"Cassette" was written up by nostr:npub1p4kg8zxukpym3h20erfa3samj00rm2gt4q5wfuyu3tg0x3jg3gesvncxf8 one saturday afternoon during SEC-04. I got stuck while standardizing memory management and walked away for a few months. Stepped back into the ring and managed to get it working yesterday.

A "cassette" is a read-only, portable relay that's been compiled to WASM. It has a standardized WASM interface (no mangle) and accepts NIP-01 messages. I believe there are others working on a similar ideas.

The cassette cli can record (write), play (read), dub (mix) and cast events from (publish) cassettes. There is optional feature flag support for NIP-45, NIP-50 and returns NIP-11 info documents. There are loaders (untested) for js/ts, go, dart, cpp, rust and python.

Use case? There's a few, mostly deterministic test fixtures, dictionaries of various kinds, books and archival use-cases.

This is a very experimental concept piece. If anything comes of this, there would likely be optimization, so any cassettes you make today could be broken tomorrow. Early adopters and tinkerers only.

https://github.com/sandwichfarm/cassette

there's a website too, but the agent went a bit strong on the marketing, and still toning it down: cassette.cafe