Event-sourcing Schema Definition Language

Schema definition language for defining aggregates, commands, events & custom types.

Heavily inspired by GraphQL syntax, you can describe aggregates which can be used for codegen in different languages.

ESDL schemas can be used for code generation.

The Rust crate currently supports code generation for:

• Rust
• TypeScript

Additional languages may be added in the future. Contributions are welcome!

aggregate BankAccount {
  open_account(initial_balance: Float!) OpenedAccount!
  deposit_funds(amount: Float!): ReceivedFunds!
  withdraw_funds(amount: Float!): SentFunds!
  transact(amount: Float!, user: User!) (SentFunds | ReceivedFunds)
}

event OpenedAccount {
  initial_balance: Float!
}

event SentFunds {
  amount: Float!
  user: User
}

event ReceivedFunds {
  amount: Float!
  user: User
}

type User {
  id: String!
  name: String
}

Types can be marked as required by adding the ! suffix.

Types can be repeated by wrapping them in [].

Remember, we can mark types as required, even in arrays.

Integrates with Thalo to generate Rust code.