A test-first development workflow, commonly called TDD, where tests are written and checked before implementation code is added.

It is for implementing features, fixes, and refactors with tests that guide and verify the code.

It makes the required behavior explicit and verifies the change through separate test, coverage, and lint stages.

tdd — Skill for Claude Code by arbiterForge/codeArbiter

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 arbiterForge/codeArbiter --skill tdd

Clone the repo

git clone --depth 1 https://github.com/arbiterForge/codeArbiter

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/arbiterforge/codearbiter/tdd/github.svg)](https://agentmods.dev/skills/arbiterforge/codearbiter/tdd)

Your own site

<a href="https://agentmods.dev/skills/arbiterforge/codearbiter/tdd"><img src="https://agentmods.dev/badge/skills/arbiterforge/codearbiter/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/arbiterforge/codearbiter/tdd"><img src="https://agentmods.dev/badge/skills/arbiterforge/codearbiter/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,547 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00033	$0.01547
Opus 5.5	$0.00013	$0.00619
Sonnet 5.5	$0.00007	$0.00309
Haiku 4.5	$0.00003	$0.00155

Measured today against content hash 0bd6ba72760e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 today.

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.

core/surface/skills/tdd/SKILL.md · 131 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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.

today Changed · +4 lines 0bd6ba72760e
9d ago Changed · -113 lines · -40 tokens per session db16f470b5bc
21d ago Changed · +74 lines 90b74f55d9fa
29d ago Changed · +4 lines 92b46277e140
1mo ago Changed · +7 lines 446f32c9eb20
1mo ago Changed · +12 lines 5f48a0c6d840
1mo ago Changed · +3 lines 1db6da939684
1mo ago First seen · 140 lines · 73 tokens per session scan A a7adfdf9e41e

Subscribe to this mod's changes

tdd is a skill published in the GitHub repository arbiterForge/codeArbiter (149 stars, last pushed today), licensed AGPL-3.0. It adds 33 tokens to every session and 1,547 once invoked, about $0.0001 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 2026-09-03.

Orchestration TDD Testing ai ai-agents ai-coding ai-governance claude

enterprise-build

Use when a locked enterprise contract and mechanical build packet exist and implementation must proceed through strict TDD, contract traceability, receipt-only progress, and staged review handoffs. Always use this for enterprise build-stage work; stop if the complete build body is unavailable.

anotherben/claude-harness · 55 tokens

enterprise-forge

Adversarial code review with mechanical checks, contract probing, and 5 adversarial lenses. Bugs recycle to contract for full TDD treatment. 3-fail circuit breaker prevents infinite loops. Use after enterprise-review.

anotherben/claude-harness · 48 tokens

full-cycle-tdd

TDD-first development workflow. Agent Harness + Superpowers TDD discipline. Every task starts with a failing test. No code without a test first. Use for bug fixes, features where correctness is critical, or when you want maximum test coverage. Invoked with /full-cycle-tdd followed by a description.

anotherben/claude-harness · 67 tokens

tdd