Jutsu Vault

I needed one place for my passwords and for the secrets my applications and AI agents use, on a server I run myself. That only makes sense if a compromised server exposes nothing: it must store ciphertext only, and it must not be able to slip a reader of its own into a share or swap a key without a client noticing.

The first version (September to October 2025, releases 0.3.0 to 0.4.0) worked, but kept the device key in the browser's IndexedDB, so anyone with the browser profile had the vault. In September 2026 I rebuilt it around a written glossary and four ADRs. Sign-in is Passkey-only, and the Passkey's PRF output unwraps the User's keys, so no usable key rests in the browser. A new Device is approved from one already signed in, with a short code shown on both screens that covers the new Device's key and the User's public keys. A Recovery Kit phrase is the only way back if every Device is lost.

Every Item has its own key, wrapped separately to each party allowed to read it: the Owner, Share recipients and Access Keys. Owners sign every Share and Access Key, clients verify the signature every time they open an Item key, and Users pin each other's public keys on first use, so a malicious server cannot add a reader or substitute a key unnoticed. The same crypto library runs in the browser and in jv, a command-line client compiled with Bun, which applications and AI agents use to read Secrets or inject them into a process's environment. An agent skill teaches coding agents to use it.

Jutsu Vault runs at vault.davblu.dev on my own VPS. Every push to main runs lint, typecheck and unit tests in GitLab CI, then deploys with Docker Compose behind a shared Traefik, applying Prisma migrations first and passing only when the health check answers from outside. Production secrets stay encrypted in the repository with dotenvx, and the deploy job verifies the dotenvx binary's checksum before handing it the key. jv installs with one command from the vault itself, for Linux, macOS and Windows. The source is private; the product is live.