pip install https://github.com/sbook/flask-mongoengine/tarball/master

from flask import Flask
from flaskext.mongoengine import MongoEngine

app = Flask(__name__)
app.config.from_pyfile('the-config.cfg')
db = MongoEngine(app)

class Todo(db.Document):
    title = db.StringField(max_length=60)
    text = db.StringField()
    done = db.BooleanField(default=False)
    pub_date = db.DateTimeField(default=datetime.datetime.now)

    meta = dict(queryset_class=db.QuerySet)

# 404 if not exists
def view_todo(todo_id):
    todo = Todo.objects.get_or_404(_id=todo_id)
..

# Paginate through todo
def view_todos(page=1):
    page = Todo.objects.paginate(page=page, per_page=10)

{% macro render_pagination(pagination, endpoint) %}
  <div class=pagination>
  {%- for page in pagination.iter_pages() %}
    {% if page %}
      {% if page != pagination.page %}
        <a href="{{ url_for(endpoint, page=page) }}">{{ page }}</a>
      {% else %}
        <strong>{{ page }}</strong>
      {% endif %}
    {% else %}
      <span class=ellipsis>…</span>
    {% endif %}
  {%- endfor %}
  </div>
{% endmacro %}

from flaskext.mongoengine.wtf import model_form

class User(db.Document):
    email = db.StringField(required=True)
    first_name = db.StringField(max_length=50)
    last_name = db.StringField(max_length=50)

class Content(db.EmbeddedDocument):
    text = db.StringField()
    lang = db.StringField(max_length=3)

class Post(Document):
    title = db.StringField(max_length=120, required=True)
    author = db.ReferenceField(User)
    tags = db.ListField(StringField(max_length=30))
    content = db.EmbeddedDocumentField(Content)

PostForm = model_form(Post)

def add_post(request):
    form = PostForm(request.POST)
    if request.method == 'POST' and form.validate():
        # do something
        redirect('done')
    return render_response('add_post.html', form=form)