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Create a server-side “callback” endpoint: Set up a secure server-side endpoint in your application
to handle the exchange of authorization codes for access tokens.
This endpoint should be accessible only by your application’s backend to ensure the security of the process.
This endpoint will receive the authorization code as a query parameter from your frontend
and communicate with Chart’s API to obtain the access token. Example:
https://example.com/api/chart/callback
.You can reuse this same endpoint to support a Redirect Chart Connect flow as well. Just make sure to add the
redirect_uri
to the whitelist in your Chart Developer Dashboard. -
Exchange the authorization code for an access token: In your server-side code, make a POST request to the
/auth/token
endpoint. The request should include the following fields in the request body’s JSON payload:client_id
: Your unique client ID from the Chart developer dashboard.client_secret
: Your unique client secret from the Chart developer dashboard.code
: The authorization code obtained from Chart Connect in the Set Up Chart Connect.redirect_uri
(optional): If using the Redirect Chart Connect Flow, include theredirect_uri
. Not required for the Embedded Flow. This is the same redirect URI you used when setting up Chart Connect. If you using Embedded Flow, do not includeredirect_uri
in the payload.
Optional Header for Async Processing You can add the optionalToken exchange examplex-chart-async: "true"
header to prevent network timeouts during long document parsing operations:Token exchange with async headerWe recommend adding thex-chart-async: "true"
header to avoid network timeouts when parsing takes longer than expected.Important Caveat: When using thex-chart-async: "true"
header, the token exchange will return immediately after pulling documents from the provider, without waiting for parsing to complete. This means there’s no longer a guarantee that tax records are fully parsed when the API call ends.You must wait for thetaxpayer_status
to change toCOMPLETED
through webhooks before you can reliably access the parsed JSON data of the retrieved documents. -
Handle the response: Chart’s
/auth/token
endpoint will respond with a JSON object containing anaccess_token
if the request is successful. Parse the JSON response body and extract theaccess_token
. - Securely store the access token: It is critical to store access tokens securely, as they grant access to sensitive user data. Implement a secure storage solution to store access tokens, treating them with the same level of security as passwords. Do not log or expose access tokens to your frontend application. Storing access tokens is covered in more depth in Store Tokens.
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Handle errors: If the
/auth/token
endpoint returns an error, your server-side code should handle it gracefully. Common error scenarios include invalid or expired authorization codes, incorrect client IDs or secrets, or mismatched redirect URIs. Display a helpful error message to the user or retry the authentication flow as needed.
Checkpoint + Next Step
After completing this step, your application will be able to exchange
authorization codes for access tokens securely and automatically. You are
ready to use the access token to make API requests to Chart’s various
endpoints.