Overview

The Fax API sends a PDF as a fax from one of your Allo lines. Sent and received faxes then appear in your conversations, next to calls and SMS.

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What you need to send a fax

• Fax on your account. Faxing is not available on every account. Without it, the API returns 403 with code FAX_NOT_AVAILABLE: contact Allo support to get it enabled.
• A line that supports fax. The line must be a US or Canada local number. Toll-free numbers and sender IDs cannot send faxes.
• Fax turned on for the line. Turn on Send and receive faxes in the number settings in the Allo app. The API cannot change this setting.
• Message credits. Each faxed page uses credits, the same balance that pays for SMS.

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How faxes appear in conversations

A fax is a conversation item of type SMS with message_type FAX. Its ID starts with msg-, like any message.

• attachments holds the faxed PDF, with a download_url valid for 30 minutes.
• page_count is the number of pages, or null while it is not known yet.
• status of a sent fax starts at PENDING and changes as the fax goes through.

To list only faxes, call Search conversation items with type: "FAX". With type: "SMS", faxes are included with the other messages.