A method of implementing network transactions based on Open Application Programming Interface, API, the method comprising: receiving a first invocation request to invoke a plurality of Open APIs from a third party development server according to a user's transaction request; determining if an invocation relationship exists among the plurality of Open APIs; and in an event that an invocation sequence exists among the plurality of Open APIs: determining an Internet Service Provider, ISP, server corresponding to a first Open API which is first-ranked in the invocation sequence of the plurality of APIs; sending the first invocation request to the determined ISP server; receiving a service page returned by the ISP server according to the first invocation request; embedding in the service page the invocation sequence of the plurality of Open APIs; sending the service page to the third party development server; receiving a second invocation request triggered by the user to invoke a second Open API which is after the first Open API according to the invocation sequence embedded in the service page; sending the second invocation request to an ISP server corresponding to the second Open API; receiving a service page from the ISP server corresponding to the second Open API according to the second invocation request; and sending the service page to the third party development server. receiving a first invocation request to invoke a plurality of Open APIs from a third party development server according to a user's transaction request; determining if an invocation relationship exists among the plurality of Open APIs; and in an event that an invocation sequence exists among the plurality of Open APIs: determining an Internet Service Provider, ISP, server corresponding to a first Open API which is first-ranked in the invocation sequence of the plurality of APIs; sending the first invocation request to the determined ISP server; receiving a service page returned by the ISP server according to the first invocation request; embedding in the service page the invocation sequence of the plurality of Open APIs; sending the service page to the third party development server; receiving a second invocation request triggered by the user to invoke a second Open API which is after the first Open API according to the invocation sequence embedded in the service page; sending the second invocation request to an ISP server corresponding to the second Open API; receiving a service page from the ISP server corresponding to the second Open API according to the second invocation request; and sending the service page to the third party development server. determining an Internet Service Provider, ISP, server corresponding to a first Open API which is first-ranked in the invocation sequence of the plurality of APIs; sending the first invocation request to the determined ISP server; receiving a service page returned by the ISP server according to the first invocation request; embedding in the service page the invocation sequence of the plurality of Open APIs; sending the service page to the third party development server; receiving a second invocation request triggered by the user to invoke a second Open API which is after the first Open API according to the invocation sequence embedded in the service page; sending the second invocation request to an ISP server corresponding to the second Open API; receiving a service page from the ISP server corresponding to the second Open API according to the second invocation request; and sending the service page to the third party development server.