Open SidemenuAPI Reference
API Reference
Close Sidemenu

Sending Commands

Sending Commandssending-commands

A Programmable Fax API command is sent with a fax_id. The fax_id allows a user to communicate to Telnyx the fax the user wants to take an action on.

The Telnys Programmable Fax API supports PDF files. To initiate sending the fax, we need to send the request to the Telnyx Programmable Fax API endpoint Developers.


With the request we need to send additional parameters containing authentication information so Telnyx knows which account to send the fax from and information about the destination and file being sent.

media_urlThe URL to the PDF used for the fax's media.
media_nameThe media_name of a file to be used for the fax's media. The media_name must point to a file previously uploaded to by the same user/organization. media_url and media_name can't be submitted together.
connection_idThe fax application ID to send the fax with.
toThe fax enabled phone number, in E.164 format, the fax will be sent to or SIP URI.
fromThe phone number, in E.164 format, the fax will be sent from.
t38_enabledThe flag to disable the T.38 protocol. Set to false to disable.
monochromeThe flag to enable monochrome, true black and white fax results. Set to true to enable.
qualityThe quality of the fax. Can be normal, high, very_high.
store_mediaShould fax media be stored on temporary URL. It does not support media_name, they can't be submitted together.
Authorizaton: BearerThe prefix to your API V2 key created in Step 2.

Available Commands and their Expected Webhooks

Telnyx sends webhooks to update on the status of Programmable Fax. Webhooks will also be sent in response to requests to list and delete faxes.

Command Associated Webhooks
Send a fax fax.queued

Response when sending command

When you send a Programmable Fax API Command, you will immediately receive an http response. Responses include, but are not limited to:

HTTP Status CodeMessageDescription
202OKThe request succeeded.
403ForbiddenThe request was valid, however the user is not authorized to perform this action.
404Not FoundThe requested resource could not be found.
422Invalid ParametersThe request has invalid parameters.
429Too many requestsThere is a limit for outbound faxes of 1500 faxes being processed at the same time.

Example: Sending Commands

To send a fax, send a POST request to the endpoint as shown in the example below.

With a API V2 Key
curl -X POST \
--data-urlencode "media_url=" \
--data-urlencode "connection_id=1232154810234" \
--data-urlencode "to=+13129457420" \
--data-urlencode "from=+19459457421" \
--header "Authorization: Bearer APIAuthKey_fromPortal"