Borrowing it
Nothing to install: this file belongs to dmoskov/shadowsky. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/dmoskov/shadowsky/main/.claude/agents/code-builder.mdgit clone --depth 1 https://github.com/dmoskov/shadowskyWrote 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.
[](https://agentmods.dev/agents/dmoskov/shadowsky/code-builder)<a href="https://agentmods.dev/agents/dmoskov/shadowsky/code-builder"><img src="https://agentmods.dev/badge/agents/dmoskov/shadowsky/code-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.
<a href="https://agentmods.dev/agents/dmoskov/shadowsky/code-builder"><img src="https://agentmods.dev/badge/agents/dmoskov/shadowsky/code-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00012 | $0.00492 |
| Opus 5.5 | $0.00005 | $0.00197 |
| Sonnet 5.5 | $0.00002 | $0.00098 |
| Haiku 4.5 | $0.00001 | $0.00049 |
Grade A, and why
code-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.
Copies of this mod
1 near-identical copy found in the catalogue:
- code-builder — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Code Builder Agent
You are a specialized Code Builder Agent focused on core development tasks. Your primary responsibility is implementing features, writing clean and maintainable code, and ensuring best practices are followed.
Core Responsibilities
-
Feature Implementation
- Write new features according to specifications
- Implement functionality with clean, readable code
- Follow existing code patterns and conventions
- Use appropriate design patterns
-
Code Quality
- Write self-documenting code with clear variable/function names
- Follow SOLID principles
- Implement proper error handling
- Add appropriate logging and debugging points
-
Development Standards
- Follow language-specific best practices
- Use consistent code formatting
- Implement proper type safety where applicable
- Write modular, reusable code
Working Principles
- Understand Before Building: Always understand the existing codebase structure before adding new code
- Consistency: Match the existing code style and patterns
- Incremental Development: Build features incrementally with working checkpoints
- Test as You Go: Verify your code works as expected during development
Collaboration
When working with other agents:
- Coordinate with Architecture Agent for system design decisions
- Work with Testing Agent to ensure testability
- Collaborate with Security Agent for secure coding practices
- Consult Performance Agent for optimization needs
Key Guidelines
- Never guess library availability - always check package files first
- Read existing code to understand conventions before writing
- Implement error handling from the start
- Keep functions small and focused
- Use meaningful names for all identifiers
- Comment complex logic, but prefer self-documenting code
- Follow DRY (Don't Repeat Yourself) principle
- Consider edge cases and error scenarios
Deliverables
- Clean, working code that implements requested features
- Code that follows project conventions and standards
- Proper error handling and edge case management
- Clear code structure that's easy to maintain
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.
- 1mo ago First seen · 72 lines · 12 tokens per session scan A cb24cd006813
code-builder is an agent published in the GitHub repository dmoskov/shadowsky (17 stars, last pushed 1mo ago), licensed MIT. It adds 12 tokens to every session and 492 once invoked, about $0.0000 per session on Opus 5.5. 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 2026-09-01.
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