# Need help with {{ctx.payload.aggregations.bucketAgg.buckets.key : null}} in watcher hence wont trigger email action
**URL:** https://discuss.elastic.co/t/need-help-with-ctx-payload-aggregations-bucketagg-buckets-key-null-in-watcher-hence-wont-trigger-email-action/234785
**Category:** Kibana
**Created:** [May 28, 2020, 5:07pm UTC](https://discuss.elastic.co/t/need-help-with-ctx-payload-aggregations-bucketagg-buckets-key-null-in-watcher-hence-wont-trigger-email-action/234785 "2020-05-28T17:07:13Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@vdalvi](https://discuss.elastic.co/u/vdalvi)
#### Post date: [May 28, 2020, 5:07pm UTC](https://discuss.elastic.co/t/need-help-with-ctx-payload-aggregations-bucketagg-buckets-key-null-in-watcher-hence-wont-trigger-email-action/234785/1 "2020-05-28T17:07:13Z")
Hi,
I am new to Kibana Watchers and I am facing issues in parsing the desired value to "ctx.payload.aggregations".
I get the below result
```auto
"ctx.payload.aggregations.numberofcmtsId.buckets.count_deriv.value": null
```
My Watcher Query is as below
```auto
{
"trigger" : {
"schedule" : { "interval" : "60s" }
},
"input" : {
"search" : {
"request" : {
"indices" : ["snmp-*"],
"body" : {
"size":0,
"query": {
"range": {
"timestamp": {
"gte": "now-90m/m",
"lte": "now-30m/m"
}
}
},
"aggs": {
"every30min": {
"date_histogram": {
"field": "timestamp",
"fixed_interval": "30m",
"order": {
"_key": "desc"
}
},
"aggs": {
"numberofcmtsId": {
"cardinality": {
"field": "cmtsId"
}
},
"count_deriv": {
"derivative": {
"buckets_path": "numberofcmtsId"
}
}
}
}
}
}
}
}
},
"condition" : {
"compare": {
"ctx.payload.aggregations.numberofcmtsId.buckets.count_deriv.value" : { "gt" : 10 }
}
},
"actions" : {
"send_email" : {
"throttle_period" : "5m",
"email" : {
"to" : "abc@xyz.com",
"subject" : "TEST: CMTS Count Watcher Notification",
"body" : ""
}
}
}
}
```
Can anyone please help on what I am doing wrong in "ctx.payload.aggregations" ? 🙂
---
### Author:  [@tsullivan](https://discuss.elastic.co/u/tsullivan)
#### Post date: [May 30, 2020, 4:53am UTC](https://discuss.elastic.co/t/need-help-with-ctx-payload-aggregations-bucketagg-buckets-key-null-in-watcher-hence-wont-trigger-email-action/234785/2 "2020-05-30T04:53:30Z")
In this query:
```auto
{
"size": 0,
"query": {
"range": {
"timestamp": {
"gte": "now-90m/m",
"lte": "now-30m/m"
}
}
},
"aggs": {
"every30min": {
"date_histogram": {
"field": "timestamp",
"fixed_interval": "30m",
"order": {
"_key": "desc"
}
},
"aggs": {
"numberofcmtsId": {
"cardinality": {
"field": "cmtsId"
}
},
"count_deriv": {
"derivative": {
"buckets_path": "numberofcmtsId"
}
}
}
}
}
}
```
I think the first `numberofcmtsId` agg bucket in the result would not have any value for `count_derive`, right? Derivatives need more than one metric for comparison, since derivatives are a value of difference between 2 metrics.
I'm not sure if you are seeing any error messages, but the issue could be that you have to add a pre-condition to `count_deriv.value` to ensure that it is not null.
For more help, I would suggest reaching out in the Elasticsearch channel of this Discuss forum. But I hope that helps all you need 🙂
-Tim
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [June 27, 2020, 4:53am UTC](https://discuss.elastic.co/t/need-help-with-ctx-payload-aggregations-bucketagg-buckets-key-null-in-watcher-hence-wont-trigger-email-action/234785/3 "2020-06-27T04:53:40Z")
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