tdd

tdd is a skill for Claude Code, Codex from friedbotstudio/baseline. It costs 82 tokens per session (3,620 once invoked), scanned A, original, Apache-2.0.

A coordinator for test-driven development, a workflow where tests are written to describe expected behavior before implementation.

In plain words
What is it for?
Use it to plan testing and implementation tasks, divide work among workers, and track verification through the development workflow.
Why use it?
It turns a development request into explicit test scenarios, implementation boundaries, and assigned work before coding starts.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/friedbotstudio/baseline/tdd
Any agent
npx skills add friedbotstudio/baseline --skill tdd
Clone the repo
git clone --depth 1 https://github.com/friedbotstudio/baseline

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/friedbotstudio/baseline/tdd.svg)](https://agentmods.dev/skills/friedbotstudio/baseline/tdd)
Your own site
<a href="https://agentmods.dev/skills/friedbotstudio/baseline/tdd"><img src="https://agentmods.dev/badge/skills/friedbotstudio/baseline/tdd.svg" alt="Measured on agentmods" height="20"></a>
Per session 82 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,620 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00082 $0.03620
Opus 5 $0.00041 $0.01810
Sonnet 5 $0.00016 $0.00724
Haiku 4.5 $0.00008 $0.00362

Measured today against content hash 6f32104b649d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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.

The scan reads SKILL.md. This mod also ships 5 executable files (drift_check.mjs, drift-reverify-guard.mjs, resolve-pointer.mjs, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/tdd/SKILL.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Character

  • Soul. The conductor who settles the whole score before the first note — which scenarios, which contract, which write set — and then holds the ensemble to it.
  • Motivation. A decision made once, in the open, is auditable. The same decision made mid-implementation is indistinguishable from drift.
  • Mantra. I close the loop I opened. A finding I raise mid-run stays mine until it is fixed or tagged with a reason.
  • Temperament. Decisive early and immovable later. Dislikes reopening a settled question mid-run, and keeps a running account of what it owes until the list is empty.
  • Voice. Announces the decision and its scope before the work starts, and names the write set out loud. When it raises something mid-run, it says who owns it and when it closes.
  • Resolve. I opened this loop. Nobody else is going to close it.

tdd — Phase 6 coordinator (post-decomposition)

This skill is a thin coordinator. It does not invoke scenario, implement, or design-ui itself. Instead, it writes a recipe + contract state file, seeds per-worker tasks into the TaskList, and yields with harness_state: "continue". The harness's next ticks pick up each worker task in order and invoke the matching skill — one Skill call per tick. The verify-tick worker is special: it has no Skill invocation at all; the harness inlines the four mechanical operations from .claude/skills/verify/SKILL.md (which is now contract-only, not Skill-tool-invocable).

Main-context decisions live here. Worker execution happens in harness ticks.

Prereq

Either an approved spec exists (.claude/state/spec_approvals/<slug>.approval) OR track_id in workflow.json is tdd-quickfix (post-§18; legacy entry_phase == "tdd" accepted on pre-§18 workflow.json files the harness preflight migrator hasn't run on yet — quickfix/bugfix direct-to-TDD route).

If neither, stop and direct the user to /triage first.

Steps

0.5 Brainstorm gate (tdd-quickfix entry only; CLAUDE.md Article XI.3)

Read the full file on GitHub · 127 lines

Files

What ships with it

5 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.

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. today First seen · 127 lines · 82 tokens per session scan A 6f32104b649d

Subscribe to this mod's changes

tdd is a skill published in the GitHub repository friedbotstudio/baseline (14 stars, last pushed yesterday), licensed Apache-2.0. It adds 82 tokens to every session and 3,620 once invoked, about $0.0004 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 2026-09-03.

Related

Other skills, from other repositories

tdd

The test-first gate. Routed to by /feature (after the spec is approved), /fix, and /refactor before any implementation code is written. Six gated phases — obligation scan, red, green, obligation verify, coverage, lint. No feature code exists before Phase 1 clears; nothing reaches commit-gate until all six are green.

arbiterForge/codeArbiter · 73 tokens

ca-feature

Start a feature: brainstorm a spec, get it approved, then drive it test-first through the pipeline. The one entry to implementation.

arbiterForge/codeArbiter · 30 tokens

ca-fix

Fix a confirmed bug: a failing regression test first, then a minimal fix, then the rest of the tdd gates.

arbiterForge/codeArbiter · 29 tokens

probe

Report this absolute source path, then read the nested routine.

arbiterForge/codeArbiter · 14 tokens

dev-standards

Enforces development workflows, quality gates, coding standards, and release processes for the deterministic-agent-control-protocol project. Use when implementing features, fixing bugs, refactoring architecture, adding integrations, updating policies, writing tests, updating documentation, or preparing releases.

elliot35/deterministic-agent-control-protocol · 56 tokens

brainstorming

The Socratic spec-refinement front of /feature, and the planning front of /sprint. Routed to BEFORE any code — it takes a one-line idea and drives it to an approved, concrete spec with testable acceptance criteria. Five gated phases — frame, shape, refine, write, review-and-approve. No implementation and no handoff to…

arbiterForge/codeArbiter · 99 tokens