Mobile POS and merchant-acquiring platform
A mobile POS product with one payment ledger across PayBy and Stripe, role-controlled GraphQL access, and payment-event processing.
API Development Services
API development services for interfaces other teams can trust.
We design and build custom REST APIs, GraphQL layers, and webhook systems for product teams that need stable contracts between applications. The work includes authorization, failure handling, versioning, observability, and usable documentation, not just a set of endpoints that works in a demo.
Bring the problem, the current workflow, or the existing code. We reply with a practical next step within one business day.
The brief
Start with what is not working.
Good software decisions begin with the constraint, not a list of features or a preferred technology.
01
Are integrations slowing down because every consumer interprets the same data differently?
02
Do API changes reach production before documentation, permissions, and failure paths are ready?
Plain answer
API development services design and build the contracts applications use to exchange data and actions. RaftLabs delivers REST APIs, GraphQL layers, and webhook systems with authorization, versioning, failure handling, tests, observability, and documentation. A focused first release starts at $15,000 and usually takes 8 to 12 weeks.
The happy path is the smallest part of an API.
The first consumer gets a response and the integration looks finished. Then a request is retried, a field changes, a token has the wrong scope, or a downstream system times out after completing the request. Without a written contract for those cases, every consumer invents its own workaround.
A dependable API makes ownership and failure explicit. It tells consumers what they may send, what they can expect back, how changes are introduced, and what happens when part of the transaction fails.
Relevant delivery record
- transactions in the first three months
- 10,000+
- UAE mobile POS project record
- payment processors behind one ledger
- 2
- PayBy and Stripe
- PCI DSS audit passed
- 2025
- Mobile POS platform
These figures come from one named API-heavy product build. They show transaction volume and an audited platform control, not a universal performance promise for every API project.
A custom API is justified when the contract between systems is part of the product.
If the left side fits, custom development may be sensible. If the right side fits, use the vendor connector or managed backend first.
A fit
01
Several applications or partners need a stable interface to the same business capability.
02
Authorization, audit history, retries, or versioning carry real operational risk.
03
The underlying business rules do not fit a standard connector or managed backend cleanly.
Not a fit
01
A supported connector already covers the data and actions you need.
02
The source system and ownership rules are still changing every week.
03
You need a one-time data transfer rather than a maintained interface.
Scope
What a production API needs
- 01
A contract built around consumers
Resources, queries, commands, and events reflect real consumer jobs. Schemas, validation, pagination, errors, and examples use consistent conventions so a second integration does not require a second interpretation. - 02
Authorization at the business boundary
Authentication proves identity; authorization controls what that identity may read or change. We model roles, scopes, tenant boundaries, and sensitive fields against the business domain, then test denied paths as carefully as allowed ones. - 03
Reliable asynchronous events
Webhook signatures, idempotency keys, retry policies, dead-letter handling, and replay tools prevent duplicate or delayed events from silently corrupting state. Operators can see which event failed and what happens next. - 04
Versioning, documentation, and operations
OpenAPI or schema documentation lives with the implementation. Contract tests catch incompatible changes. Metrics, traces, logs, rate limits, and an ownership runbook make the API supportable after launch.
Which interface pattern fits the job?
REST, GraphQL, and webhooks
| Pattern | Use it when | |
|---|---|---|
| REST | Resource operations over HTTP | Consumers need predictable commands and broad tooling support |
| GraphQL | A typed query layer | Clients need different views of a connected domain |
| Webhooks | Event delivery to a consumer endpoint | Another system should react without polling |
| Batch or files | Scheduled bulk exchange | Volume matters more than immediate response |
The choice is not ideological. A product may expose REST for commands, GraphQL for a complex interface, and webhooks for downstream events. We keep each pattern narrow enough to explain and operate.
Delivery
From API contract to supported release
Design the boundary before code makes it expensive to change.
