Stencil Ghost
Photograph street art to mint geolocated provenance records that protect artists' work from unauthorized commercial use.
The primitive.
The onchain primitive runs at the right moment in the flow and surfaces a clear, verifiable result that game designers can act on without web3 jargon.
Why this primitiveGoogle sign-in enables artists to authenticate work on-site with Google sign-in, and the server pays gas from a shared testnet wallet costs that would deter spontaneous documentation.
Required keys.
Add these in your Lovable project under Settings → Secrets before pasting the prompt below.
The build prompt.
Paste into a fresh Lovable project. Make sure all five secrets above are set first. read the build strategy →
Build "Stencil Ghost" in ONE Lovable message. Single-page demo. Sui Testnet.
CONCEPT
Photograph street art to mint geolocated provenance records that protect artists' work from unauthorized commercial use.
Discipline: Game Design & Interactive Media (street art documentation).
Onchain primitive: Google sign-in + custodial Sui wallet. Why: Google sign-in enables artists to authenticate work on-site with Google sign-in, and the server pays gas from a shared testnet wallet costs that would deter spontaneous documentation.
BUDGET (5 credits, hard limit)
- One page. No extra routes, no dashboards, no docs.
- Enable Lovable Cloud + Google sign-in only. No email/password, no other providers.
- One Move module (<=80 lines), published ONCE to Sui Testnet.
- All signing runs server-side in ONE createServerFn.
- Walrus only if the idea needs blob storage.
- Skip tests, skip CI, skip landing marketing.
STACK
- Whatever the Lovable session ships with (TanStack Start today; classic Vite+React works too).
- `bun add @mysten/sui zod`. No @mysten/dapp-kit, no @mysten/enoki.
- All Sui signing is server-side inside createServerFn (or the equivalent server route on the classic template).
AUTH + WALLET (custodial demo — be honest in the UI)
- Enable Lovable Cloud. Add Google sign-in via `supabase--configure_social_auth`
with providers=["google"], disable_providers=["email"]. No Google Cloud
console, no OAuth client — Lovable brokers it.
- Sign-in button:
import { lovable } from "@/integrations/lovable";
await lovable.auth.signInWithOAuth("google", { redirect_uri: window.location.origin });
- src/lib/sui-wallet.server.ts derives a per-user Ed25519 keypair:
import { hkdfSync } from "node:crypto";
import { Ed25519Keypair } from "@mysten/sui/keypairs/ed25519";
export function deriveKeypair(userId: string) {
const salt = process.env.SUI_WALLET_SALT!;
const seed = hkdfSync("sha256", Buffer.from(salt), Buffer.from(userId),
Buffer.from("sui-wallet:ed25519:v1"), 32);
return Ed25519Keypair.fromSecretKey(new Uint8Array(seed));
}
- UI shows the derived Sui address + Suiscan link
(https://suiscan.xyz/testnet/account/<addr>) + "Fund via Testnet faucet"
button linking to https://faucet.sui.io/?address=<addr>.
- Disclosure copy under the address card:
"Demo wallet held by the server — safe for Sui Testnet, do not use for real value."
MOVE MODULE (move/sources/stencil_ghost.move)
```move
/// Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
module creative::stencil_ghost {
use sui::event;
use sui::tx_context::{Self, TxContext};
public struct Logged has copy, drop {
author: address,
blob_id: vector<u8>,
at: u64,
}
/// Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14
public entry fun log(blob_id: vector<u8>, ctx: &mut TxContext) {
event::emit(Logged {
author: tx_context::sender(ctx),
blob_id,
at: tx_context::epoch_timestamp_ms(ctx),
});
}
}
```
PUBLISH (one-time, from the sandbox)
- Write move/Move.toml:
[package]
name = "creative"
[addresses]
creative = "0x0"
[dependencies]
Sui = { git = "https://github.com/MystenLabs/sui.git", subdir = "crates/sui-framework/packages/sui-framework", rev = "framework/testnet" }
- sui client switch --env testnet
- sui client publish --gas-budget 100000000 --json move > publish.json
- Extract packageId:
jq '.objectChanges[] | select(.type=="published") | .packageId' publish.json
- Write src/data/sui-package.json:
{ "packageId": "0x...", "module": "<mod>", "network": "testnet", "publishedAt": "<iso>" }
Import it in the server fn. Never hardcode the package id in a component.
SERVER FN (src/lib/stencil_ghost.functions.ts)
import { createServerFn } from "@tanstack/react-start";
import { requireSupabaseAuth } from "@/integrations/supabase/auth-middleware";
import { SuiClient, getFullnodeUrl } from "@mysten/sui/client";
import { Transaction } from "@mysten/sui/transactions";
import { z } from "zod";
import pkg from "@/data/sui-package.json";
import { deriveKeypair } from "./sui-wallet.server";
const MIN_GAS_MIST = 5_000_000n;
export const submit = createServerFn({ method: "POST" })
.middleware([requireSupabaseAuth])
.inputValidator((d) => z.object({ payload: z.string().min(1).max(512) }).parse(d))
.handler(async ({ data, context }) => {
const kp = deriveKeypair(context.userId);
const addr = kp.toSuiAddress();
const client = new SuiClient({ url: getFullnodeUrl("testnet") });
const bal = await client.getBalance({ owner: addr });
if (BigInt(bal.totalBalance) < MIN_GAS_MIST) {
return { ok: false, address: addr,
error: "Fund the wallet at https://faucet.sui.io/?address=" + addr };
}
const tx = new Transaction();
tx.moveCall({
target: `${pkg.packageId}::${pkg.module}::log`,
arguments: [tx.pure.vector("u8", Array.from(new TextEncoder().encode(data.payload)))],
});
const res = await client.signAndExecuteTransaction({ signer: kp, transaction: tx });
return { ok: true, address: addr, digest: res.digest,
explorer: "https://suiscan.xyz/testnet/tx/" + res.digest };
});
UI (single page)
- Signed out: hero + "Sign in with Google" button (the lovable.auth call above).
- Signed in: address card (copy button, faucet link, Suiscan account link) +
disclosure copy + <action form for street art documentation> that calls the server fn via useServerFn+useMutation.
- After success: render the returned digest as a Suiscan tx link. Keep the last 5 in local state.
- Footer: "Built during the Creative AI & Quantum Hackathon organised by StreetKode Fam during Indian Krump Festival 14"
SECRETS (Lovable Cloud -> Secrets)
- SUI_WALLET_SALT generate 64-char random via `generate_secret`.
- SUI_DEPLOYER_KEY Sui keypair (base64) used ONCE to publish the Move package.
Fund at https://faucet.sui.io/?address=<deployer-address>.
Suiscan note: a freshly derived address shows "no results" until its first tx confirms. That is expected, not a bug.
User performs a street art documentation action; app calls `stencil_ghost::log(payload)` via the server fn and shows the Suiscan tx link.
Market sizing.
Indicative figures for hackathon pitches — refine with your own research before raising.