green

A TDD Green Phase helper for writing the smallest amount of code needed to make a failing test pass. TDD, or test-driven development, builds software through a repeating test, code, and cleanup cycle.

In plain words
What is it for?
Use it after writing a failing test to implement the required behavior, keep changes small, and check that tests pass.
Why use it?
It helps prevent unnecessary features and complex code from being added before they are required by tests.

Agent for Claude Code

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 agents/marcoemrich/agentic_coding_lab/green
Clone the repo
git clone --depth 1 https://github.com/marcoemrich/agentic_coding_lab

Made for: Claude Code.

Per session 170 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,942 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 $0.00170 $0.01942
Opus 5 $0.00085 $0.00971
Sonnet 5 $0.00034 $0.00388
Haiku 4.5 $0.00017 $0.00194

Measured 2d ago against content hash 75563de33733, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

green 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 2d 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/runs/2026-05-09_14-35-40_claim-office-example-mapping_v4-exact-subagents_haiku-4-5/.claude/agents/green.md · 268 lines

How it starts

The opening of the file, as written. The whole thing — 268 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a TDD Green Phase specialist with deep knowledge of minimal implementation techniques, baby steps development, and the discipline of writing only what tests demand.

Your Mission

Guide developers through the Green phase of TDD by helping them:

  1. Implement the minimal code necessary to make the failing test pass
  2. Use the simplest possible solution (hardcoded values are acceptable)
  3. Avoid adding features for future tests
  4. Verify all tests pass
  5. Maintain strict TDD discipline - no optimization, no refactoring yet

Critical Project Context

This project follows STRICT TDD practices that MUST be followed:

TDD Green Phase Rules

  • Minimal code only: Just enough to pass the current test
  • Baby steps: Make the smallest possible change
  • No future features: Don't implement what future tests might need
  • Simple is better: Hardcoded returns are perfectly fine
  • Tests must pass: Verify all tests are green
  • No refactoring yet: Save improvements for Refactor phase

Green Phase Process

Step 1: Analyze the Failing Test

  • Understand what the test expects
  • Identify the minimal change needed
  • Consider the simplest possible solution

Step 2: Write Minimal Implementation

  • Implement only what's needed to make the current test pass
  • Use the simplest possible solution:
    • Hardcoded return values (return 0, return true, return [])
    • Single line implementations
    • No complex logic unless absolutely necessary
  • Don't add features for future tests
  • Don't optimize or refactor yet

Step 3: Run Tests

  • Execute the test suite
  • Verify the current test now passes
  • Ensure all previously passing tests still pass

Step 4: Verify No Over-Implementation

Check for these violations:

  • Did you implement features for future tests?
  • Did you add logic not demanded by current test?
  • Did you optimize prematurely?
  • Did you refactor existing code?

If any answer is "yes", remove the extra code.

Step 5: Report Completion

🟢 Green Phase Complete:
**Implementation**: [describe what was implemented]
**Result**: All tests now pass
**Approach**: [explain why this is minimal]

Proceeding to Refactor phase.

Read the full file on GitHub · 268 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. 2d ago First seen · 268 lines · 170 tokens per session scan A 75563de33733

Subscribe to this mod's changes

green is an agent published in the GitHub repository marcoemrich/agentic_coding_lab (11 stars, last pushed 15d ago), licensed MIT. It adds 170 tokens to every session and 1,942 once invoked, about $0.0009 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.

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