Solving multi-chain authentication (EVM + Solana) without vendor lock-in

Hey Product Hunt community!

As dApps expand across both Ethereum rollups and high-throughput chains like Solana, handling user identity becomes a messy architectural bottleneck:

• EVM relies on EIP-4361 (Sign-In with Ethereum).

• Solana typically falls back on arbitrary text signing or ad-hoc custom hooks.

• Backends end up managing two different session models, double cookie layers, and custom token verifications.

To eliminate this fragmentation, we implemented the open standard CAIP-122 (Sign-In with X) and released @tuwaio/siwx — an open-source, modular auth toolkit that gives developers a unified identity pipeline across EVM and Solana with zero vendor lock-in.

We just published a comprehensive technical guide breaking down the architecture, session drift handling, and end-to-end integration: https://docs.tuwa.io/guides/multi-chain-auth-siwx-caip122

Would love to hear from other builders and founders here: How are you currently managing cross-chain authentication and session states in your products?