How to get the Domino username of an App viewer


Domino passes the username of a user accessing your Domino App in an HTTP header named domino-username.

If your App framework gives you access to the HTTP headers of the active request, you can retrieve the username for use by your App code. If you allow users who are not logged in to Domino to view your Apps, for their requests to the App the value of the domino-username header will be “Anonymous.”


An App framework that can access proxied HTTP headers. This is
supported by Flask and Dash by default, but is


Consider this simple Flask example where you have the following files in your project.

An script that starts your app code listening on the correct port.

#!/usr/bin/env bash
export LC_ALL=C.UTF-8
export LANG=C.UTF-8
export FLASK_DEBUG=1
python -m flask run --host= --port=8888

A simple file that renders a template named index.html. Note that this app imports request from flask, which gives you access to the headers of the active HTTP request.

import flask
from flask import request, redirect, url_for

class ReverseProxied(object):
  def __init__(self, app): = app
  def __call__(self, environ, start_response):
      script_name = environ.get('HTTP_X_SCRIPT_NAME', '')
      if script_name:
          environ['SCRIPT_NAME'] = script_name
          path_info = environ['PATH_INFO']
          if path_info.startswith(script_name):
              environ['PATH_INFO'] = path_info[len(script_name):]
      return, start_response)

app = flask.Flask(__name__)
app.wsgi_app = ReverseProxied(app.wsgi_app)

# Homepage which uses a template file
def index_page():
  return flask.render_template("index.html")

A template file at templates/index.html that fetches the domino-username header from the requests object and renders it.

<!DOCTYPE html>
    <h1>Your username is {{ request.headers.get("domino-username") }}</h1>

If you host this App in Domino and open it, you’ll see something like the following, where the username shown will match the username of the user viewing the App.