Security model
Your CV-CUE API key
Section titled “Your CV-CUE API key”- Encrypted at rest. The key value is encrypted with AES-256-GCM before it’s written to the database. Each value gets its own encryption key, derived with HKDF-SHA256 from the master key and a random 16-byte salt, plus a random nonce. Each value is also bound to its user and connection, so a value copied into another row won’t decrypt. Values stored before this scheme were re-encrypted automatically at startup.
- Write-only. After you save it, the key value is never shown again: not on the dashboard, not in any API response, not to Claude. The dashboard shows only a masked key ID.
- Decrypted only in memory, at the moment the server opens a CV-CUE session for you. The session is cached in memory for up to 15 minutes of inactivity, then logged out.
- Never sent to Claude. Claude gets an opaque access token for CV-CUE MCP, never your CV-CUE key.
- Deleted when you say so. Deleting a connection or your account removes it immediately and ends any cached session.
The encryption key (CVCUE_MASTER_KEY) is a server secret held outside the database.
What Claude can do
Section titled “What Claude can do”Exactly what your CV-CUE API key’s role allows, and no more:
- Read-only by default. Writes need to be switched on for the connection (and allowed by the server operator). See Enabling writes.
- Confirm before write. On by default: every write returns a preview and runs only when Claude repeats the identical request with a confirmation token, after your OK. See Enabling writes.
- Confirm on destructive actions. Reboot, disconnect and delete tools also require
confirm=true. - Secrets are masked. Wi-Fi passphrases, RADIUS and CoA secrets and similar fields come back
as
***REDACTED***, and write requests containing that placeholder are refused.
Sign-in and tokens
Section titled “Sign-in and tokens”- Google sign-in identifies your account. The server keeps your Google account ID, email and name, and nothing else from Google.
- OAuth 2.1 with PKCE connects Claude. Claude registers itself, you approve it on the consent page, and Claude receives an access token (valid 1 hour) and a refresh token (30 days, rotated on each use).
- Tokens are stored as SHA-256 hashes, never in plain text.
- Disconnect any time. Connected apps on the dashboard lists every app you’ve approved; Disconnect revokes one app’s tokens immediately, and Disconnect all apps revokes every token without touching your saved connections.
- Registration is rate-limited. OAuth client registration (
/register) accepts 5 requests a minute per IP address. - Browser protections. Session cookies are signed,
HttpOnly,SameSite=LaxandSecure. Forms carry CSRF tokens, and pages can’t be framed.
Network protections
Section titled “Network protections”- The server only talks to CV-CUE hosts under
*.wifi.arista.comover HTTPS (plus Launchpad to find your server). A custom base URL elsewhere is rejected, so the server can’t be used to reach other hosts. - TLS certificates are always verified.
What the server doesn’t keep
Section titled “What the server doesn’t keep”Your network data. Tool results pass through the server to your MCP client and aren’t saved or logged. The only things Claude can write to the server are short endpoint notes about API behaviour, kept per account. Request logs contain paths and status codes, not headers or bodies.
Bring-your-own-key mode
Section titled “Bring-your-own-key mode”If you send Authorization: Bearer <key_id>:<key_value> instead of signing in, nothing is stored
at all: the key is used for that request and its cached session, then forgotten. It does live in
your MCP client’s config file, so protect that file.
Self-hosting
Section titled “Self-hosting”Everything above applies to your own deployment too, and then you hold the master key. See Self-host on Fly.io.