Use webhooks
Webhooks notify your service when videos successfully finish processing and are ready to stream or if your video enters an error state.
Subscribe to webhook notifications
To subscribe to receive webhook notifications on your service or modify an existing subscription, you will need a Cloudflare API token.
The webhook notification URL must include the protocol. Only http://
or https://
is supported.
curl -X PUT --header 'Authorization: Bearer <API_TOKEN>' \https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/stream/webhook \
--data '{"notificationUrl":"<WEBHOOK_NOTIFICATION_URL>"}'
Example response{ "result": { "notificationUrl": "http://www.your-service-webhook-handler.com", "modified": "2019-01-01T01:02:21.076571Z" "secret": "85011ed3a913c6ad5f9cf6c5573cc0a7" }, "success": true, "errors": [], "messages": []
}
Notifications
When a video on your account finishes processing, you will receive a POST
request notification with information about the video.
Note the status
field indicates whether the video processing finished successfully.
Example POST request body sent in response to successful encoding{ "uid": "dd5d531a12de0c724bd1275a3b2bc9c6", "readyToStream": true, "status": { "state": "ready" }, "meta": {}, "created": "2019-01-01T01:00:00.474936Z", "modified": "2019-01-01T01:02:21.076571Z", // ... }
When a video is done processing, the state
field returns a ready
state. Videos may sometimes return the state
field as ready
and an additional pctComplete
state that is not 100, which means higher quality renditions are still processing. When pctComplete
reaches 100, all quality resolutions are available for the video.
Error codes
If a video could not process successfully, the state
field returns error
, and the errReasonCode
returns one of the values listed below.
ERR_NON_VIDEO
– The upload is not a video.ERR_DURATION_EXCEED_CONSTRAINT
– The video duration exceeds the constraints defined in the direct creator upload.ERR_FETCH_ORIGIN_ERROR
– The video failed to download from the URL.ERR_MALFORMED_VIDEO
– The video is a valid file but contains corrupt data that cannot be recovered.ERR_DURATION_TOO_SHORT
– The video’s duration is shorter than 0.1 seconds.ERR_UNKNOWN
– If Stream cannot automatically determine why the video returned an error, theERR_UNKNOWN
code will be used.
In addition to the state
field, a video’s readyToStream
field must also be true
for a video to play.
Example error response{ "readyToStream": true, "status": { "state": "error", "step": "encoding", "pctComplete": "39", "errReasonCode": "ERR_MALFORMED_VIDEO", "errReasonText": "The video was deemed to be corrupted or malformed.", }
}
Example: POST body for successful video encoding
{ "uid": "b236bde30eb07b9d01318940e5fc3eda", "creator": null, "thumbnail": "https://customer-m033z5x00ks6nunl.cloudflarestream.com/b236bde30eb07b9d01318940e5fc3eda/thumbnails/thumbnail.jpg", "thumbnailTimestampPct": 0, "readyToStream": true, "status": { "state": "ready", "pctComplete": "39.000000", "errorReasonCode": "", "errorReasonText": "" }, "meta": { "filename": "small.mp4", "filetype": "video/mp4", "name": "small.mp4", "relativePath": "null", "type": "video/mp4" }, "created": "2022-06-30T17:53:12.512033Z", "modified": "2022-06-30T17:53:21.774299Z", "size": 383631, "preview": "https://customer-m033z5x00ks6nunl.cloudflarestream.com/b236bde30eb07b9d01318940e5fc3eda/watch", "allowedOrigins": [], "requireSignedURLs": false, "uploaded": "2022-06-30T17:53:12.511981Z", "uploadExpiry": "2022-07-01T17:53:12.511973Z", "maxSizeBytes": null, "maxDurationSeconds": null, "duration": 5.5, "input": { "width": 560, "height": 320 }, "playback": { "hls": "https://customer-m033z5x00ks6nunl.cloudflarestream.com/b236bde30eb07b9d01318940e5fc3eda/manifest/video.m3u8", "dash": "https://customer-m033z5x00ks6nunl.cloudflarestream.com/b236bde30eb07b9d01318940e5fc3eda/manifest/video.mpd" }, "watermark": null
}
Verify webhook authenticity
Cloudflare Stream will sign the webhook requests sent to your notification URLs and include the signature of each request in the Webhook-Signature
HTTP header. This allows your application to verify the webhook requests are sent by Stream.
To verify a signature, you need to retrieve your webhook signing secret. This value is returned in the API response when you create or retrieve the webhook.
To verify the signature, get the value of the Webhook-Signature
header, which will look similar to the example below.
Webhook-Signature: time=1230811200,sig1=60493ec9388b44585a29543bcf0de62e377d4da393246a8b1c901d0e3e672404
1. Parse the signature
Retrieve the Webhook-Signature
header from the webhook request and split the string using the ,
character.
Split each value again using the =
character.
The value for time
is the current UNIX time when the server sent the request. sig1
is the signature of the request body.
At this point, you should discard requests with timestamps that are too old for your application.
2. Create the signature source string
Prepare the signature source string and concatenate the following strings:
- Value of the
time
field e.g.1230811200
- Character
.
- Webhook request body (complete with newline characters, if applicable)
Every byte in the request body must remain unaltered for successful signature verification.
3. Create the expected signature
Compute an HMAC with the SHA256 function (HMAC-SHA256) using your webhook secret and the source string from step 2. This step depends on the programming language used by your application.
Cloudflare’s signature will be encoded to hex.
4. Compare expected and actual signatures
Compare the signature in the request header to the expected signature. Preferably, use a constant-time comparison function to compare the signatures.
If the signatures match, you can trust that Cloudflare sent the webhook.
Limitations
- Webhooks will only be sent after video processing is complete, and the body will indicate whether the video processing succeeded or failed.
- Only one webhook subscription is allowed per-account.
Examples
Golang
Using crypto/hmac:
package main
import ( "crypto/hmac" "crypto/sha256" "encoding/hex" "log"
)
func main() { secret := []byte("secret from the Cloudflare API") message := []byte("string from step 2")
hash := hmac.New(sha256.New, secret) hash.Write(message)
hashToCheck := hex.EncodeToString(hash.Sum(nil))
log.Println(hashToCheck)
}
Node.js
var crypto = require('crypto');
var key = 'secret from the Cloudflare API'; var message = 'string from step 2';
var hash = crypto.createHmac('sha256', key).update(message);
hash.digest('hex');
Ruby
require 'openssl'
key = 'secret from the Cloudflare API' message = 'string from step 2'
OpenSSL::HMAC.hexdigest('sha256', key, message)
In JavaScript (for example, to use in Cloudflare Workers)
const key = 'secret from the Cloudflare API'; const message = 'string from step 2';
const getUtf8Bytes = str => new Uint8Array( [...unescape(encodeURIComponent(str))].map(c => c.charCodeAt(0)) );
const keyBytes = getUtf8Bytes(key); const messageBytes = getUtf8Bytes(message);
const cryptoKey = await crypto.subtle.importKey( 'raw', keyBytes, { name: 'HMAC', hash: 'SHA-256' }, true, ['sign'] ); const sig = await crypto.subtle.sign('HMAC', cryptoKey, messageBytes);
[...new Uint8Array(sig)].map(b => b.toString(16).padStart(2, '0')).join('');