test-first-development

test-first-development is a skill for Claude Code, Codex from Stivi7/cyberpunk-context-runners. It costs 20 tokens per session (250 once invoked), scanned A, original, MIT.

A development method that writes an automated test for a behavior before implementing the change. TDD, or test-driven development, uses a failing test followed by a passing implementation.

In plain words
What is it for?
Changing behavior, fixing bugs, or refactoring when an executable test is practical, while recording the initial failure and later passing verification.
Why use it?
It checks that the test actually detects the missing behavior and helps limit implementation to what the requirement needs.

Skill for Claude CodeCodex

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

Good fit Changing behavior, fixing bugs, or refactoring when an executable test is practical, while recording the initial failure and later passing verification.

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Install with agentmods
npx agentmods add skills/stivi7/cyberpunk-context-runners/test-first-development
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 Stivi7/cyberpunk-context-runners --skill test-first-development
Clone the repo
git clone --depth 1 https://github.com/Stivi7/cyberpunk-context-runners

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-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/stivi7/cyberpunk-context-runners/test-first-development.svg)](https://agentmods.dev/skills/stivi7/cyberpunk-context-runners/test-first-development)
Your own site
<a href="https://agentmods.dev/skills/stivi7/cyberpunk-context-runners/test-first-development"><img src="https://agentmods.dev/badge/skills/stivi7/cyberpunk-context-runners/test-first-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 20 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 250 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 $0.00020 $0.00250
Opus 5 $0.00010 $0.00125
Sonnet 5 $0.00004 $0.00050
Haiku 4.5 $0.00002 $0.00025

Measured 8d ago against content hash 5e2687121302, 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-development 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.

templates/skills/core/test-first-development/SKILL.md · 39 lines

What it actually says

Test-First Development

Metadata

  • Version: 1.0.0
  • Triggers: Behavior change, bug fix, or refactor with observable behavior
  • Allowed agents: Daemon, Neon, Grid Master
  • Side effects: Adds or changes tests and implementation

When to Use

Use for executable behavior. For pure documentation or configuration without a practical executable assertion, record why a test is not appropriate and use the strongest available validation.

Inputs

Acceptance criterion, current behavior, project test conventions, and relevant command registry entry.

Procedure

  1. Write one minimal test for the desired behavior.
  2. Run it and confirm it fails for the missing behavior, not a test defect.
  3. Implement the smallest passing change.
  4. Run the focused test and relevant broader suite.
  5. Refactor only while green.
  6. Repeat for the next behavior.

Verification

Record the expected failing observation and the later passing observation. A test that never failed does not prove the change.

Output

Test added, red evidence, implementation summary, green evidence, and justified exceptions.

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 · 39 lines · 20 tokens per session scan A 5e2687121302

Subscribe to this mod's changes

test-first-development is a skill published in the GitHub repository Stivi7/cyberpunk-context-runners (4 stars, last pushed yesterday), licensed MIT. It adds 20 tokens to every session and 250 once invoked, about $0.0001 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.