PulseVM

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C++ quickstart ​

If you've written EOSIO or Antelope contracts, you already know how to write for PulseVM: eosio::contract, multi_index, check() and inline actions work the same way. Build with the public Antelope CDT and deploy the output unchanged.

New to PulseVM? Do Get started first: CLI, keys, an account and an endpoint.

1. Install the Antelope CDT ​

Use CDT 4.x from AntelopeIO/cdt releases. The release ships an Ubuntu package for x86_64:

bash
wget https://github.com/AntelopeIO/cdt/releases/download/v4.1.1/cdt_4.1.1-1_amd64.deb
sudo apt install ./cdt_4.1.1-1_amd64.deb
cdt-cpp --version

On macOS or an ARM machine, run those commands in an x86_64 Ubuntu container or VM, or build the CDT from source by following the repository's README.

2. A minimal contract ​

Save this as hello.cpp:

cpp
#include <eosio/eosio.hpp>
using namespace eosio;

class [[eosio::contract]] hello : public contract {
public:
   using contract::contract;

   [[eosio::action]]
   void greet(name account, std::string text) {
      require_auth(account);
      check(text.size() <= 256, "greeting too long");
      greetings table(get_self(), get_self().value);
      table.emplace(account, [&](auto& row) {
         row.account = account;
         row.text = text;
      });
   }

private:
   struct [[eosio::table]] greeting {
      name account;
      std::string text;
      uint64_t primary_key() const { return account.value; }
   };
   typedef multi_index<"greetings"_n, greeting> greetings;
};

3. Build ​

bash
cdt-cpp -abigen -contract=hello -o hello.wasm hello.cpp

This writes hello.wasm and hello.abi next to each other.

4. Deploy, call and read back ​

bash
pulse-ts set-code yourname1 ./hello.wasm
pulse-ts set-abi  yourname1 ./hello.abi
pulse-ts push-action yourname1 greet '{"account":"yourname1","text":"hi"}' -a yourname1
pulse-ts table yourname1 greetings

The last command returns the row you wrote:

json
{ "rows": [ { "account": "yourname1", "text": "hi" } ], "more": false }

A failed check() with a string literal surfaces as eosio assert failed: <message>, for example eosio assert failed: greeting too long.

Compatibility ​

PulseVM serves about 180 Antelope host functions: tables and secondary indexes, inline actions, check() and asserts, permission checks, name, asset and symbol types, and the hash functions. Contracts built by CDT 4.x for Leap-era chains, such as XPR Network, use this surface.

Not yet served: the CRYPTO_PRIMITIVES set (alt_bn128, mod_exp, blake2_f, sha3, k1_recover), the bls_* functions and set_finalizers. Current EOS and Telos system contracts use some of these. See Host functions.

setcode checks that the module is valid WebAssembly within the chain's limits. It doesn't check host imports. A contract that imports a function PulseVM doesn't serve deploys, then every action on it fails with failed to create wasm instance …, and nothing changes. Check the imports before you deploy:

bash
wasm-objdump -x -j Import hello.wasm      # from the WABT tools

Every name under env. must be in the Host functions list.

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