API integration services

What to check in a vendor's API

Prove the riskiest call first

Documentation does not always match behaviour. Before committing, build a small proof of concept that performs the hardest or most important operation: creating an order with your real product structure, reading a large customer list with pagination, or receiving a change notification. A day or two of proof can reveal missing fields, slow responses or undocumented limits that would otherwise surface halfway through a project.

Share the findings in plain language so the decision to proceed is informed.

Warning signs in a vendor's API

How an API integration engagement runs

1. 01

   Requirements

   What data and actions, in which direction, how often.

   Output: Integration brief

2. 02

   API assessment

   Documentation, plans, limits and terms reviewed.

   Output: Feasibility notes

3. 03

   Proof of concept

   Riskiest operation built in the sandbox.

   Output: Confirmed approach

4. 04

   Build

   Full integration with retries, logging and alerts.

   Output: Working integration

5. 05

   Operate

   Monitoring, credential renewal and version updates.

   Output: Reliable flow

Credentials and access

API credentials give access to your data in the other product. They should be issued to your organisation's account, stored in a proper secrets store rather than in code or documents, given only the permissions the integration needs and rotated when people leave or a provider changes. Record which integration uses which credential, so access can be withdrawn precisely. Where the API uses OAuth, make sure the authorising account belongs to the organisation, not to an individual who may leave.

Talking to the vendor

Vendors' developer support teams can confirm limits, upcoming changes and the right way to perform awkward operations. Ask early, keep a record of answers and check whether your plan includes developer support. For important integrations, ask how the vendor communicates breaking changes and how much notice it gives.

Beyond one API

Where several systems need connecting, the software integration pages cover choosing methods, sources of truth and reliable operation across them.

Reading the terms of use

API terms can restrict what you may do with the data, how often you may call, whether you may store data and whether a third party may build on your behalf. Some prohibit certain uses outright or require attribution. Read them for your specific purpose before building, and check how the vendor may change them. If the terms are unclear, ask the vendor in writing.

Terms matter as much as technology when the integration is central to your operations.

Checking limits against your volumes

Estimate how many calls the integration will make on a normal day and on your busiest day, including initial data loads and catch-up after an outage. Compare that with the vendor's limits for your plan. If the numbers are close, design for batching, change feeds and spreading work over time, or budget for a plan with higher limits. Discovering the limit during your busiest week is the expensive way to learn it.

A short findings report

Ask for the assessment as a short written report: what the API supports, gaps and workarounds, limits, terms and risks. It is useful whatever you decide and helps compare products if you are still choosing.

After launch

Agree who monitors the integration and renews credentials.