tdd

tdd is a skill for Claude Code, Codex from Shelpuk-AI-Technology-Consulting/agent-skill-tdd. It costs 59 tokens per session (1,880 once invoked), scanned A, original, MIT.

A required workflow for coding tasks based on test-driven development, or TDD: write a test, make the smallest change needed, and verify it. It also requires investigating the project first and recording task requirements.

In plain words
What is it for?
Use it to guide coding work through project investigation, requirement confirmation, API checks, small implementation steps, and test verification.
Why use it?
It creates a repeatable process for understanding requirements and catching mistakes as code is added. The input does not describe a particular application feature.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to guide coding work through project investigation, requirement confirmation, API checks, small implementation steps, and test verification.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd
Install

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.

Any agent
npx skills add Shelpuk-AI-Technology-Consulting/agent-skill-tdd --skill tdd
Clone the repo
git clone --depth 1 https://github.com/Shelpuk-AI-Technology-Consulting/agent-skill-tdd

Made for: Claude Code, Codex.

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 tdd

README.md
[![agentmods](https://agentmods.dev/badge/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd/github.svg)](https://agentmods.dev/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd)
Your own site
<a href="https://agentmods.dev/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd"><img src="https://agentmods.dev/badge/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd/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.

agentmods 80×15 button for tdd

Your own site · 80×15
<a href="https://agentmods.dev/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd"><img src="https://agentmods.dev/badge/skills/shelpuk-ai-technology-consulting/agent-skill-tdd/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 59 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,880 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 $0.00059 $0.01880
Opus 5 $0.00030 $0.00940
Sonnet 5 $0.00012 $0.00376
Haiku 4.5 $0.00006 $0.00188

Measured 10d ago against content hash 8500b3138dfa, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

tdd 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 10d 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.

skills/tdd/SKILL.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Working Agreement

This skill is intentionally always-on for coding tasks. Follow it exactly unless the user explicitly opts out.

Non-negotiables

  1. Serena first: Start by activating the Serena project (if the Serena tools exist in the environment). If activation fails for reasons outside your control, continue without Serena and say why.
  2. Investigate before changing anything: Understand the current state (application state, execution results, user input, logs) before proposing edits.
  3. No requirement changes without confirmation: If requirements are unclear, ask clarifying questions. Before you change/add/interpret requirements, get explicit confirmation.
  4. Create a per-task REQUIREMENTS.md before implementation:
    • Create/use root .requirements/.
    • For each task, choose a short snake_case feature name using lowercase ASCII letters, digits, and underscores only (for example, update_github_authentication).
    • Create a folder named <datetime>_<feature_name> using UTC datetime format YYYYMMDDTHHMMSSZ (for example, 20260301T143210Z_update_github_authentication).
    • If the folder already exists, append a numeric suffix (_01, _02, and so on) to avoid collisions. Example: .requirements/20260301T143210Z_update_github_authentication_01/.
    • Write the task requirements file to .requirements/<datetime>_<feature_name>/REQUIREMENTS.md using the mandated structure (below).
  5. Use up-to-date docs: When you rely on an API/package/technology detail, use Kindly Web Search (if available) to confirm signatures, version behavior, breaking changes, and deprecations.
  6. Smallest possible steps (TDD): Implement one small change at a time and test each change (unit → integration → smoke as appropriate) before proceeding.

Per-task REQUIREMENTS.md Structure (Mandated)

For each task, write REQUIREMENTS.md to .requirements/<datetime>_<feature_name>/REQUIREMENTS.md with:

  1. As Is: current behavior/state (what exists today).
  2. To Be: desired behavior/state after the change.
  3. Requirements: functional requirements (numbered).
  4. Acceptance Criteria: for every functional requirement, add explicit acceptance criteria.
  5. Testing Plan: test strategy + cases (TDD best practices).
  6. Implementation Plan: the smallest sequential code changes; for each change, include how you’ll test it.

Read the full file on GitHub · 159 lines

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. 10d ago First seen · 159 lines · 59 tokens per session scan A 8500b3138dfa

Subscribe to this mod's changes

tdd is a skill published in the GitHub repository Shelpuk-AI-Technology-Consulting/agent-skill-tdd (30 stars, last pushed 5mo ago), licensed MIT. It adds 59 tokens to every session and 1,880 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.