don-cheli-sdd: Skill for Claude Code

.agent/skills/doncheli-implement/SKILL.md

doncheli-implement is a skill for Claude Code from doncheli/don-cheli-sdd. It costs 53 tokens per session (250 once invoked), scanned A, original, Apache-2.0.

A test-first coding workflow based on TDD, or test-driven development. It writes a failing test, adds the smallest code needed to pass it, then cleans up the code without changing its behavior.

In plain words
What is it for?
Use it to implement tasks from a task list while pairing each change with tests. It checks for unfinished stubs, runs the linter, and verifies that tests pass, coverage is met, and the project builds.
Why use it?
It helps prevent untested code, unfinished placeholders, and regressions during implementation. It also checks tests, code style, coverage, and the build as work progresses.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

This is doncheli/don-cheli-sdd's own configuration. It tells Claude Code how to work on don-cheli-sdd itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything don-cheli-sdd configures →

Part of the don-cheli-sdd plugin — 28 skills, 115 commands, 1 agent shipped together

Reuse

Borrowing it

Nothing to install: this file belongs to doncheli/don-cheli-sdd. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/doncheli/don-cheli-sdd/main/.agent/skills/doncheli-implement/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/doncheli/don-cheli-sdd

Made for: Claude Code.

Or install don-cheli-sdd, the plugin that ships this one along with the rest of its 28 skills, 115 commands, 1 agent.

Wrote 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.

agentmods badge for doncheli-implement

README.md
[![agentmods](https://agentmods.dev/badge/skills/doncheli/don-cheli-sdd/doncheli-implement.svg)](https://agentmods.dev/skills/doncheli/don-cheli-sdd/doncheli-implement)
Your own site
<a href="https://agentmods.dev/skills/doncheli/don-cheli-sdd/doncheli-implement"><img src="https://agentmods.dev/badge/skills/doncheli/don-cheli-sdd/doncheli-implement.svg" alt="Measured on agentmods" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00053 $0.00250
Opus 5 $0.00026 $0.00125
Sonnet 5 $0.00011 $0.00050
Haiku 4.5 $0.00005 $0.00025

Measured 8d ago against content hash 1984310f1893, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

doncheli-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 8d 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.

.agent/skills/doncheli-implement/SKILL.md · 26 lines

What it actually says

Don Cheli: TDD Implementer

Iron Law #1: TDD is MANDATORY

Every piece of production code MUST have a test written BEFORE the implementation.

Cycle

  1. RED: Write a test that FAILS
  2. GREEN: Write MINIMUM code to make the test pass
  3. REFACTOR: Clean up without changing behavior

Rules

  • Never skip tests
  • Never mark a task complete if stubs exist (// TODO, throw new Error('not implemented'))
  • Run linter after each task
  • Check coverage >= 85% on new code
  • If a test fails 3 times, STOP and ask the user (Stop-Loss rule)

Quality Gates

  • Gate 5: All tasks have TDD pairs (test + implementation)
  • Gate 6: All tests pass, coverage met, lint clean, build succeeds
Changes

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.

  1. 8d ago First seen · 26 lines · 53 tokens per session scan A 1984310f1893

Subscribe to this mod's changes

doncheli-implement is a skill published in the GitHub repository doncheli/don-cheli-sdd (57 stars, last pushed 28d ago), licensed Apache-2.0. It adds 53 tokens to every session and 250 once invoked, about $0.0003 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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