# Fusion: GraphQL Federation Gateway > Fusion is a high-performance router for connecting GraphQL, REST, and gRPC APIs at scale, with native support for GraphQL Federation and Apollo Federation. Canonical source: https://chillicream.com/products/fusion Fusion is a high-performance router for connecting GraphQL, REST, and gRPC APIs at scale. It brings APIs from across your organization together into one coherent graph and executes every request across the services behind it. Fusion natively supports the GraphQL Federation specification and Apollo Federation, so you can federate existing APIs without locking yourself into a single ecosystem. [Get Started](https://chillicream.com/docs/fusion/getting-started) [Contact an Expert](https://chillicream.com/services/support/contact?subject=Sales&context=Fusion) ## What is Fusion? Fusion is a GraphQL gateway that sits between your clients and the APIs owned by your teams. Each team can independently develop and deploy its services using the languages, frameworks, and API technologies that best fit its needs. When a client sends a query, Fusion determines which services are needed, coordinates requests across them, and combines the results into a single response. These services can expose GraphQL, REST, or gRPC APIs, all participating in the same unified graph. Fusion composes your graph at build time, detecting schema conflicts before deployment. It supports both the GraphQL Federation specification and Apollo Federation, allowing you to connect existing subgraphs without rewriting them. If federation is new to you, start with the [GraphQL Federation page](https://chillicream.com/platform/graphql-federation). ## Performance by design - Run your graph on a high-performance router built for low latency and high throughput. - Cache query plans so repeated operations can execute without rebuilding the execution plan. - Deduplicate downstream requests to avoid fetching the same data multiple times during a single operation. - Stream results incrementally with @defer and @stream so clients can receive useful data sooner. - Precompute operation plans at build time so there is no planning overhead at runtime. network ## Centralized API security - Enforce policies centrally at the gateway before requests reach your services. - Safelist trusted GraphQL operations to reduce unexpected workloads and make API behavior more predictable. - Integrate directly with Open Policy Agent (OPA) for centralized, policy-based authorization. - Plug in custom policy providers when your organization needs its own authorization or governance logic. - Generate an audit trail for every request and persist it in Nitro for security reviews, compliance, and debugging. fusion router · policy checkpoint Web Mobile Partner Unknown op Fusion router Safelist OPA403 Custom policy denied · 403 Catalog Orders Billing audit trail · Nitro allowed · query GetOrder · trusted denied · mutation DeleteCustomer · OPA · 403 ## Deep operational insights - Trace every request with full OpenTelemetry support and see how it executes across your graph. - Combine telemetry with Fusion operation plans to understand where time is spent and which services drive latency. - Score request cost using the GraphQL Cost Specification and apply cost-based rate limiting. - Collect cost and usage data in Nitro to understand API consumption and support usage-based billing. #### Trace POST /graphql 0ms50ms100ms150.0 ms 🌐POST /graphql150.0 ms ◈operation plan145.0 ms ↪catalog26.0 ms ↪orders33.0 ms ↪billing92.0 ms billing drives 61% of latency #### Cost Cost Spec / 1,000 rate limit ok #### Usage by client web mobile partner-api usage-based billing, recorded in Nitro ## Protect your clients Composition ensures your subgraphs work together, but a valid graph can still break a client that depends on a field being changed or removed. Nitro closes that gap by comparing every schema change against the operations used by your clients. Teams can see whether a change is safe, risky, or breaking before it reaches production. In practice: [schema governance in Nitro](https://chillicream.com/products/nitro#schema). nitro registry · publish check incoming v14schema orders-api · schema.graphql `- Product.rating`breaking · publish blocked v15schema orders-api · schema.graphql `~ Product.rating @deprecated`safe · published Nitro registry incoming v14schema orders-api · schema.graphql `- Product.rating`breaking · publish blocked v15schema orders-api · schema.graphql `~ Product.rating @deprecated`safe · published Nitro registry web@2.4.0okok mobile@5.1.04,213 req / 7dok partner-apiokok Nitro registry web@2.4.0ok mobile@5.1.04,213 req / 7d partner-apiok v14schema orders-api · schema.graphql `- Product.rating`breaking · publish blocked v15schema orders-api · schema.graphql `~ Product.rating @deprecated`safe · published every change checked against registered client operations ## Built for Distributed Graphs ### Connect every API Bring GraphQL, REST, and gRPC services into the same graph and validate their contracts together during composition. ### Keep your existing stack Use the languages, frameworks, and servers your teams already know. Fusion does not require a distributed runtime or vendor-specific package inside your services. ### Adopt without disruption Run GraphQL Federation and Apollo Federation side by side, and migrate one subgraph at a time without requiring a coordinated cutover across teams. ### Performance by design Precompute operation plans, cache execution plans, deduplicate downstream requests, and stream results incrementally with @defer and @stream. ### Centralize API security Enforce policies at the gateway, integrate with Open Policy Agent or custom policy providers, and keep unauthorized traffic away from your services. ### See what happens in production Trace requests across your graph with OpenTelemetry, understand execution through operation plans, and use Nitro to analyze cost, usage, and performance. ## Featured Content - [TutorialGet started with FusionBuild your first federated graph and run it locally.Read](https://chillicream.com/docs/fusion/getting-started) - [GuideSwitch your gateway, keep your graphMove from Apollo Router, Hive Gateway, or Cosmo to Fusion while keeping the subgraphs and schemas you already have.Read](https://chillicream.com/docs/fusion/connectors/apollofederation) - [BlogThe Gateway for EveryoneLearn why Fusion supports both GraphQL Federation and Apollo Federation, and how it brings GraphQL, REST, and gRPC into one gateway.Read](https://chillicream.com/blog/2026-07-12-fusion-16-5) ## Bring your APIs together with Fusion Connect GraphQL, REST, and gRPC APIs behind one high-performance gateway and evolve your graph without locking your teams into a single federation ecosystem. [Get Started](https://chillicream.com/docs/fusion/getting-started) [Contact an Expert](https://chillicream.com/services/support/contact?subject=Sales&context=Fusion)