Chart API Implementation Guide

Chart’s developer-friendly Unified Tax API makes implementation simple and straightforward.

1. Sign up for a free account to receive credentials and pilot how Chart works.
2. Integrate Chart Connect into your frontend. (Chart Connect is the user inferface that allows your customers to safely and securely grant your application access to their tax systems.) You can opt to redirect to Chart Connect or embed it directly into your application.
3. Integrate the Chart API into your application’s backend.
4. Secure your application to maintain a smooth user experience that is both efficient and protected while using Chart.
5. Once your integration has been tested thoroughly, go live with all of your customers.

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Frontend + Backend

In a full implementation, Chart requires both a frontend and a backend application to exist. The frontend application coordinates connecting to tax systems, and the backend server securely manages the requests and responses to and from Chart APIs.

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Frontend User Interface

Before being able to pull data from a tax provider through Chart, your customer needs to consent to the data being transferred. Without consent, Chart is not authorized to pull the data on behalf of the customer. Chart Connect is our user-facing product to help you obtain customer consent, and it is a prerequisite step before calling Chart APIs.

There are two ways to integrate Chart Connect into your application’s frontend user interface.

1. Your application can embed Chart Connect using our various frontend SDKs. Embedding Chart Connect allows your customer to remain on your application’s domain during the entire connection process.
2. Your application can redirect to Chart Connect from the customer’s browser. In this case, Chart Connect is securely hosted by Chart on https://connect.trychartapi.com instead of your application. After completion, they will be redirected to a URI that you specify.

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Backend Security

Chart takes security seriously, so we require a backend server to manage all requests and responses to and from Chart APIs. Once the connection has been created via Chart Connect, you can obtain an access_token which will be used to call the Chart APIs.

We require a backend for several reasons:

1. Since the data from tax data providers is sensitive, making API requests from the backend and storing that data on the backend reduces the likelihood of this data being exposed to malicious persons.
2. Exchanging the authorization code for an access_token should always take place in your backend to ensure your client_secret and access_token are never publicly exposed.
3. Likewise, your backend should always store the access token in a secure database and should never return the access token to the frontend application.