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/dafthunk-com/dafthunk/02-development-environmentgit clone --depth 1 https://github.com/dafthunk-com/dafthunkWhat 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 | $0.00208 | $0.00208 |
| Opus 5 | $0.00104 | $0.00104 |
| Sonnet 5 | $0.00042 | $0.00042 |
| Haiku 4.5 | $0.00021 | $0.00021 |
Grade A, and why
02-development-environment 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
Tech Stack Overview
This repository uses the following technologies and tools:
Both
- pnpm for fast and efficient package management with workspace support.
- TypeScript for static typing and enhanced developer experience.
- Vitest for unit and integration testing.
- Cloudflare for edge-optimized deployment and performance.
Backend
- Hono for lightweight, expressive REST API development.
Frontend
- Vite as the build tool and dev server for lightning-fast development.
- React 19 for building interactive user interfaces.
- React Router v7 for declarative client-side routing,
react-router-domis depricated, instead import fromreact-router. - React Flow for rendering interactive node-based diagrams.
- Tailwind CSS for utility-first styling.
- shadcn/ui for headless, accessible component primitives.
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 · 29 lines · 208 tokens per session scan A 5cf3a2c08315
02-development-environment is a cursor rule published in the GitHub repository dafthunk-com/dafthunk (119 stars, last pushed 5d ago), licensed MIT. It adds 208 tokens to every session, about $0.0010 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 2026-08-30.
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