test-driven-development-contractual

test-driven-development-contractual is a skill for Claude Code, Codex from SymbolicLight-AGI/contractual-skill. It costs 33 tokens per session (945 once invoked), scanned A, original, MIT.

A test-first development guide. Test-driven development (TDD) means writing a test that fails, then adding code to make it pass, and finally cleaning up the code.

In plain words
What is it for?
Use it to write and run a failing test, implement the smallest passing change, run the tests again, and then refactor while keeping them passing.
Why use it?
It gives feature, bug-fix, and refactoring work a repeatable record that shows the expected behavior before the implementation.

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/symboliclight-agi/contractual-skill/test-driven-development
Any agent
npx skills add SymbolicLight-AGI/contractual-skill --skill test-driven-development
Clone the repo
git clone --depth 1 https://github.com/SymbolicLight-AGI/contractual-skill

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-driven-development-contractual

README.md
[![agentmods](https://agentmods.dev/badge/skills/symboliclight-agi/contractual-skill/test-driven-development.svg)](https://agentmods.dev/skills/symboliclight-agi/contractual-skill/test-driven-development)
Your own site
<a href="https://agentmods.dev/skills/symboliclight-agi/contractual-skill/test-driven-development"><img src="https://agentmods.dev/badge/skills/symboliclight-agi/contractual-skill/test-driven-development.svg" alt="Measured on agentmods" 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 945 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 $0.00033 $0.00945
Opus 5 $0.00016 $0.00473
Sonnet 5 $0.00007 $0.00189
Haiku 4.5 $0.00003 $0.00094

Measured 5d ago against content hash fa30df3becc0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-driven-development-contractual 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 5d 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.

experiments/market-validated-skills-stage2/skill-variants/contractual/test-driven-development/SKILL.md · 131 lines

How it starts

The opening of the file, as written. The whole thing — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Test-Driven Development Contract

When To Use

Use this Skill for new features, bug fixes, refactoring, and behavior changes when implementation work is requested.

Ask the human partner before using another workflow for throwaway prototypes, generated code, or configuration-only changes.

Goal

Guide the agent through test-first development: write a minimal failing test, verify it fails for the expected reason, implement the smallest passing change, verify all tests pass, then refactor while staying green.

Audience

  • Engineers implementing code changes.
  • Reviewers checking whether a change followed TDD.
  • Maintainers who need a repeatable test record before accepting behavior changes.

Inputs

  • Required: desired behavior or bug report, relevant code location, test command or framework, and expected observable outcome.
  • Optional: existing tests, reproduction steps, error output, constraints, and edge cases.
  • Privacy: do not expose secrets, credentials, or private production data in test fixtures.

If the test command, framework, or expected behavior is missing, ask for it or proceed with clearly marked assumptions.

Context

Use the repository's existing test patterns, naming conventions, and helpers. If existing code was written before the test, do not treat it as validated TDD evidence unless a failing test was observed first.

Workflow

  1. Identify the smallest behavior to test.
  2. Write one minimal test that describes the desired behavior.
  3. Run the test and verify RED: it fails for the expected missing behavior, not for a typo or setup error.
  4. If the test fails for the wrong reason, fix the test and rerun RED.
  5. Write the minimal production code needed to pass.
  6. Run the target test and relevant suite to verify GREEN.
  7. Refactor only while tests stay green.
  8. Repeat for the next behavior or edge case.
  9. Record the test command, failing evidence, passing evidence, and any remaining gaps.

Permissions

Allowed:

  • Create or modify tests.
  • Run test commands.
  • Implement minimal production code after RED is observed.
  • Refactor code after GREEN is observed.
  • Ask for human permission when an exception is needed.

Read the full file on GitHub · 131 lines

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. 5d ago First seen · 131 lines · 33 tokens per session scan A fa30df3becc0

Subscribe to this mod's changes

test-driven-development-contractual is a skill published in the GitHub repository SymbolicLight-AGI/contractual-skill (21 stars, last pushed 3mo ago), licensed MIT. It adds 33 tokens to every session and 945 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.