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/burin-labs/harn/agents-mdgit clone --depth 1 https://github.com/burin-labs/harnWrote 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/burin-labs/harn/agents-md)<a href="https://agentmods.dev/instructions/burin-labs/harn/agents-md"><img src="https://agentmods.dev/badge/instructions/burin-labs/harn/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 | $0.03779 | $0.03779 |
| Opus 5 | $0.01889 | $0.01889 |
| Sonnet 5 | $0.00756 | $0.00756 |
| Haiku 4.5 | $0.00378 | $0.00378 |
Grade A, and why
harn 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 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.
How it starts
The opening of the file, as written. The whole thing — 284 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Harn is a programming language and runtime for orchestrating AI agents.
This file is the repository contract for Codex, Claude, and other coding
agents. CLAUDE.md must remain a symlink to it. The durable design principles
live in Engineering principles:
- ambitious outcomes behind boring seams;
- one owner with many projections;
- structure over prose;
- evidence matched to claims;
- canonical paths;
- controllable autonomy;
- cross-surface convergence;
- operationally complete launches.
Ownership
- Harn owns orchestration, transcript lifecycle, replay/eval, delegated-worker lineage, capability policy, and mutation-session audit metadata.
- Hosts own native presentation, approval UX, concrete file mutations, and undo/redo semantics.
- Prefer the Harn runtime and stdlib over new host glue.
- A semantic decision has one owner. CLI, TUI, IDE, headless, and cloud behavior should be projections or adapters, not parallel implementations.
- Prefer deep modules: small interfaces that hide substantial behavior.
- Make contracts structural with types, registries, events, generated projections, and drift checks. Prose should explain the contract, not enforce it.
Working agreement
- Research, implement, verify, recover, and ship autonomously inside the approved scope.
- Pause for genuine ambiguity, destructive or out-of-scope action, production impact, exceptional spend, or new authority—not routine reversible work.
- Treat stop, wait, stand down, and pivot as control events. Do not continue stale work after one arrives.
- Start from the claim and name a plausible falsifier. Match evidence to the claim; test counts alone are not proof.
- Exercise the canonical user path for product claims and progress, interruption, recovery, and terminal state for liveness claims.
- Use multiple trials and calibrated graders for stochastic quality claims.
- "Ship" means landed on the intended main branch with required post-merge or release checks complete.
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 Changed · +42 lines · +643 tokens per session d29eb404ca64
- 5d ago First seen · 242 lines · 3,136 tokens per session scan A 87434069ace2
harn AGENTS.md is an instructions file published in the GitHub repository burin-labs/harn (20 stars, last pushed today), licensed Apache-2.0. It adds 3,779 tokens to every session, about $0.0189 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
morloc CLAUDE.md
Instructions for morloc-project/morloc, covering claude.md, project overview, general rules, checking code and other rules.
kara CLAUDE.md
Claude Code instructions for karalang/kara, covering claude.md, commands, branch management, claiming a bug (multi-session coordination) and architecture.
Lesma AGENTS.md
Instructions for alinalihassan/Lesma, covering agents.md — lesma project guide for ai agents, what lesma is, project layout, wall-clock benchmark (benchmark suite) and compilation pipeline.
mcp-dotnet-samples AGENTS.md
AGENTS.md instructions for microsoft/mcp-dotnet-samples, covering agents.md - mcp .net samples, project overview, project structure and architecture, repository organization and sample components.
Embody AGENTS.md
AGENTS.md instructions for dylanroscover/Embody, covering embody + envoy - ai instructions, critical rules, td python rules, network layout rules and mcp server safety rules.
cc-multi-cli-plugin AGENTS.md
Instructions for greenpolo/cc-multi-cli-plugin, covering agents.md, what this is, the golden rule, the request chain and build & test.