Seamless service on third-party sites

A method, comprising:

• providing, by a service provider system, webpage source code that can be edited at a remote server to generate an edited webpage source code that defines a first set of customizations for a customized checkout button, the first set of customizations causing a first portion of a first aspect of style of the customized checkout button to match a second aspect of style for a webpage hosted by the remote server, wherein the edited webpage source code is configured for use as part of the webpage that is hosted by the remote server that is separate from the service provider system and executable by a user device when accessing the webpage that enables the user device to send one or more API calls to the service provider system;
• receiving, by the service provider system, the one or more API calls and one or more identification tokens from the user device, wherein the one or more API calls include webpage instructions including a second set of customizations for the customized checkout button, the second set of customizations causing a second portion of the first aspect of style of the customized checkout button to match the second aspect of style for the webpage hosted by the remote server, and wherein the one or more identification tokens distinguish the user device and the webpage from other user devices and webpages;
• in response to receiving the one or more API calls and the one or more identification tokens, determining, by the service provider system, that the webpage is registered, by comparing the one or more identification tokens with tokens in a token database and obtaining, by the service provider system, an account balance for a user account associated with the user device and sending programming code to the user device that enables a parent iframe containing the customized checkout button, including both the first and second set of customizations, to be generated in response to being executed by the user device, the parent iframe and the customized checkout button being hosted and controlled by the service provider system and being displayed as part of the webpage,
• wherein one of a plurality of checkout processes is associated with a particular payment method, and wherein the particular payment method is selected based on both the account balance for the user account and user device information,
• wherein the customized checkout button is personalized to include at least one of a user image, a user name, or the account balance for the user account, and
• wherein at least one customization of the second set of customizations for the customized checkout button and the particular payment method are determined based both on the account balance and prior to receiving a user input that initiates a checkout process at the user device through the parent iframe;
• receiving, by the service provider system, the user input at the user device through the parent iframe, the user input including a selection of the customized checkout button to initiate the one of the plurality of checkout processes using the particular payment method;
• and
• in response to receiving the user input, communicating, by the service provider system, one or more commands to the user device through the parent iframe that enables the user device to generate a child iframe, the child iframe being hosted by the service provider system.

A non-transitory machine-readable medium having stored thereon machine-readable instructions executable to cause a machine to perform operations comprising:

• receiving one or more API calls and one or more identification tokens from a user device based on a first programming code provided for editing at a remote server to generate an edited first programming code that defines a first set of customizations for a first customized checkout button, the first set of customizations causing a first portion of a first aspect of style of the first customized checkout button to match a second aspect of style for a webpage hosted by the remote server, wherein the one or more identification tokens distinguish the user device and the webpage from other user devices and webpages, wherein the edited first programming code is used as part of the webpage that is hosted by the remote server, the edited first programming code executable by the user device when accessing the webpage that enables the user device to send the one or more API calls and the one or more identification tokens to a service provider system that is separate from the remote server that hosts the webpage, wherein the one or more API calls include webpage instructions including a second set of customizations for the first customized checkout button, the second set of customizations causing a second portion of the first aspect of style of the first customized checkout button to match the second aspect of style for the webpage hosted by the remote server;
• in response to receiving the one or more API calls and the one or more identification tokens, determining that the webpage is registered, by comparing the one or more identification tokens with tokens in a token database and obtaining an account balance for a user account associated with the user device and sending second programming code to the user device that enables the user device to generate a first iframe containing the first customized checkout button, including both the first and second set of customizations, in response to being executed by the user device, the first iframe and the first customized checkout button being hosted and controlled by the service provider system and being displayed as part of the webpage,
• wherein one of a plurality of checkout processes is associated with a particular payment method, and wherein the particular payment method is selected based on both the account balance for the user account and user device information,
• wherein the first customized checkout button is personalized to include one or more of a user image, a user name, or the account balance for the user account, and
• wherein at least one customization of the second set of customizations for the first customized checkout button and the particular payment method are determined based both on the account balance and prior to receiving a user input that initiates a checkout process at the user device through the first iframe;
• receiving the user input at the user device through the first iframe, the user input including a selection of the first customized checkout button to initiate the one of the plurality of checkout processes using the particular payment method;
• and
• in response to receiving the user input, communicating one or more commands to the user device through the first iframe that enables the user device to generate a second iframe, the second iframe being hosted by the service provider system;
• wherein the second iframe contains a second customized checkout button that includes at least one customization from each of the first set of customizations and the second set of customizations.