- Phase 101
Map consumers and boundaries
Define who calls the API, which system owns each field, and what the first bounded domain must do. We record throughput, latency, compliance, and availability constraints without pretending every endpoint needs the same service level.
- Phase 202
Design the contract
Agree resources, events, permissions, error responses, idempotency rules, and versioning. Consumer examples and a contract review expose ambiguity before implementation begins.
- Phase 303
Build and test failure paths
Implement the interface, contract tests, authentication, rate limits, retries, monitoring, and documentation. Tests cover duplicates, partial failure, timeouts, and forbidden access as well as successful requests.
- Phase 404
Release and observe
Onboard the first consumers, watch latency and errors, document operational ownership, and support the production handoff. New consumers and domains follow only after the first contract holds up in use.
Where API projects usually fail
- The endpoint exists before ownership is clear
- An API cannot settle which system owns customer status, price, or entitlement. We assign a source of truth and conflict rule before exposing the field.
- Retries create duplicate actions
- Payments, orders, and jobs need idempotency and reconciliation. A network timeout does not prove the original action failed.
- Authorization stops at login
- A valid token may still belong to the wrong role, tenant, or scope. Permission tests must cover the business object, not only the gateway.
- Breaking changes arrive by surprise
- We define compatibility, deprecation, and consumer communication before the first version ships.
Proof
Relevant API delivery
GrantHub indexes 1,600+ active grants across 21 countries so SMEs stop missing funding they qualify for
GrantHub gives businesses a single place to filter 1,600+ active grants and tax credits across 21 countries by country, industry, and business type.
Musgrave receipt scanning software case study for SuperValu and Centra
Musgrave's post-campaign report records 1,062 users and 1,610 receipt submissions. At the reporting snapshot, 1,158 were AI approved, 409 AI rejected, 4 manually approved, 10 manually rejected, and 29 remained processing.
Scope and price
A focused API release starts at $15,000.
Begin with one bounded domain, its first consumers, contract tests, documentation, and production controls.
A standard connector is usually cheaper when it already supports the required objects, actions, and failure handling.
Starting investment
Starts at $15,000
A focused release usually takes 8 to 12 weeks. Complex authorization, regulated data, legacy dependencies, and high-volume events increase the scope.
Fixed-price phase
Once the first API boundary is scoped, its price is locked in writing. New consumers or domains are priced before they enter the work.
Post-launch support
Eight weeks of support are included so production errors, consumer questions, and operating gaps can be resolved before handoff.
Useful next steps
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Read moreCommon questions
A production API engagement includes contract design, implementation, authentication and authorization, validation, consistent errors, versioning, automated tests, documentation, monitoring, and a release plan. Webhooks also need signature verification, retries, idempotency, and a visible path for failed events.
REST is a strong default for resource-based operations and broad interoperability. GraphQL helps when different clients need different views of the same domain. Webhooks notify another system when an event occurs. Many products use more than one pattern, but each should solve a specific consumer need.
Yes, if the legacy system exposes a dependable database, file, procedure, or interface. An API layer can create a safer boundary for new consumers, but it does not remove unreliable data or hidden business rules underneath. We identify that boundary before recommending an API-only approach.
A focused API for one bounded domain, including contract design, implementation, tests, documentation, and production controls, starts around $15,000. More consumers, complex authorization, regulated data, high-volume events, and legacy dependencies increase the scope.
A focused first release usually takes 8 to 12 weeks. Timing depends on domain complexity, consumer readiness, security requirements, and whether upstream systems already provide stable data and operations.
Work with us
Bring us the integration that keeps breaking.
We will map its consumers, ownership, and failure paths, then show you the smallest API release worth building.
- Scope and cost agreed before work starts. No surprises. No obligation.
- Working prototype within 3 weeks of kickoff.
- Pay by milestone. You see progress before each invoice.
- 60-day post-launch warranty. Bug fixes, UI tweaks, and deployment support. No retainer.
- All conversations are NDA-protected.