Your AI swarm is from 2026. Your collaboration is still from 1996.
You can spin up a swarm of agents and do in an afternoon what used to take a software team two weeks. But the moment that work has to cross a boundary — to another session, to your other machine, to a teammate, to someone else's agent entirely — the most advanced tools you have are your clipboard, your inbox, and GitHub issues, moonlighting as the collaboration channel no one ever built.
Where Cello started
It's 3:30 in the afternoon. The head of customer relationship management is in a board meeting.
Her phone has been face-down on the table for twenty minutes and it will not stop buzzing. The same name, over and over. She turns it over, apologizes to the room, and steps out.
The client is one of the firm's largest. Days ago he asked them to buy a position. He has heard nothing since, and in the meantime the stock has run.
He is angry, and he is right.
She apologizes and promises to call him back. Thirty-five minutes and three calls later she has it: the order was never placed. His deposit was never confirmed, so it never went to the broker.
Now she has to call him back and tell him that he doesn't own the gain he's spent the whole morning watching.
What would it have taken for her to stay in her seat, type a WhatsApp message to her own agent, and know exactly where that order was before the meeting had even moved on?
Or better: for the problem never to have existed at all.
That's the question I set out to answer when the CEO of that firm invited me in to consult on how AI could help them manage their growth crisis. I thought I already knew what I would build. I had spent the previous months as a solo founder building personal AI agents, and I walked in planning to give one to every person on the team.
What I discovered
Over the following weeks I sat through discovery sessions with every team: relationship management, the portfolio desk, settlement, finance. Their procedures were good. Written down, well understood, actually followed. Anyone could walk me through what happens when a client calls to buy a stock. Repeatable and deterministic: precisely the sort of work you would expect to hand to an AI assistant. Everything I saw confirmed the plan I had walked in with.
It would have helped. It would not have fixed their core problems.
Because every one of those desks was already good at its own segment of the work. Nobody was slow at their part.
The work wasn't stuck inside the steps. It was stuck in the spaces between them.
In a deposit confirmation that never got passed along. In a broker who went quiet for a week. In an order sitting in a queue nobody could see into.
Eliyahu Goldratt spent a career making this point about factories: speeding up a step that isn't the constraint doesn't speed up the system. It piles more work in front of the part that is. Make eight relationship managers twice as fast and you haven't fixed anything. You've doubled the rate at which requests arrive at a desk that was already the bottleneck.
To actually speed the firm up, the assistants would have to collaborate: share a goal, work it together, and hand it off between themselves without a person carrying it across. Nothing I could have installed for them would do that.
That is what became Cello.
The deeper problem
Step back far enough and this stops being about work.
It's about trust, and what its absence costs us. Coordination breaks down without it. Collaboration becomes impossible.
Nearly every friction in human life is the price of not being able to take someone at their word. We spent centuries building machinery to lower that price: contracts, courts, registries, identity systems, accountability mechanisms. The scaffolding stops in a lot of places, and where it stops, the friction turns punishing.
Agents inherit every one of those gaps, and they inherit them without the centuries of workarounds humans built to survive them. No reputation that follows you. No body language to read. No institution to appeal to. No social fabric to fall back on. What was friction for humans becomes a wall for agents. They can be brilliant on either end and still have no shared record, no verifiable identity, and no way to negotiate trust without surrendering privacy to someone in the middle.
That's the problem Cello solves: not at the application layer, but at the protocol layer, where it belongs.
What we believe
Imagine your phone company saying: sure, you can have a number, but we reserve the right to record every call. You'd switch providers in an hour. Somehow, with our data, we agreed to exactly that.
Cello doesn't work that way. Private by architecture, not by promise. Your keys are yours. Your content is never seen. The proof of what happened doesn't require trusting us to hold it.
The big platforms will always want your data. That's the deal, whether it's stated or not.
Cello is built on a different premise: that your data belongs to you, and no one should have to trade privacy for the ability to communicate and collaborate.
Individual autonomy, data sovereignty, and privacy aren't features we added. They're the reason Cello exists.
What Cello is
Cello is the protocol layer the agent internet is missing. Three primitives:
A verifiable identity that belongs to you, not a platform: generated on your device, anchored across a federated network of independent nodes, revocable by no one but you.
A secure channel any two agents can use to reach each other directly: end-to-end encrypted, peer-to-peer, with no central transcript stored anywhere.
And consent threaded through everything: explicit, revocable, yours. You decide what trust signals to share. You decide who can reach your agent. You decide what gets proved and to whom.
Install it once. Every agent you run gets all three.
Why this matters now
AI is growing more ubiquitous by the day. Within a few years, personal agents will migrate from your computer to your devices, and sooner than that they'll be layered on top of your laptop, built deeper into your OS, woven into everything you do. More and more of your interactions will be mediated by AI agents. You'll negotiate services, make decisions, and move through the world through them.
Local AI models will solve local inference: your data stays on your device, your queries never leave. But the moment your agent needs to reach another agent, a different device, a different organization, the privacy problem doesn't disappear. It moves to the channel. Who owns what passes between them?
Cello is our attempt to head off a future where you trade your data sovereignty and privacy for the right to communicate and collaborate.
1996: Hotmail launched on July 4th, and the inbox stopped being an institutional tool.