Public, token-authenticated endpoint that backs the unsubscribe link in every Agentic Flows notification email. No API key or account is required: authorization is carried entirely by the signed token, which encodes the Flow, the Send Email node, and the recipient address. Idempotent — removing an address that is no longer subscribed still succeeds. The token must have been issued for the {id} in the path.

{
  "token": "<signed-unsubscribe-token>"
}