The inbox for everything you save.
Watch the launch video with sound. It was recorded under the former PromptOS name, so the command names differ. The workflow is current.
You already have a pile of saved links. Videos you meant to watch, repos you meant to read, threads you screenshotted at midnight. They sit there because reading them is work.
3rdBrain gives that pile an inbox. Send a link from your phone. An AI watches the video, reads the repo, pulls the transcript and the timestamps, then writes a page about what the thing is for and files it where you will look for it.
Weeks later you type what you are trying to do, and the page comes back.
Send material to your inbox. Each item travels a fixed path:
- Capture into a durable inbox.
- Read the latest version of the message, including edits made after sending.
- Mine the whole source: transcripts, screenshots, timestamps, code.
- Write one page per distinct tool, workflow, prompt or idea.
- File each page by the job it helps you do.
- Cross-link related pages and update every index.
- Confirm back to you what was filed.
Your library is ordinary Markdown on your own disk. Git records every change. Anything you edit by hand stays exactly as you wrote it.
- Videos from major platforms, with transcripts, frames and timestamps.
- Websites, articles, social posts, discussions and comments.
- GitHub repositories and source code.
- PDFs, EPUBs, office documents, screenshots, image posts and photographed lecture slides.
- Podcasts and audio, including RSS feeds.
- Interactive or login-gated sources through a user-approved signed-in browser session.
3rdBrain uses a verified evidence cache so one complete source reading can support every page created from it. It needs no extra account, API key, server or model. Before LLM work begins, it reports estimated input. It preserves provider-reported usage when that data is available.
Type the job. "Prepare email replies without auto-sending." "Cheap local worker under a hosted agent."
Exact wording surfaces immediately. A small local embedding model then reranks by meaning, so the page you half-remember arrives even when you use different words from the page. Every result shows why it matched.
Filters narrow by capability, category, access model and platform. Search runs inside your browser and makes zero LLM calls.
- A page per tool, workflow, prompt or idea, written from the source.
- Verbatim prompts and commands, with timestamps back to the exact moment in a video.
- A sidebar organised by purpose, so related work sits together.
- Facets across every page, so one idea is reachable from several angles.
- Indexes and cross-links that update themselves as the library grows.
Setup builds the site and opens it in your browser. It runs on MkDocs with a theme this project owns, so the library looks like yours from the first page:
- Your logo, favicon and fonts, from
_site/overlay/assets/. - Your colour palette and typography, from
_site/overlay/stylesheets/brand.css. - A sidebar organised by purpose, plus the Discover search workspace.
- A focused reading column, a scan-friendly contents panel, and contained prompt viewers.
3rdbrain-publish puts that site on Cloudflare Pages. You choose an email allowlist so only
named people get in, or an open link. Publishing asks for consent every time and verifies the
result from outside afterwards, file by file.
| You do this | 3rdBrain delivers this |
|---|---|
| Forward a link from any device | A durable pending item in the local inbox |
| Edit the message or caption later | The latest edit becomes authoritative |
| Process a long tutorial | A source hub, a timed element map, and focused child pages |
| Save several workflows from one vendor | Each workflow gets its own purpose-based location |
| Ask what to use for a job | Ranked search results and a scenario-based Tool Index |
| Edit a filed inbox message | The existing page reopens for refresh and gets a new confirmation |
| Edit a page by hand | The next agent run preserves and works around that edit |
| Run a framework workflow | A freshness check ports compatible improvements with a receipt |
| Review aging knowledge | A report of overdue, upcoming and potentially superseded pages |
| Publish the library | A branded Cloudflare Pages site with an email allowlist or an open link |
| Skill | What it does |
|---|---|
3rdbrain-setup |
Create a local base and connect the inbox. |
3rdbrain-process |
Process everything waiting in the inbox. |
3rdbrain-curator |
Turn one source into filed, cross-linked pages. |
3rdbrain-publish |
Publish to Cloudflare Pages with access control. |
3rdbrain-connect |
Give a person or an agent read-only search access. |
3rdbrain-skillsync |
Bring every agent runtime on the machine to parity, then prove it. |
3rdbrain-stalecheck |
Report aging pages. It reads, and leaves editing to you. |
Everything lives on your machine as Markdown under Git. Publishing is a separate, explicit step with its own consent prompt. Access control is yours to set.
Every page carries the job it serves, reproducible steps, exact artifacts, limitations, and a link back to the source. Timestamps point at the moment a claim was made. Where a source contradicts itself, the page says so.
A curator can verify any claim in one click, which is what keeps a growing library worth trusting.
Before content work, 3rdBrain checks itself against this repository. A fingerprint of every framework-owned file is compared with the last verified receipt. A match is the fast path. A change triggers a reconcile, and the receipt is written only after the build, the tests and the live checks pass, with a disposition recorded for every differing file.
The receipt is evidence. It names the upstream commit, your commit, and what happened to each difference.
/plugin marketplace add qbyx-studio/3rdBrain
/plugin install 3rdbrain@3rdbrain
Codex uses one canonical shared root:
mkdir -p ~/.agents/skills
cp -R skills/3rdbrain-* ~/.agents/skills/Claude Code:
mkdir -p ~/.claude/skills
cp -R skills/3rdbrain-* ~/.claude/skills/Windows PowerShell for Codex:
Get-ChildItem skills -Directory -Filter "3rdbrain-*" | ForEach-Object {
Copy-Item -Recurse -Force $_.FullName "$env:USERPROFILE\.agents\skills\$($_.Name)"
}For Claude Code, use .claude\skills as the destination. Restart the agent after copying.
commands/ slash commands
skills/ the seven skills and their references
inbox/ the capture bot
_site/ the private site build, tools and tests
_site/starter/ the template a new base starts from
MIT. See LICENSE. The Qbyx Studio name and Qbyx logo remain the property of Qbyx Studio.
Built by Sean Cypher at
Qbyx Studio. The launch video was created with
/gloat.