# Preflight response is not successful. Status code: 502
**URL:** https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342
**Category:** Developer
**Created:** [June 10, 2022, 4:09am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342 "2022-06-10T04:09:59Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@deathrake](https://discuss.tryton.org/u/deathrake)
#### Post date: [June 10, 2022, 4:09am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/1 "2022-06-10T04:09:59Z")
Hey
I am trying to connect my angular app via tryton json-rpc. but I am not able to connect due to this
`Preflight response is not successful. Status code: 502` I am pretty sure it might be due cors setting in tryton server . can some one please point me in right direction . my angular app is on localhost while tryton is running on different server using nginx
**Update**
I change browser from safari to chrome and this is the error I got in console
`Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.`
what would be the appropriate config for cors ?
---
### Author:  [@pokoli](https://discuss.tryton.org/u/pokoli)
#### Post date: [June 10, 2022, 7:22am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/2 "2022-06-10T07:22:31Z")
This you set up the [cors allowed hosts](https://docs.tryton.org/projects/server/en/latest/topics/configuration.html#cors) on your configuration file?
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### Author:  [@deathrake](https://discuss.tryton.org/u/deathrake)
#### Post date: [June 10, 2022, 8:39am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/3 "2022-06-10T08:39:26Z")
That’s how my config file looks
```auto
[web]
listen=0.0.0.0:8000
root=/var/lib/trytond/www
cors = *
```
---
### Author:  [@ced](https://discuss.tryton.org/u/ced)
#### Post date: [June 10, 2022, 8:50am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/4 "2022-06-10T08:50:47Z")
You must set in cors a list of origins. So they must look like:
```auto
cors =
http://example.com
https://example.com
```
---
### Author:  [@deathrake](https://discuss.tryton.org/u/deathrake)
#### Post date: [June 10, 2022, 9:20am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/5 "2022-06-10T09:20:50Z")
so if my angular web app is running on localhost:4200
will this work
```auto
cors =
http://localhost:4200
```
---
### Author:  [@deathrake](https://discuss.tryton.org/u/deathrake)
#### Post date: [June 10, 2022, 10:30am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/6 "2022-06-10T10:30:13Z")
Thanks a lot this worked out for me
---
### Author:  [@system](https://discuss.tryton.org/u/system)
#### Post date: [July 10, 2022, 10:30am UTC](https://discuss.tryton.org/t/preflight-response-is-not-successful-status-code-502/5342/7 "2022-07-10T10:30:52Z")
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