Reference

Complete reference for Offramp URL parameters and configuration options.

Security Requirements must be enforced: Your backend API that generates session tokens must implement proper security measures. See Security Requirements for complete implementation guidance.

URL Format

https://pay.coinbase.com/v3/sell/input?sessionToken=<token>&partnerUserRef=<id>&redirectUrl=<url>

URL Parameters

The following table outlines parameters to generate the Offramp URL

Parameter	Req’d	Type	Description
sessionToken	Yes	String	Token generated by the Session Token API.
redirectUrl	Yes	String	URL to redirect the user to after they send crypto. Production URLs must be added to your domain allowlist (see Security Requirements). Use Offramp Transaction Status API to fetch the send to_address details.
partnerUserRef	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.
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

https://pay.coinbase.com/v3/sell/input?sessionToken=abc123xyz&partnerUserRef=user-789&redirectUrl=https://yourapp.com

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

Creating Session Tokens

To get a sessionToken, call the Session Token API from your backend:

cdpcurl -X POST 'https://api.developer.coinbase.com/onramp/v1/token' \
  -k ~/Downloads/cdp_api_key.json \
  -d '{
    "addresses": [{
      "address": "0x1234567890abcdef1234567890abcdef12345678",
      "blockchains": ["base", "ethereum"]
    }],
    "clientIp": "192.0.2.1"
  }'

See the Quickstart guide for a complete example.