Borrowing it
Nothing to install: this file belongs to joshsymonds/nix-config. 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/joshsymonds/nix-config/main/AGENTS.mdgit clone --depth 1 https://github.com/joshsymonds/nix-configWrote 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/joshsymonds/nix-config/agents-md)<a href="https://agentmods.dev/instructions/joshsymonds/nix-config/agents-md"><img src="https://agentmods.dev/badge/instructions/joshsymonds/nix-config/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/joshsymonds/nix-config/agents-md"><img src="https://agentmods.dev/badge/instructions/joshsymonds/nix-config/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 | $0.00153 | $0.00153 |
| Opus 5.5 | $0.00061 | $0.00061 |
| Sonnet 5.5 | $0.00031 | $0.00031 |
| Haiku 4.5 | $0.00015 | $0.00015 |
Grade B, and why
nix-config AGENTS.md scanned grade B with 1 finding 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
- Never invoke `sudo nixos-rebuild ... .#gnomon` directly from another What it actually says
Repository operating notes
Gnomon builds and deployment
- Never build Gnomon's Home Manager activation package or NixOS system closure on another host, especially Vermissian. Evaluating the target closure can trigger large local downloads and CUDA builds.
- For Gnomon changes, commit and push the branch, SSH to
joshsymonds@gnomon, pull the branch there, and run the build ornixos-rebuildlocally on Gnomon. - Never invoke
sudo nixos-rebuild ... .#gnomondirectly from another host's shell. The rebuild command itself must be inside the SSH command sent tojoshsymonds@gnomon.
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 · 14 lines · 153 tokens per session scan B fff813e5c4ae
nix-config AGENTS.md is an instructions file published in the GitHub repository joshsymonds/nix-config (838 stars, last pushed yesterday), licensed MIT. It adds 153 tokens to every session, about $0.0006 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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