backend-author

backend-author is an agent for Claude Code from arbiterForge/codeArbiter. It costs 55 tokens per session (808 once invoked), scanned A, original, AGPL-3.0.

A software agent for building and changing backend code, meaning the server-side part of an application. It follows test-driven development (TDD), writing a failing test before implementation, and handles input checks, framework conventions, and database access through an ORM.

In plain words
What is it for?
Use it when writing or modifying backend or server-side code. It reads the project’s technology choices from .codearbiter/tech-stack.md and requires failing tests before implementation.
Why use it?
It gives backend changes a consistent process for testing, validating user input, and using the project’s framework and database layer. This helps catch server-side errors before implementation is considered complete.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit Use it when writing or modifying backend or server-side code. It reads the project’s technology choices from .codearbiter/tech-stack.md and requires failing tests before implementation.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/arbiterforge/codearbiter/backend-author
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/arbiterForge/codeArbiter

Made for: Claude Code.

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 backend-author

README.md
[![agentmods](https://agentmods.dev/badge/agents/arbiterforge/codearbiter/backend-author/github.svg)](https://agentmods.dev/agents/arbiterforge/codearbiter/backend-author)
Your own site
<a href="https://agentmods.dev/agents/arbiterforge/codearbiter/backend-author"><img src="https://agentmods.dev/badge/agents/arbiterforge/codearbiter/backend-author/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 backend-author

Your own site · 80×15
<a href="https://agentmods.dev/agents/arbiterforge/codearbiter/backend-author"><img src="https://agentmods.dev/badge/agents/arbiterforge/codearbiter/backend-author.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 808 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00055 $0.00808
Opus 5.5 $0.00022 $0.00323
Sonnet 5.5 $0.00011 $0.00162
Haiku 4.5 $0.00006 $0.00081

Measured 1mo ago against content hash 3a9a7c3d1d60, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

backend-author scanned grade A with 1 finding 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

- No `child_process.exec()` or equivalent with `shell: true`
core/surface/agents/backend-author.md · 61 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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 Changed 3a9a7c3d1d60
  2. 1mo ago First seen · 61 lines · 55 tokens per session scan A 89d3da668d73

Subscribe to this mod's changes

backend-author is an agent published in the GitHub repository arbiterForge/codeArbiter (149 stars, last pushed today), licensed AGPL-3.0. It adds 55 tokens to every session and 808 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.