Cowbird by Anthony V

An end-to-end encrypted password manager that stores everything in your own
HashiCorp Vault.

This is the browser-extension client for cowbird; a TypeScript reimplementation of the Go/Fyne desktop app, built to be byte-compatible with it: encrypted blobs and Vault records written by either client can be read by the other.

There is no Cowbird server and no third-party service. The extension talks directly to the Vault instance you configure; all encryption and decryption happens locally, and your unlock password never leaves the device.