Configure

init python:
    scfg.configure(
        wallet="0xYourWalletAddressHere",   # where payments go (EIP-55 checked)
        testnet=True,                       # remove (or False) for real money
    )

    # Paid items. `code` (1-99) is written into players' payments forever:
    # NEVER change an item's code after release.
    scfg.add_item("chapter2", code=1, price="4.99", token="USDC", title="Chapter 2: The Fall")
    scfg.add_item("ost",      code=2, price="2.00", token="USDT", title="Original Soundtrack")

All configure() options

Option	Default	Meaning
wallet	required unless solana_wallet is given	Your EVM payout address. A wrong-case checksum raises an error, which catches typos
solana_wallet	none	Your Solana payout address (base58) to accept USDC/USDT on Solana. See Solana
testnet	False	True uses Sepolia, Arbitrum Sepolia, Polygon Amoy, Base Sepolia, Arc Testnet and Solana Devnet (USDC only)
chains	all built-ins + yours	Which networks players may pay on, in display order: ["arbitrum", "base", "arc", "polygon", "ethereum", "solana"]. Chains you added with add_chain() can be listed too. By default the EVM chains (built-in, then yours) are offered if wallet is set, followed by "solana" if solana_wallet is set
tokens	both	["USDC"], ["USDT"] or both
methods	all on	Per-method options, see below
rpc_urls	none	Your own RPC endpoints per chain, tried before the built-in public ones, e.g. {"arbitrum": ["https://arb-mainnet.g.alchemy.com/v2/KEY"]}. See below
confirmations	per chain	Override blocks to wait on EVM chains, e.g. {"ethereum": 12}. Arc's default is 1: its blocks are final. Refused for "solana", which has no block count (see Solana)
previous_wallets	none	Wallets used by earlier versions of your game, EVM (0x…) and Solana addresses can be mixed. Keeps old purchases valid after you change wallets
logo	none	An image in your game folder, e.g. "images/logo.png" (.png, .jpg or .webp). Shown at the top of the payment screens and the browser checkout page, fitted into 240 × 64 (at 1280 × 720). A wide wordmark works best
accent	"#0e7c74"	Color of selected options and the main browser button, e.g. accent=gui.accent_color. Text on it switches between white and dark automatically

Payment methods

Method	Options	What the player does
browser	enabled, timeout_min (30)	Desktop: clicks "Open checkout in browser"; a page served by the game on 127.0.0.1 connects MetaMask, Rabby, Coinbase Wallet or another extension (on Solana: Phantom, Solflare or Backpack), and sends the payment. Web build: clicks "Open wallet"; the same checkout opens over the game (offered only when the page has a wallet for the network; see Web builds)
qr	enabled, wallet_button (Android "Open wallet app"), chains (restrict)	Scans a QR code with a phone wallet (EIP-681 payment link; on Solana, a Solana Pay link)
manual	enabled, allow_tx_paste	Sends the exact amount from any wallet or exchange; can paste the transaction hash

scfg.configure(wallet="0x...", methods={"browser": {"enabled": False},
                                              "qr": {"chains": ["base", "polygon"]}})

Your own RPC endpoints and chains

Your own RPC endpoint for a built-in chain. The plugin talks to each chain through free public RPC endpoints. They work, but they rate-limit and sometimes go down. If you have an endpoint from Alchemy, Infura, QuickNode, Ankr, or your own node, pass it in rpc_urls. Your endpoints are tried first, and the built-in public ones remain as a fallback:

init python:
    scfg.configure(
        wallet="0xYourWallet",
        rpc_urls={
            "arbitrum": "https://arb-mainnet.g.alchemy.com/v2/YOUR_KEY",
            "base": ["https://base-mainnet.g.alchemy.com/v2/YOUR_KEY",
                     "https://my-backup-node.example.com"],
        },
    )

Your own chain. For an EVM chain that isn't built in (Avalanche, Optimism, Linea, your own appchain…), describe it with scfg.add_chain() before configure(). Its key then works everywhere a built-in key does: chains=, rpc_urls=, confirmations= and methods={"qr": {"chains": [...]}}.

