How to Connect an External API
Call third-party APIs from server code, handle their errors properly, and never expose your keys.
Written and reviewed by Lovable Student — Independent guides, prompts and troubleshooting notes for people building with Lovable. Expert build help provided by PromptSites.com.
Published 24 Aug 2026 · Tested with Lovable as of 24 Aug 2026

Overview
Calling an external API safely means doing it from the server, with the key stored as a secret and real error handling around the response.
Beginner explanation: If the key is in the browser, anyone can read it and use it on your account.
Technical explanation: Put the call in a server function, read the secret inside the handler, check the response status before parsing, and surface the provider status and message when it fails.
Steps
- Store the API key as a server-side secret.
- Write a server function that makes the request.
- Validate the input before calling out.
- Check the response status before parsing the body.
- Return a useful error to the interface, and log the provider detail server-side.
:::tip Check the response status before parsing JSON. Parsing first throws away the provider error message that tells you what went wrong. :::
What to check afterwards
- The call works with valid input
- Invalid input is rejected before the call
- Provider failures produce a readable message, not a blank screen
Common problems
- Key in frontend code.
- No status check before parsing.
- Swallowing errors into a generic message so you cannot diagnose anything.
Where people get stuck
If you have followed the steps and the result still is not right, the fastest path is usually to describe the exact behaviour you expected, the behaviour you got, and any error text, then ask for a fix in one focused follow-up prompt. If that loop is not converging, hand it over.
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