# Child workflows send a signal to the parent
**URL:** https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580
**Category:** Community Support
**Tags:** typescript-sdk
**Created:** [August 4, 2022, 9:46am UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580 "2022-08-04T09:46:19Z")
**Posts on this page:** 13
**Page:** 1
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 4, 2022, 9:46am UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/1 "2022-08-04T09:46:19Z")
Hi,
I need to create multiple child workflows in parent workflow and the parent needs to wait for all of the child workflows to be finished.
Can I send a signal from the child to the parent? Is there any code example in typescript?
What’s the best patern to wait for all of the child workflows to be finished?
Thanks.
---
### Author:  [@tihomir](https://community.temporal.io/u/tihomir)
#### Post date: [August 4, 2022, 2:37pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/2 "2022-08-04T14:37:04Z")
You can start them async and wait for their completion, similar to [this](https://github.com/temporalio/samples-typescript/blob/main/child-workflows/src/workflows.ts) sample ( `await Promise.all` )
---
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 4, 2022, 4:53pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/3 "2022-08-04T16:53:28Z")
Hi,
In my use case I can’t wait for all of them, I need to be able to send data back (quering the parent) if any child has finished.
Is there any way to do this?
Can I send a signal from the child to notify the parent with the result?
Thanks.
---
### Author:  [@tihomir](https://community.temporal.io/u/tihomir)
#### Post date: [August 4, 2022, 5:23pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/4 "2022-08-04T17:23:51Z")
> Can I send a signal from the child to notify the parent with the result?
Yes, you can get the parent workflow id and runid inside child via:
```auto
workflowInfo().parent?.workflowId;
workflowInfo().parent?.runId;
```
Can you explain your use case please? Would help with knowing if sending signals from child workflows is best option for it or not.
---
### Author:  [@loren](https://community.temporal.io/u/loren)
#### Post date: [August 4, 2022, 5:56pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/5 "2022-08-04T17:56:02Z")
> I can’t wait for all of them
Why not?
---
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 5, 2022, 8:19am UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/6 "2022-08-05T08:19:26Z")
Hi,
The child workflows would process some data like, for example, send some external request but that request can take time, like 5-10 minutes. An example would be: the parent creates four children, child one and two process the data stright away but the rest doesn’t(send some request or wait for some external processing that can take 5 - 10 minutes). I would like to have access to that partial results and that’s why I’d like to notify the parent when a child has finished, so I could update some parent state and query it from outside.
Thanks.
---
### Author:  [@loren](https://community.temporal.io/u/loren)
#### Post date: [August 5, 2022, 3:20pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/7 "2022-08-05T15:20:04Z")
This updates the `results` state whenever a child finishes, but still waits for all of them to complete before returning:
```auto
async function myWorkflow(): Promise {
let results = [];
await Promise.all([
executeChild().then(result => results.push[result]),
executeChild().then(result => results.push[result])
])
return 'done'
}
```
---
### Author:  [@bergundy](https://community.temporal.io/u/bergundy)
#### Post date: [August 5, 2022, 4:14pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/8 "2022-08-05T16:14:17Z")
> [@loren](#):
>
> ```auto
> executeChild().then(result => results.push[result]),
>
> ```
Should be
```ts
executeChild().then(result => results.push(result)),
```
---
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 8, 2022, 8:07am UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/9 "2022-08-08T08:07:01Z")
The main issue here is that I still need to wait for all of them to get the result.
Could I write some loop or interval checker without getting a non-deterministic error?
---
### Author:  [@lorensr](https://community.temporal.io/u/lorensr)
#### Post date: [August 8, 2022, 3:25pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/10 "2022-08-08T15:25:16Z")
The Promise.all resolves when you have all the results
---
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 9, 2022, 9:34am UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/11 "2022-08-09T09:34:27Z")
what I need to do is the ability to query the parent while is getting results from children, that’s why promise all won’t work in this case. Is there any pattern that I can use?
---
### Author:  [@loren](https://community.temporal.io/u/loren)
#### Post date: [August 9, 2022, 3:40pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/12 "2022-08-09T15:40:24Z")
The below query will first return `[]`, then [‘firstresult’], then [‘firstresult’, ‘secondresult’].
```auto
import { executeChild, defineQuery, setHandler } from '@temporalio/workflow';
const getResults = defineQuery('getResults');
async function myWorkflow(): Promise {
let results: string[] = [];
setHandler(getResults, () => results);
await Promise.all([
executeChild().then(result => results.push(result)),
executeChild().then(result => results.push(result))
]);
return 'done';
}
```
---
### Author:  [@grelo](https://community.temporal.io/u/grelo)
#### Post date: [August 9, 2022, 5:16pm UTC](https://community.temporal.io/t/child-workflows-send-a-signal-to-the-parent/5580/13 "2022-08-09T17:16:08Z")
Thanks, this was what I was looking for. I’m gonna try to write some complex workflows to see how it works.