Web3j 6 Release: Fusaka and Agentic Ready

What happened

It provides full support for Fusaka, Ethereum's biggest scaling upgrade since Dencun, closes the lingering Pectra parity gaps, and takes Web3j's first real step into the agentic era. Whether you (or your agents) are building decentralised applications or interacting with Ethereum events, this release brings Web3j up to date with the latest evolution of the protocol.

After the fork, a blob transaction built with the old proofs is rejected outright by the node, with the error unexpected eip-4844 sidecar after osaka . Before this, there was no way to produce a valid Fusaka blob transaction from Web3j alone.

Now it's one call: You sign and broadcast it exactly as you always have. Under the hood the cell proofs are computed with the KZG cell-proof routines and laid out in the exact blob-major order the spec requires.

Key facts

• It — provides: full support for Fusaka, Ethereum's biggest scaling upgrade since Dencun, closes the lingering Pectra parity gaps, and takes Web3j's first real step into the agentic era