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SUI launches GraphQL subscriptions for real-time data on Mainnet
The upgrade replaces the legacy JSON-RPC system and gives developers a single interface for both historical and live blockchain data.
Sui just flipped the switch on GraphQL subscriptions for its Mainnet, giving developers a way to stream real-time blockchain data, including checkpoints, transaction blocks, and events, through a single unified interface.
The feature uses WebSocket connections through the endpoint wss://sui-mainnet.mystenlabs.com/graphql, and comes with built-in capabilities like query-aligned filtering, automatic reconnection, and the ability to backfill from a past cursor before seamlessly transitioning to a live feed.
From JSON-RPC to GraphQL: the full migration
This launch is the final chapter in a migration away from JSON-RPC. Sui’s GraphQL RPC entered beta in 2025, became generally available in early 2026, and the legacy JSON-RPC system was fully phased out on Foundation nodes in late July 2026.
Subscriptions take this a step further. Instead of polling the network repeatedly, apps open a persistent WebSocket connection and receive updates the moment they happen.
How it works in practice
The subscription system supports three core data types: checkpoints, transaction blocks, and events. Each can be filtered using GraphQL’s native query language, which means developers don’t have to pull down everything and sort through it client-side.
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One of the more practical features is cursor-based backfilling. If an application disconnects, it can reconnect and resume from the exact point where it left off. The system delivers missed data in order before switching back to the live stream.
This approach also eliminates the need for developers to juggle multiple interfaces. Previously, accessing historical data and receiving live updates often required different tools, sometimes different protocols entirely. With GraphQL subscriptions, both flows use the same query language and the same endpoint.
The feature complements Sui’s existing gRPC streaming option, which is better suited for high-throughput, low-level integrations. GraphQL subscriptions offer a more flexible, human-readable interface that’s easier to integrate into web and mobile applications.