Rust target configuration

All fields belong under the selected target’s options object. Unknown fields are rejected.

Option	Type	Default	Contract
`crateName`	nonempty string matching `[a-z][a-z0-9_]*`	`tsonic_generated`	Generated Cargo package and crate name
`edition`	`2021` or `2024`	`2021`	Rust edition used by the generated project
`foundation`	`core`, `alloc`, or `std`	`std`	Maximum Rust language/runtime foundation
`outputType`	`lib` or `bin`	`lib`	Generated Cargo target kind
`projectFile`	nonempty string	none	Existing user-owned `Cargo.toml`

outputType: "bin" requires foundation: "std". core and alloc executables require startup, panic, allocator, linker, and platform policies that belong to a user-owned native project.

Generated and user-owned projects

Option	Generated project	User-owned project
`crateName`	Cargo package/crate name	emitted Rust crate identity where applicable
`edition`	emitted in `Cargo.toml` and used by generated Rust	used by generated Rust; the manifest must agree
`foundation`	selects crate root and runtime features	selects legal source semantics; the manifest must supply matching features
`outputType`	creates `src/lib.rs` or `src/main.rs`	controls emitted library/binary contract; native startup still belongs to Cargo
`projectFile`	absent	selects the existing `Cargo.toml`

Rust has no free-form target properties object. Target triples, profiles, features, linkers, build scripts, workspace layout, and packaging are Cargo configuration and belong in a user-owned project.

`projectFile`

The resolved file must:

exist and be a regular file named Cargo.toml;
remain outside the generated Rust output root;
describe the direct dependencies used by @tsonic/rust/crates/* imports.

In user-owned mode Tsonic emits sources only. It never reads Cargo project settings as hidden semantic evidence and never mutates the manifest.

Direct Cargo dependency aliases are semantic input for imports such as:

import { Widget } from "@tsonic/rust/crates/widget_alias/index.js";

The configured manifest must declare widget_alias directly. Transitive dependencies and package-name guessing are not searched.

Complete generated example

{
  "id": "rust",
  "surfaces": ["js"],
  "options": {
    "crateName": "acme_tool",
    "edition": "2024",
    "foundation": "std",
    "outputType": "bin"
  }
}