cold-start

cold-start is a skill for Claude Code, Codex from garrytan/gbrain. It costs 94 tokens per session (5,255 once invoked), scanned A, original, MIT.

A setup guide for filling a new personal knowledge store with useful data during its first session. It brings together sources such as email, calendars, contacts, conversations, and social-media archives, with consent before each import.

In plain words
What is it for?
Use it to bootstrap a new brain from Google data, conversation histories, contacts, and offline exports such as Google Takeout or a Twitter archive. Each import phase can be stopped independently.
Why use it?
It removes the guesswork of deciding what to import first and how to build a useful starting context. It also keeps login credentials and API keys away from the agent.

Skill for Claude CodeCodex

Part of the gbrain plugin — 19 skills, 2 plugins shipped together

Install

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.

agentmods
npx agentmods add skills/garrytan/gbrain/cold-start
Any agent
npx skills add garrytan/gbrain --skill cold-start
Clone the repo
git clone --depth 1 https://github.com/garrytan/gbrain

Made for: Claude Code, Codex.

Or install gbrain, the plugin that ships this one along with the rest of its 19 skills, 2 plugins.

Wrote 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.

agentmods badge for cold-start

README.md
[![agentmods](https://agentmods.dev/badge/skills/garrytan/gbrain/cold-start.svg)](https://agentmods.dev/skills/garrytan/gbrain/cold-start)
Your own site
<a href="https://agentmods.dev/skills/garrytan/gbrain/cold-start"><img src="https://agentmods.dev/badge/skills/garrytan/gbrain/cold-start.svg" alt="Measured on agentmods" height="20"></a>
Per session 94 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,255 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00094 $0.05255
Opus 5 $0.00047 $0.02627
Sonnet 5 $0.00019 $0.01051
Haiku 4.5 $0.00009 $0.00526

Measured 4d ago against content hash d5ba53bb2fe9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cold-start 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 4d 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.

plugin/skills/cold-start/SKILL.md · 546 lines

How it starts

The opening of the file, as written. The whole thing — 546 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cold Start — Day-One Brain Bootstrapping

You have a working brain. Search works. Now what?

An empty brain is a static database. A brain with your email history, calendar, contacts, conversations, and social media is a live context membrane that makes every future interaction smarter. This skill sequences the highest-leverage data sources to get you from zero to useful in one session.

Contract

  • Every import phase is gated on user consent (ask-user pattern) before proceeding.
  • The agent never holds raw OAuth tokens or API keys. This is a safety requirement, not a preference. Three paths satisfy it for Google data: the native connector (gbrain google setup — tokens live in gbrain's credential vault, mode 0600, never in the agent's context; see docs/guides/google-connect.md and skills/google-loops/SKILL.md), ClawVisor (a hosted credential gateway that vaults credentials, enforces task-scoped authorization, logs every API call, and requires human approval for destructive operations — needs a harness with the integration), or offline file exports (Google Takeout, Twitter archive download).
  • Each phase is independently valuable — the user can stop after any phase and still have a useful brain.
  • Progress is tracked in ~/.gbrain/cold-start-state.json so interrupted sessions can resume.
  • Entity detection and cross-linking run on every import, not as a separate pass.

Prerequisites

  • GBrain installed and initialized (gbrain doctor --json all green)
  • Brain repo cloned and synced
  • Agent has terminal access and can run gbrain CLI commands

The Priority Stack

Data sources ranked by information density × ease of import:

Priority Source Why Time Pages Created
1 Existing markdown/Obsidian Highest density — it's already structured 5 min 100s-1000s
2 Google Contacts Seeds the people/ directory — names, emails, companies 10 min 50-500
3 Google Calendar (90 days) Meeting history with attendee context 15 min 30-90
4 Gmail (recent threads) Relationship context, active threads, org chart signals 20 min 50-200
5 Conversations (ChatGPT/Claude exports) Your thinking, questions, mental models 15 min 10-100
6 X/Twitter archive Your public positions, takes, engagement patterns 20 min 30-365
7 File archives (Dropbox/Drive/local) Historical documents, old writing, photos 30+ min varies
8 Meeting transcripts (Circleback/etc.) Deep relationship context from recorded calls 20 min 10-50

Read the full file on GitHub · 546 lines

Changes

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.

  1. 4d ago First seen · 546 lines · 94 tokens per session scan A d5ba53bb2fe9

Subscribe to this mod's changes

cold-start is a skill published in the GitHub repository garrytan/gbrain (29,539 stars, last pushed today), licensed MIT. It adds 94 tokens to every session and 5,255 once invoked, about $0.0005 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.

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