How to refresh access token with custom connector (OAuth2)?

Hi ArvindBhatt  - Power BI does not automatically refresh access tokens for custom connectors. You must handle token refreshing manually within your custom connector.

Below is an example pattern for refreshing an access token:

RefreshToken = () =>
let
Response = Web.Contents("https://api.example.com/token", [
Content = Text.ToBinary("grant_type=refresh_token&refresh_token=" & RefreshToken),
Headers = [
#"Content-Type" = "application/x-www-form-urlencoded",
#"Authorization" = "Basic " & Base64EncodedClientCredentials
]
]),
ParsedResponse = Json.Document(Response),
NewAccessToken = ParsedResponse[access_token],
NewExpirationTime = DateTimeZone.UtcNow + #duration(0, 0, 0, ParsedResponse[expires_in])
in
[Token = NewAccessToken, Expiration = NewExpirationTime];

Handling authentication for Power Query connectors - Power Query | Microsoft Learn

Custom Connector with Token Refresh - Microsoft Fabric Community

Hi ArvindBhatt , thank you for reaching out to the Microsoft Fabric Community Forum.

Yes as rajendraongole1 said Power BI does not automatically refresh the access token once it expires. You will need to manually refresh the token before making API calls. Here's how you can do it:

1. When the user logs in, save the refresh token provided by the API.
2. Use the refresh token to request a new access token. This request should be sent to the API's token endpoint using the POST method.
3. Replace the old access token with the new one received from the API.

Example in M code:

let

    refreshToken = "your_refresh_token_here",

    clientId = "your_client_id_here",

    clientSecret = "your_client_secret_here",

    tokenEndpoint = "https://api.example.com/oauth2/token",

    body = "grant_type=refresh_token&refresh_token=" & refreshToken & "&client_id=" & clientId & "&client_secret=" & clientSecret,

    response = Web.Contents(tokenEndpoint, [Headers=[#"Content-Type"="application/x-www-form-urlencoded"], Content=Text.ToBinary(body)]),

    newAccessToken = response[access_token]

in

    newAccessToken

If this helps, please consider marking it 'Accept as Solution' so others with similar queries may find it more easily. If not, please share the details.
Thank you.

Hi v-hashadapu rajendraongole1 
I tried generating new access token from the refresh token but issue with that is i am not able to save the new access token as Credentials so that i can use the new access token instead generating it everytime.
There is no method in power query which saves the new credentials.
Also one more question when the access token or refresh token gets expired it does not ask me for re-authentication. powerbi keeps on using old token.

shared GetValidToken = () =>
    let
        // Fetch the stored credentials from Power BI
        tokens = Extension.CurrentCredential(),
        accessToken = tokens[access_token],
        refreshToken = tokens[refresh_token],
        expiresAtText = tokens[expires],
        // expiration time (text format)
        // Convert expiration time from Text to DateTime
        expiresAt = DateTime.FromText(expiresAtText),
        // Get the current time
        currentTime = DateTime.LocalNow(),
        // Check if the token has expired
        isTokenExpired = expiresAt <= currentTime,

        // If expired, refresh the token
        newTokens =
            if isTokenExpired then
                let
                    // Call the refresh token method to get a new access token
                    refreshedTokens = TokenMethod("refresh_token", refreshToken),
                    // "dan" is placeholder for code_verifier
                    newAccessToken = refreshedTokens[access_token],
                    // New access token
                    newRefreshToken = refreshedTokens[refresh_token],
                    // New refresh token
                    newExpiresAt = refreshedTokens[expires]
                    // New expiration time
                    // Store the new tokens in Power BI credentials
                in
                    Extension.CurrentCredential(
                        [
                            access_token = newAccessToken,
                            refresh_token = newRefreshToken,
                            expires = newExpiresAt
                        ]
                    )
            else
                tokens,
        // Return the existing tokens if not expired
        // Return the valid access token
        validAccessToken = newTokens[access_token]
    in
        validAccessToken;

Hi ArvindBhatt , Hope your issue is solved. If it is, please consider marking it 'Accept as solution', so others with similar issues may find it easily. If it isn't, please share the details. Thank you.

Hi ArvindBhatt , Hope your issue is solved. If it is, please consider marking the answer 'Accept as solution', so others with similar issues may find it easily. If it isn't, please share the details. Thank you.

Hi @ArvindBhatt , Hope your issue is solved. If it is, please consider marking the answer 'Accept as solution', so others with similar issues may find it easily. If it isn't, please share the details.
Thank you.