COG is an AI-assisted second brain that stores knowledge in Markdown files and uses agents, skills, and version control to evolve it over time. It helps people manage knowledge and contacts while supporting several coding-agent tools; the catalogue entries are COG’s skills, agents, instructions, rules, and plugin surfaces.
Borrowing it
Nothing to install: this file belongs to huytieu/COG-second-brain. 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/huytieu/COG-second-brain/main/AGENTS.mdgit clone --depth 1 https://github.com/huytieu/COG-second-brainWrote 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/huytieu/cog-second-brain/agents-md)<a href="https://agentmods.dev/instructions/huytieu/cog-second-brain/agents-md"><img src="https://agentmods.dev/badge/instructions/huytieu/cog-second-brain/agents-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/huytieu/cog-second-brain/agents-md"><img src="https://agentmods.dev/badge/instructions/huytieu/cog-second-brain/agents-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 | $0.12002 | $0.12002 |
| Opus 5.5 | $0.04801 | $0.04801 |
| Sonnet 5.5 | $0.02400 | $0.02400 |
| Haiku 4.5 | $0.01200 | $0.01200 |
Grade A, and why
COG-second-brain AGENTS.md scanned grade A with 1 finding 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 18d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
2. Classifies claims: environment-dependent (verify with `ls`/`curl`/`gh`) vs preference/judgment (check only for contradiction with newer entries) How it starts
The opening of the file, as written. The whole thing — 1,105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
COG: Agentic Second Brain - Universal Agent Commands
This document defines the available commands/skills for AI agents interacting with COG (Cognition + Obsidian + Git) - a self-evolving agentic second brain system.
Compatible with: OpenAI agents, Claude (via this file), and any AI that reads markdown.
Note: Claude Code users should use
.claude/skills/and Kiro users should use.kiro/powers/for native support. This file serves as universal documentation for all other agents.
Available Commands
/onboarding
Description: Personalize COG for your workflow - creates profile, interests, and watchlist files with a smart, conversational setup.
Triggers:
/onboarding- "onboarding"
- "setup COG"
- "setup my profile"
- "get started"
Purpose: Welcome new users and collect essential information to personalize their COG experience through natural conversation - not sequential form-filling. Creates profile documents stored as markdown files within the vault.
How it works:
- Asks ONE open-ended question: "Tell me about yourself - name, role, and what you're interested in"
- Intelligently parses the response to extract name, role, interests, projects, news sources, and competitive watchlist
- Only asks a follow-up if required info (name, role, interests) is still missing
- Asks about agent mode preference (solo vs team) during confirmation
- Confirms extracted info before creating files
- Matches role to a role pack (
.claude/roles/*.md) for personalized skill and integration recommendations - Discovers integrations — presents role-specific recommendations, asks which tools the user already uses
- Creates
00-inbox/MY-PROFILE.mdwith role_pack, agent_mode, and preferences - Creates
00-inbox/MY-INTERESTS.mdwith topics for daily briefs - Creates
00-inbox/MY-INTEGRATIONS.mdwith active/disabled integrations - Optionally creates project structures in
04-projects/and03-professional/COMPETITIVE-WATCHLIST.md(only if mentioned) - Generates a welcome guide with role-ordered skills and integration status
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.
- 18d ago Changed · +1 lines · +67 tokens per session 3d7c99f7b714
- 22d ago Changed · +22 lines · +284 tokens per session b9c874831335
- 1mo ago Changed · +42 lines · +587 tokens per session 71fac9871261
- 1mo ago First seen · 1,040 lines · 11,064 tokens per session scan A 9c1afc2a88ff
COG-second-brain AGENTS.md is an instructions file published in the GitHub repository huytieu/COG-second-brain (1,305 stars, last pushed 18d ago), licensed MIT. It adds 12,002 tokens to every session, about $0.0480 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). 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
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.
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).
deno copilot-instructions.md
Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.