Development

API integration services

We connect payment, e-invoicing, SMS and third-party services to your system securely.

We connect payment providers, e-invoicing and accounting services, SMS providers and other third-party services to your system. We design and document REST APIs so that your own systems can talk to each other. The contact form on this website is connected to the customer relationship management system of ONLINEKURUM through such an API. If the connection fails, a submission is not lost: it is held and sent again.

The problem we solve

Integrations break quietly. When a payment service does not respond, an invoice is rejected or an SMS cannot be sent, most systems tell nobody. The problem surfaces when a customer calls. Transfers done by hand carry a similar risk: the same record is entered twice or not at all. Every month the team spends extra hours checking whether the two systems match. The rules and versions of third-party services also change over time. A reliable integration needs a structure that notices an error, retries the request and keeps a record of every step.

How we work

  1. Mapping the flow and the contract

    We map which data goes from which system to which, and when. We review the documentation of the service and write the fields, error codes and limits into a written integration specification. This specification makes sure both sides understand in the same way what the integration does and what it does not do.

  2. Secure connection

    We keep credentials out of the code, in environment settings that only the server can read. We verify requests with signatures or tokens and use service accounts that have only the permissions they need.

  3. Designing for failure

    We decide up front what happens when the other service does not respond or returns an error. Failed requests wait in a queue, are retried at set intervals and every attempt is recorded. Even if the same request is sent twice, no second record is created on the other side.

  4. Testing and monitoring

    We test the integration first in the test environment of the service, then with a small share of real data. After launch we monitor the error rate and set up alerts that inform your team when something unexpected happens.

What we deliver

  • A written integration specification with fields, error codes and limits
  • A connection with retries and logging
  • A REST API and its documentation
  • Test scenarios and error alerts

Frequently asked questions

Which services do you integrate with?

Payment providers, e-invoicing and accounting services, SMS providers and customer relationship management systems are typical examples. We can work with any service that offers a documented API. For systems without an API, we look at alternatives such as file transfers together with you.

Do we lose data when the other service is down?

No, we design the integration for that case. Records that cannot be sent wait in a queue and are sent again when the service responds. If a record cannot be sent within a set time, your team receives an alert.

Can you build an API for our own system?

Yes. We design, version and document the REST API that your mobile app, your partners or your other systems will use. Authentication, permissions and rate limits are defined up front as part of the design.

What happens when a provider changes its API?

Providers usually announce new versions in advance. As part of maintenance we follow these announcements, review the impact of the change and plan the move before the old version is switched off. Because we keep the integration code separate from the rest of your system, a change at one provider affects only that part.

What does the cost of an integration depend on?

The cost depends on the number of services to connect, the directions in which data flows and how much detail the handling of errors needs. A one-way transfer with a well documented service takes less time than a two-way flow that connects several systems. We set the scope once the integration specification is written.

Tell us what you need to connect

Describe in a few sentences what you want to build. We review your needs and write back with how we can move forward.