# Experimental Features

Some BoltFFI features are behind an experimental flag. The API for these features may change between releases, so they require an explicit opt-in.

Java, C#, and Python bindings are generally available and no longer require experimental opt-in.

| Feature                     | Key                        | Status                      |
| --------------------------- | -------------------------- | --------------------------- |
| Dart target                 | `dart`                     | In progress                 |
| Kotlin Multiplatform target | `kotlin_multiplatform`     | Initial JVM/Android actuals |
| TS async streams            | `typescript.async_streams` | Functional                  |

## Enabling

### CLI flag

Pass `--experimental` to include experimental targets during that command run:

```bash
boltffi generate all --experimental
boltffi pack all --experimental
```

### Config file

Add the feature key to `experimental` in `boltffi.toml`:

```toml
experimental = ["kotlin_multiplatform", "typescript.async_streams"]
```

The CLI flag applies to a single command. The config array applies to every build.

## Feature Details

### Kotlin Multiplatform

**Key:** `kotlin_multiplatform`

Enables `boltffi generate kmp` and includes Kotlin Multiplatform output during `boltffi generate all --experimental`. The generated module contains `commonMain` declarations plus `jvmMain` and `androidMain` actuals that delegate to the existing Kotlin/JNI bindings.

This is an initial target slice. Kotlin/Native `cinterop` actuals for iOS/macOS are not generated yet.

### TypeScript Async Streams

**Key:** `typescript.async_streams`

Enables `AsyncIterable` stream generation for TypeScript/WASM targets. Without this flag, stream methods are skipped during TypeScript codegen.

## Graduating from Experimental

When a feature stabilizes, it moves out of the experimental list. The `--experimental` flag and config entry are no longer required. Existing code continues to work without changes.