What is first-plan-lens-python?

A Python project detector for the planning stage. It identifies frameworks, packaging tools, layouts, type checking, validation, asynchronous code and testing setup from project files.

Use it to inspect projects using Django, FastAPI, Flask, Litestar, Celery, data-app tools or common Python packaging systems, and to record their typing, validation, async and testing conventions.

It helps an agent understand how a Python project is built before suggesting changes. This reduces advice that conflicts with the project's framework, package layout or development tools.

first-plan-lens-python — Skill for Claude Code by vynazevedo

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.

Any agent

npx skills add vynazevedo/first-plan --skill lens-python

Clone the repo

git clone --depth 1 https://github.com/vynazevedo/first-plan

Made for: Claude Code.

Or install fp, the plugin that ships this one along with the rest of its 19 skills, 19 commands, 4 agents, 1 hook.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/vynazevedo/first-plan/lens-python/github.svg)](https://agentmods.dev/skills/vynazevedo/first-plan/lens-python)

Your own site

<a href="https://agentmods.dev/skills/vynazevedo/first-plan/lens-python"><img src="https://agentmods.dev/badge/skills/vynazevedo/first-plan/lens-python/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/vynazevedo/first-plan/lens-python"><img src="https://agentmods.dev/badge/skills/vynazevedo/first-plan/lens-python.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 983 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 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.

Model	Per session	Once invoked
Fable 5.1	$0.00054	$0.00983
Opus 5.5	$0.00022	$0.00393
Sonnet 5.5	$0.00011	$0.00197
Haiku 4.5	$0.00005	$0.00098

Measured 1mo ago against content hash fb1c7b2626f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

first-plan-lens-python 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 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.

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.

skills/lens-python/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Lens Python

Detecção fina

Sinal	Variante
`manage.py` na raiz	Django
`fastapi` em deps	FastAPI
`flask` em deps	Flask
`litestar` em deps	Litestar
`celery` em deps	Worker
`streamlit` em deps	Data app
`dagster`, `airflow`, `prefect`	Data pipeline
`setup.py` apenas	lib legacy
`pyproject.toml` com `[tool.poetry]`	Poetry
`pyproject.toml` com `[tool.uv]` ou `uv.lock`	uv
`pyproject.toml` com `[build-system]` setuptools	setuptools moderno
`Pipfile`	pipenv

Extração de padrões

Packaging

Layout src/ vs flat
Namespace package vs regular
Versão Python suportada (requires-python)
Optional dependencies / extras

Type checking

mypy / pyright / pyre / ty
Configuração strictness (strict = true?)
Cobertura de tipos visível

Validação

Pydantic (v1 ou v2?) - dominante em FastAPI
attrs (validação opcional)
marshmallow
dataclasses + manual validation

Async

asyncio direto
anyio (compatibilidade)
trio
async libs (httpx vs requests, asyncpg vs psycopg)

Testing

pytest (dominante) ou unittest stdlib
conftest.py em pasta tests/ -> fixtures globais
Markers customizados (pytest.mark.integration)
Coverage tool (coverage.py)
Mocks: unittest.mock, pytest-mock, responses (HTTP)

Web frameworks - padrões

FastAPI:

Routers em app/routers/
Dependency injection via Depends()
Pydantic schemas em app/schemas/
ORM tipicamente SQLAlchemy + Alembic migrations

Django:

Apps em app/<name>/ com models.py, views.py, urls.py, admin.py
Settings em <project>/settings.py
Migrations geradas
Templates em templates/

Flask:

Application factory pattern (create_app())?
Blueprints
Extensions (Flask-SQLAlchemy, Flask-Login, etc)

ORM

SQLAlchemy 1.x vs 2.x (style mudou drasticamente)
Django ORM
Tortoise ORM (async)
Peewee
Raw SQL via psycopg / sqlite3

Logging

stdlib logging (dominante)
structlog (estruturado)
loguru (alternativa moderna)

Read the full file on GitHub · 133 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.

1mo ago First seen · 133 lines · 54 tokens per session scan A fb1c7b2626f4

Subscribe to this mod's changes

first-plan-lens-python is a skill published in the GitHub repository vynazevedo/first-plan (24 stars, last pushed 1mo ago), licensed MIT. It adds 54 tokens to every session and 983 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.

Claude Code Languages Planning Python ai-coding aider cline codex context

first-plan-lens-python

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

How it starts

Lens Python

Detecção fina

Extração de padrões

Packaging

Type checking

Validação

Async

Testing

Web frameworks - padrões

ORM

Logging

What this file has done since we first saw it

Other skills, from other repositories

Hive Parallelism Stack (High Performance)

claude-api

agentic-development

aws-dynamodb

supabase-python

typescript