sysio.code Tutorial

Overview

The sysio.code permission is used to allow a contract account to execute inline actions using its active permission.

What is sysio.code?

The sysio.code permission is a special authority flag that enables a smart contract on the account to authorize inline actions, which is required when those actions modify the blockchain state.

Prerequisites

• Install the currently supported version of clio.

note

| The clio tool is bundled with the Wire software. Installing Wire Sysio will install the clio and kiod command line tools.

• You have access to a local Wire node.
• You have authority over the sysio account and access to the account's private key.
• You have created an account (e.g., alice) and imported its private key. For more information, see how to create an account.
• You are familiar with the basic clio set account commands. For reference, see set account.

REMINDER

The install process has already set up the wallet for the root user. To interact with clio, ensure you are on the root user. Run sudo su - to switch to the root user before proceeding with the tutorial.

Step 1: Check the Current Permission

Before adding the sysio.code permission, check the current permission authority for your account. You can use the following command:

clio get account alice

Step 2: Add sysio.code permission to alice's account

To enable inline actions for your contract, you need to add the sysio.code permission to the desired permission (typically active). Use this command:

clio set account permission alice active --add-code -p alice@active

Arguments:

• alice is the account you want to update.
• active is the permission where you want to add sysio.code.
• --add-code instructs the command to include the code permission.
• -p alice@active authorizes the transaction using the account’s active permission.

Example Output:

executed transaction: ab5752ecb017f166d56e7f4203ea02631e58f06f2e0b67103b71874f608793e3  160 bytes  231 us
#         sysio <= sysio::updateauth            {"account":"alice","permission":"active","parent":"owner", ... }

Step 3: Verify the Permission Update

After adding the permission, run the following:

clio get account alice

Check that the active permission now lists sysio.code.

created: 2025-06-30T18:01:49.000
permissions: 
     owner     1:    1 SYS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV
        active     1:    1 SYS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV, 1 [email protected]

permission links: 
     sysio.any: 

memory: 
     quota:         0 bytes  used:         0 bytes

net bandwidth:  
     used:                 0 bytes
     available:            0 bytes
     limit:                0 bytes

cpu bandwidth:
     used:                 0 us   
     available:            0 us   
     limit:                0 us   

subjective cpu bandwidth:
     used:                 0 us   

Step 4: Deploy a Contract That Uses Inline Actions

Create a simple contract that sends an inline action back to the same account.

mkdir -p inline-contract && touch inline-contract/inlinecontract.cpp && cd inline-contract

Add the following code to inlinecontract.cpp:

#include <sysio/sysio.hpp>

class [[sysio::contract]] inlinecontract : public sysio::contract {
public:
   using sysio::contract::contract;

   [[sysio::action]]
   void testinl(name user) {
      sysio::action(
         sysio::permission_level{ get_self(), "active"_n },
         get_self(),
         "inlinecall"_n,
         std::make_tuple(user)
      ).send();
   }

   [[sysio::action]]
   void inlinecall(name user) {
      sysio::print("Inline action executed for: ", user);
   }
};

Build the Contract

Compile the contract using the Wire CDT. Run:

cdt-cpp -abigen  -contract inlinecontract -o inlinecontract/inlinecontract.wasm inlinecontract.cpp -I include

Create a Contract Account and Deploy the Contract

Create an account called inlinectr:

clio create account sysio inlinectr SYS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV SYS6MRyAjQq8ud7hVNYcfnVPJqcVpscN5So8BhtHuGYqET5GDW5CV -p sysio@active

Then, deploy your contract by setting the contract code on your account:

clio set contract inlinectr inline-contract -p inlinectr

Give inlinectr a policy:

clio push action sysio.roa addpolicy '{"owner": inlinectr, "issuer": nodedaddy, "netWeight": "0.0100 SYS", "cpuWeight": "0.0100 SYS", "ramWeight": "0.0100 SYS", "timeBlock": 1, "networkGen": 0 }' -p nodedaddy@active

Step 6: Test the Inline Actions

Now that your contract is deployed with inline action capability, test it by pushing actions.

Execute the testinl Action

The testinl action triggers an inline call to the inlinecall action. To test, run:

clio push action inlinectr testinl '["alice"]' -p inlinectr@active

If everything is set up correctly, you should see output indicating that the inline action was executed.

executed transaction: 1d00f751c6fb6c7a2636eecc7fec4b2d4e0baf7066cfa84e800b3d31c6890537  104 bytes  237 us
#     inlinectr <= inlinectr::testinl           {"user":"alice"}
#     inlinectr <= inlinectr::inlinecall        {"user":"alice"}
>> Inline action executed for: alice
warning: transaction executed locally, but may not be confirmed by the network yet         ]