API Development
Connected Systems, Seamless Integration
We design and build robust APIs that power your applications and connect your systems. From RESTful services to GraphQL endpoints, we create APIs that are secure, well-documented, and production-ready. Every API we build includes OpenAPI specification, authentication (OAuth 2.0 or JWT), rate limiting, error handling, and a test suite. We work with UK businesses across e-commerce, fintech, healthcare, and SaaS — connecting Stripe, HubSpot, Salesforce, Xero, and custom legacy systems.
API development in the UK costs £5,000–£40,000+ depending on complexity, integration count, and whether you need REST or GraphQL. Launchwork Digital designs and builds secure APIs — with OAuth authentication, OpenAPI documentation, rate limiting, and tested endpoints — typically delivered in 4–12 weeks. Most UK businesses need API work when connecting a website, mobile app, CRM, or payment system.
Key Features
What you get when you work with us on your api development project.
RESTful APIs
Well-structured REST APIs following industry best practices and standards.
GraphQL
Flexible, efficient data fetching with GraphQL schemas tailored to your needs.
Authentication & Security
OAuth, JWT, and API key management for secure access control.
Documentation
Comprehensive API documentation with interactive examples and SDKs.
Third-Party Integrations
Connect your systems with payment providers, CRMs, ERPs, and more.
Technologies We Use
Explore Our Insights
In-depth articles related to api development.
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Frequently Asked Questions
Common questions about our api development services.
What's the difference between REST and GraphQL APIs?
REST uses multiple endpoints (GET /users, GET /orders) and is simpler to implement. GraphQL uses a single endpoint where clients request exactly what they need, reducing over-fetching. We recommend REST for simpler integrations and GraphQL for complex frontends with varying data needs.
How do you secure APIs against attacks?
We implement authentication (OAuth 2.0, JWT), rate limiting, input validation, encryption (TLS), and monitoring for suspicious patterns. We also follow OWASP API security guidelines and conduct security testing before launch.
Can you integrate with our existing systems and third-party services?
Yes, integration is our specialty. We've connected systems with Salesforce, HubSpot, SAP, Xero, payment providers, shipping APIs, and hundreds of other services. We document all integrations and provide ongoing support.
Do you provide API documentation?
Every API we build includes comprehensive documentation with interactive examples (Swagger/OpenAPI), authentication guides, error reference, and sample code in multiple languages. Good documentation makes your API a pleasure to use.
How long does it take to build a custom API?
A simple internal REST API with 5–10 endpoints takes 2–4 weeks. A typical business API with authentication, rate limiting, and third-party integrations is 4–8 weeks. Complex APIs with GraphQL schemas, real-time subscriptions, and multi-tenant architecture run 8–14 weeks. We work in 2-week sprints so you see and test endpoints continuously rather than waiting for a single launch.
Do you build webhooks and event-driven integrations?
Yes — webhooks are a core part of most modern APIs we ship. We build outbound webhook delivery (with retries, signed payloads, and replay queues), inbound webhook receivers from Stripe, GitHub, HubSpot, Shopify, and others, plus event-driven architectures using AWS EventBridge, Google Pub/Sub, or self-hosted RabbitMQ where the workload demands it. We document every event payload in OpenAPI.
How much does API development cost in the UK?
API development in the UK typically costs £5,000–£15,000 for simple integrations (single third-party service, standard authentication), £15,000–£40,000 for complex APIs (custom data models, multiple integrations, high availability requirements), and £40,000+ for enterprise-scale systems with microservices architecture. Most straightforward REST APIs connecting a website to a CRM or payment processor fall in the £8,000–£20,000 range. We provide fixed-price quotes after a free scoping call.
How long does API development take?
Simple API integrations (connecting a website to Stripe, Mailchimp, or a standard CRM) take 2–4 weeks. Custom REST APIs with authentication, rate limiting, and documentation take 4–8 weeks. Complex systems with GraphQL schemas, multiple integrations, or microservices take 8–16 weeks. We deliver in iterative sprints with weekly demos so you can review progress throughout.
Do you integrate with Salesforce, HubSpot, or Xero?
Yes. We regularly build integrations with Salesforce, HubSpot, Xero, QuickBooks, Stripe, PayPal, Shopify, WooCommerce, and custom legacy systems. Integration work typically involves either using the platform's REST API or webhooks, building middleware to translate data formats, and handling authentication (OAuth flows for most modern platforms). We document every integration so your team understands how data flows between systems.
REST or GraphQL — which should I choose?
REST is the right choice for most UK businesses: simpler to implement, easier to debug, well-supported by every platform, and sufficient for the majority of integrations. GraphQL is worth the added complexity when you have a frontend that needs to query very different data shapes (e.g., a mobile app and a web dashboard pulling from the same API with different field requirements). We'll recommend the right approach after understanding your use case.
What documentation do you provide with the API?
Every API we deliver includes an OpenAPI (Swagger) specification, an interactive Postman collection, authentication setup instructions, and environment variable documentation. For public APIs, we also provide a developer portal with code examples in JavaScript, Python, and cURL. Documentation is not an afterthought — it's part of the delivery definition.