An API integration checklist turns “connect these tools” into a project that can be built and verified. Define which information moves, which system owns it, when the transfer occurs, and how your team will handle failures.
An API is an interface that lets software exchange information or request actions. The business requirement should remain understandable without reading the API documentation: a confirmed customer change updates the operations record, for example, while an incomplete change goes to review.
1. Define the event and the business result
Name the event that starts the integration and the result that means it succeeded. For customer onboarding, the trigger might be an approved account, and success might mean a matching operations record with the required fields. Keep optional notifications separate from the essential record update so failures can be diagnosed.
Decide whether the integration should respond to events or check for changes on a schedule. Confirm the options provided by the actual systems before committing to an approach.
2. Establish data ownership
Create a field map showing the source, destination, expected format, and owner for each value. Define how records are matched and what happens when they already exist. A customer name is rarely enough to establish a reliable match.
- Which identifier connects the records?
- Which system is authoritative for each field?
- What should an empty value mean: no change, missing information, or a request to clear it?
- How should dates, time zones, and allowed status values be represented?
3. Plan access and environments
Identify the credentials and permissions required by the integration. Separate test and production access where the systems support it. Record who owns the accounts and how access can be revoked or updated. The project should include a way to test without creating misleading customer records or messages.
Review the provider’s current authentication and usage documentation. Limits and available features depend on the specific service and account configuration.
4. Handle duplicates and retries
A connection failure can leave the sender unsure whether the receiver completed an action. A retry must therefore be designed around the action’s effect. If the same event arrives twice, the integration should recognize it instead of creating another customer or repeating a consequential action.
For a concrete provider example, Stripe’s webhook documentation explains that duplicate events can occur and describes ways to identify already-processed events. Check each provider’s delivery behavior rather than assuming all APIs behave identically.
5. Make failure visible
Record enough context to identify the affected business record and the step that failed. Avoid placing credentials or unnecessary personal information in logs. Provide a review path for validation problems and a recovery process for temporary outages.
- Who is notified when updates stop?
- Can an operator tell whether a record is pending, completed, or failed?
- What must be checked before retrying an action?
- How are records reconciled after an outage?
6. Agree on acceptance tests
Use representative examples of the business process. A successful response code is not sufficient if the wrong record was changed or a required field was lost. Include incomplete input, an existing record, a duplicate event, denied access, and an unavailable destination.
For each case, write the expected result in business terms. A duplicate request might leave one record and a clear processing history. A missing required field might leave the original request unchanged and create a review item.
7. Prepare the handover
Document the field map, credentials owner, event flow, known limits, monitoring, and recovery steps. Give the receiving team a way to run the acceptance checks after a change. Include recurring provider costs and maintenance responsibilities in the operating plan.
Our software handover checklist explains how to test whether the next operator can use the documentation.
What should you send an integration developer?
Provide the systems involved, a diagram or written description of the current process, sample records with sensitive details removed, and a list of required outcomes. Include who can grant access and who will approve the test results. These details help identify unknowns before an estimate becomes a commitment.
Rantum Solutions offers API, system, and data integration services. To plan a connection between your business tools, share your integration requirements.