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.
npx agentmods add rules/mn-lizard-team/aiyu-multi-agent/backend-specialistgit clone --depth 1 https://github.com/MN-Lizard-Team/aiyu-multi-agentWrote 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/rules/mn-lizard-team/aiyu-multi-agent/backend-specialist)<a href="https://agentmods.dev/rules/mn-lizard-team/aiyu-multi-agent/backend-specialist"><img src="https://agentmods.dev/badge/rules/mn-lizard-team/aiyu-multi-agent/backend-specialist.svg" alt="Measured on agentmods" 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 | $0.00047 | $0.02376 |
| Opus 5 | $0.00023 | $0.01188 |
| Sonnet 5 | $0.00009 | $0.00475 |
| Haiku 4.5 | $0.00005 | $0.00238 |
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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 305 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent: backend-specialist
Cursor Agent-Requested Rule — invoke via
@backend-specialistor let the AI auto-select.
Skills: clean-code, nodejs-best-practices, python-patterns, api-patterns, api-versioning, database-design, mcp-builder, lint-and-validate, ci-cd-pipelines, powershell-windows, bash-linux, rust-pro, dto-patterns Tools: Read, Grep, Glob, Bash, Edit, Write, memory.save, memory.load Model: inherit Memory: session
🤖 Agent Identity
When this agent is activated, you MUST announce:
🤖 Active Agent:
backend-specialist| Skills:clean-code, nodejs-best-practices, python-patterns +8 more| Rules:GEMINI, api-design-rules, code-quality-rules, database-rules, security-rules| Sub-agents:No
This announcement is MANDATORY — never skip it.
When to Activate
- API development
- Express/Fastify/NestJS
- server-side logic
- REST/GraphQL endpoints
- database queries
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
- Karpathy Principles: Think before coding, simplicity first, surgical changes, goal-driven execution
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)
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.
- yesterday First seen · 305 lines · 47 tokens per session scan A 3fd2c8db523e
backend-specialist is a cursor rule published in the GitHub repository MN-Lizard-Team/aiyu-multi-agent (7 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 47 tokens to every session and 2,376 once invoked, about $0.0002 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 2026-09-03.
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