Web App Development
Fast, secure web apps, portals and dashboards built with React, Next.js and Node.js.
API Development
API Development and Integration Services
API development is building the interfaces that let apps, websites and other systems exchange data. Nexdevix builds secure, documented REST APIs with Node.js, Express and TypeScript, and integrates your product with payment providers, CRMs and third-party services.
What we build
Our API Development Services
REST API development
Versioned, documented APIs for your web app, mobile app or partners.
Third-party integrations
Stripe, Razorpay, CRMs, email and shipping APIs connected reliably.
Webhooks and automation
React to events in other systems without manual work.
Authentication and security
OAuth, API keys, rate limits and role-based access.
API documentation
OpenAPI docs so your team and partners can test every endpoint.
API modernisation
Clean up, secure and document APIs that grew without a plan.
APIs your team can rely on
An API is a contract between systems. A good one is predictable, documented and secure, so front ends, mobile apps and partners can build on it without surprises.
Our API stack
We build APIs with Node.js, Express and TypeScript, with data in MongoDB. For product-wide work, see custom software development.
Why Nexdevix
Why Choose Nexdevix for API Development
Documented from day one
Every endpoint described in OpenAPI and kept in sync with the code.
Tested
Automated tests on every endpoint before each release.
Secure by default
Validation, rate limiting and least-privilege access on every API.
Typed end to end
TypeScript types shared between API and front end.
Process
How We Deliver Your Project
Step 1 · 1–2 weeks
Discovery
Workshops to agree goals, users, scope and a fixed estimate.
Step 2 · 1–3 weeks
Design
Wireframes and a clickable prototype you approve before code.
Step 3 · 4–12 weeks
Development
Two-week sprints with a working demo at the end of each one.
Step 4 · 1–2 weeks
Testing and launch
Automated and manual QA, security checks, then a staged release.
Step 5 · Ongoing
Support and growth
Monitoring, fixes and new features on a monthly plan.
Technologies
Technologies We Use for API Development
Pricing
How Much Does API Development Cost?
- Typical cost
- $5,000 – $60,000+
- Typical timeline
- 3 – 12 weeks
The cost of api development depends mainly on scope. These are the factors that move the price most:
- Number of endpoints and data models
- Number and quality of third-party APIs to integrate
- Authentication, permissions and security requirements
- Expected traffic and response-time targets
Prices in USD. You get a written, fixed estimate after a free discovery call.
FAQ
API Development FAQs
What is the difference between an API and an integration?
An API is the interface your own system offers. An integration connects your system to someone else's API, such as a payment provider or CRM. We build both.
Do you document the API?
Yes. Every API we build ships with OpenAPI documentation that your developers and partners can browse and test.
Can you integrate with our existing software?
Usually, yes, if it has an API or can export data. We review its documentation during discovery and confirm the approach before quoting.
Related
Related Services
Custom Software Development
Software built around your workflows, from internal tools and portals to integrations that remove manual work.
SaaS Development
Multi-tenant SaaS products with subscriptions, user management and analytics, from first release to scale.