How to integrate CloudWatch with Asayer and see backend errors alongside session replays.

1. Create a Service Account

  1. Login to your AWS account.
  2. Go to IAM dashboard.
  3. Click on Users.
  4. Click on Add user button.
  5. Set the name to "asayer_cw".
  6. In access type, select Programmatic access.
  7. Click on Next: Permissions button.
  8. Choose Attach existing policies directly
  9. In the list of permissions, choose CloudWatchReadOnlyAccess.
  10. Click Next: Tags button.
  11. Click Next: Review button.
  12. Click Create user button.
  13. Copy the Access key ID and the Secret access key.

2. Enable CloudWatch in Asayer

Put your Access key ID and Secret access key in Asayer dashboard under Preferences > Integrations, select the region and select the log group that you want to track from the dropdown list.

CloudWatch Integration in Asayer

3. Propagate asayerSessionId

To link a CloudWatch event with the recorded user session, a unique id has to be propagated from your frontend to your backend on each request you want to track. This can be done using a custom HTTP header. In the below example, we use the fetch function to send that header.

const headers = {
Accept: 'application/json',
'Content-Type': 'application/json',
if (window.asayer && {
headers['X-Session-Id'] =; // Inject asayer_session_id
fetch('', {

In order for Asayer to associate a Cloudwatch log entry with the recorded user session, a unique id has to be propagated as part of each backend error you wish to track.

Below is an example in Python using Monkey Patching.

import sys
import traceback
old_tb = traceback.print_exception
old_f = sys.stdout
old_e = sys.stderr
class F:
def write(self, x):
if ASAYER_SESSION_ID is not None and x != '\n':
old_f.write(f"[asayer_session_id={ASAYER_SESSION_ID}] {x}")
def flush(self):
def tb_print_exception(etype, value, tb, limit=None, file=None, chain=True):
if ASAYER_SESSION_ID is not None:
value = type(value)(f"[asayer_session_id={ASAYER_SESSION_ID}] " + str(value))
old_tb(etype, value, tb, limit, file, chain)
traceback.print_exception = tb_print_exception
sys.stderr = F()

The name of the tag `asayer_session_idW is case sensitive.