WhatsApp Store AI Assistant
AI-powered conversational sales assistant transforming WhatsApp into an automated store with instant replies and product management.
APIs & integrations
API development and third-party integration services
API development is building the interface that lets your applications, partners and tools exchange data reliably. Integration is connecting your software to services you already use, such as payments, WhatsApp, Shopify, CRMs, Google sign-in or accounting tools. I build secure REST and GraphQL APIs with Node.js and connect systems so data moves without copy-and-paste.
Common API and integration projects
- A backend API for a new web or mobile app, designed for both clients from the start
- Connecting a store, CRM or booking system so orders and leads appear automatically
- Payments with Stripe, including webhooks that keep subscriptions and orders in sync
- Messaging through the WhatsApp Cloud API, email or SMS triggered by events in your system
- Sign-in with Google or other OAuth providers
- Giving partners or customers secure, documented access to your data
What's included
API design
Resources, endpoints or GraphQL schema, naming and error formats agreed before implementation, so frontend and backend can work in parallel.
Secure implementation
Authentication, authorisation on every request, input validation, rate limiting and secrets kept out of the code.
Third-party integrations
Stripe, Shopify, WhatsApp Cloud API, OpenAI, Google APIs, Firebase and other services connected through their official APIs.
Webhooks and background jobs
Verified webhook handlers, retries and queues so events are processed once and failures are visible.
Documentation
Endpoint reference and examples so your team, partners or another developer can use the API confidently.
Monitoring
Logging and error tracking so integration failures are noticed before customers report them.
Integrations should fail safely
Every external service is occasionally slow, unavailable or returns something unexpected. A good integration assumes that: it validates what it receives, retries sensibly, avoids processing the same event twice and records failures where someone will see them. That is the difference between an integration that works in a demo and one you can rely on.
For APIs that others will consume, I keep the design consistent and versioned, so new features can be added without breaking existing clients.
How the project runs
- Map the data flowWhich system owns which data, what triggers each exchange and what should happen when something fails.
- Design the contractEndpoints or schema, authentication method, payloads and error responses, reviewed before coding.
- Build and testImplementation against sandbox accounts with automated tests for important paths.
- HardenRate limits, retries, idempotency, logging and security review.
- Document and launchReference documentation, production credentials set up securely and monitoring switched on.
Technology choices
- Node.js and ExpressFast, maintainable REST APIs and integration services.
- GraphQLFlexible queries for apps with many related data types, and for APIs such as Shopify's.
- OAuth 2.0 and NextAuthSecure sign-in and delegated access to third-party accounts.
- Webhooks and queuesReliable processing of events from payment, messaging and commerce platforms.
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What affects cost and timeline
- Number of systems and endpoints involved
- Quality and limits of the third-party APIs
- Security, authentication and compliance requirements
- Data volume and real-time versus scheduled synchronisation
- Documentation and testing expectations
Every estimate starts from your requirements. Request a quote with your users, must-have features, timeline and budget range, and I will reply with questions and a suggested first phase.
Frequently asked questions
REST or GraphQL: which should we use?
REST is simple, widely understood and suits most APIs. GraphQL helps when clients need flexible queries across many related data types. The choice depends on your clients and data, not on trends.
Can you integrate with a system that has no public API?
Sometimes. Options include scheduled exports and imports, database-level integration with permission, or the vendor's partner API. Each has trade-offs that we review before building.
How do you keep API keys and customer data safe?
Secrets are stored in environment configuration, not in code. Every request is authenticated and authorised on the server, inputs are validated and access is logged where needed.
What happens if a third-party service goes down?
Integrations are built with timeouts, retries and queues where appropriate, so temporary outages do not lose data, and persistent failures raise alerts.
Can you document an existing API?
Yes. I can review an existing API, document it and recommend improvements to security, consistency and performance.
Have a project in mind?
Tell me what you want to build, who will use it and when you need it. I will reply with questions and a practical next step.
Discuss your project