When going to integrations and connecting the Telnyx API Key it sends an error and I believe it is from vapi because I already tried th API key and it works. Could you please try to solve this as soon as possible. This situation is some what urgent for my clients. Thank you for your assistance. https://cdn.discordapp.com/attachments/1408405275534299206/1408405276058451998/Captura_de_ecra_2025-08-21_194713.png?ex=68a99f20&is=68a84da0&hm=46e700dc54c0938ace8601e5e5a73d639174d067d265e257069c50a3dc343c7f&

Same here. Same error with elevenlabs. EDIT: Elevenlabs works. Misconfiguration on the api-rights by me

Can you try entering it on the phone numbers page instead? When you open

create phone number

then create a telnyx integration, it will ask for an API key. Another way to integrate your Telnyx key is through the /credential API endpoint, and enter it through the cURL request. Let us know if you encounter any issues.

Unless I am blind the /credential API endpoint is not documented i.e. i don't know in which format to call against it. Create phone number does not work. My guess currently is that you use Telnyx api v1 endpoints but the default api keys one creates on telnyx are v2. On telnyx, there exists a way to make v1 credentials but that is broken for my account -- i've already contacted their support about that.

I am also having this issue. Following this thread

@bill-smalls @millionaire Current workaround, that worked for me. My use case is inbound only: Follow https://docs.vapi.ai/advanced/sip/telnyx instructions, you can ignore "Retrieve your Vapi private key" and on step 2.4 the value needs to be "your-unique-id", not "sip:@sip.vapi.ai" otherwise telnyx will throw an error while trying to save the number configuration

curl -X POST https://api.vapi.ai/credential \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "provider": "telnyx",
    "name": "My Telnyx Credential",
    "apiKey": "YOUR_TELNYX_API_KEY"
  }'

To add your telnyx credential through the API endpoint, you can use the above cURL request as a guide. Once you receive the response with the credential_id, you can use that to create the phone number in VAPI through the /phone-number endpoint.

We will check with the team to see if we are creating v1 keys or v2