Cookie Tab

Cookie Tab settles an invoice from whatever token the payer holds, in one signature. The homepage at cookie-tab.pages.dev leads with a live invoice for 700 TRASHCOIN on the demo jar, which is registered to the CookOven name cookietab.cook. A wallet holding only COOK is short of that token, so paying it quotes both the Cookiebox and Candy Shop aggregators, verifies the winning route against the payer's own balances, and puts the swap, the transfer and a cookiejar:1 memo into one transaction that confirms together or not at all. On chain: cookiescan.io/tx/3R1C9BBUH3K42jGQHfP5qSqkx4p4hxeWZyva5c5hHERogspxRnkK2X1C3pwAXKVvFYEykoG1ZWXvBhzxffnp5hFL, a swap plus a payment in 11 instructions under one signature. A route too long for the 1,232-byte limit falls back to swap-then-pay and says so before anything is signed. That composed checkout shipped on 2026-09-12. An earlier description of the swap as a separate transaction predates it. Under the invoice the page steps through the confirmed transaction one instruction at a time, each with its program id and an explorer link, so the evidence can be read without a wallet. A request can carry an invoice reference, which goes on chain in the memo. #/jar/<recipient>?ref=<reference> then reads paid, part-paid, unpaid, or no record when the read did not cover the jar, from chain data alone, and that page is the receipt. A payment from a second wallet under the reference AGENT-DEMO (cookiescan.io/tx/5JNP7ewsp5YxEGeoMdFuB4P9QM8N9VwBnr3RZSEpTjY42bxfLVk32fZ3Z1eSxHcz4SEJLGXbf7Sso5JE63Z9rCwQ) reconciled from its memo with nothing coordinated off chain. Requests are priced in a token or in US dollars at the Cookiescan price when opened. A tip jar leaves the amount open. The payer can add 1% for the Cookie Jar, Cookie Chain's community treasury, as a second transfer in the same transaction. Cookie Tab reads that public address the way it reads any jar. cookie-mcp's transfer takes the memo as of its PR #3, merged 2026-09-14 and on main ahead of a release, so an agent on that build can pay the same link and appear in the jar. There is no backend. The request is base64url JSON in the URL fragment, which never reaches a server. Every payment is one transaction plus an SPL Memo tagged cookiejar:1, and a public jar page rebuilds the recipient's history from getSignaturesForAddress over the wallet and its token accounts and the transactions' own balance deltas. .cook names resolve with one PDA read against the CookOven registry, and a name listed for sale is refused rather than paid into escrow. The link, memo and transaction formats are in docs/wire-format.md. Cookie Tab does not hold keys, takes no fee and deploys no program. 160 unit and render tests run with no network. 28 live checks run against the real chain and ecosystem APIs with no key and no funds.