> ## Documentation Index > Fetch the complete documentation index at: https://docs.crossmint.com/llms.txt > Use this file to discover all available pages before exploring further. # Transfer Tokens > Transfer tokens between wallets using Crossmint's APIs **You are viewing docs for the previous version of the Wallets SDK.** We recommend upgrading to V1. See the [updated version of this page](/wallets/guides/transfer-tokens) or the [V1 migration guide](/wallets/guides/migrate-to-v1). ## Prerequisites * **Wallet**: [Create a wallet](/wallets/v0/guides/create-wallet) to transfer from. * **Operational Signer**: The signing wallet must be registered as an operational signer on the wallet. You can do this [at wallet creation](/wallets/v0/guides/create-wallet) by passing `delegatedSigners`, or afterward by [registering a signer](/wallets/v0/guides/signers/registering-a-signer). * **Test Tokens**: Fund your wallet with [USDXM testnet tokens](/wallets/v0/guides/get-staging-tokens) before transferring. * **API Key**: Get an API key with the `wallets:transactions.create` scope. In staging, all scopes are included by default. ## What is a token transfer? A token transfer moves a token from one wallet address to another onchain. This creates an onchain transaction that costs gas, which Crossmint handles for you. Once the blockchain confirms the transaction, the transfer is final and cannot be reversed. ## Sending tokens ```typescript theme={null} import { useWallet } from '@crossmint/client-sdk-react-ui'; const { wallet } = useWallet(); const { hash, explorerLink } = await wallet.send("0x0D282906CDD8F6934d60E4dCAa79fa5B1c7a1925", "usdxm", "3.14"); ``` See the [React SDK reference](/sdk-reference/wallets/v0/react/hooks#wallet-methods) for more details. ```typescript theme={null} import { CrossmintWallets, WalletsApiClient, createCrossmint } from "@crossmint/wallets-sdk"; import { privateKeyToAccount } from "viem/accounts"; const crossmint = createCrossmint({ apiKey: "", }); const crossmintWallets = CrossmintWallets.from(crossmint); const apiClient = new WalletsApiClient(crossmint); const account = privateKeyToAccount( process.env.EXTERNAL_WALLET_PRIVATE_KEY as `0x${string}` ); const wallet = await crossmintWallets.getWallet( "", { chain: "base-sepolia", signer: { type: "external-wallet" } } ); // 1. Create the transaction in prepare-only mode const { transactionId } = await wallet.send( "0x0D282906CDD8F6934d60E4dCAa79fa5B1c7a1925", "usdxm", "3.14", { experimental_prepareOnly: true, experimental_signer: `external-wallet:${account.address}`, } ); // 2. Fetch the pending transaction to get the message that needs signing const txResponse = await apiClient.getTransaction( wallet.address, transactionId ); if ("error" in txResponse) { throw new Error(`Failed to get transaction: ${JSON.stringify(txResponse)}`); } const pendingApproval = txResponse.approvals?.pending[0]; if (!pendingApproval) { throw new Error("No pending approval found"); } // 3. Sign the pending approval message with your viem private key const signature = await account.signMessage({ message: { raw: pendingApproval.message as `0x${string}` }, }); // 4. Submit the approval const result = await wallet.approve({ transactionId, options: { experimental_approval: { signature, signer: `external-wallet:${account.address}`, }, }, }); console.log("Transaction approved:", result); ``` See the [SDK reference](/sdk-reference/wallets/v0/typescript/classes/Wallet#send) for all parameters and return types. ```typescript theme={null} import { useWallet } from '@crossmint/client-sdk-react-native-ui'; const { wallet } = useWallet(); const { hash, explorerLink } = await wallet.send("0x0D282906CDD8F6934d60E4dCAa79fa5B1c7a1925", "usdxm", "3.14"); ``` See the [React Native SDK reference](/sdk-reference/wallets/v0/react-native/hooks#wallet-methods) for more details. ```swift theme={null} import CrossmintClient import Wallet let sdk = CrossmintSDK.shared let wallet = try await sdk.crossmintWallets.getOrCreateWallet( chain: .baseSepolia, signer: .email("user@example.com") ) let result = try await wallet.send("0x0D282906CDD8F6934d60E4dCAa79fa5B1c7a1925", "usdxm", 3.14) ``` Transfers must be approved by one of the wallet's [signers](/wallets/v0/concepts/wallet-signers). The SDK handles this automatically, but with the REST API you may need to craft, sign, and submit the approval manually. Call the [transfer token](/api-reference/wallets/transfer-token) endpoint. ```bash cURL theme={null} curl --request POST \ --url https://staging.crossmint.com/api/2025-06-09/wallets//tokens/base-sepolia:usdc/transfers \ --header 'Content-Type: application/json' \ --header 'X-API-KEY: ' \ --data '{ "recipient": "", "amount": "3.14", "signer": "external-wallet:" }' ``` ```js Node.js theme={null} const url = 'https://staging.crossmint.com/api/2025-06-09/wallets//tokens/base-sepolia:usdc/transfers'; const payload = { recipient: "", amount: "3.14", signer: "external-wallet:" }; const options = { method: 'POST', headers: { 'X-API-KEY': '', 'Content-Type': 'application/json' }, body: