Power BI custom connector Token exchange in header

Hi joseph_singh_fr ,

Instead of “hardcoding” user name and password and then using Anonymous authentication, you should have your connector obtain the credentials at run‐time (from the data source settings) and then perform the token exchange in M. First create the function below to obtain the credentials that the user has supplied and then calls the token endpoint by sending a proper header:

GetFinalToken = (Server as text, SpiderApiInstance as text) as text =>
  let
    // Get the credentials from the data source settings.
    // When using “Basic” authentication, Extension.CurrentCredential() returns a record with Username and Password.
    Credentials = Extension.CurrentCredential(),

    // Extract username and password
    Username = Credentials[Username],
    Password = Credentials[Password],

    // Create base64-encoded Basic header (make sure to choose Base64 encoding)
    BasicToken = "Basic " & Binary.ToText(Text.ToBinary(Username & ":" & Password), BinaryEncoding.Base64),

    // build the URL to the token endpoint; note: do not embed credentials in the URL
    TokenUrl = "https://" & Server & "/" & SpiderApiInstance & "/token",

    // Make the call to the token endpoint.
    // Notice that we include a set of headers (including our Auth header) for our token request.
    TokenResponse = Web.Contents(TokenUrl, [
         Headers = [
            #"Content-Type" = "application/json",
            #"Authorization" = BasicToken,
            #"Accept" = "application/json",
            #"Cache-Control" = "no-cache"
         ]
    ]),

    // Extract the metadata headers which include the final token.
    ResponseHeaders = Value.Metadata(TokenResponse)[Headers],
    FinalToken = ResponseHeaders[Token]
  in
    FinalToken;

Then in the main query function call GetFinalToken to obtain the token and use it for subsequent calls:

MyAPIQuery = (Server as text, SpiderApiInstance as text, resourcePath as text) as any =>
  let
    // Get the final token using the helper function.
    FinalToken = GetFinalToken(Server, SpiderApiInstance),
    
    // Now build the header that will be passed when calling the secured resource.
    AuthTokenHeader = "Bearer " & FinalToken,
    
    ResourceUrl = "https://" & Server & "/" & SpiderApiInstance & "/" & resourcePath,
    
    // Make the secured call with the token in the header.
    Response = Web.Contents(ResourceUrl, [
         Headers = [
            #"Content-Type" = "application/json",
            #"Accept" = "application/json",
            #"Authorization" = AuthTokenHeader
         ]
    ]),
    Result = Json.Document(Response)
  in
    Result;

Best Regards