telnyx-fax-python
Telnyx Fax - Python
Installation
pip install telnyx
Setup
import os
from telnyx import Telnyx
client = Telnyx(
api_key=os.environ.get("TELNYX_API_KEY"), # This is the default and can be omitted
)
All examples below assume client is already initialized as shown above.
Error Handling
All API calls can fail with network errors, rate limits (429), validation errors (422), or authentication errors (401). Always handle errors in production code:
import telnyx
try:
result = client.messages.send(to="+13125550001", from_="+13125550002", text="Hello")
except telnyx.APIConnectionError:
print("Network error — check connectivity and retry")
except telnyx.RateLimitError:
# 429: rate limited — wait and retry with exponential backoff
import time
time.sleep(1) # Check Retry-After header for actual delay
except telnyx.APIStatusError as e:
print(f"API error {e.status_code}: {e.message}")
if e.status_code == 422:
print("Validation error — check required fields and formats")
Common error codes: 401 invalid API key, 403 insufficient permissions,
404 resource not found, 422 validation error (check field formats),
429 rate limited (retry with exponential backoff).
Important Notes
- Phone numbers must be in E.164 format (e.g.,
+13125550001). Include the+prefix and country code. No spaces, dashes, or parentheses. - Pagination: List methods return an auto-paginating iterator. Use
for item in page_result:to iterate through all pages automatically.
List all Fax Applications
This endpoint returns a list of your Fax Applications inside the 'data' attribute of the response. You can adjust which applications are listed by using filters. Fax Applications are used to configure how you send and receive faxes using the Programmable Fax API with Telnyx.
GET /fax_applications
page = client.fax_applications.list()
page = page.data[0]
print(page.id)
Returns: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), application_name (string), created_at (string), id (string), inbound (object), outbound (object), record_type (string), tags (array[string]), updated_at (string), webhook_event_failover_url (uri), webhook_event_url (uri), webhook_timeout_secs (integer | null)
Creates a Fax Application
Creates a new Fax Application based on the parameters sent in the request. The application name and webhook URL are required. Once created, you can assign phone numbers to your application using the /phone_numbers endpoint.
POST /fax_applications — Required: application_name, webhook_event_url
Optional: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), inbound (object), outbound (object), tags (array[string]), webhook_event_failover_url (uri), webhook_timeout_secs (integer | null)
fax_application = client.fax_applications.create(
application_name="fax-router",
webhook_event_url="https://example.com",
)
print(fax_application.data)
Returns: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), application_name (string), created_at (string), id (string), inbound (object), outbound (object), record_type (string), tags (array[string]), updated_at (string), webhook_event_failover_url (uri), webhook_event_url (uri), webhook_timeout_secs (integer | null)
Retrieve a Fax Application
Return the details of an existing Fax Application inside the 'data' attribute of the response.
GET /fax_applications/{id}
fax_application = client.fax_applications.retrieve(
"1293384261075731499",
)
print(fax_application.data)
Returns: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), application_name (string), created_at (string), id (string), inbound (object), outbound (object), record_type (string), tags (array[string]), updated_at (string), webhook_event_failover_url (uri), webhook_event_url (uri), webhook_timeout_secs (integer | null)
Update a Fax Application
Updates settings of an existing Fax Application based on the parameters of the request.
PATCH /fax_applications/{id} — Required: application_name, webhook_event_url
Optional: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), fax_email_recipient (string | null), inbound (object), outbound (object), tags (array[string]), webhook_event_failover_url (uri), webhook_timeout_secs (integer | null)
fax_application = client.fax_applications.update(
id="1293384261075731499",
application_name="fax-router",
webhook_event_url="https://example.com",
)
print(fax_application.data)
Returns: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), application_name (string), created_at (string), id (string), inbound (object), outbound (object), record_type (string), tags (array[string]), updated_at (string), webhook_event_failover_url (uri), webhook_event_url (uri), webhook_timeout_secs (integer | null)
Deletes a Fax Application
Permanently deletes a Fax Application. Deletion may be prevented if the application is in use by phone numbers.
