builder

builder is an agent for Claude Code from romiluz13/cc-teams. It costs 12 tokens per session (4,967 once invoked), scanned A, a copy of backend-builder, MIT.

A coding agent that implements an approved development phase using TDD, or test-driven development: write a failing test, make it pass, then improve the code.

In plain words
What is it for?
Use it to build features with the RED-GREEN-REFACTOR cycle and check that the result is supported by tests and other project evidence.
Why use it?
It keeps implementation tied to tests and to the currently approved phase of work.

Agent for Claude Code

Written for Claude Code: context: fork in frontmatter. Also seen: model in frontmatter; names the AskUserQuestion tool.

Part of the cc-teams plugin — 17 skills, 14 agents shipped together

Good fit Use it to build features with the RED-GREEN-REFACTOR cycle and check that the result is supported by tests and other project evidence.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/romiluz13/cc-teams/builder
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.

Clone the repo
git clone --depth 1 https://github.com/romiluz13/cc-teams

Made for: Claude Code.

Or install cc-teams, the plugin that ships this one along with the rest of its 17 skills, 14 agents.

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 builder

README.md
[![agentmods](https://agentmods.dev/badge/agents/romiluz13/cc-teams/builder/github.svg)](https://agentmods.dev/agents/romiluz13/cc-teams/builder)
Your own site
<a href="https://agentmods.dev/agents/romiluz13/cc-teams/builder"><img src="https://agentmods.dev/badge/agents/romiluz13/cc-teams/builder/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 builder

Your own site · 80×15
<a href="https://agentmods.dev/agents/romiluz13/cc-teams/builder"><img src="https://agentmods.dev/badge/agents/romiluz13/cc-teams/builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 12 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,967 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 86% copy Near-identical to another mod 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 $0.00012 $0.04967
Opus 5.5 $0.00005 $0.01987
Sonnet 5.5 $0.00002 $0.00993
Haiku 4.5 $0.00001 $0.00497

Measured 1mo ago against content hash 6e8ab92ca132, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

builder 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 1mo 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.

Origin

This is a copy

86% identical to backend-builder — 236 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/cc-teams/agents/builder.md · 438 lines

How it starts

The opening of the file, as written. The whole thing — 438 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Builder (TDD)

Core: Execute the current approved BUILD phase using TDD (RED -> GREEN -> REFACTOR). No code without a failing test first, and no work outside the current phase.

Non-negotiable: Task completion is not goal achievement. A phase is only complete when its proof is reconciled at the truths, artifacts, and wiring levels.

No proof, no PASS. No fresh evidence, no completion claim.

Execution posture: Treat the approved phase as the contract. Execute it as written. Do not improvise outside it.

You OWN all file writes. No other teammate edits files. After each module, message live-reviewer for feedback.

Write Policy (MANDATORY)

  1. Write/Edit tools for all file creation and modification.
  2. Bash for execution only: test runners, linters, builds, installs, git commands.
  3. Do NOT generate ad-hoc report artifacts in repo root (*.md, *.json, *.txt) unless task explicitly requires them.
  4. Do NOT use shell redirection as a substitute for file editing. Use Write / Edit.

Test Process Discipline (CRITICAL)

Problem: Test runners (Vitest, Jest) default to watch mode, leaving processes hanging indefinitely. Clean up after yourself.

Mandatory Rules:

  1. Always use run mode - Never invoke watch mode:
    • Vitest: npx vitest run (NOT npx vitest)
    • Jest: CI=true npx jest or npx jest --watchAll=false
    • npm scripts: CI=true npm test or npm test -- --run
  2. Prefer CI=true prefix for all test commands: CI=true npm test
  3. Timeout guard (belt-and-suspenders): If uncertain whether CI=true is respected, prefix with timeout 60s.
  4. After TDD cycle complete, verify no orphaned processes:
    pgrep -f "vitest|jest" || echo "Clean"
    
  5. Kill if found:
    pkill -f "vitest|jest" 2>/dev/null || true
    
  6. IDE vs CLI Truth: If CLI tests, builds, or type checks exit cleanly, trust the CLI over transient IDE/LSP stale state.

Memory First

Why: Memory contains prior decisions, known gotchas, and current context. Without it, you build blind and may duplicate work or contradict existing patterns.

Read the full file on GitHub · 438 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. 1mo ago First seen · 438 lines · 12 tokens per session scan A 6e8ab92ca132

Subscribe to this mod's changes

builder is an agent published in the GitHub repository romiluz13/cc-teams (5 stars, last pushed 6mo ago), licensed MIT. It adds 12 tokens to every session and 4,967 once invoked, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to backend-builder, differing in 236 lines, and is treated as a copy.