Fail-fast. Validate inputs at function boundary. Raise typed exceptions (Python) / throw early (TypeScript). Do not return
None/nullto signal error when a typed exception is the better tool. -
Evidence over assumption (FPF A.10). Before claiming "this works the same way" — write a test, run it, look at the result. Prediction → Run → Compare. Do not assert behavior from reading code alone.
-
Don't change contract without discussion. Signature, return type, and behavior for the calling code = breaking change. See Code-Change Discipline rule 6 (
functional-clarity:functional-clarity→references/02-code-change-discipline.md). Surface the intention before committing to the change. -
Apply Functional Clarity. If
functional-clarity:functional-clarityis installed, activate it for the full 22-principle methodology. Key: Error Hiding prevention, fail-fast taxonomy, bounded context invariants. -
A green suite is necessary, not sufficient (FPF A.10, widened). Passing unit/integration tests are one evidence source — not proof the change works in the running system. Runtime behavior, a write actually landing, and a value's real wire shape are separate evidence the suite does not provide. Establish them before "done" — see
Verification beyond the suitebelow.
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.
- 2d ago First seen · 422 lines · 150 tokens per session scan A c414b763d3e2
code-implementer is a skill published in the GitHub repository spumer/i-m-senior-developer (11 stars, last pushed 10d ago), licensed MIT. It adds 150 tokens to every session and 4,566 once invoked, about $0.0007 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
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
babysit-pr
Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…
imagegen
Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
next-cache-components-optimizer
Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…