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 instructions/jdx/fnox/agents-mdgit clone --depth 1 https://github.com/jdx/fnoxWhat 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 | $0.02001 | $0.02001 |
| Opus 5 | $0.01001 | $0.01001 |
| Sonnet 5 | $0.00400 | $0.00400 |
| Haiku 4.5 | $0.00200 | $0.00200 |
Grade A, and why
fnox 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 today.
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 — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Fnox Development Guide
mbx build cache
mise install installs mbx 1.3. mise run activates the project's transparent
Cargo wrapper, so compilation-heavy mise tasks and hk checks use ordinary
cargo commands. Standalone Cargo commands require an activated mise shell. If
the wrapper fails or creates a development papercut, rerun the exact equivalent
command from CONTRIBUTING.md with MBX_DISABLE=1; this unblocks work without
weakening the check. If bypassed Cargo succeeds, surface the mismatch and recommend a
mr-boxington Discussion with
the repository and commit, OS, mbx --version, mbx doctor, and both commands
and outputs. Redact secrets, absolute cache paths, remote URLs, namespaces, and
other sensitive or identifying details. Do not permanently disable the wrapper,
and do not post externally without user authorization.
Conventional Commits
Format: <type>(<scope>): <description> (lowercase, imperative mood)
Types: feat, fix, refactor, docs, style, perf, test, chore, security
Scopes: command names (get, set, exec, list, provider), provider names (age, 1password, bitwarden, bitwarden-sm, aws-kms, aws-sm, aws-ps, keychain, keepass, infisical, passwordstate, pass, proton-pass), subsystems (config, encryption, env, deps)
Examples: fix(aws-sm): handle pagination for large secret lists, feat(exec): add --no-inherit flag
Minimum Supported Rust Version (MSRV)
rust-version in the workspace Cargo.toml is kept behind the latest stable
Rust on purpose. fnox is built from source by packagers that provide their own,
often older, rustc — Linux distro packages (cargo install against a
distro-provided toolchain) and nixpkgs (one shared, conservative rustc for the
whole tree). Raising the MSRV can make fnox unbuildable there.
Do not raise the MSRV to satisfy a dependency. If a dependency bump requires
a newer rustc than our declared MSRV (the msrv CI job, cargo msrv verify,
will fail), pin that dependency to its last MSRV-compatible version instead.
.cargo/config.toml sets resolver.incompatible-rust-versions = "fallback" so
cargo update/cargo add prefer MSRV-compatible versions automatically.
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.
- today Changed · +3 lines · +49 tokens per session 9589ed3e4e7c
- 2d ago First seen · 146 lines · 1,952 tokens per session scan A d5f6d4582546
fnox AGENTS.md is an instructions file published in the GitHub repository jdx/fnox (2,124 stars, last pushed today), licensed MIT. It adds 2,001 tokens to every session, about $0.0100 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.
Other instructions, from other repositories
cliare AGENTS.md
Instructions for modiqo/cliare, covering cliare agent instructions, quality bar, rust standards, commit hygiene and verification.
litellm-rs CLAUDE.md
Instructions for majiayu000/litellm-rs, covering claude.md, version management, automated version bumping (ci/cd), commit message format and version info in code.
opencode AGENTS.md
AGENTS.md instructions for anomalyco/opencode, covering branch names, commits and pr titles, style guide, general principles and destructuring.
vscode committing.instructions.md
Guidelines for creating git commits — respecting signing configuration, verification hooks, and referencing GitHub issues.
daisyui code_generation_with_git.instructions.md
Instructions for saadeghi/daisyui, covering activation, initial setup, development loop, error handling and session end.
planning-with-files AGENTS.md
AGENTS.md instructions for OthmanAdi/planning-with-files, covering agents.md — planning-with-files agent reference card, commit rules, release checklist (12 steps), version bump scope and changelog format.