Borrowing it
Nothing to install: this file belongs to hbkdad/arc. 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/hbkdad/arc/main/CLAUDE.mdgit clone --depth 1 https://github.com/hbkdad/arcWrote 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/hbkdad/arc/claude-md)<a href="https://agentmods.dev/instructions/hbkdad/arc/claude-md"><img src="https://agentmods.dev/badge/instructions/hbkdad/arc/claude-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/hbkdad/arc/claude-md"><img src="https://agentmods.dev/badge/instructions/hbkdad/arc/claude-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 | $0.00508 | $0.00508 |
| Opus 5.5 | $0.00203 | $0.00203 |
| Sonnet 5.5 | $0.00102 | $0.00102 |
| Haiku 4.5 | $0.00051 | $0.00051 |
Grade A, and why
arc CLAUDE.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 2mo 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 — 27 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This repo builds ACR — Adaptive Cognitive Runtime, a local-first, model-independent AI orchestration runtime.
Full specification (roles, principles, architecture, milestones, security model, required report format): → ACR_MASTER_SYSTEM_PROMPT.md
Read it in full before any implementation work. Do not ask for a summary in place of reading it.
Start every session with
Non-negotiables (see master file for full list)
- Only build the next incomplete milestone (master §65–66). One smallest-complete vertical slice at a time — never the whole system in one session.
- Never rewrite unrelated modules, remove working behavior without justification, or claim a feature works without running its tests.
- Minimal context: don't load the whole repo, whole README, or full history into a task — retrieve only what's relevant (master §7–8).
- Default deny on permissions; no secrets in code, logs, memory, or Git (master §37–41).
- End every session with the Required Session Report (master §73): STATUS, IMPLEMENTED, FILES CHANGED, TESTS, TOKEN OPTIMIZATION, SECURITY, DECISIONS, NEXT STEP.
Repo layout
Modular monorepo (master §5): apps/, packages/, core/, memory/, context/, skills/, agents/, routing/, providers/, tools/, learning/, telemetry/, security/, benchmarks/, migrations/, tests/, scripts/, examples/, docs/. Core domain logic must not depend on UI, provider implementations, or deployment platforms.
Today this lives as one src/acr/ package with each domain as a submodule (acr.memory, acr.agents, ...) rather than literal top-level directories — a deliberate, revisit-when-needed choice, not drift; see docs/adr/0001-src-layout-single-package.md. The dependency-direction rule still applies at the submodule level: nothing under acr.core/acr.memory/etc. may import a concrete provider adapter or acr.dashboard/acr.cli — only acr.providers.base's abstract interface.
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.
- 2mo ago First seen · 27 lines · 508 tokens per session scan A abf5c1af1b3c
arc CLAUDE.md is an instructions file published in the GitHub repository hbkdad/arc (4 stars, last pushed 3mo ago), licensed MIT. It adds 508 tokens to every session, about $0.0020 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 2026-08-31.
arc CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| arc CLAUDE.mdhbkdad/arc | Instructions file | 4 | 3mo ago | MIT | A | 508 | Claude Code |
| 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 |