The Numbers API enables you to search for, view, and activate numbers.

Download the OpenAPI specification here.

Contact Sinch support here: Support@sinch.com


The Numbers API uses client_id and secret to authenticate requests. You can view and manage your API keys here.

Authentication to the API is performed via HTTP Basic Auth. Use your client_id as the basic auth username and your secret as the password.

 --url 'https://numbers.api.sinch.com/v1/projects/{projectId}/availableNumbers?regionCode=US' \
 --header 'Accept: application/json' \
 -u {clientId}:{clientSecret}

We also support OAuth for short lived tokens. To get an OAuth token, you will post your client_id and secret to the Sinch endpoint.

--url 'https://auth.sinch.com/oauth2/token' -d grant_type=client_credentials --user <client_id>:<client_secret>

You then will use the token generated by the above as the bearer in your requests.