Adrian Tobey

Install this plugin to turn your WP installation into a proxy service to connect your WordPress plugins to Infusionsoft using their Oauth API. 
This plugin was created to create an Oauth connect for FormLift and is now being released for global use for other developers.
This plugin is only for developers who plan on distributing their own plugins among the WordPress community with the need of connecting those plugins via Oauth to Infusionsoft.
Because of the limitations of Oauth, a proxy server is needed to keep your Infusionsoft Developer App’s client_id and client_secret protected as you do not want to place those in your 
plugins files as that could create a massive breach of security, and Infusionsoft might revoke your developer priviledges.
So, follow the setup procedure on <a href="https://oauth.formlift.net" rel="nofollow ugc">This Page</a> to setup your plugin to use this plugin on your proxy site to connect to Infusiosnoft.
To see how to integrate this with your WordPress plugins, visit the plugin homepage at <a href="https://oauth.formlift.net" rel="nofollow ugc">oauth.formlift.net</a>.
<h3>Disclaimers</h3>
By using this plugin in conjuction with your own, you are required to tell your users the following in your reamdme.txt for compliance reasons in all parts of the world:
By using the Ouathentication method for [Your Plugin Here], you consent to anonymous API usage statatics being collected by infusionsoft for the following reasons. 
* To provide API usage information to help us create a better plugin. 
* To engage API throttling in the event too many API requests are made within a short period of time.
By using [Your Plugin Here] you also consent to the use of [Your Proxy Site] as a connection service between [Your Plugin Here] and Infusionsoft. We reserve the right 
to refuse any API authentication requests made and collect anonymous usage statistics.
However, any API requests made by [Your Plugin Here] will communicate directly with Infusionsoft and forgo [Your Proxy Site]. [Your Proxy Site] only acts as a communication 
service between [Your Plugin Here] and Infusionsoft during the initial Authentication procedure and subsequent refreshing of autentication tokens. No client information of any kind, such as names, email addresses, or phone numbers 
is ever sent through [Your Proxy Site].

Infusionsoft Proxy Service

This plugin is for Infusionsoft Wordpress plugin developers only. Setup your WordPress as a super fast Proxy service for your wordpress based Infusion …

Ryan Nevius

An add-on for Contact Form 7 (CF7) that provides a straightforward method to capture leads, tag customers, and send contact form data to InfusionSoft. Supports HTML5 input types.
NOTE: This plugin requires Contact Form 7 version 3.9 or later.
This plugin is not offered, sponsored, associated with or endorsed by Infusion Software, Inc.

Contact Form 7 – InfusionSoft Add-on

thank you

Plugin has really clean and easy to follow code, with helpful comments. It doesn't have certain referral tracking fields we needed to send to InfusionSoft, but adding them was incredibly easy because of how well written this plugin is.

Very Clean Code

An add-on for Contact Form 7 that provides a way to capture leads, tag customers, and send contact form data to InfusionSoft.

Infusionsoft Proxy Service vs Contact Form 7 – InfusionSoft Add-on