# C# api access error
**URL:** https://community.rapyd.net/t/c-api-access-error/58326
**Category:** ⚙️ API
**Created:** [January 18, 2023, 10:42pm UTC](https://community.rapyd.net/t/c-api-access-error/58326 "2023-01-18T22:42:41Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@globale](https://community.rapyd.net/u/globale)
#### Post date: [January 18, 2023, 10:42pm UTC](https://community.rapyd.net/t/c-api-access-error/58326/1 "2023-01-18T22:42:41Z")
using c# httpclient the error received is {“status”:{“error\_code”:“UNAUTHORIZED\_API\_CALL”,“status”:“ERROR”,“message”:“”,“response\_code”:“UNAUTHORIZED\_API\_CALL”,“operation\_id”:“6896974b-27dc-4cf8-bc46-c3151c913276”}}
i have checked the headers, the signature, timestamp and all match Postman (which works!), i also tried running postman, copied the timestamp and salt from the request, used those in the c# request and got the identical signature so i know the sig hashing is fine, but still same error! very frustrating
calling /v1/data/countries so no body
any help would be appreciated
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### Author:  [@Community\_Team](https://community.rapyd.net/u/Community_Team)
#### Post date: [January 24, 2023, 5:16pm UTC](https://community.rapyd.net/t/c-api-access-error/58326/2 "2023-01-24T17:16:56Z")
Thanks @globale, it looks like it is an unauthorized call, it may be more due to the endpoint, or base URI you are using. Yes, [List Countries](https://docs.rapyd.net/build-with-rapyd/reference/country-object#list-countries) should work in Sandbox and Production.
Just confirming your base uri/url is
[https://sandboxapi.rapyd.net/v1](https://sandboxapi.rapyd.net/v1) or
[https://api.rapyd.net/v1](https://api.rapyd.net/v1).
Typically if this was an issue with the signature request or headers it would come up as an unauthenticated error (`UNAUTHENTICATED_API_CALL`).
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### Author:  [@juliapak](https://community.rapyd.net/u/juliapak)
#### Post date: [January 25, 2023, 3:53am UTC](https://community.rapyd.net/t/c-api-access-error/58326/3 "2023-01-25T03:53:36Z")
yes you need the hashed header data (api key and secret) in the request. I’ll show you how i do mine, I use dart not C++ though …
