Here we report on the progress of the leading builders in the zk Cross-Chain ecosystem, documenting recent significant releases, technical breakthroughs and general updates.
Featuring: @Agglayer, @EspressoSys, @PolyhedraZK, @AcrossProtocol, @union_build, @Orbiter_Finance, @Gasp_xyz, & @hyperbridge
@Agglayer published an article explaining the security tradeoffs between optimistic and pessimistic proof systems in crosschain interoperability: https://agglayer.dev/blogs/pessimistic-proofs-vs-optimistic-fraud-proofs-securing-crosschain -interop
The article explains how optimistic systems rely on delayed fraud detection, risking user funds during dispute windows. Pessimistic proofs, by contrast, require cryptographic validation before execution, preventing fraud entirely.
Agglayer’s model uses ZKPs to secure value transfers and messaging across chains, offering safer, trust-minimized interoperability without third-party dependencies or delays.
The project also shared a guide on how to transfer crypto between blockchains, focusing on using bridges over exchanges for a decentralized approach: https://agglayer.dev/blogs/how-to-transfer-crypto-between-blockchains-a-step-by-step-guide
It outlines key steps, including selecting a method, preparing wallets, choosing a trusted bridge, and verifying completion.
The guide also introduces Agglayer’s unified bridging solution, which promises simpler, trust-minimized cross-chain transfers without wrapped tokens, leveraging @ethereum’s security.
Partnerships
@EspressoSys has integrated with @MoltenL3, an @arbitrum Orbit L3 chain, to provide faster and more secure crosschain trading: https://medium.com/@espressosys/molten-integrates-with-espresso-for-faster-secure-crosschain-trading-5ad16876574a
The partnership delivers sub-second soft confirmations backed by Espresso’s five-second BFT-secured finality. @UniDexFinance traders benefit from quicker execution, reduced counterparty risk, and reorg protection.
The integration also improves interoperability across chains, allowing applications to access liquidity and execute trades without settlement delays.
Accelerator program
Espresso also launched The Brew House, a six-week accelerator supporting six crosschain projects - five from its Build & Brew Hackathon and one external: https://medium.com/@espressosys/introducing-the-brew-house-a-six-week-accelerator-for-crosschain-innovation-03e5ea14953c
Running July 21-Aug 29, teams receive mentorship, technical guidance, and access to $80,000 in grants.
The program, backed by the @espressoFNDN and Arbitrum partners, aims to bridge the gap between hackathon prototypes and production-ready, composable blockchain applications.
@union_build has launched Auro BTC, a native Bitcoin liquid staking token (LST) designed for seamless crosschain DeFi use: https://union.build/blog/auro-btc-union-native-bitcoin-lst
Unlike existing LSTs, Auro BTC leverages Union’s ZK interoperability to offer secure, decentralized custody and composability across @ethereum, @cosmos, and more. This completes Union’s BTCfi strategy and brings in Gandalf, a DeFi veteran, to lead expansion efforts and drive broader adoption of Bitcoin-native yield products.
Following the launch of Auro BTC, Union is taking the next step by becoming a Bitcoin Supercharged Network (BSN) through integration with @babylonlabs_io Genesis: https://union.build/blog/bitcoin-supercharged-network-bsn
This upgrade enables Bitcoin to help secure the network, while BTC stakers earn rewards. Union will receive 25 million BABY tokens to fuel BTCfi incentives, strengthening its role as a crosschain infrastructure layer and expanding Auro BTC’s presence in decentralized finance.
Finally, Union and @escher_fi have introduced a chain-abstracted liquid staking system that allows users to stake from any connected network with a single action.
The process removes the need for bridging or switching wallets and enables seamless participation in staking and DeFi: https://union.build/blog/chain-abstracted-liquid-staking-union-token-escher
On a recent episode of @HouseofZK Radio, @vreeland, CSO at @PolyhedraZK, joined @alicelingl where they discussed the latest advancements in Polyhedra's infrastructure: https://x.com/HouseofZK/status/1945470322972795069
Topics included Polyhedra’s shift from bridging to zkML, the role of ProofCloud in developer onboarding, and the impact of real-time proving on new applications.
They also explored how these tools support trust-minimized AI deployment.
Watch now at https://hozk.io/radio#59-Eric-Vreeland-CSO-at-Polyhedra
@AcrossProtocol published a post explaining how its V4 architecture enables seamless crosschain functionality by replacing custom adapters with a unified system based on intents and ZKPs: https://x.com/AcrossProtocol/status/1947348327315435548
In this model, relayer repayment data is validated and stored on @ethereum, then proven on destination chains using ZKPs anchored in finalized Ethereum state.
This approach removes the need for canonical bridges, reduces integration complexity, and allows Across to support a broader range of chains, including those lacking native Ethereum state verification.
@Orbiter_Finance have announced several new integrations and partnerships, including:
@NanoLabsLtd: Partnered to develop infrastructure for compliant stablecoin transfers across chains, supporting assets pegged to major global currencies like USD, HKD, and offshore RMB:https://x.com/Orbiter_Finance/status/1942559957725110786
@injective: Integrated Injective to enable fast and secure cross-chain transfers into a finance-focused L1 ecosystem optimized for tokenized assets and RWAs: https://x.com/Orbiter_Finance/status/1945395071047884939
@0G_labs: Added support for 0G Labs testnet, expanding Orbiter’s cross-chain capabilities into the largest decentralized AI Layer 1 ecosystem: https://x.com/Orbiter_Finance/status/1946846626523537466
@Gasp_xyz is shifting focus from @ethereum to @Bitcoin, announcing itself as a Bitcoin-native L2 for trustless, secure DeFi: https://x.com/Gasp_xyz/status/1943658991856328790
Citing Ethereum L2s’ shift toward enterprise models, Gasp aims to solve Bitcoin’s fee and activity stagnation by building an expressive, OP_CAT-based L2 with no bridges or wrapped assets.
Its roadmap includes RISC-V smart contracts, MEV minimization, gas-free AMMs, and native Bitcoin collateral for financial applications.
@hyperbridge announced that users can join the @Polkadot DeFi Singularity campaign by moving assets to @ethereum or other supported chains: https://blog.hyperbridge.network/polkadot-defi-singularity-is-live/
Participants who provide liquidity on @Uniswap V4 receive added incentives on top of standard fees and passive yield.
