risc0 std support and making Bonsai work with other VMs (not just EVM)

[IaroslavMazur]

Hello, risc0 team & community!

I'm a member of the Sablier team. We are currently evaluating various technologies for potential use in our future products, and risc0 has caught our attention thanks to its promising features and capabilities.

For context: I've gone through the whole RISC Zero @ ZK HACK III workshop, as well as the What does RISC V have to do with RISC Zero's zkVM presentation, the risc0 documentation (high-level) and several articles on the lower-level stuff (such as RISC-V and ZKPs).

Still, there are several technical uncertainties I'd like to clear out, in order to better understand how to properly use the risc0 ZK technology.

What's your current support and recommendations for the std Rust environment?

In December of 2022 (when the RISC Zero @ ZK HACK III videos were released), the std support was deemed "experimental", but not discouraged (see this time reference). One bug (related to the String data type) was mentioned specifically, alongside a workaround for it.

However, enough time has passed since then - and, maybe, you've already fixed the std-related problems. Therefore, my question: do you still consider the risc0 std support experimental - or do we get the green light for safely using it?

Can Bonsai only work with EVM?

Given that Layer 2s (with their ZK proof generation "on L2", followed by ZK verification on L1) are a common use-case for ZKPs, and, also, the following quote from the Bonsai documentation: Bonsai enables boundless computation on any blockchain, I assume that Bonsai isn't limited to only work with the Ethereum Virtual Machine, but can also be used with other VMs.

Could you confirm this, please?

Thank you in advance for your time and help!

[it09]

Hello Iaroslav!
That is an excellent questions!
std support
We provide partial std support and are continue adding more feature support. While we are working on the docs to reflect current std support, I want to share this file with you the way it's structured: the lines that say "unsupported" are things that we either don't support or we have different ways of supporting. We don't support threads, locking processes, pipes, networking, file systems, and time. It says here that we don't support io, but we have a different way of supporting them.

Can Bonsai only work with EVM?
No. zkVM and Bonsai are for general purposes and are not limited to EVM. Our repo has more examples, here is a NEAR light client example. Also bitcoin L2 is built on Risc0 zkVM.
Generally speaking, think of Risc0 zkVM as a superset to zkEVM. You can build zkEVM on zkVM, and we did it here, and we did zeth in 4 weeks:))

[IaroslavMazur]

Hello, @it09, and thank you for your reply!

std support

I've looked at the way system bindings are set for risc0's zkVM and how the functions of the modules with limited support do nothing or panic with an error (via the unsupported() function).

With the above in mind, would it be correct to say that unless the risc0 API malfunctions or throws that "unsupported" error, you shouldn't consider limiting your project (that is using the risc0 technology) to just the no-std environment?

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Bonsai with any blockchain

Thank you for the confirmation and the relevant examples!

By the way, congrats on the speedy delivery of zeth!

[IaroslavMazur]

@it09, I've followed up with some extra (and more specific) questions via my Support Ticket in the risc0 Discord

[it09]

some functionality that marked as unsupported in that file is actually supported via different means For example io is marked as unsupported, but we have a different support for it. What std functionality are you looking for?

[IaroslavMazur]

What std functionality are you looking for?

Would you mind if we continue discussing the specifics on Discord?

Given the experimental nature of the risc0's applicability to Sablier, it'd be best if we keep this private, until it materializes into something certain.