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/ribeirogab/zeno-agent/agents-mdgit clone --depth 1 https://github.com/ribeirogab/zeno-agentWrote 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/ribeirogab/zeno-agent/agents-md)<a href="https://agentmods.dev/instructions/ribeirogab/zeno-agent/agents-md"><img src="https://agentmods.dev/badge/instructions/ribeirogab/zeno-agent/agents-md.svg" alt="Measured on agentmods" 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 | $0.01502 | $0.01502 |
| Opus 5 | $0.00751 | $0.00751 |
| Sonnet 5 | $0.00300 | $0.00300 |
| Haiku 4.5 | $0.00150 | $0.00150 |
Grade A, and why
zeno-agent 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 3d 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 — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Zeno — Agent Instructions
Zeno is a personal agent. The per-instance operating manual lives in ~/.zeno/profiles/<profile>/AGENTS.md (off-repo, owner-only). The canonical scaffold lives at templates/profile/AGENTS.md; the zeno CLI writes it verbatim on zeno profile create (the template is static — no placeholder substitution). This repo is Zeno's workspace: identity, capabilities, configuration, and operating knowledge.
Before starting any work
- Read
.vault/_index/home.mdfor project-specific knowledge. - Read
.vault/constitution.mdfor non-negotiable principles. - If asked to implement, modify, or create something, assess: "Can I describe the complete solution in one sentence?" — Yes → implement; No → invoke
/brainstorming→spec.md→/writing-plans→plan.md+tasks.md→ implement; Almost (1-2 open decisions) → ask whether to spec or go direct. If the user is asking, investigating, or exploring — just answer.
Work ethic — never the lazy path
When you see two ways to do something — quick-and-shallow vs. correct-and-thorough — default to correct. You may surface the lighter option with tradeoffs, but never silently pick the worse one to finish faster. Cutting corners now creates work later. If the task is hard, do it right; don't redefine "done" downward.
When stuck or in doubt — read the vault first
.vault/ is your project brain. Before grinding on a hard problem, before guessing, before asking the user a question whose answer might already be captured: search .vault/learnings/, .vault/conventions/, .vault/rules/, the relevant spec, and .vault/constitution.md. Use recall or grep. Reading the vault is the first move, not the last. If it answers the question, cite the note; if it almost does, update the note after you fill the gap.
After completing any task
If you discovered something non-obvious — a gotcha, constraint, or surprising behavior — create an atomic note in .vault/learnings/ using .vault/templates/learning.md. Link it to the relevant spec with a wikilink. Do this without asking. Generated/temporary output (screenshots, scratch scripts, dumps) goes under tmp/ per .vault/rules/generated-files-location.md.
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.
- 3d ago First seen · 78 lines · 1,502 tokens per session scan A 224ce2451e92
zeno-agent AGENTS.md is an instructions file published in the GitHub repository ribeirogab/zeno-agent (9 stars, last pushed 3mo ago), licensed MIT. It adds 1,502 tokens to every session, about $0.0075 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 2026-08-31.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.