How can I set a cookie in a request using Fiddler?

Question

I need to set a cookie before I issue a request to a Web site using Fiddler. How do I do this?

Answer 1

When running Fiddler as a reverse Proxy you can modify the response headers via FiddlerScript by adding a line in the OnBeforeResponse method:

static function OnBeforeResponse(oSession: Session) {
    // ...
    oSession.oResponse["Set-Cookie"] = "sessionToken=abc123; Expires=Wed, 09 Jun 2021 10:18:14 GMT";
}

Also check Fiddler docs about Modifying a Request or Response for more info.