Halo Lab’s approach to API development starts with the contract — endpoints, data shapes, authentication, and error handling agreed in an OpenAPI or GraphQL schema before the first function is written.
We build RESTful and GraphQL APIs for web products, mobile backends, and third-party integrations — with full documentation, versioning strategy, and test coverage structured for teams that need to build against the API directly.
3 main challenges holding back your growth
Outgrown identity
Your company has grown, but the brand no longer reflects scale or direction.
Outgrown identity
Your company has grown, but the brand no longer reflects scale or direction.
Outgrown identity
Your company has grown, but the brand no longer reflects scale or direction.
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No API contract defined upfront
Contract discovered during integration — frontend and mobile rebuild constantly.
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Undocumented endpoints
APIs shipped without docs — every consumer reverse-engineers the behaviour.
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No versioning strategy
Breaking changes shipped without notice — integrations fail across the board.
“All projects in which we’ve involved Halo Lab have been great successes, but their leadership on our brand refresh is worth highlighting.”
“We’ve had feedback from users, investors, and employees, and everyone has said that Halo Lab did a fantastic job with the branding.”
“We’re proud of their branding services. They not only do what we tell them but also make suggestions to help us improve our offerings.”
What we deliver
API development from
contract to documentation
API Design
Contract-first API design — endpoints, data shapes, auth, and error handling defined upfront.
REST APIs
RESTful API development — resource-oriented, stateless, and versioned from the first release.
GraphQL APIs
GraphQL schema design and resolver implementation — typed, efficient, and query-flexible.
Authentication
OAuth 2.0, JWT, and API key authentication — scoped permissions and token lifecycle managed.
Documentation
OpenAPI or GraphQL schema documentation — interactive reference your team builds against directly.
API Testing
Unit, integration, and contract tests — covering every endpoint, error state, and edge case.
Versioning
Versioning strategy defined before release — breaking changes managed without breaking consumers.
Third-Party Integration
Payment, auth, analytics, and communication APIs integrated and tested as part of the build.
Our most ambitious work
How we work
Our process for your
API development
Start with a strategy call where we align on your goals, challenges, and priorities, and set a clear direction for the entire branding process.
3–4 Days
Research & analysis
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Requirements & Contract
We map consumer requirements — frontend, mobile, or third-party — and define the API contract before any implementation begins.
2–3 Days API contract
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Schema & Architecture
We design the OpenAPI spec or GraphQL schema — endpoints, types, auth flows, and versioning strategy documented and agreed.
1–2 Days API schema
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API Build
We implement endpoints, resolvers, authentication, business logic, and third-party integrations sprint by sprint.
2–6 Weeks API build
Testing & Review
Unit tests, integration tests, and contract tests written for every endpoint — edge cases and error states covered before release.
3–5 Days Test suite
Documentation & Handoff
Interactive API documentation published and a structured handoff delivered — your team builds against the API directly from day one.
1–2 Days API docs
Start with a strategy call where we align on your goals, challenges, and priorities, and set a clear direction for the entire branding process.
3–4 Days
Research & analysis
Industries we serve
API development for
diverse products
Healthcare
API development for clinical platforms — FHIR-compatible, secure, and documented for integration.
Financial Services
API development for fintech — payment gateway, banking, and compliance API integration built securely.
Logistics
API development for fleet and ops — real-time tracking, routing, and third-party integration APIs.
Real Estate
API development for property platforms — listing, search, and transaction APIs built for scale.
Education
API development for EdTech — LMS, content delivery, and subscription APIs designed and documented.
Web3 & Blockchain
API development for Web3 — on-chain data, wallet, and smart contract interaction APIs built securely.
Wellness/Fitness
API development for health platforms — wearable data, tracking, and subscription APIs built to spec.
Information Technology
API development for SaaS and enterprise — internal APIs, partner integrations, and public API layers.
6 reasons why clients
choose Halo Lab
Team with industry depth
Strategy before design
Custom-only approach
Expertise for complex needs
Clear, collaborative process
Flexible value for any budget
100+ verified
love letters
“Halo Lab is very organized in planning to achieve the goals within the set deadlines. We feel they were part of our internal team project.”
“Their experts have a very diverse range of skills and always find a solution to exposed issues. The communication process was clear.”
“During the collaboration, Halo Lab prioritized our people, always taking into account our input and ideas and giving all team members a voice.”
“The Halo Lab team unified branding across our patients’ app, showcasing professionalism, convenience, and consistency.”
“Halo recreated our existing portal with a modern and beautiful experience, greatly increasing usability and delight for the end user.”
“Halo Lab is brilliant. We were impressed with their timely delivery, cost-effectiveness, and the people who knew what they were doing!”
“The value we get from Halo Lab and their quality designs sets them apart from others. They are the right mix of price, talent, and style.”
“We gave the Halo Lab team a chance, and we immediately knew they were the ones we wanted to work with.”
“The Halo Lab work pleasantly surprised us, and bringing in their professional design team has been a worthy investment for us.”
“When collaborating with Halo Lab, we felt that communication was straightforward and that the deliverables fit what we expected.”
“Halo Lab has helped us with a rebrand and defined a new name, logo, and color palette. We’ve had a great experience working with them.”
12 years
We’ve built one of the most trusted agencies
150+
Specialists in design, engineering & product management
78%
Returning clients in Europe & North America
FAQ
Why invest in branding services?
Why invest in branding services?
What does API development include?
API contract design, REST or GraphQL implementation, authentication, third-party integrations, OpenAPI or GraphQL schema documentation, test suite, versioning strategy, and engineering handoff.
Do you build REST or GraphQL APIs?
Both. REST is our default for resource-oriented services and mobile backends. GraphQL is recommended when consumers need flexible queries or when multiple frontends need different data shapes from one API.
Do you write API documentation?
Yes. Every API is documented using OpenAPI (Swagger) for REST or a typed schema for GraphQL — with an interactive reference your frontend, mobile, and integration teams can build against directly.
How long does API development take?
Most API builds take 3 to 8 weeks from contract design to documented handoff, depending on the number of endpoints, integration complexity, and whether authentication flows are in scope.
Do you handle authentication and security?
Yes. OAuth 2.0, JWT bearer tokens, and API key authentication are standard. Rate limiting, input validation, and security headers are configured as part of every API build before handoff.
Can you integrate third-party APIs?
Yes. Payment providers, identity platforms, analytics, communication services, and data APIs are integrated and tested as part of the build — with error handling and retry logic defined.
Do you manage API versioning?
Yes. A versioning strategy is defined before the first release — covering URL versioning, deprecation timelines, and change management so consumers are never broken by an unannounced update.
Do you write tests for APIs?
Yes. Unit tests, integration tests, and contract tests are written for every endpoint — covering happy paths, error states, auth failures, and edge cases before the API is handed off.
Do you offer ongoing API support?
Yes. Ongoing API development retainers are available — covering new endpoints, schema updates, performance optimisation, and versioning management as your product and integrations grow.