Connect your systems, automate your workflows, and build products that talk to each other. 5labs designs and builds robust APIs that power web applications, mobile apps, and third-party integrations. Whether you need a REST API for your SaaS platform, a GraphQL layer for your frontend, or payment gateway integrations with Stripe and PayPal, our Edinburgh-based engineers deliver APIs that are fast, secure, and thoroughly documented.
Modern software rarely exists in isolation. Your web application needs to communicate with mobile apps, your CRM needs to sync with your email platform, and your checkout process needs to process payments securely. APIs make all of this possible. At 5labs, we build the connective tissue that holds your digital ecosystem together, designing APIs that are clean, performant, and built to last.
Based in Edinburgh, our backend engineers specialise in REST API and GraphQL development, third-party service integrations, webhook systems, and microservices architecture. We build APIs that handle millions of requests, authenticate users securely with OAuth 2.0 and JWT, and come with comprehensive documentation so your team or external partners can integrate with confidence. Every API we build follows industry best practices for versioning, error handling, rate limiting, and security.
APIs are the backbone of our web development and mobile app development projects. Building a product from scratch? Our custom software and SaaS development teams architect API-first systems that scale gracefully as your user base grows.
Reliable APIs and integrations that connect your entire technology stack
We design and build RESTful APIs that follow OpenAPI standards, with clear endpoint structures, proper HTTP methods, meaningful status codes, and pagination. Your APIs will be consistent, predictable, and easy for any developer to work with.
For applications that need flexible data fetching, we implement GraphQL APIs that let clients request exactly the data they need. No over-fetching, no under-fetching. Ideal for mobile apps and complex frontends with varied data requirements.
We integrate payment processors including Stripe, PayPal, GoCardless, and Worldpay into your applications. From one-off payments and subscriptions to marketplace payouts and invoicing, we handle the complexity so your checkout works flawlessly.
We connect your systems to CRMs (Salesforce, HubSpot), accounting tools (Xero, QuickBooks), email platforms (Mailchimp, SendGrid), and hundreds of other services. Data flows automatically between your tools, eliminating manual data entry.
We implement OAuth 2.0, OpenID Connect, JWT tokens, and API key management to secure your endpoints. Rate limiting, input validation, and encryption ensure your API is protected against abuse and common attack vectors.
Every API we build comes with interactive documentation generated from OpenAPI specifications. Your developers and integration partners get a clear reference with example requests, response schemas, and authentication guides.
A structured approach to building APIs that scale
We work with your team to define the API's consumers, data models, authentication requirements, and integration points. This phase produces an API specification document that serves as the contract between frontend and backend teams.
We design the endpoint structure, request/response formats, error handling strategy, and versioning approach. For REST APIs we follow OpenAPI 3.0 standards. For GraphQL we define schemas, types, queries, and mutations before writing any code.
Our engineers build the API with clean, well-tested code. We write unit tests and integration tests alongside the business logic, ensuring each endpoint behaves correctly under normal conditions and edge cases alike.
We test the API against real third-party services, payment processors, and client applications. Load testing confirms the API performs under expected traffic volumes, and security testing checks for vulnerabilities before launch.
We generate interactive API documentation, deploy to your production environment, and configure monitoring. Your team receives everything needed to start consuming the API immediately.
APIs evolve as your product grows. We provide ongoing support for bug fixes, new endpoint development, performance tuning, and version management. Breaking changes are handled through proper versioning so existing consumers are never disrupted.
Proven technologies for building reliable, high-performance APIs
Node.js (Express, Fastify), Python (Django REST, FastAPI), PHP (Laravel), Go. We choose the right language and framework based on your performance requirements, team expertise, and existing technology stack.
REST (OpenAPI 3.0), GraphQL (Apollo, Hasura), gRPC, WebSockets. We select the right protocol for each use case, whether that is a public-facing REST API, a real-time WebSocket connection, or an internal gRPC service.
PostgreSQL, MongoDB, Redis, RabbitMQ, AWS API Gateway, Swagger/OpenAPI, Postman. We build APIs on robust databases and messaging systems, with proper caching and gateway management for production workloads.
Extend your API with these complementary development services
Common questions about our API and integration services
An API (Application Programming Interface) allows different software systems to communicate with each other. If you want your mobile app to pull data from your website, your checkout to process payments through Stripe, or your CRM to sync with your email tool, you need APIs. They are the building blocks of modern connected software.
REST is the standard choice for most APIs. It is well understood, widely supported, and works well for straightforward CRUD operations. GraphQL is better suited to applications where different clients need different data shapes, such as a mobile app and web dashboard consuming the same backend. We assess your specific requirements and recommend the best approach.
A simple REST API with basic CRUD endpoints might start from £2,000. More complex projects involving multiple third-party integrations, payment processing, real-time features, and comprehensive documentation typically range from £5,000 to £25,000. We provide a detailed quote after understanding your requirements and the systems involved.
We implement multiple layers of security. Authentication is handled via OAuth 2.0, JWT tokens, or API keys depending on the use case. We apply rate limiting to prevent abuse, validate all input data, encrypt data in transit with TLS, and follow OWASP API security guidelines. For sensitive endpoints, we add additional measures like IP whitelisting and request signing.
Yes. We regularly integrate with CRMs (Salesforce, HubSpot, Zoho), accounting platforms (Xero, QuickBooks), payment processors (Stripe, PayPal), email services (Mailchimp, SendGrid), and many other third-party tools. If the service has an API, we can connect it to your systems.
Yes. Every API we build includes interactive documentation generated from OpenAPI (Swagger) specifications. The documentation includes endpoint descriptions, request and response examples, authentication guides, error code references, and a sandbox environment for testing. This makes it straightforward for your team or external developers to integrate.
A straightforward REST API can be built in 2 to 4 weeks. Projects involving complex business logic, multiple third-party integrations, real-time features, or microservices architecture typically take 6 to 12 weeks. We provide a detailed timeline during the planning phase so you can coordinate with your frontend and mobile development teams.
Microservices architecture breaks a large application into smaller, independent services that each handle a specific business function. Each service has its own database and API, and services communicate with each other through well-defined interfaces. This approach makes it easier to scale, deploy, and maintain individual parts of your system without affecting the rest.
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