backend-builder

backend-builder is an agent for Claude Code from zstevovich/claude-apd. It costs 16 tokens per session (481 once invoked), scanned A, original, MIT.

A backend-focused helper agent for TaskFlow, a project built with Node.js, Express, TypeScript, PostgreSQL, Prisma, and Zod.

In plain words
What is it for?
Building API endpoints, services, repositories, validation, and other backend changes in the TaskFlow codebase.
Why use it?
It gives backend work a defined role and set of project rules, so API and data-layer changes follow the stated workflow.

Agent for Claude Code

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the claude-apd plugin — 11 skills, 5 agents, 8 hooks, 1 MCP server shipped together

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/zstevovich/claude-apd/backend-builder
Clone the repo
git clone --depth 1 https://github.com/zstevovich/claude-apd

Made for: Claude Code.

Or install claude-apd, the plugin that ships this one along with the rest of its 11 skills, 5 agents, 8 hooks, 1 MCP server.

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-builder

README.md
[![agentmods](https://agentmods.dev/badge/agents/zstevovich/claude-apd/backend-builder.svg)](https://agentmods.dev/agents/zstevovich/claude-apd/backend-builder)
Your own site
<a href="https://agentmods.dev/agents/zstevovich/claude-apd/backend-builder"><img src="https://agentmods.dev/badge/agents/zstevovich/claude-apd/backend-builder.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 481 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 5.1 $0.00016 $0.00481
Opus 5 $0.00008 $0.00241
Sonnet 5 $0.00003 $0.00096
Haiku 4.5 $0.00002 $0.00048

Measured 5d ago against content hash f1e234ec7b04, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

backend-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 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

examples/nodejs-react/.claude/agents/backend-builder.md · 56 lines

What it actually says

You are the backend builder for TaskFlow.

Stack

  • Node.js 20 + Express 5 + TypeScript
  • PostgreSQL 16 + Prisma ORM
  • Zod for validation

Workflow

  1. Read the spec card and understand the requirements
  2. Load relevant skills if they exist
  3. Implement the changes
  4. Respect the max 3-4 edit operations per dispatch
  5. Do not overlap with other agents

FORBIDDEN

  • NEVER commit changes — git add, git commit, git push are FORBIDDEN. The orchestrator controls commits using the APD_ORCHESTRATOR_COMMIT=1 prefix.
  • NEVER create types from the specification — always read the backend code
  • NEVER add AI signatures — style is human
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 · 56 lines · 16 tokens per session scan A f1e234ec7b04

Subscribe to this mod's changes

backend-builder is an agent published in the GitHub repository zstevovich/claude-apd (5 stars, last pushed 1mo ago), licensed MIT. It adds 16 tokens to every session and 481 once invoked, about $0.0001 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 2026-08-31.