According to Foresight News, Starknet has proposed community upgrades to versions V0.12.3 and V0.13.0, and plans to migrate its testnet to Sepolia after the deprecation of Goerli. The Goerli testnet will be supported until the end of 2023. V0.12.3 will introduce feeder gateway deprecation and make changes to the __validate__ of account contracts, while V0.13.0 will include a new transaction type V3. This transaction type will lay the foundation for STRK transaction fees payment, excluding ETH, fee markets, paymaster, and nonce generalization.
In addition, V0.13.0 will come with a new Cairo version v2.4.0 7, introducing string literals and basic string operations. The upgrade timeline is as follows: November 19th for V0.12.3 Goerli testnet upgrade; December 11th for V0.12.3 mainnet upgrade, one week ahead of the previously announced date; December 5th for V0.13.0 Goerli testnet upgrade, which may be delayed by one week to December 13th; and January 22nd, 2024 for V0.13.0 mainnet, pending governance voting.
Starknet will begin migrating to the Sepolia testnet on November 15th. At that time, full nodes, API services, SDKs, and other Starknet development tools will also begin migrating to Sepolia.