Kusama JSON-RPC API
The public Substrate JSON-RPC 2.0 interface to the Kusama relay chain. Probed live on 2026-07-19: 130 methods are advertised by rpc_methods, spanning chain (blocks/headers), state (storage, metadata, runtime version), author (extrinsic submission), system (health, properties, peers), payment (fee queries), and the newer spec-versioned chainHead_v1 / archive_v1 / transaction_v1 / transactionWatch_v1 families defined by the Polkadot JSON-RPC interface specification. Available over HTTPS (request/response) and WSS (subscriptions). No authentication.
Kusama JSON-RPC API is one of 21 APIs that Kusama publishes on the APIs.io network, described by an AsyncAPI event-driven specification.
Tagged areas include JSON-RPC, Blockchain, and Substrate. The published artifact set on APIs.io includes an AsyncAPI specification.
This event API exposes 0 operations across 10 channels, and defines 6 schemas. It is described by AsyncAPI 3.0.0, at version 1.24.0-660acefe665.
The API connects through a single server, kusama-rpc.polkadot.io (wss).
Metadata
The identity and technical contract details declared by the specification.
Messages & Schemas 6
The contract defines 6 schemas that model the data carried by its messages. Each schema is shown below with its type and property counts.
Specification
The full machine-readable AsyncAPI contract behind this narrative.
Source
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Other APIs Kusama publishes across the network.