EVM Signature

Understand how EVM wallet kind affects the signature format sent to Omniston.

This document explains how to choose the correct EVM signature format when sending signed data to Omniston.

In the EVM flow, signatures are passed to Omniston in two places:

• as the permit signature inside allowance data

• as the final order signature

For the explanation of wallet kinds themselves, see EVM Wallet kind.

Why wallet kind matters

Different EVM wallet kinds do not always use the same signature representation for the final order signature.

Because of that, the signature bytes sent to Omniston for the order must be formatted according to the wallet kind that produced the signature.

Signature formats used by Omniston

Omniston uses two signature shapes:

• compact 64-byte signature

• raw 65-byte signature

The correct one must be chosen based on where the signature is used.

Where Signatures Are Sent To Omniston

Permit signature

This is used only when the allowance method includes an off-chain permit, such as:

• EIP-2612

• Permit2

For permit signatures, the signature sent to Omniston must always be raw 65-byte.

This does not change based on wallet kind.

Order signature

This is the final signature of the EVM order itself.

For order signatures, the required signature format depends on wallet kind.

Wallet kind	Order signature format to send to Omniston
EOA	compact 64-byte
Delegated EOA	compact 64-byte
Contract wallet	raw 65-byte