Hot Chocolate vs WunderGraph Cosmo

Hot Chocolate is an open-source GraphQL server for.NET that runs on ASP.NET Core and builds a GraphQL schema from C# types and resolvers. Developers can define typed schemas through implementation-first or code-first methods. It supports GraphQL over HTTP and WebSocket, plus Server-Sent Events for streaming responses. Documentation describes schema downloads, a Nitro GraphQL IDE endpoint, and a command-line interface for schema export. Data integrations include Entity Framework, MongoDB, and Marten; DataLoaders and batch resolvers help batch and cache related requests. OpenTelemetry instrumentation covers server, execution, and DataLoader activity. Security guidance recommends query cost analysis, pagination and execution-depth limits, and timeouts for public APIs; trusted documents can restrict private APIs to registered operations. Servers can act as Fusion subgraphs. Hot Chocolate implements the GraphQL 2025 specification and GraphQL over HTTP, and supports spec-compliant clients including Strawberry Shake, Relay, and Apollo Client. It is MIT licensed for commercial or private use. Community support is free; paid Startup support starts at $450 per month and includes two critical incidents.

WunderGraph Cosmo is an open-source GraphQL Federation platform for platform teams, offering schema checks, guardrails and observability. It unifies GraphQL, REST, gRPC and Kafka in a federated graph and supports Apollo Federation versions 1 and 2 across existing GraphQL services. Cosmo Router is a Go-based, Apache 2.0-licensed router and gateway. Teams can deploy it with Docker, Kubernetes or an AWS Lambda-optimized binary, or use WunderGraph’s managed service. The Schema Registry checks composition, breaking changes, client traffic and linting. Subscriptions work over WebSockets and Server-Sent Events, and event-driven subscriptions can use Kafka, NATS, SQS or RabbitMQ. Cosmo Streams supports Kafka, NATS including JetStream, and Redis. Observability includes OpenTelemetry tracing and Prometheus metrics, which can be exported to compatible backends. The free Developer plan includes one federated graph, 10M requests/month, 10 subgraphs, one team member and seven-day retention. Launch costs $499 a month; Scale costs $3,499 a month. Enterprise pricing is custom. Managed plans include SOC 2 and HIPAA compliance; the site also identifies ISO 27001 certification.