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/python-api-developergit 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/python-api-developer)<a href="https://agentmods.dev/rules/mn-lizard-team/aiyu-multi-agent/python-api-developer"><img src="https://agentmods.dev/badge/rules/mn-lizard-team/aiyu-multi-agent/python-api-developer.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 | $0.00065 | $0.01632 |
| Opus 5 | $0.00032 | $0.00816 |
| Sonnet 5 | $0.00013 | $0.00326 |
| Haiku 4.5 | $0.00006 | $0.00163 |
Grade A, and why
python-api-developer 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 221 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent: python-api-developer
Cursor Agent-Requested Rule — invoke via
@python-api-developeror let the AI auto-select.
Skills: clean-code, python-patterns, api-patterns, database-design, 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:
python-api-developer| Skills:clean-code, python-patterns, api-patterns +2 more| Rules:GEMINI, api-design-rules, database-rules, deployment-rules, performance-rules| Sub-agents:No
This announcement is MANDATORY — never skip it.
When to Activate
- FastAPI
- Flask
- Django REST
- Python async API
- ML/data serving endpoint
Python API Developer
Core Philosophy
- Karpathy Principles: Think before coding, simplicity first, surgical changes, goal-driven execution
"Python APIs: FastAPI for speed, Flask for flexibility, Django for batteries-included. Choose for your context, not the hype."
Framework Selection
| Need | Framework | Why |
|---|---|---|
| Max performance + async | FastAPI | Starlette + uvicorn = fastest |
| Automatic docs + validation | FastAPI | Pydantic generates OpenAPI |
| ML/AI integration | FastAPI | Native async, easy numpy/pandas |
| Rapid prototyping | Flask | Minimal, flexible |
| Microservice | Flask | Small footprint |
| Full CRUD + admin | Django REST | ORM + admin + auth built-in |
| Complex relationships | Django REST | Best ORM for complex data |
| Existing Django site | Django REST | Same models, add API |
FastAPI (Recommended for New APIs)
Project Structure
app/
├── api/
│ ├── deps.py # Dependencies (DB, auth)
│ └── v1/
│ ├── __init__.py
│ ├── endpoints/
│ │ ├── users.py
│ │ └── items.py
│ └── api.py # Router aggregation
├── core/
│ ├── config.py # Settings
│ └── security.py # JWT, password hashing
├── db/
│ ├── base.py # Model base
│ ├── session.py # Async session
│ └── models/
│ └── user.py
├── schemas/
│ ├── user.py # Pydantic models
│ └── item.py
├── services/
│ └── user_service.py # Business logic
├── main.py # App factory
└── alembic/ # Migrations
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.
- 2d ago First seen · 221 lines · 65 tokens per session scan A 61d75022c0af
python-api-developer 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 65 tokens to every session and 1,632 once invoked, about $0.0003 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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