Generating an Offramp URL

Coinbase Offramp is accessed by creating and directing users to a URL with query parameters specific to their request.

Create Offramp URL with App ID

To create URLs without a session token, disable Require secure initialization on the Onramp page in CDP.

Full API endpoint list

For a complete list of all API endpoints supported by Onramp/Offramp, visit our API Reference section.

Offramp URL parameters

The following table outlines parameters to generate the Offramp URL

Parameter	Req’d	Type	Description
appId	Yes	String	The Project ID found on the project Dashboard. Not required if using sessionToken.
addresses	Yes	Record<Address>	User address which cashout is being initiated from. Not required if using sessionToken. Referenced as from_address in Offramp Transaction Status API Addresses that the purchased crypto should be sent to. An object whose keys are addresses and values are arrays of networks each address supports. (e.g. addresses={"0x1":["base"]})
redirectUrl	Yes	String	URL to redirect the user to send crypto to the destination after they send crypto. Add your redirectUrl in your onramp app domain allowlist on CDP portal and use Offramp Transaction Status API to fetch the send to_address details.
partnerUserId	Yes	String	Unique ID representing the end-user. Must be less than 50 chars. Use with the Offramp Transaction Status API to retrieve transactions made during the session.
sessionToken	No	String	Token generated by the Session Token API. Only required if Require secure initialization is true. If sessionToken is included, appId and addresses parameters are not used.
defaultNetwork	No	String	Default network that should be selected when multiple networks are present
defaultAsset	No	String	Default asset that should be selected when multiple assets are present
presetCryptoAmount	No	Number	Preset crypto amount value
presetFiatAmount	No	Number	Preset fiat amount value (for USD, CAD, GBP, EUR only). Ignored if presetCryptoAmount is also set.
defaultCashoutMethod	No	String	Default payment method to cashout fiat (“FIAT_WALLET”, “CRYPTO_ACCOUNT”, “ACH_BANK_ACCOUNT”, “PAYPAL”)
fiatCurrency	No	String	e.g: USD, CAD, GBP, etc.
disableEdit	No	Boolean	If set to true, prevents users from editing their order in the One-Click Sell flow. By default, this is set to false.

Example URL without Session Token

https://pay.coinbase.com/v3/sell/input?appId=58a3fa2e-617f-4198-81e7-096f5e498c00&partnerUserId=testUser&addresses={"0x4315d134aCd3221a02dD380ADE3aF39Ce219037c":["ethereum","base"]}&assets=["ETH","BTC"]&redirectUrl=https://www.coinbase.com/onramp-redirect

All transactions made during the session are linked to partnerUserId which can be used with the Transaction Status API to retrieve these transactions later.

Getting a Session Token

Session tokens are optional. Developers can create session token to securely authenticate users and manage sessions.

Call the Session Token API to obtain a token, then pass that token as the sessionToken query string parameter when generating Offramp URLs.

The token expires after a short period of time and can only be used once. A new token must be obtained for every new session.

Full API endpoint list

For a complete list of all API endpoints supported by Onramp/Offramp, visit our API Reference section.

Method

POST

URL

https://api.developer.coinbase.com/onramp/v1/token

Request Parameters

The Session Token API is an RPC endpoint that accepts parameters as JSON in the request body.

Name	Type	Req	Description
addresses	Address[]	Y	List of addresses that the purchased crypto should be sent to. Each entry in this array is an object containing an address and a list of blockchains the address supports.
assets	String[]	N	List of assets that will be available for the user to buy/send. Assets can either be symbols e.g. “ETH” or “BTC”, or UUIDs retrieved from the Buy Options API. This optional parameter acts as a filter on the addresses parameter. If it is included then only the assets in this list that are available on one of the supported blockchains in the Addresses list will be available to the user. See the See the Buy Options API for the full list of assets.

Address Parameters

An Address object accepts the following parameters:

Parameter	Req’d	Type	Description
address	Yes	String	Destination address where the purchased tokens will be sent.
blockchains	Yes	String[]	List of blockchains enabled for the associated address. All tokens available per blockchain are displayed to the user. Available blockchains include: “ethereum”, “bitcoin”, “base”, “avachain”, “optimism”, “solana”, “polygon”, “arbitrum”, “stellar” and many more. See the Buy Options API for the full list.

Response Fields

The Session Token API returns a JSON response including the following fields.

Name	Description
token	A unique string to be passed the URL as sessionToken parameter when manually generating a URL to initialize the onramp widget (the resulting URL will look like https://pay.coinbase.com/buy/select-asset?sessionToken=<token>&<other params>). This token is associated with the parameters and App ID header provided in the request. This token can only be used once.
channel_id	Not yet functional. Upcoming implementation: A socket.io channel ID that can be used to receive events from the Onramp API while the customer goes through the transaction flow.

Example Request/Response

Request (cURL)

cdpcurl -X POST 'https://api.developer.coinbase.com/onramp/v1/token' \
  -k /tmp/cdp_api_key.json \
  -d '{"addresses": [{"address": "0x4315d134aCd3221a02dD380ADE3aF39Ce219037c", "blockchains": ["ethereum"]}]}'