Tool Open source
dquickts is a MIT-licensed fork of Fabrice Bellard's QuickJS embeddable JavaScript engine. It adds durable execution: running JavaScript can be suspended at safe points, including in the middle of a loop, with the heap, closures, pending jobs, modules, and suspended call stack serialized to a snapshot and later restored in another process. Full snapshots and incremental base-and-delta snapshots are supported, as are host calls that remain suspended until the host supplies a result.
The engine runs TypeScript directly by erasing types during parsing and compiling runtime constructs such as enums, namespaces, parameter properties, and decorators to bytecode; it does not perform type checking. Its qjs executable includes a durable REPL whose functions, variables, objects, and closures survive restarts. The repository also provides Rust bindings derived from rquickjs, exposing suspension, snapshotting, durable host calls, and TypeScript evaluation.
Snapshots require compatible engine builds and matching native registries, and cannot include several forms of host or shared state, including SharedArrayBuffer memory, unsupported opaque host objects, or code running on the C stack. The repository includes C and Rust APIs, command-line tools, tests, and documentation.
1 use taken from transcripts — each links to the moment in the video.
A fork of Fabrice Bellard's Quick JS JavaScript engine that adds durable execution, allowing JavaScript to be paused at safe points and resume later.
1 in the library.