import "polkadot"; contract ChainExtension { // Implementation on the node: // https://github.com/hyperledger-solang/solang-substrate-ci/blob/substrate-integration/runtime/src/chain_ext.rs#L43 function fetch_random(bytes32 _seed) public returns (bytes32) { bytes seed = abi.encode(_seed); (uint32 ret, bytes output) = chain_extension(1101, seed); assert(ret == 0); return abi.decode(output, (bytes32)); } }