Two weeks of coverage have already mapped who decides whether your agent can pay – the authorization axis – and where the money actually clears – the workflow axis. The third axis, what an agent transaction costs, got four new answers in five days, and they do not convert into each other.
Evervault went first, on the session. Its rate card prices Browser Tokens at $0.25 per card session – “each card in a session is billed separately” – and $0.05 per credential, free in the same session as a card. The page sits behind a $995-per-month Platform fee. Browser Tokens launched October 20 at Money20/20; the pricing page itself is dated October 23. The unit is the security container, not the purchase.
Sierra and Stripe shipped the same day. In the Sierra announcement, published October 20, the customer keys card digits mid-call and the digits route straight to Stripe; the agent sees only payment status and the last four digits. The payment itself runs on Stripe’s rail, whose published card bills 2.9% + 30¢ per successful domestic transaction, with +1.5% for international cards and +1% where currency conversion is required. Stripe’s agent-facing primitive bills differently again: $0.15 per Shared Payment Token issued, a line the page describes as “a secure payment primitive that helps agents facilitate purchases on behalf of customers.” Sierra’s own platform sits above all of it on an outcomes model – its team’s line is that you pay for results, not tokens. Cedar’s agent Kora completes 71.3% of started payments, a Sierra-reported figure with no published methodology.
Visa, BILL and Billtrust, also on October 20, tied the unit to the paperwork. Their live pilot routes approved buyer payments through supplier portals, with the payment path tied to a specific invoice; the release FAQ states that “The agent only executes eligible payments that have already been approved by the buyer.” The release publishes no fee table, no general availability date, and no participant counts. The unit is the invoice; the price is not on the page.
Mastercard’s Agent Pay for Machines early access is the fourth. Its investor release confirms microtransactions “some only fractions of a cent,” but mastercard.com’s press pages refused our fetch and no pricing or early-access terms are published – those details remain vendor-reported behind a login, and they are labeled that way here.
A fresh sweep of the market from October 22 through October 27 found no further qualifying launch, so the count stands at four. Four live products, four units: per card session, per successful transaction, per invoice, per fraction-of-a-cent machine payment – and one of them will not tell you its price at all. A Q4 buyer trying to cost an agent rollout cannot divide these into a common denominator, because the market has not agreed what one agent transaction is. Until it does, cost per transaction stays a vendor-defined variable rather than a number you can put in a spreadsheet.