Home > Uncategorized > Return Asynchronous responses from #dialogflow-fulfillment

Return Asynchronous responses from #dialogflow-fulfillment


If you are writing a Dialogflow webhook in node, you’re probably using dialogflow-fulfillment , and if you’re reading this post, you’ve run into the issue where DialogFlow is not returning properly when you carry out an asynchronous call.

Let’s see a typical syncronous case first;

intentMap.set(‘Default Welcome Intent’, welcome);


function welcome(agent) {

Which returns Welcome, when the Default Welcome Intent is fired.

In this next typical use case, where I want to record failed queries, i.e. queries that trigger the fallback intent in a database. The Database is asyncronous, so it will fire a callback once the data is stored.

intentMap.set(‘Default Fallback Intent’, fallback);


function fallback(agent) {
database.recordFailure(request.body.queryResult.queryText, function(text)
agent.add(“Sorry, I couldn’t help you”);

Now, if you run this with the fallback intent, then you may notice that the data is stored in the database, but you get an error response back, rather than the “Sorry, I couldn’t help you” message

The trick is, to wrap the function in a promise like so;

function fallback(agent) {
return new Promise ( (resolve, reject) => {
database.recordFailure(request.body.queryResult.queryText, function(text)
return resolve();

And call resolve() once you’re ready to reply to the user.

Categories: Uncategorized
  1. Yamini
    July 24, 2019 at 12:06 pm

    Hi, I am trying to do similar thing in a setTimeOut within promise, want to trigger a custom event once the time is complete. console.log works but event is not triggered. Please help.

    Below is the code snippet:
    function payment(agent){
    const delay = t => new Promise(resolve => setTimeout(resolve, t));
    return delay(5000).then(() => {console.log(‘Hello’);


    • Abhishek
      April 24, 2020 at 6:52 am

      Hey Have you resolve this ?
      can you let me know if this is possible delay in dialogflow response


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