dart_monty_core 0.110.0 · monty 1.1.0
dart_monty_core runs Python in Dart through
pydantic-monty, a sandboxed Python
interpreter written in Rust. Dart programs can provide typed inputs, host
functions, OS operations, host-directory mounts, resource limits, and type
checking. Results return as typed MontyValue objects.
Dart applications cannot load new behavior without shipping a new binary. Monty lets an application run supplied Python under resource limits while exposing only selected host functions and OS operations. Pydantic runs a security bug bounty for the interpreter at hackmonty.com.
Each session runs outside the application process. Native sessions use child processes, and browser sessions use Web Workers. A sandbox crash ends its worker and session without ending the application. The pool replaces the worker for a later checkout.
dart pub add dart_monty_coreimport 'package:dart_monty_core/dart_monty_core.dart';
Future<void> main() async {
final value = await Monty.withPool(
(monty) => monty.withSession((session) async {
await session.feedRun(
'def fib(n): return n if n < 2 else fib(n - 1) + fib(n - 2)',
);
return session.feedRun('fib(10)');
}),
);
print(value); // MontyInt(55)
}The example evaluates Fibonacci in a pooled session.
| Platform | Worker | Setup |
|---|---|---|
| Dart VM and AOT on macOS, Linux, and Windows | Child process | Supply a worker or enable the native build hook |
| dart2js and dart2wasm | Web Worker | The package supplies the worker assets |
See Native worker for native worker setup, browser asset serving, caching, integrity checks, Flutter packaging, and platform details.
Host-directory mounts require the native mount library and are unavailable in
browsers. OSAccess provides an in-memory filesystem on every platform.
- Documentation index
- Execution model
- Host functions and async
- OS access
- Host directory mounts
- Telemetry
- Fake sessions
- Upstream divergences and limitations
- Package versioning
The API reference documents values, errors, snapshots, limits, callbacks, and
session methods. The package exports test doubles from
package:dart_monty_core/dart_monty_core_testing.dart and host-backed virtual
files from package:dart_monty_core/unsafe_callback_file.dart.
Contributor commands and repository rules are in AGENTS.md.
MIT.