vault-ask

Listed on mcpservers.org Vault Ask MCP server

Zero-knowledge, one-time secret sharing. End-to-end encrypted in the browser. The server only ever stores ciphertext. Supports both sending and requesting secrets without requiring any account.

Part of the Erseni open-source components.

Status: early development. API and on-disk format may change until the first tagged release.

Primary development happens in Erseni's internal monorepo. This repository is a public mirror, kept in sync via Jenkins after every successful production deploy. Issues and merge requests are welcome; see CONTRIBUTING.md.

Features

• Send a secret: create a one-time link, recipient decrypts in the browser, secret self-destructs after viewing.
• Request a secret: create an inbound link, send it to a third party (customer, colleague) who submits a secret without an account. You retrieve it once with your private key.
• End-to-end encryption: AES-GCM 256 for sending, X25519 + ECIES for requesting. All crypto in the browser via the native Web Crypto API. The server never sees plaintext.
• No accounts: neither sender nor receiver needs to sign up.
• Auditable: deterministic build, source SHA embedded in every HTML response, SRI hashes on every script.
• Secrets for AI agents: cli/ contains vault-ask, a CLI and MCP server that request a secret from a person and hand it to exactly one command or file, masked in every output and never shown to the agent, and that send a generated secret to a person as a one-time link.

Where it runs

The component runs as part of Erseni Vault, hosted in the EU. It is not a standalone application: it depends on Erseni's internal framework, and this repository cannot be installed or self-hosted on its own. The source is published so that the cryptography and the server behaviour can be audited.

vault-ask in cli/ is the exception: it is a standalone Node.js tool that talks to Erseni Vault.

Security model

• Secret plaintext never leaves the sender's browser.
• Encryption keys are transported in the URL fragment (#k=...), which browsers never send to servers.
• Secrets are deleted on first retrieval (atomic DELETE ... RETURNING).
• Expired secrets are purged every minute by a cron job.
• No access logs, no IP retention, no backups of the secrets tables.

See docs/ARCHITECTURE.md and docs/THREAT-MODEL.md.

Verifying a running instance

Every page served by a secrets-component instance includes a <meta name="build-sha" content="..."> tag. Match that SHA against a tag in this repository to confirm the deployed code.

curl -s https://secrets.example.com/send | grep build-sha

License

AGPL-3.0-or-later. See LICENSE.

Security disclosure

See SECURITY.md.