I'm stupid and megalomaniacal enough to strumble into developing a stripped-down, minimalist CouchDB implementation in Rust. I call it Microcouch. I've already got it pretty far in JavaScript.
There are HTTP and SQLite adapters, and a replicator. Replication already works with quiet well performance and memory characteristics between two HTTP databases, including attachments. However, these are processed inline (as base64).
To run the test, a running CouchDB server is needed:
docker run -e COUCHDB_USER=admin -e COUCHDB_PASSWORD=password -p 5984:5984 couchdb
in another terminal, run
COUCHDB_URL=http://admin:password@127.0.0.1:5984 cargo test
(c) 2022-2024 Johannes J. Schmidt