code✓ Pass

SKILL.md Content

---
name: code
description: ALWAYS follow this style when writing Python / JavaScript code
---

- Prefer libraries to writing code. Prefer popular, modern, minimal, fast libraries
- Write readable code. Keep happy path linear and obvious. Write flow first, then fill in code. Name intuitively
- Keep code short
  - Data over code: Structures beat conditionals. Prefer config.{json|yaml|toml|...} if >= 30 lines
  - DRY: Helpers for repeated logic, precompute shared intermediates
  - Early returns fail fast and reduce nesting. Skip defensive fallbacks, existence checks, ... unless essential
  - YAGNI: Skip unused imports, variables, and code
- Change existing code minimally. Retain existing comments. Follow existing style
- Use type hints and docstrings (document contracts and surprises, not mechanics)
- Don't comment readable code. If commenting, only comment non-obvious stuff that'll trip future maintainers: why, why not alternatives, pitfalls, invariants, input/output shape, ...
- When tests exists, or writing new code, add tests first. Keep tests fast
- Replace PII in committed code, tests, docs with similar REALISTIC dummy data
- Show status & progress for long tasks (>5s)
- Make re-runs efficient for long tasks (>1min). Restarting should resume. Log state, cache & flush data and LLM/API/HTTP requests, etc.
- Read latest docs for fast moving packages: GitHub README, `npm view package-name readme`, https://context7.com/$ORG/$REPO/llms.txt, ...

## Python

Prefer `uv run`, `uvx` over `python` or `python3`

Unless `pyproject.toml` is present, add dependencies to script:

```py
#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.12"
# dependencies = ["scipy>=1.10", "httpx"]
# ///
```

Preferred libs:

- `typer` / `click` not `argparse`
- `httpx` not `requests`
- `lxml` not `xml`
- `pandas` not `csv`
- `orjson` over `json` if speed/datetime matters
- `tenacity` for retries
- `pytest`
- `python-dotenv`

Use one of these for exception tracebacks with locals:

```python
from rich.traceback import install; install(show_locals=True)
from loguru import logger; logger.add(sink=lambda m: print(m, end=""), diagnose=True, backtrace=True)
```

## HTML

Prefer modern HTML:

- Loading: loading="lazy", fetchpriority="low", <link rel="preload" as="image">
- Forms: inputmode=, enterkeyhint=, autocomplete=, list=, autocapitalize=, spellcheck=, form=
- UI: popover, popovertarget=, formmethod="dialog", inert, <details name=""> for accordions, <dialog>, <meter>, <progress>, <track>, <data>
- Media: picture srcset=, video preload=, crossorigin=, playsinline=, muted=, autoplay=, loop=, controls=, poster=

Prefer SVG favicons e.g.

```html
<link rel="icon" type="image/svg+xml" href="data:image/svg+xml,%3Csvg%20xmlns ... %3C%2Fsvg%3E"/>
```

designed with Unicode and rich typography, e.g.:

```html
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64" width="128">
  <rect fill="#2563eb" width="64" height="64" rx="10"/>
  <text x="32" y="35" text-anchor="middle" dominant-baseline="middle" font-size="40">🌈</text>
</svg>
```

## JavaScript

Preferred JS style:

- Bootstrap. Minimize custom CSS. Prefer declarative data-* patterns
- Hyphenated HTML class/ID names (id="user-id" not id="userId")
- Use modern browser APIs and ESM2022+: Use `?.`, `??`, destructuring, spread, implicit returns (`=>` over `=> { return }`)
- Avoid TypeScript, but enable `// @ts-check`. `.d.ts` is OK for packages
- Loading indicator while awaiting fetch()
- Error handling only at top level. Render errors for user
- Helpers: `const $ = (s, el = document) => el.querySelector(s); $('#id')...`
- Prefer lit-html > .insertAdjacentHTML / .innerHTML >> .createElement + setting attributes
- Prefer vitest + jsdom for unit tests, Playwright for end-to-end tests
- Import maps: `<script type="importmap">{ "imports": { "package-name": "https://cdn.jsdelivr.net/npm/package-name@version" } }</script>`

Preferred libs:

```js
import * as d3 from "d3"; // @7/+esm for visualizations
import hljs from "highlight.js"; // @11/+esm highlight Markdown code; link CDN CSS
import { html, render } from "lit-html"; // @3/+esm for DOM updates
import { unsafeHTML } from "lit-html/directives/unsafe-html.js";
import { marked } from "marked"; // @17/+esm
import { parse } from "partial-json"; // @0.1/+esm parse streamed JSON. `const { x } = parse('{"x":"incomplete')`

import { asyncLLM } from "asyncllm"; // @2 streams LLM responses. `for await (const { content, error } of asyncLLM(baseURL, { method: "POST", body: JSON.stringify({...}), headers: { Authorization: `Bearer ${apiKey}` } }))`
import { bootstrapAlert } from "bootstrap-alert"; // @1 for notifications. `bootstrapAlert({ title: "Success", body: "Toast message", color: "success" })`
import { geminiConfig, openaiConfig } from "bootstrap-llm-provider"; // @1 LLM provider modal. `const { baseUrl, apiKey, models } = await openaiConfig()`
import saveform from "saveform"; // @1 to persist form data. `saveform("#form-to-persist")`
```

Debug front-end apps with Playwright (prefer CDP on localhost:9222) using .evaluate(); view screenshot images, console logs.

## Tmux

Use tmux outside the sandbox for interactive REPLs/TUIs, long running commands: servers, services, sub-agents: codex/claude/...

```bash
tmux new-session -d -s $SESSION 'uv run --with pandas,httpx,lxml python -iqu'
tmux pipe-pane -t $SESSION -o "cat >> /tmp/$LOG"
tmux send-keys -t $SESSION 'print(1 + 2)' C-m
cat /tmp/$LOG
tmux capture-pane -p -t $SESSION -S -5
```

License

Declared license: MIT

MIT License

Copyright (c) 2026 majiayu000

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

View the license in the source repository — the version published there is authoritative.