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This document outlines the JSON-RPC API endpoints and types definitions for developers crafting an SDK for use with Casper networks.

Creating a Casper SDK

The Casper Association provides a JavaScript SDK that is compliant with this SDK Standard. However, those that prefer other languages may build an SDK using their language of choice.

For examples of such SDKs, please refer to our SDK Client Libraries section.


The Casper platform uses a custom serialization format. To this end, we've established a serialization standard that describes the format, which SDK developers must implement in their language of choice.

SDK Standard Index

Guidance for JSON-RPC SDK ComplianceGuide on the requirements for a compliant Casper SDK.
Required JSON-RPC Methods for Minimal ComplianceMethods required for a minimally compliant Casper SDK.
Transactional JSON-RPC MethodDescription of account_put_deploy, the only means by which users can send their compiled Wasm (as part of a Deploy) to a node on a Casper network. Also includes the speculative_exec method.
Informational JSON-RPC MethodsDescriptions of methods that return information from a network or node within a network.
Proof-of-Stake JSON-RPC MethodsDescriptions of methods that pertain to Proof-of-Stake functionality on a Casper network.
TypesInformation on types used within JSON-RPC methods.
CL TypesInformation specifically relating to CL Types.