The first successful API request is encouraging. It tells me the connection can work. I still want to know what my product does when that connection fails.
A third-party service becomes part of the user's experience, even though I do not control it.
Read beyond the quickstart
I check official documentation for the API version I use: authentication, response shape, errors, rate limits, retries and any callbacks. A short example usually cannot explain the whole integration.
This is also how I approach AI-generated code. An example is a starting point I still need to verify.
Keep private credentials private
Calls requiring a secret key belong in trusted server code. A frontend environment variable does not hide a value included in the browser bundle.
The server should validate the request and the user's permission before calling the provider. I keep test and production configurations separate where the provider supports that.
Define waiting and retrying
I use an appropriate timeout and a clear loading state. If the timeout expires, I do not assume a write operation definitely failed. The provider may still complete it.
Before retrying a create or payment action, I check the provider's idempotency and reconciliation rules. I limit retries, respect rate limits and avoid an endless loop against a struggling service.
Check unexpected responses
I test a missing field, empty body, invalid JSON and a provider error. A successful HTTP status does not guarantee the response contains the values my code needs.
I validate important fields before using them. I also distinguish invalid user input, internal configuration errors and provider downtime so the interface does not blame the wrong person.
Verify callbacks
Where webhooks are used, I follow the provider's signature-verification method. I check which stored operation the event belongs to and handle duplicate deliveries safely.
I only acknowledge according to the provider's requirements once the event is safely accepted. Slow work may need separate processing so a quick response does not lose the operation.
Let the rest of the product keep working
I ask what can continue during an outage and how to preserve the person's progress. A pending operation needs honest wording instead of a success claim before confirmation.
This is part of building for unstable connections: the person needs to know whether to wait, check a result or retry safely.
Leave evidence I can use
I record safe references, stages and response categories while excluding secrets and unnecessary personal data. Those references help me investigate a reported problem without asking the user to reconstruct everything.
I cannot make a provider always respond. I can make my application handle waiting, failure and recovery with care.