Borrowing it
Nothing to install: this file belongs to firelex/jeff-code. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/firelex/jeff-code/main/AGENTS.mdgit clone --depth 1 https://github.com/firelex/jeff-codeWrote 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/instructions/firelex/jeff-code/agents-md)<a href="https://agentmods.dev/instructions/firelex/jeff-code/agents-md"><img src="https://agentmods.dev/badge/instructions/firelex/jeff-code/agents-md/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.
<a href="https://agentmods.dev/instructions/firelex/jeff-code/agents-md"><img src="https://agentmods.dev/badge/instructions/firelex/jeff-code/agents-md.svg" alt="Reviewed on agentmods" width="80" 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 | $0.01972 | $0.01972 |
| Opus 5.5 | $0.00789 | $0.00789 |
| Sonnet 5.5 | $0.00394 | $0.00394 |
| Haiku 4.5 | $0.00197 | $0.00197 |
Grade A, and why
jeff-code AGENTS.md 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 23d 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 — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Development Rules
Conversational Style
- Keep answers short and concise
- No emojis in commits, issues, PR comments, or code
- No fluff or cheerful filler text (e.g., "Thanks @user" not "Thanks so much @user!")
- Technical prose only, be direct
- Use concise, clear, simple language. Define unavoidable jargon before using it.
- Explain non-trivial designs and problems as: problem, concrete example or short trace, then solution. State why the solution is necessary and distinguish it from optional complexity.
- Prefer concrete behavior and small illustrations over abstract summaries, dense terminology, or unexplained lists of changes.
- When the user asks a question, answer it first before making edits or running implementation commands.
- When responding to user feedback or an analysis, explicitly say whether you agree or disagree before saying what you changed.
Code Quality
- Read files in full before wide-ranging changes, before editing files you have not fully inspected, and when asked to investigate or audit. Do not rely on search snippets for broad changes.
- No
anyunless absolutely necessary. - Inline single-line helpers that have only one call site.
- Check node_modules for external API types; don't guess.
- No inline imports (
await import(),import("pkg").Type, dynamic type imports). Top-level imports only. - In
packages/coding-agent, resolve package assets through helpers insrc/config.ts. Do not use__dirnamedirectly; the helpers account for source checkouts, npm installations, and standalone binaries. - Never remove or downgrade code to fix type errors from outdated deps; upgrade the dep instead.
- Use only erasable TypeScript syntax (Node strip-only mode) in code checked by the root config (
packages/*/src,packages/*/test,packages/coding-agent/examples): no parameter properties,enum,namespace/module,import =,export =, or other constructs needing JS emit. Use explicit fields with constructor assignments. - Always ask before removing functionality or code that appears intentional.
- Do not preserve backward compatibility unless the user asks for it.
- Never hardcode key checks (e.g.
matchesKey(keyData, "ctrl+x")). Add defaults toDEFAULT_EDITOR_KEYBINDINGSorDEFAULT_APP_KEYBINDINGSso they stay configurable. - Never modify
packages/ai/src/models.generated.tsdirectly; updatepackages/ai/scripts/generate-models.tsinstead, then regenerate. Including the resultingmodels.generated.tsdiff is always OK, even if regeneration includes unrelated upstream model metadata 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.
- 23d ago First seen · 126 lines · 1,972 tokens per session scan A fe7c40275593
jeff-code AGENTS.md is an instructions file published in the GitHub repository firelex/jeff-code (32 stars, last pushed 1mo ago), licensed MIT. It adds 1,972 tokens to every session, about $0.0079 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 2026-10-14.
jeff-code AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| jeff-code AGENTS.mdfirelex/jeff-code | Instructions file | 32 | 1mo ago | MIT | A | 1,972 | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |