Payment Modes

The SDK supports multiple payment modes for different use cases.

Mode Comparison

Signature Mode (Default)

Uses cryptographic signatures instead of real payments. Perfect for development.

const client = new QueryFlowClient(privateKey);
// or explicitly:
const client = new QueryFlowClient(privateKey, { mode: "signature" });

Pros:

• ✅ Free for testing
• ✅ No testnet AVAX needed
• ✅ Instant (no blockchain confirmation)

Cons:

• ❌ Not suitable for production

Transaction Mode (Recommended for Production)

Sends real AVAX payments on Avalanche Fuji testnet.

const client = new QueryFlowClient(privateKey, { mode: "tx" });

Pros:

• ✅ Simple native AVAX payments
• ✅ No token approvals needed
• ✅ Full x402 compliance

Cons:

• ⚠️ Requires testnet AVAX (get free from faucet)
• ⚠️ ~2-3 second confirmation time

Thirdweb Mode

For frontend apps using the Thirdweb SDK. Uses the x-payment header format.

const client = new QueryFlowClient(privateKey, { mode: "thirdweb" });

Note: For most programmatic/agent use cases, we recommend mode: "tx".

Accessing Transaction Hash

After a successful query in tx mode, you can access the payment transaction hash:

const result = await client.market({ assets: ["BTC"], timeframe: "24h" });
console.log("Tx Hash:", client.lastTxHash);