There are two possiable reasons for why your Function has completed with the error: 'runtime application timed out'.
The most common reason is that your Function has exceeded the 5 second execution time limit. You can determine this by looking at the execution logs on the Function instance page. The last log line after execution will tell you how many milliseconds the Function took to execute. If the processing time is greater than 5,000 milliseconds then your Function was terminated by Twilio.
The other more subtle reason your Function ended with an application timeout is because of an incorrect invocation of callback(). If the callback() method is not being called or is unreachable your Function will continue executing until it reaches the timelimit and ultimately fail. The Function Execution documentation provides extensive details on the funcitonality and usage of the callback() method. Below are several examples of how to correctly use callback() to complete execution and emit a response.
exports.handler = function(context, event, callback) {
// Fetch already initialized Twilio REST client
const twilioClient = context.getTwilioClient();
twilioClient.messages.create({
from: from,
to: to,
body: 'create using callback'
}, function(err, result) {
console.log('Created message using callback');
console.log(result.sid);
callback();
});
}
The most common reason we have seen that a Function appears not to run is misue of callback(). If the callback() method is not being called or is unreachable your Function will continue executing until it reaches the timelimit and ultimately fail. This makes it appear as if your Function is not executing because there is no response emitted. The Function Execution documentation provides extensive details on the funcitonality and usage of the callback() method. Below are several examples of how to correctly use callback() to complete execution and emit a response.
exports.handler = function(context, event, callback) {
// Providing neither error or response will result in a 200 OK
callback();
}
You can generate Voice TwiML using the Twilio Node library which comes packaged within your Function.
exports.handler = function(context, event, callback) {
const twiml = new Twilio.twiml.VoiceResponse()
twiml.dial().sip("sip:jack@example.com")
callback(null, twiml);
}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Dial>
<Sip>sip:jack@example.com</Sip>
</Dial
</Response>
You can generate Messaging TwiML using the Twilio Node library which comes packaged within your Function.
exports.handler = function(context, event, callback) {
const twiml = new Twilio.twiml.MessagingResponse();
twiml.message('The Robots are coming! Head for the hills!');
callback(null, twiml);
}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Message>The Robots are coming! Head for the hills!</Message>
</Response>
Simply return your object as outlined in the Function Execution documentation.
exports.handler = function(context, event, callback) {
// Construct an Object
let responseObject = { "result": "winner winner!" };
// Twilio Functions will detect an object, serialize to JSON and set the content-type header to application/json automatically
callback(null, responseObject);
}
You can send CORS headers by using the Twilio Response object described in the Function Execution documentation.
exports.handler = function(context, event, callback) {
let response = new Twilio.Response();
// Build list of headers
let headers = {
"Access-Control-Allow-Origin": "example.com",
"Access-Control-Allow-Methods": "GET,PUT,POST,DELETE",
"Access-Control-Allow-Headers": "Content-Type"
};
// Set headers in response
response.setHeaders(headers);
callback(null, response);
}
Not yet, currently, Functions and Assets can only be accessed through the Twilio Console. But keep and eye on this space for updates. Please reach out to us via support or our Google Group to express interest in this feature.
Not today, currently, Functions are event driven and can only be invoked by HTTP.
Absolutely! In addition to our Programmable SMS and Programmable Voice quickstarts, you can find a variety of templates within our catalogue within the Create Function page.
During the beta period, we currently have a limit of 50 functions per account.
We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd browsing the Twilio tag on Stack Overflow.
exports.handler = function(context, event, callback) {
// Fetch already initialized Twilio REST client
const twilioClient = context.getTwilioClient();
twilioClient.messages.create({
from: from,
to: to,
body: 'create using callback'
}, function(err, result) {
console.log('Created message using callback');
console.log(result.sid);
callback();
});
}
exports.handler = function(context, event, callback) {
// Providing neither error or response will result in a 200 OK
callback();
}
exports.handler = function(context, event, callback) {
const twiml = new Twilio.twiml.VoiceResponse()
twiml.dial().sip("sip:jack@example.com")
callback(null, twiml);
}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Dial>
<Sip>sip:jack@example.com</Sip>
</Dial
</Response>
exports.handler = function(context, event, callback) {
const twiml = new Twilio.twiml.MessagingResponse();
twiml.message('The Robots are coming! Head for the hills!');
callback(null, twiml);
}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Message>The Robots are coming! Head for the hills!</Message>
</Response>
exports.handler = function(context, event, callback) {
// Construct an Object
let responseObject = { "result": "winner winner!" };
// Twilio Functions will detect an object, serialize to JSON and set the content-type header to application/json automatically
callback(null, responseObject);
}
exports.handler = function(context, event, callback) {
let response = new Twilio.Response();
// Build list of headers
let headers = {
"Access-Control-Allow-Origin": "example.com",
"Access-Control-Allow-Methods": "GET,PUT,POST,DELETE",
"Access-Control-Allow-Headers": "Content-Type"
};
// Set headers in response
response.setHeaders(headers);
callback(null, response);
}