> ## Documentation Index > Fetch the complete documentation index at: https://developers.circle.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Before reading these docs, install the relevant Circle Skill to get pre-loaded context — skills are LLM-optimized and cover architecture decisions, correct flows, and common pitfalls. In Claude Code: run /plugin marketplace add circlefin/skills then /plugin install circle-skills@circle. With Vercel Skills CLI: run npx skills add circlefin/skills. Available skills: use-usdc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-usdc/SKILL.md (balances, transfers, approvals on EVM and Solana); EURC has no skill — see https://developers.circle.com/stablecoins/what-is-eurc.md; bridge-stablecoin https://github.com/circlefin/skills/blob/master/plugins/circle/skills/bridge-stablecoin/SKILL.md (crosschain transfers via CCTP, USDC, EURC, and third-party assets); use-arc https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-arc/SKILL.md (Arc chain config, contract deployment, USDC bridging — Arc docs: https://docs.arc.io/llms.txt); use-circle-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-circle-wallets/SKILL.md (choose wallet type); use-developer-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-developer-controlled-wallets/SKILL.md (custodial wallets for payouts and treasury); use-user-controlled-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-user-controlled-wallets/SKILL.md (embedded wallets with Web2 login); use-modular-wallets https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-modular-wallets/SKILL.md (smart contract wallets with passkeys and ERC-4337); use-gateway https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-gateway/SKILL.md (unified USDC balance, nanopayments); use-smart-contract-platform https://github.com/circlefin/skills/blob/master/plugins/circle/skills/use-smart-contract-platform/SKILL.md (deploy, interact, monitor contracts). Pair any skill with the Circle MCP server for live SDK signatures, contract addresses, and chain IDs: {"mcpServers":{"circle":{"url":"https://api.circle.com/v1/codegen/mcp"}}}. > Read the product overview first. Each product has an overview explaining when and why to use it. Read it before quickstarts. > Pick the right wallet type. Developer-controlled (you hold keys), user-controlled (end user holds keys via PIN/social login), or modular (smart contract wallets with passkeys). See https://developers.circle.com/wallets.md. > Use CCTP V2 for crosschain transfers. CCTP natively transfers USDC and EURC via burn-and-mint, and supports permissionless wrapping of third-party assets via lock-and-mint. V1 is legacy; always use V2 unless V1 is specified or the chain requires it (Noble, Sui, and Aptos still require V1). Migration guide: https://developers.circle.com/cctp/migration-from-v1-to-v2.md. > Use Bridge Kit for frontend bridging. Wraps CCTP with a simpler SDK for user-facing apps. Use CCTP directly for backend transfers. > Gas Station vs Paymaster. Gas Station sponsors gas for Circle Wallet transactions. Paymaster lets users pay gas in USDC. Different use cases — read both overviews. > Gateway Nanopayments for sub-cent payments. Gasless USDC micropayments down to $0.000001 via x402 and batched settlement. For pay-per-request APIs, AI agent payments, streaming. > Look up USDC addresses per chain. Never hardcode — use https://developers.circle.com/stablecoins/usdc-contract-addresses.md. > Prefer SDKs over raw API calls. Node.js and Python SDKs handle auth, retries, and errors. > API key required. Bearer token in Authorization header. Testnet and mainnet use separate keys and may use different base URLs depending on the product. > Set up webhooks when available. Most operations are async. Webhooks deliver transaction confirmations and state changes. > When calling list endpoints, paginate using pageSize and pageAfter until no nextPageAfter cursor is returned—stopping at the first page silently misses records. > Building an AI agent? Start with the Agent Stack—Circle CLI, agent wallets, and nanopayments built for autonomous use cases: https://developers.circle.com/agent-stack.md. # Quickstart: