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.
npx agentmods add instructions/agentpilled/clipbrain/claude-mdgit clone --depth 1 https://github.com/agentpilled/ClipBrainWhat 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 | $0.02475 | $0.02475 |
| Opus 5 | $0.01238 | $0.01238 |
| Sonnet 5 | $0.00495 | $0.00495 |
| Haiku 4.5 | $0.00248 | $0.00248 |
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 3d 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 — 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
captionTracksdata, fetched same-origin so YouTube cookies are included). Falls back to reading the transcript panel DOM if the script extraction fails. Sends ayoutube-capturemessage 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 viachrome.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 askindle-importmessages. 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.compermission 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. Sendsgmail-capturemessages to the service worker. Handles threaded conversations (joins all messages). Usesgmail://URL scheme for dedup. Slugs stored asemail/{from-slug}/{subject-slug}. - service-worker.js — Background service worker. Listens for the
capture-pagekeyboard command, injects the content script, receives extracted content (typescaptured,kindle-import, andyoutube-capture), and POSTs it to the local HTTP server. YouTube captures go to/api/capture-youtube. Manages an offline queue inchrome.storage.localand flushes it viachrome.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/readabilitynpm package).
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.
- 3d ago First seen · 167 lines · 2,475 tokens per session scan A b07f49ca72cd
ClipBrain CLAUDE.md is an instructions file published in the GitHub repository agentpilled/ClipBrain (24 stars, last pushed 2mo ago), licensed MIT. It adds 2,475 tokens to every session, about $0.0124 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.
Other instructions, from other repositories
Browser4 CLAUDE.md
Instructions for platonai/Browser4, covering browser4 — project context for claude, architecture, key dispatch chain (cli → browser), batch commands and e2e test structure.
agentic-playwright selectors.instructions.md
Instructions for idavidov13/agentic-playwright, covering selector strategy, critical, instructions, phase 1: open and authenticate and phase 2: explore like a user.
scrapai-cli CLAUDE.md
Instructions for discourselab/scrapai-cli, covering claude.md, 1. who you are, 2. hard rules, 3. tools and 4. before you start: confirm the project.
chromeboost CLAUDE.md
Instructions for lordamdal/chromeboost, covering chromeboost — repo-developer guide, what chromeboost is, repository layout, development commands and tests/antibot/ (run locally; not in ci).
skills CLAUDE.md
Instructions for aemcoder/skills, covering claude.md, repository structure, slicc browser automation conventions, stateless tab targeting (since slicc pr #188) and tab-new returns a targetid.
xgrower-extension CLAUDE.md
Instructions for JoyyyceD/xgrower-extension, covering x grower extension — architecture notes, architecture, key files, auth flow and quota system.