Generator Configuration

WeaveFFI reads an optional TOML configuration file that lets you customise names, packages, and prefixes used by each code generator. When no configuration file is provided, every option falls back to a sensible default.

Passing the configuration file

Use the --config flag on the generate command:

weaveffi generate api.yml -o generated --config weaveffi.toml

When --config is omitted, all options use their default values.

File format

The configuration file is plain TOML. All keys are top-level — there are no nested tables. Every key is optional; omit a key to keep its default.

Minimal example

An empty file (or no file at all) is valid — defaults apply to everything:

# weaveffi.toml — all defaults

Full example

# weaveffi.toml

# Swift module name used in Package.swift and the Sources/ directory.
swift_module_name = "MyApp"

# Java/Kotlin package name for the Android JNI wrapper.
android_package = "com.example.myapp"

# npm package name emitted in the Node.js loader.
node_package_name = "@myorg/myapp"

# WASM module name used in the JavaScript loader.
wasm_module_name = "myapp_wasm"

# Prefix for C ABI symbol names (e.g. myapp_math_add instead of weaveffi_math_add).
c_prefix = "myapp"

# When true, strip the module name from generated identifiers where applicable.
strip_module_prefix = true

Configuration options

swift_module_name

Controls the Swift package and module name. The generated Package.swift references this name, and the source directory is created as Sources/{swift_module_name}/.

swift_module_name = "CoolLib"

Produces Sources/CoolLib/CoolLib.swift and a matching Package.swift:

// Package.swift
let package = Package(
    name: "CoolLib",
    ...
    targets: [
        .target(name: "CoolLib", path: "Sources/CoolLib"),
    ]
)

android_package

Sets the Java/Kotlin package for the generated JNI bridge. The package determines the directory structure and the package declaration at the top of the generated .kt file.

android_package = "com.example.myapp"

Produces:

package com.example.myapp

node_package_name

Sets the package name used in the generated Node.js loader. This is the name consumers use in require() or import statements.

node_package_name = "@myorg/cool-lib"

wasm_module_name

Sets the module name used in the generated WASM JavaScript loader and TypeScript declarations.

wasm_module_name = "coolapp_wasm"

c_prefix

Replaces the default weaveffi prefix on all C ABI symbol names. This affects every generated header and every language binding that references C symbols.

c_prefix = "myapp"

With an API module named math containing a function add, the exported C symbol becomes myapp_math_add instead of the default weaveffi_math_add.

strip_module_prefix

When set to true, generated identifiers omit the module name where the target language supports namespacing natively.

strip_module_prefix = true

Common recipes

iOS/macOS project

swift_module_name = "MyAppFFI"
c_prefix = "myapp"

weaveffi generate api.yml -o generated -t swift,c --config weaveffi.toml

Android project

android_package = "com.example.myapp.ffi"
c_prefix = "myapp"

weaveffi generate api.yml -o generated -t android --config weaveffi.toml

Node.js package

node_package_name = "@myorg/myapp-native"

weaveffi generate api.yml -o generated -t node --config weaveffi.toml

All targets with custom prefix

swift_module_name = "MyAppFFI"
android_package = "com.example.myapp"
node_package_name = "@example/myapp"
wasm_module_name = "myapp_wasm"
c_prefix = "myapp"

weaveffi generate api.yml -o generated --config weaveffi.toml