Data API Gateway

Overview#

A government data registry serving multiple agencies rarely has the luxury of a uniform API landscape. Some consuming systems expect REST, others speak GraphQL, and legacy platforms buried in critical infrastructure still rely on gRPC or raw WebSocket connections. Each of those clients historically required its own integration path, its own authentication configuration, and its own rate limiting scheme. The result is a fragmented surface where policy enforcement is inconsistent and a single bad actor can saturate a backend service that dozens of other clients depend on.

The Data API Gateway solves this by acting as a single, policy-enforced entry point for all API traffic. It handles authentication, rate limiting, caching, circuit breaking, and protocol translation before requests reach backend services. For intelligence agencies, financial crime units, and healthcare data controllers, the gateway ensures that no endpoint is reachable without proper security controls, regardless of which protocol the client is using.

Key Features#

• Multi-Protocol Support: Handle REST, GraphQL, gRPC, and WebSocket traffic through a single gateway with automatic protocol translation so clients can consume APIs in their preferred format.
• Protocol Translation: Automatically translate between protocols, allowing REST clients to access GraphQL backends or web clients to consume gRPC services through JSON transcoding.
• Intelligent Rate Limiting: Protect backend services with configurable rate limits that adapt based on usage patterns, maximising legitimate traffic throughput while blocking abuse. Hard caps on in-memory rate limiter buckets prevent memory exhaustion.
• Response Caching: Reduce backend load and improve response times with multiple caching strategies including cache-aside, write-through, write-behind, and refresh-ahead with configurable invalidation rules.
• Request and Response Transformation: Rewrite paths, modify headers, filter sensitive fields, convert formats, and aggregate multiple backend calls into single client responses.
• Authentication and Authorisation: Enforce centralised authentication and authorisation policies across all APIs with support for multiple identity providers. Tenant scoping is applied at the gateway layer before any request reaches a backend service.
• Circuit Breaker Protection: Prevent cascading failures by automatically detecting and isolating unhealthy backends, with graceful degradation and automatic recovery when services come back online.
• Real-Time Communication: Support full-duplex WebSocket connections with connection pooling, automatic reconnection, message compression, and presence detection. All WebSocket channels carry organization_id scoping.
• Health Check Monitoring: Automatically detect backend failures and route traffic to healthy instances, with configurable health check intervals and failover behaviour.
• Standardised Error Handling: Return consistent error formats to clients regardless of which backend protocol or service generated the error, reducing client-side error handling complexity.

Use Cases#

• Unified API Access: Provide a single, consistent API entry point for all clients regardless of whether backend services use REST, GraphQL, or gRPC, reducing integration complexity for partner agencies and third-party consumers.
• API Security Enforcement: Apply consistent authentication, authorisation, and rate limiting policies across all APIs from a central location. No endpoint is exposed without proper security controls, a critical requirement for defence and law enforcement environments.
• Performance Optimisation: Reduce backend load and improve client response times by caching frequently requested data at the gateway layer with intelligent invalidation strategies.
• Legacy System Modernisation: Expose legacy backend services through modern API protocols without modifying the backend, using the gateway's protocol translation capabilities.
• Traffic Management: Control API traffic with rate limiting, request throttling, and circuit breakers to protect backend services during traffic spikes or partial outages.

Integration#

The Data API Gateway sits in front of all backend services and integrates with the platform's authentication, monitoring, and logging infrastructure to provide unified API management with centralised policy enforcement and observability.

Open Standards#

• OAuth 2.0 (RFC 6749) and Bearer Token Usage (RFC 6750): The gateway enforces centralised OAuth 2.0 authorisation for all inbound API traffic, accepting Bearer tokens and delegating token validation to the platform identity provider before any request reaches a backend service.
• JSON Web Token (RFC 7519): All authentication contexts are carried as RS256-signed JWTs; the gateway validates audience, issuer, and expiry claims on every request, including both user-facing and service-to-service (S2S) tokens.
• RFC 6455 (WebSocket Protocol): Full-duplex WebSocket connections are managed at the gateway layer with origin validation, close-code enforcement (1008 for policy violation), connection pooling, and per-connection organisation scoping per the RFC 6455 framing specification.
• OpenAPI 3.1 (OAS 3.1): The gateway exposes its own machine-readable contract as an OpenAPI 3.1 document published at the RFC 8615 well-known URI, enabling client code generation and automated conformance testing for all REST endpoints.
• OASIS XACML 3.0: Attribute-based access control policies are expressed using OASIS XACML 3.0 attribute categories and URNs; the gateway's authorisation layer evaluates these policies before forwarding requests to backend services.
• W3C Trace Context: The gateway parses and propagates W3C Trace Context traceparent and tracestate headers on every request, generating fresh identifiers where none are present and emitting them on responses to enable end-to-end distributed tracing.
• RFC 9421 HTTP Signatures and RFC 9530 Content-Digest: Service-to-service calls routed through the gateway are authenticated using RFC 9421 HTTP Signatures with SHA-256 content digests, binding request headers and body to a cryptographic proof of origin and preventing replay attacks.

Last Reviewed: 2026-02-05 Last Updated: 2026-04-14