Screen Recording S3 Export Failing with 403 on PutObject via EventBridge Trigger

General Discussion
1

The screen recording archival pipeline is dropping half the sessions before they hit the S3 bucket. Configured the export in the admin console under Recordings > Settings, but the EventBridge rule only fires for the initial handshake, not the actual media stream. Lambda Data Action returns a 403 Access Denied on PutObject, even though the execution role has S3:PutObject and S3:ListBucket attached. Checked the policy ARN three times. It’s valid.

Console logs show the webhook hitting the trigger endpoint, then timing out. The GC UI says the recording is processing, but the S3 inventory stays empty. Tried adjusting the retention policy and toggling the secure storage flag, doing jack all. The CloudFormation stack for the receiving endpoint looks clean.

Type: AWS::Lambda::Function
Properties:
 FunctionName: gc-screen-ingest
 Handler: index.handler
 Runtime: nodejs18.x
 Role: !GetAtt IngestExecutionRole.Arn
 Environment:
 Variables:
 BUCKET_NAME: prod-gc-captures

The payload structure seems off. EventBridge is passing a recordingId but the Lambda expects a captureSessionUUID. Don’t know if that’s a GC naming mismatch or just how the integration maps the fields. CloudWatch shows the function starting, then aborting after 2.1 seconds.

{"timestamp": "2024-05-18T14:22:01Z", "status": "FAILURE", "error": "Timeout waiting for media chunk", "traceId": "req-88a2c...

Network traces indicate the request leaves the VPC via the NAT gateway, hits the GC edge, and never completes the multipart upload. The admin console mentions a manifest file, but nothing about chunk boundaries or how the screen capture sessions actually serialize.

2
  • The Lambda is probably choking on the bearer token scope rather than the IAM role itself. The documentation states “Export jobs require a valid bearer token with recordings:export and analytics:export scopes.” You mentioned the policy ARN checks out, but if the Data Action is reusing a cached session token, it’s definitely missing those specific scopes. Try spinning up a fresh client credentials token right before the export call.
  • Run this against the auth endpoint to verify the scope injection:
curl -X POST "https://api.mypurecloud.com/api/v2/oauth/token" \
 -H "Content-Type: application/x-www-form-urlencoded" \
 -d "grant_type=client_credentials&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET&scope=recordings:export analytics:export"
  • Feed that access_token into your Lambda environment variable and pass it to the export job creator. The payload structure has to match exactly what the endpoint expects, otherwise the gateway drops it before it even reaches S3. The docs note “Export configurations must include a valid destinationArn and a matching recordingType filter.”
{
 "destinationArn": "arn:aws:s3:::your-bucket/path/prefix",
 "recordingType": "screen",
 "enabled": true,
 "filters": {
 "type": "screen"
 }
}
  • You can see the JSON aligns with the schema, yet the 403s keep popping up on the PutObject step. Why does the EventBridge trigger only catch the handshake and skip the actual media stream chunks? The token rotation mid-sync usually breaks the chain if the Lambda isn’t refreshing it every fifteen minutes. Token drift is a real pain. Check your secret manager rotation schedule. The expiration window is probably misaligned.