(PureBasic) Amazon SP-API Request an LWA access token

See more Amazon SP-API Examples

Request an LWA access token, make a secure HTTP POST to the LWA authentication server (https://api.amazon.com/auth/o2/token)

For more information, see https://developer-docs.amazon.com/sp-api/docs/connecting-to-the-selling-partner-api

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkHttpResponse.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkHttpRequest.pb"

Procedure ChilkatExample()

    ; This example assumes the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Implements the following CURL command:

    ; curl -X POST https://example.com/auth/o2/token \
    ;   -H "Host: api.amazon.com" \
    ;   -H "Content-Type: application/x-www-form-urlencoded;charset=UTF-8" \
    ;   -d "grant_type=refresh_token" \
    ;   -d "refresh_token=Aztr|..." \
    ;   -d "client_id=foodev" \
    ;   -d "client_secret=Y76SDl2F"

    ; Use the following online tool to generate HTTP code from a CURL command
    ; Convert a cURL Command to HTTP Source Code

    req.i = CkHttpRequest::ckCreate()
    If req.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpRequest::ckAddParam(req,"grant_type","refresh_token")
    CkHttpRequest::ckAddParam(req,"refresh_token","Aztr|...")
    CkHttpRequest::ckAddParam(req,"client_id","foodev")
    CkHttpRequest::ckAddParam(req,"client_secret","Y76SDl2F")

    CkHttpRequest::ckAddHeader(req,"Host","api.amazon.com")

    resp.i = CkHttp::ckPostUrlEncoded(http,"https://api.amazon.com/auth/o2/token",req)
    If CkHttp::ckLastMethodSuccess(http) = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        ProcedureReturn
    EndIf

    statusCode.i = CkHttpResponse::ckStatusCode(resp)
    Debug "Status Code = " + Str(statusCode)

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoad(json,CkHttpResponse::ckBodyStr(resp))
    CkHttpResponse::ckDispose(resp)

    CkJsonObject::setCkEmitCompact(json, 0)
    Debug CkJsonObject::ckEmit(json)

    If statusCode <> 200
        Debug "Failed."
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkJsonObject::ckDispose(json)
        ProcedureReturn
    EndIf

    ; Success returns this JSON:

    ; {
    ;   "access_token": "Atza|...",
    ;   "refresh_token": "Atzr|...",
    ;   "token_type": "bearer",
    ;   "expires_in": 3600
    ; }

    ; Save the JSON token to a file for use in subsequent calls.
    ; (this example is passing a relative file path.  You don't need to save to a file
    ; if, for example, you keep the access token in-memory for subsequent use...)
    success.i = CkJsonObject::ckWriteFile(json,"qa_data/tokens/sp_api_lwa_token.json")

    Debug "access_token: " + CkJsonObject::ckStringOf(json,"access_token")
    Debug "Success."


    CkHttp::ckDispose(http)
    CkHttpRequest::ckDispose(req)
    CkJsonObject::ckDispose(json)


    ProcedureReturn
EndProcedure