Many agencies keep one ChatGPT project per client. It works well for drafting, but every project sits in one shared workspace, and keeping clients apart depends on people picking the right project every time.
Brainstead gives each client its own brain: its own storage bucket and encryption key in AWS Frankfurt (eu-central-1), its own Slack app and its own agent. One brain's credentials have no permission on another's, and the agent can't post anywhere. It runs on Claude by default, or another frontier model your client chooses.
Design-partner stage · priced per client brain, not announced
Side by side
| Question | ChatGPT, one project per client | Brainstead |
|---|---|---|
| Where client material lives | One shared workspace, kept apart by projects and naming | Its own storage bucket and encryption key per client, in AWS Frankfurt |
| Who can post on the client's channels | Whatever you've connected it to | Not the agent: it holds no channel credential and writes drafts only |
| Access to your tools | Whatever was granted when it was connected | Read-only by default; write is a per-tool switch, and every call is logged |
| The client's voice | Pasted into each project's instructions and files | Kept in the brain: the client's site, brand files and skills |
| Unsupported claims | Up to the reviewer to spot | Marked [NEEDS-FACT] in the draft, with notes for the reviewer |
Row by row
In a ChatGPT workspace, client projects share one account boundary. In Brainstead, naming the client creates a dedicated bucket and encryption key, and credentials for one brain have no permission on another brain's bucket or key. A brain you don't own returns "not found", so its existence isn't even confirmed.
A chat tool can act on whatever it's connected to. Brainstead's agent holds no credential for Slack, LinkedIn or a client's site. It writes a draft with a SHA-256 fingerprint, and a person sends it.
Brainstead connects ClickUp, Notion and other tools read-only by default, enforced at our proxy rather than by instructions to the model. The owner switches write access on per tool, and every change is logged.
Project instructions drift as people edit them. Brainstead keeps the voice in the brain as plain markdown: up to 25 pages of the client's site, brand files and skills, with sources named in the reviewer notes.
A chat model fills gaps fluently. Brainstead's drafts mark a claim it can't source as [NEEDS-FACT], so the reviewer sees the gap instead of a guess.
Fair to say
ChatGPT is quick to start, flexible, and many people on your team already know it. For brainstorming, research and one-off writing, a project per client is a reasonable setup. Brainstead is for the work where a client's material, voice and channels need to stay provably separate.
How to
Create a brain with the client's name. Its own storage bucket and encryption key are created in AWS Frankfurt (eu-central-1).
The brain reads up to 25 pages into knowledge/website/, so it starts from the client's own words.
Copy the ChatGPT project's custom instructions and the approved copy you uploaded there into brand/ as markdown files.
Invite it to the client's channel, for example #harbour-marketing.
Ask both for the same piece, for example @brain-harbour /draft a LinkedIn post about our Q3 launch, and read the reviewer notes and [NEEDS-FACT] markers side by side.
When to switch
A client's security questionnaire asks how their material is kept apart from other clients'. Two account managers write in two different versions of the same client's voice. Someone pasted the wrong brief into the wrong project. Each of these is a sign the separation depends on habit rather than on the system.
Questions
Yes. Many teams keep ChatGPT for open-ended work and use a client's brain for drafts that go to that client.
Each brain has its own bucket and key, and one brain's credentials can't open another's. The audit log records every tool call, refusal and access change.
Send the client our security page. It lists what's enforced today and what's in development, in plain words.
A brain is plain markdown: knowledge, brand voice and skills. Export, so you can take it with you, is in development.
Brainstead is priced per client brain, not per seat. Pricing isn't announced yet.
It isn't a general chat assistant, and it isn't certified yet: SOC 2 and a DPA are in progress.
Related
Each client brain also works with Slack, Brand voice, ClickUp and Client isolation. See what runs today and what's in development, the security page for questionnaires, or start from the Brainstead home page.