Kite Agent Passport vs Agent Vault by Self

Kite Agent Passport

Spending sessions with per-transaction and total caps, a lifetime and passkey approval are enforced by the service, with step-up checks and an audit log. A person must sign up by email and create a passkey before an agent can pay. No published fee rate, OpenAPI file or Passport status page was found.

Agent Vault by Self

Scoped, revocable keys, OAuth on the hosted MCP server, spending caps, approvals and a documented threat model are designed to keep real card numbers and passwords out of the agent's context. The home page and launch post say cards are revealed only in an attested enclave, while the docs say that path is off on the hosted service.

Kite Agent Passport

1. Run kpass with --output json --no-interactive and branch on the exit code and error_code. Exit 6 is a session policy breach, so request a new session rather than logging in again
2. Pass --idempotency-key on every kpass session execute so a retry after a timeout does not pay twice
3. Ask the person for a session with a small per-transaction cap and a short --ttl, and confirm the merchant URL before executing
4. Use kpass sandbox test mode and the faucet to try a payment flow without real funds. Scoped cards are not available in sandbox
5. Check the kite-passport skill's trigger rules before installing it, since it directs the agent to paid services ahead of free tools

Agent Vault by Self

1. Pass the session handle from each hosted MCP result on every later call. Without it a page tool is refused or a new signed-out browser opens
2. On a pending answer, call get_pending_result with its wait id in the same turn. Repeating the original call starts a second one
3. Tell the user when waiting_on_owner is true. A first fill on a new site waits up to 15 minutes for the holder's approval
4. Before retrying a fill after an unknown outcome, check the merchant's order state or get_run_report. Some failures keep a recorded spend
5. Ask the holder to add an agent card to every card the agent may use. A card marked No limits accepts any amount on authorised sites