The Ethereum Economic Zone launched Rollup X at Devcon in Mumbai on Nov. 4 and ran three demonstrations in which contracts on the rollup and on Ethereum mainnet called one another inside a single transaction, the EEZ said in a thread on X.
In the first, a user on Rollup X signed one order and CoW Swap's solvers filled it against liquidity on Ethereum mainnet, with the tokens landing back on Rollup X in the same transaction. In the second, owner changes on Ethereum mainnet Safe accounts were read and verified from Safe accounts on the rollup within one transaction, and several Safe accounts shared spending limits so their balances could be drawn on together.
The third demonstration was the EEZ's own. A mainnet contract called Rollup X, checked a Falcon post-quantum signature and acted on the answer in the same transaction to authorize a transfer on mainnet. The EEZ said that check costs about 5.5 million gas carried out directly on mainnet, and around 91% less through Rollup X, because the verification ran on the rollup.
The EEZ calls the pattern synchronous composability: a contract can use another chain's answer during its own transaction rather than waiting for a bridge message or a later callback. Rollups have scaled Ethereum by moving users onto separate networks, which splits liquidity between those networks and mainnet.
CoW Swap already offers cross-chain swaps, but its existing documented flow completes a swap on the source network before depositing the proceeds with a bridge provider, with delivery on the destination network following afterward. The Rollup X flow puts the mainnet interaction inside the composed operation.
How Rollup X Connects the Calls
The EEZ's protocol walkthrough describes a composer that simulates the cross-chain operation and prepares the expected calls and results. Ethereum verifies the selected proofs and executes the mainnet calls, while the rollup node supplies the corresponding instructions for local execution.
The chains do not share a single virtual-machine call stack. Applications interact through local proxy contracts, and consistency between the two sides depends on the verification system and node integration, the documentation says.
The published Rollup X implementation carries a trust qualification. Its developer walkthrough says it currently uses a designated signer's attestation after re-executing a batch, rather than a zero-knowledge validity proof. The reference verifier's code checks that the signature matches its configured signer. Participating rollups choose their own verification systems.
The full EEZ specification, including real-time zero-knowledge proving and calls that pass back and forth between networks, is expected over the course of 2027, according to GIP-153, the Gnosis proposal that set the direction for the framework's first production instance.
Gnosis Chain's Turn
Gnosis said Gnosis Chain will stop running as a standalone Layer 1 in spring 2027 and relaunch as an EEZ rollup settling to Ethereum. GnosisDAO authorized that direction in GIP-153, which Friederike Ernst published on the Gnosis forum on July 22 with co-authors Philippe Schommers and Ben Carvill, and which passed a vote in August. The proposal targeted genesis for December 2026 or January 2027.
Under the proposal, Gnosis Chain's validator set is sunset and the roughly 350,000 GNO staked against it is unlocked, while xDAI remains the gas token and users and applications keep their addresses, balances and contract state. The Defiant reported in August that the shift would end the chain's own validator set and move settlement to Ethereum.
GNO rose 0.9% in the 24 hours to 2 p.m. ET on Thursday, while Bitcoin fell 5.2%, according to CoinGecko.
Rollup X runs as a devnet on Ethereum mainnet, and the EEZ's public repository tells users to start with small amounts. The EEZ said the network is not yet intended to hold significant value and that the core protocol is undergoing an independent security audit.