# Xero Migration Guide

## Upgrading to 2.0.0

You can now choose your preferred xero authentication method. You can choose between `client_credentials` and `bearer_token` authentication methods.

For the bearer strategy, please visit the [pkce-flow documentation](https://developer.xero.com/documentation/guides/oauth2/pkce-flow) for more detailed information about how to get access token.
For the client_credentials strategy, please visit the [client-credentials-flow documentation](https://developer.xero.com/documentation/guides/oauth2/custom-connections) for more detailed information about how to set the authentication flow. 

### Using postman to get access token 
- Move to Authorization tab of an empty http request and selected Oauth 2.0
- Set use token type as `access token`
- Set header prefix as `Bearer`
- Set grant type as `Authorization code`
- Check `Authorize using browser`
- Set Auth URL as `https://login.xero.com/identity/connect/authorize`
- Set Access token URL as `https://identity.xero.com/connect/token`
- Set Client ID, Client secret, Scope defined as your Xero settings
- Set state as any number Eg: `123`
- Set Client Authentication as `Send as Basic Auth Header`
  Click `Get New Access Token` for retrieving access token

Then authorize your source with the required information. 
1. Go to set up `The Source` page.
2. Enter your Xero application's access token or Client ID and Client Secret.
3. Click `Reset saved source` button.


## Upgrading to 1.0.0

The authentication schema is now using `access_token` instead of Oauth 2.0. Visit the Xero documentation - https://developer.xero.com/documentation/guides/oauth2/pkce-flow for more detailed information about how to get access token.
Optionally, you may get your access_token via Postman:
- Move to Authorization tab of an empty http request and selected Oauth 2.0
- Set use token type as `access token`
- Set header prefix as `Bearer`
- Set grant type as `Authorization code`
- Check `Authorize using browser`
- Set Auth URL as `https://login.xero.com/identity/connect/authorize`
- Set Access token URL as `https://identity.xero.com/connect/token`
- Set Client ID, Client secret, Scope defined as your Xero settings
- Set state as any number Eg: `123`
- Set Client Authentication as `Send as Basic Auth Header`
Click `Get New Access Token` for retrieving access token

Then authorize your source with `access_token`.
1. Go to set up `The Source` page.
2. Enter your Xero application's access token.
3. Click `Reset saved source` button. 


As Xero API now only supports date-precision, instead of second precision filtering through If-Modified-Since header, reads are now streamlined to incremental through client side.