Solidity Language Status

Solang is source compatible with the Ethereum Foundation Solidity Compiler version 0.7, with some caveats. Many language features have only recently been implemented, and have many unit tests. As with any new project, bugs are possible. Please report any issues you may find to github.


  • immutable is not supported. Note this is impossible to implement on any than chain other than Ethereum; this is purely an ethereum feature
  • libraries are always statically linked into the contract code
  • Solang generates WebAssembly or BPF rather than EVM. This means that the assembly {} statement using EVM instructions is not supported

Unique features to Solang:

  • Solang can target different blockchains and some features depending on the target. For example, Parity Substrate uses a different ABI encoding and allows constructors to be overloaded.
  • Events can be declared outside of contracts
  • Base contracts can be declared in any order
  • There is a print() function for debugging
  • Strings can be formatted with python style format string, which is useful for debugging: print("x = {}".format(x));

Target Status

Parity Substrate

Solang works with Parity Substrate 2.0. This target is the most mature and has received the most testing so far.


Solang has a new target for Solana. This is in early stages right now, however it is under active development.


ewasm has been tested with Hyperledger Burrow. Please use the latest master version of burrow, as ewasm support is still maturing in Burrow.

Some language features have not been fully implemnented yet on ewasm:

  • The built in function abi.encode(), abi.encodeWithSelector(), abi.encodeWithSignature(), and abi.encodePacked()
  • Contract storage variables types string and bytes are not implemented

Hyperledger Sawtooth

This is merely a proof-of-concept target, and has seen very little testing. On sawtooth, many Solidity concepts are impossible to implement:

  • Return values from contract calls
  • Calling other contracts
  • Value transfers
  • Instantiating contracts