Sending funds from your Circle hosted wallets to external blockchain wallets is one of the most basic primitives of the Circle Accounts API.
# 1. Get an API key
The Accounts API uses [API keys](🔗) as the mechanism to authenticate client requests. The API key must be set in the `
Authorization` header of the request sent from your backend server. The format of the header is `
To obtain an API key for the sandbox environment, simply create an account and generate a new key in settings - it only takes a few seconds.
Once you have generated your API key, record it in a secure place.
# 2. Fund Your Wallet
If you haven't already, make sure you [fund your wallet for testing](🔗).
# 3. Send Funds
To send funds externally, you need to start by choosing the hosted wallet you will send from (`
source`) and the blockchain address to send to (`
You can use your [master wallet](🔗) as the source wallet. If you haven't noted your master wallet id yet, use [this guide](🔗) to obtain it.
USDC, EUROC, BTC, and ETH on Testing Networks
The [sandbox environment](🔗) is connected to the [USDC testing networks](🔗) and [EUROC testing networks](🔗) of the blockchains where [supported](🔗).
For BTC and ETH, we use **testnet** and **Goerli**, respectively.
The destination blockchain address you use has to be a valid address on the desired testing network. Refer to [Supported Chains and Currencies](🔗) to see each chains test network that we use.
For the purpose of this guide, we will transfer funds to the deposit address of the [USDC faucet service on Ethereum Goerli](🔗). That address is `
You can transfer any amount you want, provided your source wallet has sufficient balance.
To send funds externally, you will use the [create transfer endpoint](🔗).
Since the Accounts API [supports multiple chains and currencies](🔗), you have to specify the `
currency` and `
chain` you want to utilize. You can create a USDC transfer to an Ethereum address by using the command below.
Similarly, you can create a USDC transfer to an Algorand address by using the command below.
In either case, you should receive a response like the below.
# 4. Check the Status of the Transfer
You can use the [get transfer endpoint](🔗) to retrieve details about the status of the transaction. You can use it as in the command below.
You will receive a response like below.
The very first state transition for a transfer sets the `
status` to `
pending` and the `
transactionHash` to `
null` - at that point Circle has just started processing the on-chain send.
At this point you can consider the transaction complete because it has been successfully broadcasted to the network. Circle's systems will continue to track the transfer for the appropriate number of confirmations and its `
status` will at that point change to `
complete`. Except for a few specialized applications you do not have to worry about waiting for the `
complete` state - that's important when receiving external transfers. You can [read more about block confirmations here](🔗).
🎉 Congratulations! You have successfully sent cryptocurrency using the Circle Accounts API.
Make sure you check our quickstart guide on [receiving external funds](🔗).
# 5. Ready for the next step?
If you are in advanced stages of experimenting with our APIs and want to plan moving to production, please start by [applying for a Circle Account](🔗) and subsequently [reach out to sales](🔗). We'll be happy to walk you through to the next steps.
We can't wait to see what you are going to build!