Accounts

Everything in Evolve is an account. This account-centric model is the foundation of the entire system.

What is an Account?

An account has three components:

The AccountCode Trait

Every account implements the AccountCode trait:

pub trait AccountCode: Send + Sync {
    fn execute(
        &self,
        env: &mut dyn Environment,
        request: InvokeRequest,
    ) -> SdkResult<Vec<u8>>;
 
    fn query(
        &self,
        env: &dyn EnvironmentQuery,
        request: InvokeRequest,
    ) -> SdkResult<Vec<u8>>;
}

The #[account_impl] macro generates this implementation for you.

System Accounts

Reserved AccountId values with special behavior:

System accounts have hardcoded handlers in the invoker.

Inter-Account Calls

Accounts communicate through message passing:

// Account A calls Account B
env.do_exec(account_b_id, &message, funds)?;
 
// Internally:
// 1. Invoker creates checkpoint
// 2. Funds are transferred (if any)
// 3. Account B's code executes
// 4. On error: checkpoint restored
// 5. On success: changes committed

Message Dispatch

The #[account_impl] macro generates:

1. Message structs for each function
2. Function IDs from SHA-256 of function name
3. Dispatch logic in AccountCode::execute/query

Storage Isolation

Each account's storage is prefixed by its AccountId:

[AccountId][FieldPrefix][Key] => Value
 
Example:
[0x0A][0x01][alice] => 1000  // Account 10, field 1, key "alice"

This prevents accounts from accidentally (or maliciously) accessing each other's state.

No Sudo Model

There is no privileged escalation in Evolve. All execution is account-driven:

• No "admin" accounts with special powers
• No way to bypass account code
• All state changes go through the account's execute method
• System accounts are explicitly defined and limited in scope