Send & request, recipient search

Summary. The send flow is a small state machine (pick a recipient, enter an amount, review, hold to send) with a type-ahead recipient search that resolves usernames, verifies pasted keys against Nostr profiles, and gates unverified keys behind a confirmation. The same surface issues requests (invoices).

Motivation

Paying should feel like a chat app: start typing a name, see suggestions, tap, confirm. But pasted keys are dangerous (typos send money into the void), so the picker has to verify what you give it and warn when it can’t. And because Grin payments are interactive, the UI must clearly show progress while the two legs complete.

How it works

The flow (SendFlow) moves through stages: Recipient → Amount → Review → Sending → Success / Failed.

• Recipient search. As you type, the wallet matches local contacts instantly and runs a debounced (~0.4 s) network lookup in parallel. Results render as tappable cards:
  • A name / @handle resolves via NIP-05 → a verified card (name@domain).
  • A pasted npub/hex/nprofile triggers a kind 0 profile fetch. A key with a published profile shows “✓ on nostr”; a key with no profile is shown as unverified.
  • Unverified keys are gated: tapping one asks “Pay an unverified key?” with Keep looking / Pay anyway. (Goblin’s own domain skips the gate; foreign domains don’t.)
• Amount. A centered numpad (mobile) or typed field (desktop). Over-balance entry flashes red and shakes rather than silently failing.
• Note. An optional memo, editable in a modal, travels in the message’s subject tag.
• Review → hold to send. The review hero shows recipient, amount, fee and note; a hold-to-send gesture (a deliberate ~1.5 s press) confirms, and is hard to do by accident. This dispatches the payment.
• QR / scan-to-pay. The recipient row and the home header offer a camera scanner; “My Code” shows your own nprofile QR so someone can scan to pay you. See QR & camera.

Requests reuse the surface: choose Request instead of Pay to issue an Invoice-1 to a contact (or broadcast a “requesting X ツ” code). Incoming requests appear as approve/decline cards; see Cancel & decline.

The Activity feed and home “recent contacts” strip are built by joining the GRIM transaction log with nostr tx_meta (goblin/src/gui/views/goblin/data.rs).

Reference

In goblin/src/gui/views/goblin/send.rs:

• SendFlow + Stage enum; Recipient, Candidate, LookupResult types.
• Debounced lookup → NIP-05 resolve / kind 0 fetch; the unverified-key confirm gate.
• request: bool switches Pay ↔ Request; scan via CameraContent + ScanTab.
• Dispatch: WalletTask::NostrSend / NostrRequest (amount, recipient hex, note, relay hints).
• Profile verification: NostrService::fetch_profile_blocking() (client.rs).
• Feed/contacts model: goblin/src/gui/views/goblin/data.rs.

References

• What happens after you hold-to-send: The payment flow.
• Avatars on the cards: Avatars & identicons.