Sandbox: Transfers

Test transfers to crypto addresses and emails in Sandbox

Overview

Transfers move funds to external addresses, other Coinbase users, or payment methods. In Sandbox, all transfers are simulated—webhooks fire and status transitions occur, but no real transactions happen.

Prerequisites

The following instructions use cdpcurl and a Sandbox API key. Install cdpcurl to begin.

1. Simulate transfer by target type

Set your account ID:

export ACCOUNT_ID="account_db458f63-..."

Get your account ID

cdpcurl -k $CDP_API_KEY \
  'https://sandbox.cdp.coinbase.com/platform/v2/accounts' | sed '1d' | jq -r '.accounts[].accountId'

a. To reserved addresses

You can use any valid address format for the network—it doesn’t need to be a real or funded address. Use reserved addresses below to test specific error scenarios.

Use these reserved addresses to test specific success and failure scenarios:

Any funds sent in Live to these addresses will be lost. In Sandbox, they are simulated and used for testing purposes only.

Reserved Address	Simulated Outcome
0x1111111111111111111111111111111111111111	Success
0x2222222222222222222222222222222222222222	Transfer invalid target
0x3333333333333333333333333333333333333333	Invalid address
0x4444444444444444444444444444444444444444	Unsupported network

Success

Below is a simulation using 0x1111... to test successful transfer handling:

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"network\": \"base\",
      \"address\": \"0x1111111111111111111111111111111111111111\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 2xx with normal transfer response

Transfer invalid target

Below is a simulation using 0x2222... to test malformed target error handling:

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"network\": \"base\",
      \"address\": \"0x2222222222222222222222222222222222222222\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 400

{
  "errorType": "invalid_request",
  "errorMessage": "'target' is invalid: must match one of [Account, Payment Method, Onchain Address, Email Instrument]. Account requires 'accountId'; Payment Method requires 'paymentMethodId'; Onchain Address requires 'network'; Email Instrument requires 'email'"
}

Invalid address

Below is a simulation using 0x3333... to test invalid address error handling:

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"network\": \"base\",
      \"address\": \"0x3333333333333333333333333333333333333333\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 400

{
  "errorType": "invalid_request",
  "errorMessage": "Invalid onchain address for network base."
}

Unsupported network

Below is a simulation using 0x4444... to test invalid network parameter handling:

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"network\": \"base\",
      \"address\": \"0x4444444444444444444444444444444444444444\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 400

{
  "errorType": "invalid_request",
  "errorMessage": "base is not a supported network."
}

The target address can be any valid format for the network—it doesn’t need to be a real or funded address. Use reserved addresses to test specific scenarios.

b. To reserved email addresses

Send to a Coinbase user by email. In Sandbox, only whitelisted test emails work:

Test Email	Description
[e-mail]	Returns successful validation
[e-mail]	Returns successful validation

You can also use the following reserved email addresses to simulate deterministic error responses:

Reserved Email	Simulated Outcome
[e-mail]	Invalid email target (fails validation and execution)
[e-mail]	Execution failure

Invalid email target

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"email\": \"[e-mail]\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"10\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 400

{
    "correlationId": "90d67ad3-d067-41d8-816f-10f3a0144502",
    "errorLink": "https://docs.cdp.coinbase.com/api-reference/v2/errors#invalid-request",
    "errorMessage": "Target email is invalid.",
    "errorType": "invalid_request"
}

Execution failure

This address passes validateOnly requests with a 200 response, but returns a 422 error when the transfer is actually executed. Use it to test the scenario where validation succeeds but execution fails.

validateOnly (200)

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"email\": \"[e-mail]\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"10\",
    \"asset\": \"usdc\",
    \"validateOnly\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 200

{
    "createdAt": "2026-04-21T20:20:14.346144124Z",
    "expiresAt": "2026-04-22T20:20:14.346122223Z",
    "source": {
        "accountId": "account_e99fd363-c817-424e-bf91-03dedc3bc2cd",
        "asset": "usdc"
    },
    "sourceAmount": "1.07",
    "sourceAsset": "usdc",
    "status": "quoted",
    "target": {
        "asset": "usdc",
        "email": "[e-mail]"
    },
    "targetAmount": "1.07",
    "targetAsset": "usdc",
    "updatedAt": "2026-04-21T20:20:14.346144124Z"
}

execute (422)

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usdc\"
    },
    \"target\": {
      \"email\": \"[e-mail]\",
      \"asset\": \"usdc\"
    },
    \"amount\": \"10\",
    \"asset\": \"usdc\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Expected response: HTTP 422

{
    "correlationId": "90d67ad3-d067-41d8-816f-10f3a0144502",
    "errorMessage": "Sandbox: simulated execution failure.",
    "errorType": "invalid_request"
}

Get your account ID

cdpcurl -k $CDP_API_KEY \
  'https://sandbox.cdp.coinbase.com/platform/v2/accounts' | sed '1d' | jq -r '.accounts[].accountId'

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usd\"
    },
    \"target\": {
      \"email\": \"[e-mail]\",
      \"asset\": \"usd\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usd\",
    \"execute\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Any email not in the whitelist returns a 4xx error. This prevents privacy concerns around validating real email addresses in Sandbox.

c. To reserved payment methods

For testing fiat withdrawals to external banks (Fedwire, SWIFT), see the Payment Methods guide.

Payment methods have pre-built test scenarios for different use cases (e.g., active vs inactive methods).

2. Validate before executing

Use validateOnly: true to verify recipient details (like email addresses or crypto addresses) before executing a transfer.

Get your account ID

cdpcurl -k $CDP_API_KEY \
  'https://sandbox.cdp.coinbase.com/platform/v2/accounts' | sed '1d' | jq -r '.accounts[].accountId'

cdpcurl -k $CDP_API_KEY \
  -X POST \
  -d "{
    \"source\": {
      \"accountId\": \"$ACCOUNT_ID\",
      \"asset\": \"usd\"
    },
    \"target\": {
      \"email\": \"[e-mail]\",
      \"asset\": \"usd\"
    },
    \"amount\": \"5.00\",
    \"asset\": \"usd\",
    \"validateOnly\": true
  }" \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

A 2xx response means the transfer would succeed. A 4xx response includes an errorType explaining why validation failed.

Use the reserved addresses from section 1.a to test validation scenarios for crypto addresses (e.g., validate with 0x3333... to test invalid address handling).

3. List transfers

View all transfers for your account:

cdpcurl -k $CDP_API_KEY \
  'https://sandbox.cdp.coinbase.com/platform/v2/transfers'

Example response

{
  "transfers": [
    {
      "transferId": "transfer_8b707d29-4690-4948-b645-de1cd1f5fd05",
      "status": "completed",
      "source": {
        "accountId": "account_db458f63-418a-4a91-a045-fab93ac35c3f",
        "asset": "usd"
      },
      "target": {
        "paymentMethodId": "paymentMethod_398435cb-03bd-5568-b8d5-44accd7ce305",
        "asset": "usd"
      },
      "sourceAmount": "5",
      "sourceAsset": "usd",
      "targetAmount": "5",
      "targetAsset": "usd",
      "createdAt": "2026-02-11T23:19:24.086Z",
      "updatedAt": "2026-02-11T23:19:24.183Z"
    }
  ]
}

What to read next

Create Transfer

API reference for creating transfers

List Transfers

API reference for listing transfers