(Swift 3,4,5...) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    let http = CkoHttp()!

    // 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

    let req = CkoHttpRequest()!
    req.addParam("grant_type", value: "refresh_token")
    req.addParam("refresh_token", value: "Aztr|...")
    req.addParam("client_id", value: "foodev")
    req.addParam("client_secret", value: "Y76SDl2F")

    req.addHeader("Host", value: "api.amazon.com")

    var resp: CkoHttpResponse? = http.postUrlEncoded("https://api.amazon.com/auth/o2/token", req: req)
    if http.lastMethodSuccess == false {
        print("\(http.lastErrorText!)")
        return
    }

    var statusCode: Int = resp!.statusCode.intValue
    print("Status Code = \(statusCode)")

    let json = CkoJsonObject()!
    json.load(resp!.bodyStr)
    resp = nil

    json.emitCompact = false
    print("\(json.emit()!)")

    if statusCode != 200 {
        print("Failed.")
        return
    }

    // 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...)
    var success: Bool = json.writeFile("qa_data/tokens/sp_api_lwa_token.json")

    print("access_token: \(json.string(of: "access_token")!)")
    print("Success.")

}