DELETE /fax_applications/{id}
fax_application = client.fax_applications.delete(
"1293384261075731499",
)
print(fax_application.data)
Returns: active (boolean), anchorsite_override (enum: Latency, Chicago, IL, Ashburn, VA, San Jose, CA, Sydney, Australia, Amsterdam, Netherlands, London, UK, Toronto, Canada, Vancouver, Canada, Frankfurt, Germany), application_name (string), created_at (string), id (string), inbound (object), outbound (object), record_type (string), tags (array[string]), updated_at (string), webhook_event_failover_url (uri), webhook_event_url (uri), webhook_timeout_secs (integer | null)
View a list of faxes
GET /faxes
page = client.faxes.list()
page = page.data[0]
print(page.id)
Returns: client_state (string), connection_id (string), created_at (date-time), direction (enum: inbound, outbound), from (string), from_display_name (string), id (uuid), media_name (string), media_url (string), preview_url (string), quality (enum: normal, high, very_high, ultra_light, ultra_dark), record_type (enum: fax), status (enum: queued, media.processed, originated, sending, delivered, failed, initiated, receiving, media.processing, received), store_media (boolean), stored_media_url (string), to (string), updated_at (date-time), webhook_failover_url (string), webhook_url (string)
Send a fax
Send a fax. Files have size limits and page count limit validations. If a file is bigger than 50MB or has more than 350 pages it will fail with file_size_limit_exceeded and page_count_limit_exceeded respectively.
POST /faxes — Required: connection_id, from, to
Optional: black_threshold (integer), client_state (string), from_display_name (string), media_name (string), media_url (string), monochrome (boolean), preview_format (enum: pdf, tiff), quality (enum: normal, high, very_high, ultra_light, ultra_dark), store_media (boolean), store_preview (boolean), t38_enabled (boolean), webhook_url (string)
fax = client.faxes.create(
connection_id="234423",
from_="+13125790015",
to="+13127367276",
)
print(fax.data)
Returns: client_state (string), connection_id (string), created_at (date-time), direction (enum: inbound, outbound), from (string), from_display_name (string), id (uuid), media_name (string), media_url (string), preview_url (string), quality (enum: normal, high, very_high, ultra_light, ultra_dark), record_type (enum: fax), status (enum: queued, media.processed, originated, sending, delivered, failed, initiated, receiving, media.processing, received), store_media (boolean), stored_media_url (string), to (string), updated_at (date-time), webhook_failover_url (string), webhook_url (string)
View a fax
GET /faxes/{id}
fax = client.faxes.retrieve(
"182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e",
)
print(fax.data)
Returns: client_state (string), connection_id (string), created_at (date-time), direction (enum: inbound, outbound), from (string), from_display_name (string), id (uuid), media_name (string), media_url (string), preview_url (string), quality (enum: normal, high, very_high, ultra_light, ultra_dark), record_type (enum: fax), status (enum: queued, media.processed, originated, sending, delivered, failed, initiated, receiving, media.processing, received), store_media (boolean), stored_media_url (string), to (string), updated_at (date-time), webhook_failover_url (string), webhook_url (string)
Delete a fax
DELETE /faxes/{id}
client.faxes.delete(
"182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e",
)
Cancel a fax
Cancel the outbound fax that is in one of the following states: queued, media.processed, originated or sending
POST /faxes/{id}/actions/cancel
response = client.faxes.actions.cancel(
"182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e",
)
print(response.data)
Returns: result (string)
Refresh a fax
Refreshes the inbound fax's media_url when it has expired
POST /faxes/{id}/actions/refresh
response = client.faxes.actions.refresh(
"182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e",
)
print(response.data)
Returns: result (string)
Webhooks
Webhook Verification
Telnyx signs webhooks with Ed25519. Each request includes telnyx-signature-ed25519
and telnyx-timestamp headers. Always verify signatures in production:
# In your webhook handler (e.g., Flask — use raw body, not parsed JSON):
@app.route("/webhooks", methods=["POST"])
def handle_webhook():
payload = request.get_data(as_text=True) # raw body as string
headers = dict(request.headers)
try:
event = client.webhooks.unwrap(payload, headers=headers)
except Exception as e:
print(f"Webhook verification failed: {e}")
return "Invalid signature", 400
# Signature valid — event is the parsed webhook payload
print(f"Received event: {event.data.event_type}")
return "OK", 200
The following webhook events are sent to your configured webhook URL.
All webhooks include telnyx-timestamp and telnyx-signature-ed25519 headers for Ed25519 signature verification. Use client.webhooks.unwrap() to verify.
