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Introduction

For advanced users with experience developing applications on EVM-based blockchains, we’ve provided our own lightweight, custom-made for Unity, Ethereum library: SequenceEthereum. SequenceEthereum should provide everything you need to build your Unity app on the EVM, without all the extra bells and whistles that the popular Nethereum library provides. While SequenceEthereum is heavily tested, in general, when working with asynchronous methods in the library, you should consider them to be “unsafe”, in that they may throw Exceptions when used improperly. In general, wrapping async calls that can potentially throw Exceptions in try catch blocks is a best practice; particularly in Unity, where Tasks can fail silently when throwing exceptions - making debugging difficult when not wrapping calls in try catch blocks.

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Important Components

When working with the SequenceEthereum library it can be helpful to understand some of the main “components” and how they logically fit together.

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Client

Clients handle the connection to blockchain networks, making various RPC requests. Any time you wish to query the blockchain or submit a transaction, you will need a client. As a rule of thumb, if a method requires a client, you should expect that you will be making a web request and will need to work with async tasks and be prepared to catch any exceptions that are thrown.

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Sequence.Wallet.IWallet

A wallet keeps track of its own private/public key pair and address and is responsible for providing its private key to the signer when signing transactions.

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Transaction

A transaction, as implemented in EthTransaction, contains all the data and parameters for an EVM transaction. The object is used for initiating its RLP encoding (transactions must be signed and RLP encoded when submitted). Note that all transactions are encoded with a chain id included to protect against replay attacks, see EIP-155.

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Contract

A contract is responsible for creating transactions (for method calls) and messages (for queries) agaisnt it. These transactions are later signed by the wallet and submitted (along with query messages) using a client.