What is ClipBrain CLAUDE.md?

Project instructions for ClipBrain, a Chrome extension and local web server that save webpage content, YouTube transcripts, and Kindle highlights to a personal knowledge base.

Use them when changing the browser extension, the local server, content extraction, or the command-line tool that stores captured information.

They give an agent the project’s architecture and rules, reducing the risk of editing the wrong component or misunderstanding how captured content flows through the system.

How agentpilled/ClipBrain configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to agentpilled/ClipBrain. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/agentpilled/ClipBrain/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/agentpilled/ClipBrain

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/agentpilled/clipbrain/claude-md/github.svg)](https://agentmods.dev/instructions/agentpilled/clipbrain/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/agentpilled/clipbrain/claude-md"><img src="https://agentmods.dev/badge/instructions/agentpilled/clipbrain/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/agentpilled/clipbrain/claude-md"><img src="https://agentmods.dev/badge/instructions/agentpilled/clipbrain/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 2,475 This file is loaded in full into every session.

When invoked 2,475 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.02475	$0.02475
Opus 5.5	$0.00990	$0.00990
Sonnet 5.5	$0.00495	$0.00495
Haiku 4.5	$0.00248	$0.00248

Measured 2mo ago against content hash b07f49ca72cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ClipBrain 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.

CLAUDE.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ClipBrain — Chrome Extension + HTTP Server

What it does

A Chrome extension (Manifest V3) that captures web page content and sends it to a local HTTP server, which stores it in a ClipBrain knowledge base via the gbrain CLI.

This project uses the installed gbrain CLI. ./setup.sh installs it globally with Bun if it is missing.

Architecture

Chrome Extension

MV3 service workers do NOT have DOM access, so the work is split:

content-script.js — Injected into the active tab on demand. Has DOM access. On YouTube video pages, extracts the video ID, title, channel name, and transcript (from the page's inline captionTracks data, fetched same-origin so YouTube cookies are included). Falls back to reading the transcript panel DOM if the script extraction fails. Sends a youtube-capture message with the transcript segments already extracted. On all other pages, runs Mozilla's Readability.js to extract the article text. Sends the extracted data back to the service worker via chrome.runtime.sendMessage.
kindle-content-script.js — Auto-injected on read.amazon.com/notebook*. Parses Kindle highlights/notes from the Notebook page and sends them to the service worker as kindle-import messages. Shows a floating "Import to ClipBrain" button in the bottom-right corner.
gmail-content-script.js — Injected into Gmail after the user grants the optional mail.google.com permission from the popup. Detects open emails, extracts subject, sender, date, and clean body text (stripping Gmail UI chrome, signatures, tracking pixels). Shows a floating "Clip to ClipBrain" button when an email is open. Supports both button click and Cmd+Shift+S. Sends gmail-capture messages to the service worker. Handles threaded conversations (joins all messages). Uses gmail:// URL scheme for dedup. Slugs stored as email/{from-slug}/{subject-slug}.
service-worker.js — Background service worker. Listens for the capture-page keyboard command, injects the content script, receives extracted content (types captured, kindle-import, and youtube-capture), and POSTs it to the local HTTP server. YouTube captures go to /api/capture-youtube. Manages an offline queue in chrome.storage.local and flushes it via chrome.alarms.
toast.js — Injected into the page to show a brief success/failure notification.
lib/readability.js — Vendored copy of Mozilla Readability.js (from @mozilla/readability npm package).

Read the full file on GitHub · 167 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.

2mo ago First seen · 167 lines · 2,475 tokens per session scan A b07f49ca72cd

Subscribe to this mod's changes

ClipBrain CLAUDE.md is an instructions file published in the GitHub repository agentpilled/ClipBrain (24 stars, last pushed 4mo ago), licensed MIT. It adds 2,475 tokens to every session, about $0.0099 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.

Browser automation Memory and context

ClipBrain CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
ClipBrain CLAUDE.mdagentpilled/ClipBrain	Instructions file	24	4mo ago	MIT	A	2,475	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

ClipBrain: Instructions file for Claude Code