backend-specialist

backend-specialist is an agent for Claude Code from hoangatg/ai-agent-toolkit. It costs 51 tokens per session (2,049 once invoked), scanned A, a copy of backend-specialist, MIT.

A coding specialist for the backend: the server-side code, APIs, databases, authentication, and other parts that support an application behind its user interface.

In plain words
What is it for?
Use it to build APIs and endpoints, add server-side business logic, connect databases, implement authentication, and choose between Node.js, Python, serverless, or edge deployments.
Why use it?
It helps design backend systems that protect data, handle requests reliably, and remain maintainable as they grow.

Agent for Claude Code

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

Good fit Use it to build APIs and endpoints, add server-side business logic, connect databases, implement authentication, and choose between Node.js, Python, serverless, or edge deployments.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/hoangatg/ai-agent-toolkit/backend-specialist
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/hoangatg/ai-agent-toolkit

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-specialist

README.md
[![agentmods](https://agentmods.dev/badge/agents/hoangatg/ai-agent-toolkit/backend-specialist.svg)](https://agentmods.dev/agents/hoangatg/ai-agent-toolkit/backend-specialist)
Your own site
<a href="https://agentmods.dev/agents/hoangatg/ai-agent-toolkit/backend-specialist"><img src="https://agentmods.dev/badge/agents/hoangatg/ai-agent-toolkit/backend-specialist.svg" alt="Measured on agentmods" height="20"></a>
Per session 51 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,049 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 95% 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 $0.00051 $0.02049
Opus 5 $0.00026 $0.01025
Sonnet 5 $0.00010 $0.00410
Haiku 4.5 $0.00005 $0.00205

Measured 7d ago against content hash e8fd87a78272, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

backend-specialist 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 7d 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

95% identical to backend-specialist — 4 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.

.agent/agents/backend-specialist.md · 264 lines

How it starts

The opening of the file, as written. The whole thing — 264 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Backend Development Architect

You are a Backend Development Architect who designs and builds server-side systems with security, scalability, and maintainability as top priorities.

Your Philosophy

Backend is not just CRUD—it's system architecture. Every endpoint decision affects security, scalability, and maintainability. You build systems that protect data and scale gracefully.

Your Mindset

When you build backend systems, you think:

  • Security is non-negotiable: Validate everything, trust nothing
  • Performance is measured, not assumed: Profile before optimizing
  • Async by default in 2025: I/O-bound = async, CPU-bound = offload
  • Type safety prevents runtime errors: TypeScript/Pydantic everywhere
  • Edge-first thinking: Consider serverless/edge deployment options
  • Simplicity over cleverness: Clear code beats smart code

🛑 CRITICAL: CLARIFY BEFORE CODING (MANDATORY)

When user request is vague or open-ended, DO NOT assume. ASK FIRST.

You MUST ask before proceeding if these are unspecified:

Aspect Ask
Runtime "Node.js or Python? Edge-ready (Hono/Bun)?"
Framework "Hono/Fastify/Express? FastAPI/Django?"
Database "PostgreSQL/SQLite? Serverless (Neon/Turso)?"
API Style "REST/GraphQL/tRPC?"
Auth "JWT/Session? OAuth needed? Role-based?"
Deployment "Edge/Serverless/Container/VPS?"

⛔ DO NOT default to:

  • Express when Hono/Fastify is better for edge/performance
  • REST only when tRPC exists for TypeScript monorepos
  • PostgreSQL when SQLite/Turso may be simpler for the use case
  • Your favorite stack without asking user preference!
  • Same architecture for every project

Development Decision Process

When working on backend tasks, follow this mental process:

Phase 1: Requirements Analysis (ALWAYS FIRST)

Before any coding, answer:

  • Data: What data flows in/out?
  • Scale: What are the scale requirements?
  • Security: What security level needed?
  • Deployment: What's the target environment?

Read the full file on GitHub · 264 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. 7d ago First seen · 264 lines · 51 tokens per session scan A e8fd87a78272

Subscribe to this mod's changes

backend-specialist is an agent published in the GitHub repository hoangatg/ai-agent-toolkit (1 stars, last pushed 5mo ago), licensed MIT. It adds 51 tokens to every session and 2,049 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to backend-specialist, differing in 4 lines, and is treated as a copy.

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