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/humzakt/dev-starter-kit/pythongit clone --depth 1 https://github.com/humzakt/dev-starter-kitWhat 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 | $0.00000 | $0.00218 |
| Opus 5 | $0.00000 | $0.00109 |
| Sonnet 5 | $0.00000 | $0.00044 |
| Haiku 4.5 | $0.00000 | $0.00022 |
Grade A, and why
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 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.
What it actually says
Python Rules
Imports
- Sort with isort (Ruff handles this)
- Group: stdlib → third-party → local
- Use absolute imports from
src
Functions
- Type hints on all parameters and return values for public functions
- Keep functions under 50 lines — extract helpers if longer
- Use
*to force keyword-only arguments where it improves clarity
Error Handling
- Catch specific exceptions:
except ValueErrornotexcept Exception - Never use bare
except: - Log errors with context before re-raising
- Use custom exception classes for domain-specific errors
Data
- Use dataclasses or Pydantic models for structured data
- Avoid raw dicts for complex structures
- Use Enum for fixed sets of values
Performance
- Use generators for large sequences
- Prefer list/dict comprehensions over explicit loops for simple transformations
- Use
functools.lru_cachefor expensive pure function calls
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 · 33 lines · 0 tokens per session scan A 4619c9223028
python is a cursor rule published in the GitHub repository humzakt/dev-starter-kit (3 stars, last pushed 6mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 218 tokens. 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 2026-08-31.
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