test-first

test-first is a skill for Claude Code, Codex from s-hiraoku/synapse-a2a. It costs 48 tokens per session (399 once invoked), scanned A, original, no licence file.

A guide to test-first development, often called test-driven development or TDD, where tests are written before the code they check. It covers test design, edge cases, coverage, and the Arrange-Act-Assert pattern.

In plain words
What is it for?
Use it when planning tests, defining requirements through examples, or implementing code with tests written first.
Why use it?
It helps clarify expected behavior before implementation and makes missing cases easier to spot.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it when planning tests, defining requirements through examples, or implementing code with tests written first.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/s-hiraoku/synapse-a2a/test-first
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 s-hiraoku/synapse-a2a --skill test-first
Clone the repo
git clone --depth 1 https://github.com/s-hiraoku/synapse-a2a

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 test-first

README.md
[![agentmods](https://agentmods.dev/badge/skills/s-hiraoku/synapse-a2a/test-first.svg)](https://agentmods.dev/skills/s-hiraoku/synapse-a2a/test-first)
Your own site
<a href="https://agentmods.dev/skills/s-hiraoku/synapse-a2a/test-first"><img src="https://agentmods.dev/badge/skills/s-hiraoku/synapse-a2a/test-first.svg" alt="Measured on agentmods" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 399 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00048 $0.00399
Opus 5 $0.00024 $0.00199
Sonnet 5 $0.00010 $0.00080
Haiku 4.5 $0.00005 $0.00040

Measured 8d ago against content hash aa88a2d6c639, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

test-first 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.

.agents/skills/test-first/SKILL.md · 40 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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.

  1. 8d ago First seen · 40 lines · 48 tokens per session scan A aa88a2d6c639

Subscribe to this mod's changes

test-first is a skill published in the GitHub repository s-hiraoku/synapse-a2a (14 stars, last pushed 24d ago), with no licence file. It adds 48 tokens to every session and 399 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 2026-08-30.