Describe it.
Your own model writes it.
The vault covers the tools we thought were worth building. This is for the one you need that is not in it. Bring your own model key, describe the extension, and get a Manifest V3 starter you can read before you install.
4 steps · about 3 minutes · nothing to install first
- 1
Paste your own API key and validate it
Pick your provider — Claude, ChatGPT, Gemini or Perplexity — and paste that provider's own API key. It is hidden as you type, with an eye to check it.
Press Validate & load models. The key goes from your browser straight to the provider: it never passes through our servers, is never stored, and reloading the page clears it.
You pay your provider for what you use. We charge nothing for this and meter nothing.
- 2
Pick a model your account can actually use
The list is fetched from your account, so it is exactly what your key can call — newest first. We ship no list of our own, because which models an account can reach depends on its tier.
Anything too new to be listed can be typed in by hand.
A model that refuses a setting older ones accept is retried without it, so a reasoning model works the same as any other.
- 3
Describe the extension in a sentence
Write it the way you would ask a colleague: "Highlight every link on this page that points off-site, and show me the count."
Behind it sits a long instruction: Manifest V3 only, the fewest permissions that can do the job, no network calls, no inline scripts, no remote code, and a popup that explains its own failures. The same rules the vault's own templates are built to.
Vague is fine. The model takes the smallest sensible reading and writes down what it assumed.
- 4
Read it, download it, load it in Chrome
Every file is shown before you download anything, with the permissions it asks for and any warning the scan raised.
The ZIP is a folder holding the code, three icons, and documents generated from the manifest: INSTALL, PERMISSIONS, PRIVACY, TESTING and ORIGIN. Load it exactly like a vault template.
A model wrote it seconds ago and nobody has run it. Read popup.js before you install it — that is the point of getting source.
What this is, and what it is not
Your key, your account, your bill
The request is made by your browser directly to the provider you chose. It does not pass through our servers, we never see the key, and nothing is written to disk — which is why there is no "remember my key" box. You are billed by your provider for what you use.
Checked, but not reviewed
Before the download, the output is scanned for network calls, host permissions, inline scripts and unsafe file paths, and a manifest that is not Manifest V3 is refused outright. Those are structural checks, not a review. No warning is not a pass.
Not one of the vault templates
The 150+ pre-built templates are ours, and an automated check enforces that none of them makes a network call, on every release. Nothing enforces that here, because a model wrote this code seconds ago. TESTING.md in the ZIP says exactly which checks ran.
Common questions
Do I need a paid ChromeExtendMe licence to use this?
No. The builder is free to use and open to anyone. You bring your own model key and pay your own provider. The vault licence covers the pre-built templates, which are a separate thing.
Where does my API key go?
From your browser to the model provider you selected, and nowhere else. It does not pass through our servers, it is not logged, and it is never written to local storage or a cookie — reload the page and it is gone. Switching provider will not send it to the wrong company either: a key that does not match the selected provider is refused before any request is made.
Which models can I choose?
Whatever your own key can call. The list is fetched from your account when you validate the key, so a higher tier sees more and a lower tier sees only what it can actually use. Any model id can also be typed in by hand.
What exactly do I get?
A ZIP containing a folder with manifest.json, the popup HTML, CSS and JavaScript, three generated icons, the model's README, and five documents generated from the manifest: INSTALL, PERMISSIONS, PRIVACY, TESTING and ORIGIN. It loads in Chrome the same way a vault template does.
Is the generated code safe?
It is checked, not reviewed. The scan looks for network calls, host permissions, inline scripts and unsafe paths, and refuses a manifest that is not Manifest V3. It cannot tell you whether the logic is correct or whether the extension does what you asked. Read popup.js before you install it.
Do the pre-built templates use AI?
No. No template in the vault calls a model or carries an API key, and an automated check enforces it. This builder is a tool on the website for making something the vault does not have. It adds nothing to the templates.
Can I sell what it generates?
We claim nothing over it — it came from your model, your account and your prompt, so your provider's terms are what apply. ORIGIN.md in the ZIP records where it came from.
Build one now
Free to use, no licence required. Bring a key from Claude, ChatGPT, Gemini or Perplexity and you are three minutes from a working starter.
Open the builder