Launching today
hidane
A Firestore emulator without Java, in one Rust binary
4 followers
A Firestore emulator without Java, in one Rust binary
4 followers
hidane replaces the official Cloud Firestore emulator with a single Rust binary: no JDK, a 5.5 ms start, 7.4 MiB idle. It speaks gRPC, REST and WebChannel, enforces Security Rules, and runs under firebase-tools, where Firestore-triggered Cloud Functions fire as with the official emulator (new in v0.4). Parity is measured, not claimed: hidane's tests replay 20,224 answers recorded from the official emulator, and firebase-js-sdk's own browser suite passes.
Launch Team
Framer AI AgentsDesign and publish professional sites with AI
Promoted
Hi, I'm Hiroki, the maker. firebase-tools 15 made Java 21 a requirement for the Firestore emulator, and the emulator was already the slowest part of my test runs, so I rebuilt it as a single Rust binary.
The rule I hold myself to: no claim of compatibility without a test behind it. Scripts record how the official emulator answers, edge cases included, and hidane's tests replay every recording. Where the official emulator has a bug, hidane does not copy it and the difference is documented.
It covers documents, queries, aggregations, vector search, transactions, listeners and exports. It enforces Security Rules the way the official emulator does, with its denial messages, coverage report and debug() output, and firebase-js-sdk's own browser test suite passes on it as on the official emulator, so browser apps and Flutter Web work too.
New in v0.4.0: Firestore-triggered Cloud Functions, v1 and v2, fire under hidane exec -- firebase emulators:start with the same data as with the official emulator, and the Go, Python and Java server SDKs are verified against both emulators.
If your test suite gets a different answer from hidane than from the official emulator, please open an issue. That is the most useful feedback.
hey hiroki, congrats on hidane! we're launching benson today too: https://www.producthunt.com/products/benson-2. good luck with the launch.