init python:
    # Avalanche C-Chain, real money (used when testnet=False).
    scfg.add_chain(
        "avalanche",
        name="Avalanche",                  # shown on the network button
        chain_id=43114,
        rpc=["https://api.avax.network/ext/bc/C/rpc"],
        tokens={"USDC": "0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E"},
        confirmations=3,
        explorer_tx="https://snowtrace.io/tx/{}",
        native_symbol="AVAX",
        fee_hint="low",
    )
    # The same key for testing (used when testnet=True): Avalanche Fuji.
    scfg.add_chain(
        "avalanche", testnet=True,
        name="Avalanche Fuji", chain_id=43113,
        rpc=["https://api.avax-test.network/ext/bc/C/rpc"],
        tokens={"USDC": "0x5425890298aed601595a70AB815c96711a31Bc65"},
        confirmations=3,
        explorer_tx="https://testnet.snowtrace.io/tx/{}",
        native_symbol="AVAX",
    )

    scfg.configure(
        wallet="0xYourWallet",
        testnet=True,
        chains=["base", "avalanche"],      # leave out to offer all built-ins + yours
    )

add_chain() argument	Meaning
key	Your name for the chain: lowercase letters, digits, _, -. It is stored in players' receipts, so never change it after release. It can't reuse a built-in key ("arc" is built in now: if your game added Arc itself, delete that add_chain() call; purchases it recorded stay valid, see Arc)
name	Shown to players on the network button (at most 32 characters)
chain_id	The EVM chain id (see chainlist.org). Wallets use it to switch networks, and QR codes carry it
rpc	One URL or a list, tried in order. https:// only, except http://127.0.0.1 / http://localhost for a local test node. The last one is also handed to the player's browser wallet if it needs to add the network, so put a public endpoint last
tokens	{"USDC": "0x…"} and/or "USDT". Copy addresses from Circle's / Tether's official lists, never from a block explorer search
confirmations	Blocks to wait before a payment counts. Use the chain's finality: a few for fast-finality chains, more for chains that reorg
explorer_tx	Transaction page with {} where the hash goes
native_symbol	The gas token ("AVAX", "ETH", …), named in "you need gas" warnings. Default "ETH"
fee_hint	"lowest", "low" (default) or "high", shown under the network name
testnet	False (default) adds the chain for real-money games; True for configure(testnet=True) games. Add it twice with the same key to have both
max_log_range	Blocks per eth_getLogs call to start with (default 1000). The plugin shrinks it by itself when an endpoint complains

Rules your chain must follow (checked when the game starts where possible):

• EVM only. The plugin finds payments through ERC-20 Transfer events over Ethereum JSON-RPC (eth_getLogs, eth_getTransactionReceipt, …). Tron, Bitcoin and other non-EVM chains can't be added this way. Solana is built in: see Solana.
• The token must not be the chain's gas coin. On chains like Arc, where USDC is the gas coin, a plain wallet send logs no ERC-20 event at the token contract, so add_chain() would miss it. Arc is built in for that reason (see Arc).
• 6-decimal tokens only. The item code lives in the last four of six decimals. This rules out BNB Chain's USDC/USDT (18 decimals). The plugin can't check this offline, so confirm decimals() on the explorer before you ship.
• The endpoint must serve eth_getLogs for recent blocks. Most do; check it with a test payment on the chain's testnet.
• Test it first. Make one payment on the testnet version of your chain, then one small real payment, before you release.

Item options

scfg.add_item(item_id, code, price, token, title, min_price=None)

• item_id: lowercase letters, digits, _ and -.
• price: a string like "4.99" (at most 2 decimals). Floats are refused.
• min_price: the lowest amount that still unlocks the item (defaults to price).
  • Sales: you can pass a lower amount to pay() as long as it's at least min_price.
  • Raising a price later: keep min_price at the old price, so earlier buyers stay unlocked.