Runnable examples against the sandbox of Fax for Agents, https://faxforagents.com.
Fax for Agents is a fax API, a hosted MCP server and SDKs built so AI agents can send and receive faxes. It is made by JSB Holdings LLC and built by Synapse. The repository is mirrored on GitLab.
Every example needs a test key (ffa_test_...), created at https://app.faxforagents.com, in
FAXFORAGENTS_API_KEY. A test API key reaches the sandbox only. No carrier, no cost, the destination
number picks the outcome.
| Example | What it shows |
|---|---|
python-agent/ |
An agent loop with the Python SDK: prepare, quote, approval when needed, send, poll |
typescript-agent/ |
The same loop with the TypeScript SDK |
claude-code/ |
A .mcp.json for the hosted MCP server and a prompt that sends a sandbox fax |
n8n/ |
A workflow: inbound webhook, signature check on the raw body, notify |
curl/ |
The raw flow in five calls |
| Destination | Outcome |
|---|---|
+15550000001 |
delivered |
+15550000002 |
busy on attempt 1, delivered on attempt 2 |
+15550000003 |
partial after 3 pages |
+15550000004 |
no answer on all 3 attempts, failed |
+15550000005 |
accepted, no outcome, unknown |
+15550000006 |
provider timeout, unknown |
+15550000007 |
failed with invalid_number |
any other +1 number |
delivered |
A fax is delivered only when the carrier's evidence is on the attempt. partial and unknown
never retransmit on their own. Every example stops there and asks a person.
MIT. See LICENSE. Security reports go to hello@faxforagents.com, see SECURITY.md.