Webhooks

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Introduction

When using API endpoints you only get data back when you make a call. This is great for when you want to know the current state of something now, but it’s not ideal for when you want to know when something changes in the future.

Webhooks are a way to receive real-time updates from Runa whenever something changes the moment it happens.

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Receiving webhooks

At their core webhooks are just a POST request to a URL you provide; a bit like a reverse API call. Normally you would provision an endpoint specifically for receiving Runa webhooks.

Your endpoint should return a 200 status code to indicate that the webhook was received and processed successfully.

As your webhook endpoint will be accessible from the internet, you should verify that each request is coming from Runa.

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Webhook events

We currently support the following webhook events:

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Adding an endpoint

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Testing your endpoint

You can send simulated events to your endpoint to verify your handler is working as expected. In the webhook portal select the endpoint you want to test and select the Testing tab.

Choose the event type you want to test and click the Send Example button. After the event is sent you will see a record in the Message Attempts table. Click into the record to see details.

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Securing your endpoint

As your endpoint for receiving webhooks will be accessible from the internet, you should secure it to ensure only events from Runa are accepted.

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Signature verification

Every event we send is signed with a signature. You can verify the signature by checking the svix-signature header in the request. Our webhook partner Svix offers a set of useful libraries that make verifying webhooks very simple. Here is an example using Javascript:

import { Webhook } from "svix";

const secret = "whsec_MfKQ9r8GKYqrTwjUPD8ILPZIo2LaLaSw";

// These were all sent from the server
const headers = {
  "svix-id": "msg_p5jXN8AQM9LWM0D4loKWxJek",
  "svix-timestamp": "1614265330",
  "svix-signature": "v1,g0hM9SsE+OTPJTGt/tmIKtSyZlE3uFJELVlNIOLJ1OE=",
};
const payload = '{"test": 2432232314}';

const wh = new Webhook(secret);
// Throws on error, returns the verified content on success
const payload = wh.verify(payload, headers);

For more information, including support for other languages, see the webhook verification documentation on Svix’s website.

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IP allowlisting

In case your webhook receiving endpoint is behind a firewall or NAT, you may need to allow traffic from Svix’s IP addresses.

This is the full list of IP addresses that webhooks may originate from:

52.215.16.239
54.216.8.72
63.33.109.123

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Failure handling

If we are unable to deliver a webhook to your endpoint, we will retry several times before giving up. If all attempts to a specific endpoint fail for a period of 5 days, the endpoint will be disabled.

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Retrying failed deliveries

Svix attempts to deliver each webhook message based on a retry schedule with exponential backoff. Each message is attempted based on the following schedule, where each period is started following the failure of the preceding attempt:

• Immediately
• 5 seconds
• 5 minutes
• 30 minutes
• 2 hours
• 5 hours
• 10 hours
• 10 hours (in addition to the previous)

For example, an attempt that fails four times before eventually succeeding will be delivered roughly 35 minutes and 5 seconds following the first attempt.

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Manual retries

You can also use the application portal to manually retry each message at any time, or automatically retry all failed messages starting from a given date.

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Failure recovery

If all attempts to a specific endpoint fail for a period of 5 days, the endpoint will be disabled. To re-enable a disabled endpoint, go to the webhook dashboard, find the endpoint from the list and select “Enable Endpoint”.

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Recovering/Resending failed messages

If your service has had downtime or was misconfigured you may have missed some messages. You can resend specific messages or resend all failed messages starting from a given date.

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Resending a single message

If you want to replay a single event, you can find the message from the UI and click the options menu next to any of the attempts.

From there, click “resend” to have the same message send to your endpoint again.

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Resending all failed messages

If you need to recover from a service outage and want to replay all the failed messages since a given time, you can do so from the Endpoint page. On an endpoint’s details page, click Options > Recover Failed Messages.

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Troubleshooting

There are some common reasons why your webhook endpoint is not working as expected.

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Not using the raw payload body when verifying the signature

This is the most common issue. When generating the signed content, we use the raw string body of the message payload.

If you convert JSON payloads into strings using methods like stringify, different implementations may produce different string representations of the JSON object, which can lead to discrepancies when verifying the signature. It’s crucial to verify the payload exactly as it was sent, byte-for-byte or string-for-string, to ensure accurate verification.

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Sending a non 2xx response

When we receive a response with a 2xx status code, we interpret that as a successful delivery even if you indicate a failure in the response payload. Make sure to use the right response status codes so we know when message are supposed to succeed vs fail.

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Responses timing out

If a message delivery attempt takes longer than 15 seconds to get a 2xx response, we will consider it a failed delivery.

If your endpoint needs to complete complex work we suggest you simply receive the message and add it to a queue to be processed asynchronously.