# Goblin Goblin is a private, pay-by-username wallet for [GRIN ツ](https://grin.mw) — confidential digital cash on [Mimblewimble](https://github.com/mimblewimble/grin), with no amounts or addresses on the chain. Instead of passing slatepack files back and forth, you **pay a `username` (or an `npub`)** and the payment is delivered for you as an **end-to-end encrypted message over [nostr](https://github.com/nostr-protocol/nips), routed through [Tor](https://www.torproject.org)**. Relays only ever see ciphertext — never the amount, the sender, or the recipient. Tor hides your IP from the relay; the relay and encryption hide the rest — content, sender, timing. Goblin is a fork of the **Grim** egui GRIN wallet: it keeps Grim's full GRIN node/wallet engine and layers a Nostr-native, mobile-first payments experience on top. ## What it does - **Send to people** — pay a `username` or `npub`; the GRIN slatepack travels as a [NIP-17](https://nips.nostr.com/17) gift-wrapped DM ([kind 1059](https://nostrbook.dev/kinds/1059)) over Tor and is applied automatically by the recipient's wallet. No files to swap, no need to both be online at once. - **Manual slatepacks too** — when you need to pay or get paid without a handle, **Settings → Wallet → Slatepacks** exposes the classic by-hand flow: create a slatepack to send, or paste one to receive, finalize, or pay. - **In-app identity** — a nostr payment key that is deliberately *not* part of your seed, so you can rotate it any time to stay unlinkable without touching your funds. An optional human-readable `name` comes from the goblin.st identity service. - **Private by construction** — GRIN's address-less, confidential chain; your payments and identity (nostr relays, NIP-05 lookups, price) are routed through [Tor](https://www.torproject.org), so who-pays-whom never touches the clear net. The GRIN node connection — block sync and broadcasting your transaction — is direct: public chain data, the same for everyone, and not tied to your identity. Keys, names and history stay on your device. - **Configurable amount pairing** — show balances against a world currency, Bitcoin, or sats (rates fetched over Tor), or turn the preview off. - **Cross-platform** — Linux, macOS, Windows, Android, built in pure Rust on [egui](https://github.com/emilk/egui). ## How a payment travels ``` you ──slatepack──▶ NIP-17 gift wrap (kind 1059, NIP-44 encrypted) │ Tor │ ┌─────────────┴─────────────┐ your relays recipient's DM relays (kind 10050) └─────────────┬─────────────┘ ▼ recipient ◀──unwrap, verify seal author, apply slatepack ``` The wrap is [NIP-44](https://nips.nostr.com/44)-encrypted, and delivery uses the recipient's DM relay list ([kind 10050](https://nostrbook.dev/kinds/10050)). Tor hides your IP from the relay; the relay and the encryption above hide the rest — content, sender, timing. Both parties only need one relay in common. The default set is the Goblin relay plus large public relays (`relay.damus.io`, `nos.lol`), and the set is editable in **Settings → Relays**. ## Build ### Desktop (Linux / macOS / Windows) Goblin links [Tor](https://www.torproject.org) **in-process** via [arti](https://gitlab.torproject.org/tpo/core/arti) — the wallet is a single self-contained binary, no sidecar, nothing separate to install: ``` git submodule update --init --recursive cargo build --release ./target/release/goblin ``` Goblin's identity and payment traffic — nostr relays, NIP-05 lookups and price fetches — rides Tor: the money-path relay is dialed directly at its pinned `.onion` address, and any relay without one (e.g. a recipient's arbitrary DM relay) is reached over a Tor exit to its clearnet host. The GRIN node connection (block sync and transaction broadcast) is **not** routed through Tor — it connects directly, as it carries only public chain data that isn't linked to your wallet. ### Android Install the Android SDK / NDK, then from the repo root: ``` ./scripts/android.sh build|release v7|v8|x86 ``` `v7`/`v8`/`x86` is the device CPU architecture for `build`; for `release` pass a version in `major.minor.patch` form. ## Identity service (`goblin-nip05d`) The optional `name` service lives in `goblin-nip05d/` (axum + SQLite) and is deployed at [goblin.st](https://goblin.st). It implements [NIP-05](https://nips.nostr.com/5) resolution, [NIP-98](https://nips.nostr.com/98)-authenticated registration and release (names are never transferred — on a key rotation you release the old name and re-register, or import your existing identity). The wallet is fully usable — and fully anonymous — without it. Avatars aren't stored or served — clients render them from the pubkey (an npub gradient with the username's first letter, else the Grin mark). ## License Apache License v2.0. ## Credits 🤖 Built with AI pair-programming assistance (Claude) The underlying cross-platform GRIN wallet engine is the upstream **Grim** project.