FVM

What is the FVM?

Filecoin today lacks general programmability. As a result, it is not possible to deploy user-defined behaviour, or "smart contracts", to the blockchain. The goal of the FVM project is to add general programmability to the Filecoin blockchain. They predict this will unleash a proliferation of new services and tools that can be built and deployed to the Filecoin network, without requiring network upgrades, involvement from core implementation maintainers, changes in the embedded actors, or spec alterations.

For more information, please refer to the FVM Specs context-and-goals web page.

FVM architecture

The native FVM runtime is WebAssembly (WASM), and users can technically write actors in any programming that compiles to WASM. However, there are language-specific overheads that users need to be aware of (e.g. runtime, garbage collection, stdlibs, etc.) They affect the WASM output leading to bloated WASM bytecode and inefficient execution. There will be on-chain code size limits to consider too.

Rust is the primary language recommendation for writing efficient user-defined actors. Hence, the reference FVM SDK is built in Rust.

For more information, please refer to the FVM Specs architecture web page.