tdd

tdd is a skill for Claude Code, Codex from AyushParkara/syntra. It costs 32 tokens per session (264 once invoked), scanned A, original, Apache-2.0.

A test-driven development guide: write a test that fails, write the smallest code that makes it pass, then clean up the code. Test-driven development, or TDD, is a way to build software by letting tests lead each change.

In plain words
What is it for?
Use it when adding or changing behavior: create one focused test, confirm it fails for the right reason, implement the minimum fix, and then refactor safely.
Why use it?
It catches misunderstandings early and keeps code changes small, while existing tests help show that earlier behavior still works.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: model in frontmatter.

Good fit Use it when adding or changing behavior: create one focused test, confirm it fails for the right reason, implement the minimum fix, and then refactor safely.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ayushparkara/syntra/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 AyushParkara/syntra --skill tdd
Clone the repo
git clone --depth 1 https://github.com/AyushParkara/syntra

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/ayushparkara/syntra/tdd/github.svg)](https://agentmods.dev/skills/ayushparkara/syntra/tdd)
Your own site
<a href="https://agentmods.dev/skills/ayushparkara/syntra/tdd"><img src="https://agentmods.dev/badge/skills/ayushparkara/syntra/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/ayushparkara/syntra/tdd"><img src="https://agentmods.dev/badge/skills/ayushparkara/syntra/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 264 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 $0.00032 $0.00264
Opus 5 $0.00016 $0.00132
Sonnet 5 $0.00006 $0.00053
Haiku 4.5 $0.00003 $0.00026

Measured 8d ago against content hash 83773700cb3e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 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.

syntra/skills/tdd/SKILL.md · 28 lines

What it actually says

You practice strict test-driven development. The cycle is RED → GREEN → REFACTOR.

RED — write a failing test first:

  1. Write the smallest test that captures the next bit of desired behavior.
  2. Run it. Confirm it FAILS for the right reason (the behavior doesn't exist yet). A test that passes immediately tested nothing.

GREEN — make it pass with the simplest code: 3. Write the minimum code to make the test pass. No extra features. 4. Run the test. Confirm it now passes, and existing tests still pass.

REFACTOR — clean up with the safety net: 5. Improve naming, remove duplication, simplify — tests stay green throughout.

Rules:

  • Never write production code without a failing test demanding it.
  • One behavior per test; descriptive test names.
  • If a test passes on first run, it's suspect — verify it actually exercises the path.
  • Keep the cycle tight: small test, small code, repeat.

Output: Show the test first, confirm RED, then the code, confirm GREEN.

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 · 28 lines · 32 tokens per session scan A 83773700cb3e

Subscribe to this mod's changes

tdd is a skill published in the GitHub repository AyushParkara/syntra (5 stars, last pushed 28d ago), licensed Apache-2.0. It adds 32 tokens to every session and 264 once invoked, about $0.0002 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.