What is a harness?
The model is the meat. The harness is the shell. A fresh one is next to useless on day one, and setting it up is the job.
November 1, 20265 min read7 chaptersBy Chris Johnston
01 · THE LOBSTER
The model is the meat. The harness is the shell.
- ToolsThe claws
- ConnectorsThe antennae
- MemoryThe tail
- PermissionsThe back plate
- ScheduleThe legs
02 · THE MEAT
The model knows a lot. On its own it can do nothing.
The model is the part that reads, writes and reasons. It is very good, and it keeps getting better. It is also soft.
A bare model lives in a text box. It does not know your customers. It cannot open your inbox. It forgets you when the window closes, and it only speaks when spoken to.
03 · THE SHELL
A harness is everything around the model.
The harness is the software that runs the model. It loads the instructions, hands it tools, plugs it into your systems, keeps its memory, enforces the rules and wakes it up on time. Then it delivers what the says to wherever your people are.
Five pieces. Every you have heard of is some model inside some version of this shell. The full definition lives in the glossary: harness.
01 · THE CLAWS
Tools
What it can do. Send the email, update the record, run the report.
02 · THE ANTENNAE
Connectors
Where it reaches. Your inbox, your CRM, your books, your drive.
03 · THE TAIL
Memory
What it keeps. Yesterday's work, your preferences, the file it wrote last week.
04 · THE BACK PLATE
Permissions
Who sees what. What it may read, and which actions wait for a person's OK.
05 · THE LEGS
Schedule
When it moves. Jobs that run at seven in the morning without anyone asking.
04 · DAY ONE
Day one, it is next to useless.
Install any harness and you get the slots, not the pieces. It has no access to your systems, no idea how your business runs, no rules about who sees what, and no jobs on its calendar. It has nothing to work with.
You have to give it your APIs. You have to manage who sees what. That setup is the work.
This is the part nobody puts in the launch video. It is also the part that decides whether the ever earns its keep.
05 · CHAT OR
A chat app waits. AAn works.
A chat app is a model with a thin shell. You open it, you prompt it, it answers. It is built for everyone, so it is shaped for no one in particular.
AAn is the same model in the full shell: connected to your systems, remembering last week, working inside rules your team set, and running on a schedule whether you are at your desk or not. The model did not change. The shell did.
A bad has no work, no connectors and no access to your data. A good one has all three.
06 · ANY SHELL
It does not matter which harness.
There are many harnesses, a few model providers, a handful of clouds and a few kinds of hardware. They are converging. Use the one that fits this year and move when a better one ships.
A lobster grows by molting: it sheds the old shell and forms a bigger one. 1 grow the same way. The model gets swapped for a better one. The harness gets swapped for a better one. What carries over is what you wrote down: the instruction files, the connectors, the documentation.
What matters is the interface to your humans.
That is why we stay harness-agnostic, and why every we build works from files your team can read and change.
07 · THE JOB
Building the shell is what we do.
We connect your systems, set who sees what, write the instructions, put the work on a schedule and build the screen your team uses to work with it: Your Everything App. Then we run the first ninety days with you and hand over the keys.
Why it matters now is in The Singularity. What machine-made work looks like when nobody shapes it is in Everything in a Box.
