MCP servers can't both stay open and stay safe — so Stream Vessel lets each user vouch for their own app
Letting users trust their own MCP clients, without opening a phishing hole
Most OAuth-enabled MCP servers accept any redirect URI, and a May 2026 study found 95.8% of 119 tested servers did — enough for a one-click account takeover, as Obsidian Security showed against Square's server. But strict allowlists lock out legitimate self-registered clients like Claude Code. Stream Vessel keeps the operator allowlist and adds a per-user list of up to 10 trusted HTTPS addresses, checked at sign-in rather than registration, so no code or error ever reaches an untrusted host.
The user does approve, but on false information. A redirect allowlist is what makes an approval mean what the user thinks it means: whatever the name says, the keys can only go where the list says.