API Development and Integration Services

API design and an OpenAPI specification, implementation in REST or GraphQL, authentication and authorization, rate limiting and pagination, automated contract and integration tests, a sandbox environment, generated reference documentation, and monitoring. If the work is integrating an existing third-party API instead of building one, the same discipline applies to the client side: validation, retries, idempotency, and alerting.

API development means building an interface that other systems call, typically to expose your own data or functionality. API integration means connecting your systems to somebody else's API, such as a payment processor, CRM, or shipping provider. Most projects involve both, because the integration usually needs somewhere to put the data and an endpoint for the other side to call back into.

REST suits broad, cacheable, resource-shaped access and is what most third parties expect to consume. GraphQL suits front ends that need many related objects in one round trip and would otherwise make a dozen REST calls. The deciding question is who the consumers are: if it is your own application, GraphQL often wins; if it is other companies, REST with an OpenAPI spec is easier for them to adopt.

We design against the OWASP API Security Top 10. In practice that means authorization checked at the object and property level rather than just at login, proper authentication with scoped tokens, rate limiting and payload limits to prevent resource exhaustion, no sensitive data leaking through error messages, and an accurate inventory of which versions and environments are exposed. Those checks are tested, not just reviewed.

Axiom projects run between $500 and $35,000 depending on scope, with monthly retainers between $250 and $10,000 for ongoing work. A single well-defined third-party integration sits at the low end. A multi-consumer public API with sandbox, documentation, versioning, and SLAs sits at the upper end. Everything is quoted against an approved scope document.

That is usually the point. Most engagements connect systems that are each working fine on their own but do not talk: a CRM, an accounting package, a website, and a warehouse system. We build the integration layer between them rather than proposing a replacement, because replacing a working system to fix a data-flow problem is an expensive way to solve the wrong thing.

We build against versioned endpoints where the vendor offers them, validate payloads at the boundary so an unexpected shape fails loudly rather than writing bad data, and alert on integration errors. When a vendor announces a deprecation, the fix is a scoped change rather than an archaeology project, because the integration is documented and tested.

Yes, and it is generated from the specification rather than written separately, which is the only reliable way to stop documentation drifting from behaviour. You get reference documentation, worked examples, a sandbox or test credentials, and a changelog. Postman found 93% of teams struggle with API collaboration; almost all of that is a documentation problem.