Use Anthropic with MonstarX
In shortPaste an Anthropic API key into the Anthropic row in Backend → Cloud. MonstarX's builder can then list the Claude models your key can use and ask one of them for a written answer, billed to your Anthropic account. The key is for the builder only — your app never gets it.
Ask Claude models a question with your own key.
- Type
- Business tool · API key
- Category
- AI and media
- Connect with
- API key
Anthropic makes the Claude family of AI models. Connect your own Anthropic API key (a password-like code that lets software use your Anthropic account) and MonstarX’s builder — the AI you chat with — can ask a Claude model of your choice for text while it works on your project: a second opinion on some copy, a draft written by a specific model, or a quick comparison of how two models answer the same prompt.
This is a business tool: the builder uses the key for you, and the answers come back into your chat. The app you build never gets this key. If you want your app to have AI features, see Add AI features to your app or connect OpenAI or OpenRouter for the app.
What can MonstarX do with it?
Section titled “What can MonstarX do with it?”| What MonstarX can do | When |
|---|---|
| List the models your key can use, with their exact model names | Any mode |
| Ask one model a question — a single prompt of up to 30,000 characters — and read its text answer (up to 4,096 tokens, 1,024 unless it asks for more) | Any mode, for a specific request |
What it never does: put the key into your app’s code, send pictures or files, keep a conversation going over several messages, or change anything in your Anthropic account.
Before you start
Section titled “Before you start”- An account in the Claude Console with API billing set up. API use is paid as you go and is separate from any Claude.ai subscription.
- You own the MonstarX project. Only the owner can connect or disconnect a tool.
Get your key
Section titled “Get your key”-
Sign in to the Claude Console and open Settings → API keys.
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Click Create key and give it a name such as
MonstarX. -
Scope the key to one workspace (for example your Default Workspace). MonstarX does not send a workspace ID, so a key that works in several workspaces is refused when you connect it.
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Choose an expiration that suits you, create the key and copy it. The Console shows it only once.
Connect it in MonstarX
Section titled “Connect it in MonstarX”-
Open your project and click Backend in the top bar, then Cloud.
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Scroll to Connectors, find Anthropic and click Connect.
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Paste the key into the API key field and click Connect.
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MonstarX checks the key by listing your models. When it works, the row says Connected. If the key is wrong or not scoped to a workspace, you see Anthropic’s error and nothing is saved.
Ask MonstarX to use it
Section titled “Ask MonstarX to use it”| You type | What happens |
|---|---|
| “Which Claude models can my Anthropic key use?” | MonstarX lists the models and their names. |
| “Ask Claude Haiku for ten short taglines for a pilates studio, then use your favourite on the homepage.” | It sends the prompt with your key, reads the answer and, in Build mode, puts a tagline on the page. |
| “Give the same welcome-email prompt to two Claude models and show me both answers side by side.” | It asks each model once and puts the two answers in the chat. |
Security and privacy
Section titled “Security and privacy”- Stays with MonstarX. The key is stored encrypted on MonstarX’s servers. It is never written into your app’s code or given to your app.
- One project. The key works only in the project where you connected it.
- Your prompts go to Anthropic. What MonstarX sends in a request is processed by Anthropic under your account’s terms.
- Disconnect any time. Click Disconnect beside Anthropic in BackendCloud and confirm Disconnect Anthropic from this project?. MonstarX forgets the key. To stop the key working everywhere, disable or delete it on the Console’s API keys page as well.
Good to know
Section titled “Good to know”- Costs are yours. Every answer is billed to your Anthropic account at the model’s normal API price. Listing models is free.
- The builder’s own work is separate. MonstarX builds your app with its own AI, which counts toward your MonstarX plan as usual. Connecting a key does not change which model builds your app.
- One prompt in, text out: no system prompt, no pictures, no tools. Long answers stop at the token limit.
Frequently asked questions
Section titled “Frequently asked questions”Why does connecting fail with a message about a workspace?
Your key works in several workspaces, so Anthropic needs to know which one to use, and MonstarX does not send that. Create a new key scoped to a single workspace and connect that one.
Can my app use this key to call Claude?
No. The key is for MonstarX's builder only. For AI in your app, use the built-in AI (see Add AI features to your app) or connect OpenRouter, which also offers Claude models.
Does connecting Anthropic make MonstarX build with Claude?
No. MonstarX keeps building your app with its own models. Your key is used only when the builder asks a Claude model something on your behalf.
Is my Claude.ai subscription enough?
No. The Claude API is billed separately, through the Claude Console. A Claude.ai Pro or Max plan does not include API use.