Borrowing it
Nothing to install: this file belongs to the-sid-dani/second-brain-os. 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/the-sid-dani/second-brain-os/main/CLAUDE.mdgit clone --depth 1 https://github.com/the-sid-dani/second-brain-osWrote 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/the-sid-dani/second-brain-os/claude-md)<a href="https://agentmods.dev/instructions/the-sid-dani/second-brain-os/claude-md"><img src="https://agentmods.dev/badge/instructions/the-sid-dani/second-brain-os/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/the-sid-dani/second-brain-os/claude-md"><img src="https://agentmods.dev/badge/instructions/the-sid-dani/second-brain-os/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 | $0.04165 | $0.04165 |
| Opus 5.5 | $0.01666 | $0.01666 |
| Sonnet 5.5 | $0.00833 | $0.00833 |
| Haiku 4.5 | $0.00417 | $0.00417 |
Grade A, and why
second-brain-os 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 7d 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 — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Second-Brain OS — Project Instructions for <assistant.name>
This file is project-scoped instructions only. Persona, user, and tooling context live in dedicated files — do not duplicate them here.
Load Order at Session Start
- @SOUL.md — <assistant.name>'s persona, voice, boundaries
- @USER.md — <user.name>'s profile, role, communication preferences, team
- @IDENTITY.md — <assistant.name>'s name, version, origin
- @TOOLS.md — Available tools and capabilities
- @README.md — Project map and update rules
If anything below conflicts with those files, those files win.
Configuration — source of truth for skills
Skills (/new-project, /archive-project, /prune-projects, the intent-detector hook) read the values below as the source of truth. To fork this workspace for your own use, run /bootstrap — it walks through these values interactively and rewrites this section. Every skill references these paths and identity values symbolically (e.g., <workspace.projects>) and adapts automatically.
workspace
workspace.root=<workspace.root>(default:workspace; rename toworkspace,brain,<assistant>-workspace, etc.)workspace.inbox=0-Inboxworkspace.projects=1-Projectsworkspace.areas=2-Areas— thin Area workstations (PARA Areas): rules + memory + a generated index only; starts empty (see the Area model below)workspace.resources=4-Resourcesworkspace.archive=5-Archive— archived projects keep their code in an ignoredapp/subtreeworkspace.area_apps=2-Areas/<area>/apps— shipped, maintained apps (MCP servers, dashboards, sites) owned by an Area; each is gitignored with its own git and anapp.manifest.jsonworkspace.project_apps=1-Projects/COD-*/app— a code project's single gitignoredapp/subtree while it is being built
Resolved paths (combine the above): <workspace.root>/<workspace.projects> → e.g., workspace/1-Projects.
templates (under <workspace.root>/<workspace.resources>/templates/)
templates.project_claude=project-claude-template.md— for non-code project CLAUDE.mdtemplates.project_memory=project-memory-template.md— for any project's memory.mdtemplates.code_claude=code-project-claude-template.md— for code-repo project CLAUDE.mdtemplates.persona=persona/— for persona file templates (used by/bootstrap)
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.
- 7d ago Changed · +21 lines · +768 tokens per session 22a245e1bf87
- 1mo ago First seen · 192 lines · 3,397 tokens per session scan A 8c1a2be27ee4
second-brain-os CLAUDE.md is an instructions file published in the GitHub repository the-sid-dani/second-brain-os (3 stars, last pushed 7d ago), licensed MIT. It adds 4,165 tokens to every session, about $0.0167 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.
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).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
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.
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).