(API Development)
APIs built clean,
documented, and
production-ready.
WebAnts is a London API development agency. We build REST APIs, GraphQL APIs, webhooks, and third-party integrations in TypeScript and Node.js, with tests, OpenAPI documentation, and a runbook included.
Get a free quote
100%
APIs shipped with tests
OpenAPI
Documentation included
4.9★
Rated on Google & Clutch
£0
Prepayment required
(What we build)
REST, GraphQL, webhooks,
integrations, all in-house.
01
REST API Development
Clean, versioned RESTful APIs built in Node.js and TypeScript, with proper resource naming, HTTP status codes, pagination, filtering, and error handling. OpenAPI documentation included.
02
GraphQL API Development
Flexible GraphQL APIs with schemas, resolvers, mutations, and subscriptions. Apollo Server or Pothos, with DataLoader for N+1 query prevention and authentication middleware.
03
Third-party Integrations
Connect your platform to payment processors (Stripe, GoCardless), CRMs (HubSpot, Salesforce), communication tools (Twilio, SendGrid), and any other service with a published API.
04
Webhook Development
Incoming webhook handlers with signature verification, idempotency keys, retry queues, and dead-letter handling. Outgoing webhooks with event subscriptions and delivery tracking.
05
API Gateway & Middleware
Rate limiting, API key management, request validation, response caching, and logging, built as reusable middleware or as a standalone API gateway layer.
06
Authentication & Authorisation
JWT, OAuth 2.0, API key, and session-based auth. Role-based access control (RBAC), row-level security, and multi-tenant permission models implemented correctly from day one.
07
API Documentation
Auto-generated OpenAPI / Swagger docs with interactive Swagger UI or Redoc. Written developer guides, authentication setup instructions, and Postman collections included.
08
API Migrations & Rewrites
Migrate legacy SOAP or monolithic APIs to modern REST or GraphQL. Strangler-fig migrations that keep production running while you transition endpoints incrementally.
(How we work)
Contract first.
Code second.
Scoping
Map data flows, endpoint requirements, auth model, and integration points. Define the API contract before any code is written, OpenAPI schema or GraphQL SDL agreed upfront.
Build
Endpoints built with tests, error handling, and documentation in parallel. Staging environment deployed on Vercel, Railway, or your infrastructure.
Integration & Testing
Integrated with your frontend or third-party consumers. Load testing, security testing, and end-to-end scenario coverage before handover.
Handover & Documentation
Full OpenAPI spec, Postman collection, developer guide, and deployment runbook. We walk through the codebase with your team if needed.
(Deliverables)
Documented, tested,
and ready to ship.
- OpenAPI / GraphQL schema (agreed upfront)
- TypeScript source code
- Unit & integration test suite
- Interactive API documentation
- Postman / Bruno collection
- Authentication implementation
- Rate limiting & error handling
- Deployment & runbook documentation
(Stack)
“WebAnts built something better than I’d ever imagined, shipped faster than any agency I’ve worked with.”
LaTisha Ebanks
Marketing Director, North Pointe Marketing
(FAQ)
Common questions about
API development.
REST or GraphQL, which should I choose?
REST is usually the better choice for public-facing APIs, simple CRUD operations, or when you need broad client compatibility. GraphQL excels when different clients need different data shapes, when you want to reduce over-fetching, or when you're building a data-rich product with complex relationships. We recommend based on your specific use case, and we're comfortable building either.
How do you handle API authentication?
The most common pattern we implement is JWT-based authentication with refresh token rotation for web and mobile clients, plus API key authentication for server-to-server integrations. For third-party OAuth flows (Google, GitHub, etc.) we use proven libraries like Lucia or Auth.js. We never roll our own crypto, we use established, audited implementations.
Do you write tests for the APIs you build?
Yes, testing is included in every API project, not an add-on. We write unit tests for business logic, integration tests for each endpoint (covering happy path and error cases), and end-to-end tests for critical flows. Test coverage report is included in the handover pack.
Can you integrate our system with [specific third-party service]?
Almost certainly yes. We've integrated with Stripe, GoCardless, HubSpot, Salesforce, Xero, QuickBooks, Twilio, SendGrid, Mailchimp, Zapier, Google Workspace, various property portals, and many others. If the third-party has a published API, we can integrate it. We'll review their documentation during scoping and flag any constraints.
How much does API development cost?
A simple REST API with 5–10 endpoints, JWT auth, and basic documentation typically costs £3,000–£6,000. A more complex API with GraphQL, third-party integrations, webhooks, and comprehensive testing typically costs £8,000–£20,000. Large enterprise API projects start from £25,000. Flat written quote after a scoping call.
Do you handle deployment and infrastructure, or just the code?
Both. We can deliver just the code and documentation if you have your own DevOps team. Or we can handle the full deployment, containerised with Docker, deployed to Vercel, Railway, Render, AWS, or GCP, with environment configuration, secret management, and monitoring setup included.
Need an API built right? →
Free scoping call. OpenAPI contract agreed first. Flat quote. No prepayment.
WebAnts is a London API development agency. We build REST APIs, GraphQL APIs, webhooks, and third-party integrations in TypeScript and Node.js. All APIs are shipped with unit tests, integration tests, OpenAPI documentation, and a Postman collection. Based in London, serving clients across the UK and worldwide. 4.9★ rated on Google and Clutch.