Borrowing it
Nothing to install: this file belongs to nexus-substrate/nexus-agents. 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/nexus-substrate/nexus-agents/main/CLAUDE.mdgit clone --depth 1 https://github.com/nexus-substrate/nexus-agentsWrote 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/nexus-substrate/nexus-agents/claude-md)<a href="https://agentmods.dev/instructions/nexus-substrate/nexus-agents/claude-md"><img src="https://agentmods.dev/badge/instructions/nexus-substrate/nexus-agents/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/nexus-substrate/nexus-agents/claude-md"><img src="https://agentmods.dev/badge/instructions/nexus-substrate/nexus-agents/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 | $0.16434 | $0.16434 |
| Opus 5.5 | $0.06574 | $0.06574 |
| Sonnet 5.5 | $0.03287 | $0.03287 |
| Haiku 4.5 | $0.01643 | $0.01643 |
Grade A, and why
nexus-agents 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 8d 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 — 713 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Nexus Agents - Claude Code Instructions
Project: Governance substrate for AI coding agents — adversarial review, drift-detected rules, tamper-evident append-only audit chain (threat model: tamper-evident, not tamper-proof), closed-loop telemetry. The agents (Claude/Codex/Gemini/OpenCode) do the engineering; nexus-agents enforces the rules they have to follow, reviews their work adversarially, and audits everything they touch. Repository: github.com/nexus-substrate/nexus-agents Owner: @williamzujkowski
Where the rest lives. Everything harness-agnostic — the CLI quick reference, the
NEXUS_*environment table, Operating Rules, the Discovered-Issues protocol, Workflows, Governance quality, File References and the MCP tool list — now lives inAGENTS.mdand is injected into the generated block above (#5151). It used to sit in this file only, so Codex, Gemini CLI and OpenCode never saw it. Content outside the generated block is ungated by construction, which is how the TypeScript pin drifted.
Mission
Nexus-agents is a self-improving autonomous engine for an organization's technical work, built to extend toward its broader functions over time. It runs the engineering lifecycle end to end — form/refine intent → research → plan (agile PM: epics → child issues) → develop (multi-CLI) → adversarial-consensus review → QA + security gates → measure outcomes → self-tune. The routing/strategy self-improvement loop is wired and default-on (outcome telemetry → strategy distillation → bounded routing adjustment, enforce-by-default since v2.96). Coding was the deliberate bootstrap: build an engine good enough to extend itself to the remaining functions and keep improving how it works.
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.
- 8d ago Changed · -2 lines · -204 tokens per session 2ba864afe109
- 14d ago Changed · +79 tokens per session 0c6bcc9d0b30
- 15d ago Changed · +9 tokens per session 07d4cba4aedc
- 19d ago Changed · +9 tokens per session 83ad3aba3af2
- 20d ago Changed · -1 lines · -87 tokens per session 7c59bd453345
- 21d ago Changed · +39 lines · +711 tokens per session e93463429ecd
- 25d ago Changed · +8 tokens per session c05e432a4792
- 1mo ago Changed · +8 tokens per session 5294766dd519
- 1mo ago Changed · +20 tokens per session 3933ca9ab644
- 1mo ago First seen · 677 lines · 15,881 tokens per session scan A b81166742885
nexus-agents CLAUDE.md is an instructions file published in the GitHub repository nexus-substrate/nexus-agents (23 stars, last pushed today), licensed MIT. It adds 16,434 tokens to every session, about $0.0657 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 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
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