JSON.stringify(payload) }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```python Python theme={null} import requests url = "https://staging.crossmint.com/api/2025-06-09/wallets//tokens/base-sepolia:usdc/transfers" payload = { "recipient": "", "amount": "3.14", "signer": "external-wallet:" } headers = { "X-API-KEY": "", "Content-Type": "application/json" } response = requests.post(url, json=payload, headers=headers) print(response.json()) ``` See the [API reference](/api-reference/wallets/transfer-token) for more details. The next steps depend on which signer type you specified in the previous step. [Server](/wallets/guides/signers/server-signer) signers derive a private key from your signer secret using HKDF-SHA256 and sign transactions locally. When using the **SDK**, signing and approval are handled automatically — no additional steps are needed. When using the **REST API** directly, you must: 1. Derive the signing key from your signer secret (scoped to your project, environment, and chain). See the derive-server-signer helper for a reference implementation. 2. Sign the approval message returned from the transaction creation step. 3. Submit the signature via the [approve transaction](/api-reference/wallets/approve-transaction) endpoint. Crossmint recommends using the Wallets SDK for server signer flows. The SDK handles key derivation and signing automatically. See the [Server Signer guide](/wallets/guides/signers/server-signer) for full configuration and setup details. [Device](/wallets/guides/signers/device-signer) signers generate a P256 keypair inside the device's secure hardware (Secure Enclave, Android Keystore, or browser Web Crypto API). Because the private key never leaves the device, device signers are **client-side only** and cannot be used directly with the REST API. Crossmint recommends using the React, React Native, or Swift SDK for device signer flows. The SDK handles device key generation, storage, and signing automatically. See the [Device Signer guide](/wallets/guides/signers/device-signer) for setup instructions. For [External Wallet](/wallets/guides/signers/add-signers) signers, you must manually sign the approval message and submit it via the API. The response from Step 1 includes a pending approval with a `message` field that must be signed exactly as returned. From the previous step's response, extract: * `id` - The transaction ID (used in the next step) * `approvals.pending[0].message` - The hex message to sign Sign the message using your external wallet. The message is a raw hex string and must be signed exactly as returned. Here's an example using an EVM wallet with [Viem](https://viem.sh/): ```typescript theme={null} import { privateKeyToAccount } from "viem/accounts"; // The message from tx.approvals.pending[0].message const messageToSign = ""; // Sign the message exactly as returned (raw hex) const account = privateKeyToAccount(`0x${""}`); const signature = await account.signMessage({ message: { raw: messageToSign }, }); ``` [Email and phone](/wallets/guides/signers/configure-recovery) signers require client-side OTP verification and key derivation, which the Crossmint SDK handles automatically. While REST API signing is technically possible, Crossmint does not recommend it because you would still need client-side SDK integration for the signing step. Crossmint recommends using the React, React Native, Swift, or Node.js SDK examples instead. The SDK handles the full signing flow for email and phone signers. [Passkey](/wallets/guides/signers/add-signers) signers use WebAuthn for biometric or password manager authentication, which requires browser interaction. While REST API signing is technically possible, Crossmint does not recommend it because you would still need client-side SDK integration for the WebAuthn signing step. Crossmint recommends using the React, React Native, Swift, or Node.js SDK examples instead. The SDK handles the full passkey signing flow automatically. Skip this step if using the **SDK with a server signer** — the SDK handles signing and approval automatically. Call the [approve transaction](/api-reference/wallets/approve-transaction) endpoint with the signature from Step 2 and the transaction ID from Step 1. ```bash cURL theme={null} curl --request POST \ --url https://staging.crossmint.com/api/2025-06-09/wallets//transactions//approvals \ --header 'Content-Type: application/json' \ --header 'X-API-KEY: ' \ --data '{ "approvals": [{ "signer": "external-wallet:", "signature": "" }] }' ``` ```js Node.js theme={null} const url = 'https://staging.crossmint.com/api/2025-06-09/wallets//transactions//approvals'; const payload = { approvals: [{ signer: "external-wallet:", signature: "" }] }; const options = { method: 'POST', headers: { 'X-API-KEY': '', 'Content-Type': 'application/json' }, body: JSON.stringify(payload) }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```python Python theme={null} import requests url = "https://staging.crossmint.com/api/2025-06-09/wallets//transactions//approvals" payload = { "approvals": [{ "signer": "external-wallet:", "signature": "" }] } headers = { "X-API-KEY": "", "Content-Type": "application/json" } response = requests.post(url, json=payload, headers=headers) print(response.json()) ``` See the [API reference](/api-reference/wallets/approve-transaction) for more details. You can poll the transaction status to confirm it completed successfully. ```bash cURL theme={null} curl --request GET \ --url https://staging.crossmint.com/api/2025-06-09/wallets//transactions/ \ --header 'X-API-KEY: ' ``` ```js Node.js theme={null} const url = 'https://staging.crossmint.com/api/2025-06-09/wallets//transactions/'; const options = { method: 'GET', headers: { 'X-API-KEY': '' } }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```python Python theme={null} import requests url = "https://staging.crossmint.com/api/2025-06-09/wallets//transactions/" headers = { "X-API-KEY": "" } response = requests.get(url, headers=headers) print(response.json()) ``` ### Complete example Here's a complete, copy-pastable example for the `external-wallet` signer flow using Viem: ```typescript theme={null} import { privateKeyToAccount } from "viem/accounts"; // ============================ // Config (replace placeholders) // ============================ const API_BASE_URL = "https://staging.crossmint.com"; const API_VERSION = "2025-06-09"; const API_KEY = ""; const WALLET_ADDRESS = ""; const CHAIN = "base-sepolia"; const TOKEN = "usdc"; // The externally-owned address that will sign the approval message: const EXTERNAL_WALLET_ADDRESS = ""; const RECIPIENT_ADDRESS = ""; const AMOUNT = "0.69"; const headers = { "X-API-KEY": API_KEY, "Content-Type": "application/json", }; // ============================ // STEP 1: Create the transaction // ============================ const createTransferUrl = `${API_BASE_URL}/api/${API_VERSION}/wallets/${WALLET_ADDRESS}/tokens/${CHAIN}:${TOKEN}/transfers`; const createTransferPayload = { recipient: RECIPIENT_ADDRESS, amount: AMOUNT, signer: `external-wallet:${EXTERNAL_WALLET_ADDRESS}`, }; const createTransferRes = await fetch(createTransferUrl, { method: "POST", headers, body: JSON.stringify(createTransferPayload), }); if (!createTransferRes.ok) { throw new Error( `Failed to create transfer: ${createTransferRes.status} ${await createTransferRes.text()}` ); } const tx = await createTransferRes.json(); const txId = tx.id; const messageToSign = tx?.approvals?.pending?.[0]?.message; if (!messageToSign) { throw new Error( "No approval message found. Ensure signer is external-wallet and that an approval is pending." ); } console.log("txId:", txId); console.log("messageToSign:", messageToSign); // ============================ // STEP 2: Sign the approval message (Viem) // ============================ // IMPORTANT: sign the message EXACTLY as returned (a raw hex string). const account = privateKeyToAccount(`0x${""}`); const signature = await account.signMessage({ message: { raw: messageToSign }, }); console.log("signature:", signature); // ============================ // STEP 3: Submit the signature // ============================ const submitApprovalUrl = `${API_BASE_URL}/api/${API_VERSION}/wallets/${WALLET_ADDRESS}/transactions/${txId}/approvals`; const submitApprovalPayload = { approvals: [ { signer: `external-wallet:${EXTERNAL_WALLET_ADDRESS}`, signature, }, ], }; const submitApprovalRes = await fetch(submitApprovalUrl, { method: "POST", headers, body: JSON.stringify(submitApprovalPayload), }); if (!submitApprovalRes.ok) { throw new Error( `Failed to submit approval: ${submitApprovalRes.status} ${await submitApprovalRes.text()}` ); } const approvalResult = await submitApprovalRes.json(); console.log("approvalResult:", approvalResult); // ============================ // STEP 4 (optional): Check transaction status // ============================ const getTxUrl = `${API_BASE_URL}/api/${API_VERSION}/wallets/${WALLET_ADDRESS}/transactions/${txId}`; const getTxRes = await fetch(getTxUrl, { method: "GET", headers }); if (!getTxRes.ok) { throw new Error( `Failed to fetch transaction: ${getTxRes.status} ${await getTxRes.text()}` ); } const txStatus = await getTxRes.json(); console.log("txStatus:", txStatus); ``` See the [API reference](/api-reference/wallets/transfer-token) for all supported locator formats. ## Verify your transfer Once the transfer completes, you can verify it in two ways: 1. **View the onchain transaction** using the `explorerLink` returned by the `send` method (available in the React and React Native SDKs): ```typescript theme={null} console.log("View transaction:", explorerLink); // Example: https://sepolia.basescan.org/tx/0xe5844116732d6cd21127bfc100ba29aee02b82cc4ab51e134d44e719ca8d0b48 ``` When using the Node.js SDK with `experimental_prepareOnly` mode, `explorerLink` is not returned. You can check the transaction status using the `transactionId` via the [API reference](/api-reference/wallets/get-transaction). 2. **Check the recipient's balance** programmatically using the [check balances API](/wallets/v0/guides/check-balances). ## Next steps Track transactions and receive completion notifications Query token balances across your wallets Try out the API in the interactive playground