Bring your own key

Why you bring your own AI key, and what it costs

You do not need a key to try it. Your 14-day trial runs on our key with US$5 of AI usage included. This page is about what happens when you subscribe.

Every tool on FitOut Insider that writes something for you is powered by Claude, made by Anthropic. Rather than us buying that capacity and selling it back to you, you buy it directly. It takes about ten minutes to set up once, and then you never think about it again.

Why not just include it in the price

We could. Some platforms do. But to include it we would have to guess how much you are going to use, price for the heaviest user, and add a margin on top. That means the quantity surveyor generating two documents a month pays for the site manager generating one hundred.

Buying it directly means you pay for exactly what you use, at the price Anthropic charges, with nothing added. If you have a quiet month you pay almost nothing. It also means your subscription price is not carrying a hidden AI budget that goes up every time the technology does.

There is a second reason, and it matters more than the money. Your key is yours. Your usage sits in your own account, under your own billing, and you can see exactly what has been spent and on what. Nothing about your projects passes through an allowance we control.

What it actually costs

These are measurements taken on this platform in September 2026, not a general estimate. Anthropic bills in US dollars, so your figure in pounds moves with the exchange rate.

A toolbox talk, COSHH assessment or permitabout 5 cents
A full RAMSabout 12 cents
A construction phase plana few cents for a short one, up to about 27 cents for a fully detailed one
A full AI programmeabout 50 cents
The same, with a 50,000-character scopeabout 70 cents

The programme is the expensive one because it makes one call to build the skeleton and then a separate call for every phase in the job. That is eleven to thirteen calls on the projects we have measured, so the figure moves with the number of phases. Everything else here is a single call. Ten RAMS is about $1.20.

A month with two programmes and thirty documents costs about $3. A heavy month with four programmes and eighty documents costs about $8. Even that heavy month is under ten per cent of a Solo subscription, and a quiet month is close to nothing.

Setting it up, once

You do this when you subscribe, not before.
  1. Go to platform.claude.com and register for an Anthropic account. It is free and takes a minute.
  2. Add a payment card and buy some credit at platform.claude.com/settings/billing. You are not committing to a subscription - it is credit you draw down.
  3. Create an API key at platform.claude.com/settings/workspaces/default/keys. Press Create key, give the key a name, and set the expiry - we suggest never. Choose your workspace (for example, the default one), then press Create key again. The new key starts sk-ant-.
  4. Copy the key. Anthropic shows it only once: when you press Done the window closes and you cannot read the key again. If you ever need it, create another key the same way and delete the old one.
  5. In FitOut Insider go to Settings, then AI Settings, paste the key and press Activate. We encrypt it before it is stored and never show it again.
  6. When the status turns green and says active, you can close the settings and start using your own AI allowance.

That is the whole thing. You will not need to touch it again unless you want to check your spending, which you can do any time in your Anthropic console.

Questions people ask

Yes, two ways. Your Anthropic console shows exactly what you were charged, broken down by day. Inside FitOut Insider, under Settings, Usage and Plan, you get your requests, your token counts and an estimated cost for the month at Anthropic's published rates. The console is the bill. Ours is an estimate, so you can see roughly where you are without leaving the platform.
Generation stops until you top up. Nothing is lost, and everything already generated stays in your account.
For your trial, yes: it runs on our key. Once you subscribe, the key has to be created under your own account, because that is what keeps the billing and the data yours.
It is encrypted before it is stored, it is never sent back to your browser after saving, and it is deleted when you close your account.
No. Your 14-day trial runs on our key with US$5 of AI usage included, so you can set up a project and generate from the start. You connect your own key when you subscribe, and the platform warns you before the trial credit runs out.