Swift Compiler

Emi ships with a Swift compiler, so the same definitions that drive your Go backend and JavaScript front end can also power native iOS and macOS clients. The generated Swift is plain Foundation based code (it falls back to FoundationNetworking on Linux), so it does not pull in any third party dependency.

The Swift compiler generates type-safe request/response objects and an action wrapper per action, mirroring the behaviour of the other Emi compilers.

Compiling a module

emi swift --path module.yaml --output ./Sources/Generated

Without --output, the generated virtual files are printed (as JSON) to the terminal so you can inspect them before writing anything to disk.

Sub commands

The full Swift compiler (emi swift) generates everything for a module. If you only need a slice of the output, two focused sub commands are available:

Command	Description
emi swift	Compiles the entire Swift module (actions, DTOs, headers).
emi swift:dto	Generates only the Swift DTO objects.
emi swift:headers	Generates the headers, usable in both client and server code.

Options

Flag	Description
—path	Path of the Emi definition file (.yaml or .json) on disk.
—output	Directory the generated Swift files are written to. Omit it to print to stdout.
—tags	Comma separated compile features to add or remove.

Example

For the postsModule from the OpenAPI page, emi swift generates an GetSinglePostAction.swift file that starts like this:

import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif
/**
 Action to communicate with the action GetSinglePostAction
 */
struct GetSinglePostActionMeta {
    let name: String = "GetSinglePostAction"
    let url: String = "/posts/:id"
    let method: String = "Get"
}

struct GetSinglePostActionResponse {
    let statusCode: Int
    let headers: [String: String]
    let payload: Data?
    // ...
}

Each action carries its metadata (name, URL, method) and a strongly typed response, so the calling code never has to hardcode routes or guess the response shape.