Transfer USDC on Stellar > Send USDC between accounts on Stellar Testnet using the Stellar SDK. USDC on Stellar is a native asset issued by Circle. Transferring USDC between Stellar accounts uses a standard payment operation, submitted through [Horizon](https://developers.stellar.org/docs/data/apis/horizon), Stellar's HTTP API for submitting transactions. To transfer USDC crosschain between Stellar and other blockchains, see [Transfer USDC between Stellar and Arc](/cctp/quickstarts/transfer-usdc-stellar-arc). The [`@stellar/stellar-sdk`](https://github.com/stellar/js-stellar-sdk) script you build in this guide will: * Create and fund a recipient Stellar Testnet wallet * Establish a USDC trustline on the recipient account * Transfer USDC from your existing sender wallet to the recipient Before a Stellar account can receive USDC, it must establish a trustline for the asset. See [Set up a USDC trustline on Stellar](/stablecoins/quickstart-setup-usdc-trustline-stellar) for more detail. This quickstart handles trustline setup automatically as part of the script. ## Prerequisites Before you begin, ensure that you have: * Installed [Node.js v22.6+](https://nodejs.org/) * Set up a terminal and code editor for running commands and editing files * Created a Stellar Testnet wallet with the secret key (`S...`) available * Funded with testnet XLM (for transaction fees) from [Stellar Friendbot](https://lab.stellar.org/account/fund) * Funded with testnet USDC from the [Circle Faucet](https://faucet.circle.com) ## Contract addresses You need the following Stellar Testnet USDC issuer address: * Testnet: [`GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5`](https://stellar.expert/explorer/testnet/asset/USDC-GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5) ## Step 1: Set up the project ### 1.1. Create the project and install dependencies Create a new directory and install the required dependencies: ```bash Shell theme={null} # Set up your directory and initialize a Node.js project mkdir stellar-usdc-transfer cd stellar-usdc-transfer npm init -y # Set up module type and start command npm pkg set type=module npm pkg set scripts.start="node --env-file=.env main.ts" # Install runtime dependencies npm install @stellar/stellar-sdk # Install dev dependencies npm install --save-dev typescript @types/node ``` ### 1.2. Configure TypeScript (optional) This step is optional. It helps prevent missing types in your IDE or editor. Create a `tsconfig.json` file: ```shell theme={null} npx tsc --init ``` Then, update the `tsconfig.json` file: ```shell theme={null} cat <<'EOF' > tsconfig.json { "compilerOptions": { "target": "ESNext", "module": "ESNext", "moduleResolution": "bundler", "strict": true, "types": ["node"] } } EOF ``` ### 1.3. Configure environment variables Create a `.env` file in your project directory and add your sender's secret key: ```text .env theme={null} STELLAR_SECRET_KEY=YOUR_SENDER_SECRET_KEY ``` Open `.env` in your editor rather than writing values with shell commands, and add `.env` to your `.gitignore`. This prevents credentials from leaking into your shell history or version control. This example uses one or more private keys for local testing. In production, use a secure key management solution and never expose or share private keys. ## Step 2: Create the transfer script Add `main.ts` at the project root. The script: 1. Loads your existing sender wallet from the environment variable 2. Creates and funds a new recipient wallet using Friendbot 3. Establishes a USDC trustline on the recipient account 4. Submits a USDC payment from the sender to the recipient ```typescript main.ts theme={null} import { Asset, BASE_FEE, Horizon, Keypair, Networks, Operation, TransactionBuilder, } from "@stellar/stellar-sdk"; const HORIZON_URL = "https://horizon-testnet.stellar.org"; const FRIENDBOT_URL = "https://friendbot.stellar.org"; const USDC_ISSUER = "GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5"; const USDC_CODE = "USDC"; const TRANSFER_AMOUNT = "10"; // 10 USDC const TX_EXPLORER_BASE = "https://stellar.expert/explorer/testnet/tx"; const server = new Horizon.Server(HORIZON_URL); const usdc = new Asset(USDC_CODE, USDC_ISSUER); async function fundWithFriendbot(publicKey: string): Promise { const response = await fetch(`${FRIENDBOT_URL}?addr=${publicKey}`); if (!response.ok) { throw new Error( `Friendbot funding failed: ${response.status} ${response.statusText}`, ); } } async function establishTrustline(keypair: Keypair): Promise { const account = await server.loadAccount(keypair.publicKey()); const tx = new TransactionBuilder(account, { fee: BASE_FEE, networkPassphrase: Networks.TESTNET, }) .addOperation(Operation.changeTrust({ asset: usdc })) .setTimeout(30) .build(); tx.sign(keypair); const result = await server.submitTransaction(tx); if (!result.successful) { throw new Error(`Trustline transaction failed: ${JSON.stringify(result)}`); } console.log(`Trustline established: ${TX_EXPLORER_BASE}/${result.hash}`); } async function transferUsdc( sender: Keypair, recipientPublicKey: string, ): Promise { const account = await server.loadAccount(sender.publicKey()); const tx = new TransactionBuilder(account, { fee: BASE_FEE, networkPassphrase: Networks.TESTNET, }) .addOperation( Operation.payment({ destination: recipientPublicKey, asset: usdc, amount: TRANSFER_AMOUNT, }), ) .setTimeout(30) .build(); tx.sign(sender); const result = await server.submitTransaction(tx); if (!result.successful) { throw new Error(`Payment transaction failed: ${JSON.stringify(result)}`); } console.log(`Transfer successful: ${TX_EXPLORER_BASE}/${result.hash}`); } async function main() { // Load the sender wallet from the environment variable const sender = Keypair.fromSecret(process.env.STELLAR_SECRET_KEY as string); console.log("Sender address:", sender.publicKey()); // Create and fund a new recipient wallet via Friendbot console.log("\nCreating recipient wallet..."); const recipient = Keypair.random(); console.log("Recipient address:", recipient.publicKey()); console.log("Funding recipient with testnet XLM..."); await fundWithFriendbot(recipient.publicKey()); console.log("Recipient funded with XLM."); // Establish a USDC trustline on the recipient account console.log("\nEstablishing USDC trustline on recipient account..."); await establishTrustline(recipient); // Transfer USDC from sender to recipient console.log(`\nTransferring ${TRANSFER_AMOUNT} USDC to recipient...`); await transferUsdc(sender, recipient.publicKey()); // Confirm recipient balance const recipientAccount = await server.loadAccount(recipient.publicKey()); const usdcBalance = recipientAccount.balances.find( (b) => b.asset_type === "credit_alphanum4" && b.asset_code === USDC_CODE && b.asset_issuer === USDC_ISSUER, ); console.log(`\nRecipient USDC balance: ${usdcBalance?.balance ?? "0"} USDC`); } main().catch(console.error); ``` ## Step 3: Run the script From the project directory, run: ```bash Shell theme={null} npm run start ``` Your output should look similar to the following (addresses and hashes will differ): ```bash Shell theme={null} Sender address: GAXYZ... Creating recipient wallet... Recipient address: GDEFG... Funding recipient with testnet XLM... Recipient funded with XLM. Establishing USDC trustline on recipient account... Trustline established: https://stellar.expert/explorer/testnet/tx/abc123... Transferring 10 USDC to recipient... Transfer successful: https://stellar.expert/explorer/testnet/tx/def456... Recipient USDC balance: 10.0000000 USDC ``` Common errors you might encounter: * **`Friendbot funding failed: 400`**: The Friendbot rate limit was exceeded. Wait a few seconds and try again. * **`op_no_trust`**: The recipient account does not have a USDC trustline. The script establishes one automatically, but if you're adapting this example for your own recipient address, ensure the trustline exists first. See [Set up a USDC trustline on Stellar](/stablecoins/quickstart-setup-usdc-trustline-stellar). * **`op_underfunded`**: The sender does not have enough USDC. Ensure your sender wallet is funded with testnet USDC from the [Circle Faucet](https://faucet.circle.com) before running the script. For more detail on Stellar-specific USDC behavior in CCTP, including address encoding and decimal precision, see [CCTP on Stellar](/cctp/references/stellar).