| Event | Description |
|---|---|
fax.delivered |
Fax Delivered |
fax.failed |
Fax Failed |
fax.media.processed |
Fax Media Processed |
fax.queued |
Fax Queued |
fax.sending.started |
Fax Sending Started |
Webhook payload fields
fax.delivered
| Field | Type | Description |
|---|---|---|
data.record_type |
enum: event | Identifies the type of the resource. |
data.id |
uuid | Identifies the type of resource. |
data.occurred_at |
date-time | ISO 8601 datetime of when the event occurred. |
data.event_type |
enum: fax.delivered | The type of event being delivered. |
data.payload.call_duration_secs |
integer | The duration of the call in seconds. |
data.payload.connection_id |
string | The ID of the connection used to send the fax. |
data.payload.direction |
enum: inbound, outbound | The direction of the fax. |
data.payload.fax_id |
uuid | Identifies the fax. |
data.payload.original_media_url |
string | The original URL to the PDF used for the fax's media. |
data.payload.media_name |
string | The media_name used for the fax's media. |
data.payload.to |
string | The phone number, in E.164 format, the fax will be sent to or SIP URI |
data.payload.from |
string | The phone number, in E.164 format, the fax will be sent from. |
data.payload.user_id |
uuid | Identifier of the user to whom the fax belongs |
data.payload.page_count |
integer | Number of transferred pages |
data.payload.status |
enum: delivered | The status of the fax. |
data.payload.client_state |
string | State received from a command. |
meta.attempt |
integer | The delivery attempt number. |
meta.delivered_to |
uri | The URL the webhook was delivered to. |
fax.failed
| Field | Type | Description |
|---|---|---|
data.record_type |
enum: event | Identifies the type of the resource. |
data.id |
uuid | Identifies the type of resource. |
data.occurred_at |
date-time | ISO 8601 datetime of when the event occurred. |
data.event_type |
enum: fax.failed | The type of event being delivered. |
data.payload.connection_id |
string | The ID of the connection used to send the fax. |
data.payload.direction |
enum: inbound, outbound | The direction of the fax. |
data.payload.fax_id |
uuid | Identifies the fax. |
data.payload.original_media_url |
string | The original URL to the PDF used for the fax's media. |
data.payload.media_name |
string | The media_name used for the fax's media. |
data.payload.to |
string | The phone number, in E.164 format, the fax will be sent to or SIP URI |
data.payload.from |
string | The phone number, in E.164 format, the fax will be sent from. |
data.payload.user_id |
uuid | Identifier of the user to whom the fax belongs |
data.payload.failure_reason |
enum: rejected | Cause of the sending failure |
data.payload.status |
enum: failed | The status of the fax. |
data.payload.client_state |
string | State received from a command. |
meta.attempt |
integer | The delivery attempt number. |
meta.delivered_to |
uri | The URL the webhook was delivered to. |
fax.media.processed
| Field | Type | Description |
|---|---|---|
data.record_type |
enum: event | Identifies the type of the resource. |
data.id |
uuid | Identifies the type of resource. |
data.occurred_at |
date-time | ISO 8601 datetime of when the event occurred. |
data.event_type |
enum: fax.media.processed | The type of event being delivered. |
data.payload.connection_id |
string | The ID of the connection used to send the fax. |
data.payload.direction |
enum: inbound, outbound | The direction of the fax. |
data.payload.fax_id |
uuid | Identifies the fax. |
data.payload.original_media_url |
string | The original URL to the PDF used for the fax's media. |
data.payload.media_name |
string | The media_name used for the fax's media. |
data.payload.to |
string | The phone number, in E.164 format, the fax will be sent to or SIP URI |
data.payload.from |
string | The phone number, in E.164 format, the fax will be sent from. |
data.payload.user_id |
uuid | Identifier of the user to whom the fax belongs |
data.payload.status |
enum: media.processed | The status of the fax. |
data.payload.client_state |
string | State received from a command. |
meta.attempt |
integer | The delivery attempt number. |
meta.delivered_to |
uri | The URL the webhook was delivered to. |
fax.queued
| Field | Type | Description |
|---|---|---|
data.record_type |
enum: event | Identifies the type of the resource. |
data.id |
uuid | Identifies the type of resource. |
data.occurred_at |
date-time | ISO 8601 datetime of when the event occurred. |
data.event_type |
enum: fax.queued | The type of event being delivered. |
data.payload.connection_id |
string | The ID of the connection used to send the fax. |
data.payload.direction |
enum: inbound, outbound | The direction of the fax. |
data.payload.fax_id |
uuid | Identifies the fax. |
data.payload.original_media_url |
string | The original URL to the PDF used for the fax's media. |
data.payload.media_name |
string | The media_name used for the fax's media. |
data.payload.to |
string | The phone number, in E.164 format, the fax will be sent to or SIP URI |
data.payload.from |
string | The phone number, in E.164 format, the fax will be sent from. |
data.payload.user_id |
uuid | Identifier of the user to whom the fax belongs |
data.payload.status |
enum: queued | The status of the fax. |
data.payload.client_state |
string | State received from a command. |
meta.attempt |
integer | The delivery attempt number. |
meta.delivered_to |
uri | The URL the webhook was delivered to. |
fax.sending.started
| Field | Type | Description |
|---|---|---|
data.record_type |
enum: event | Identifies the type of the resource. |
data.id |
uuid | Identifies the type of resource. |
data.occurred_at |
date-time | ISO 8601 datetime of when the event occurred. |
data.event_type |
enum: fax.sending.started | The type of event being delivered. |
data.payload.connection_id |
string | The ID of the connection used to send the fax. |
data.payload.direction |
enum: inbound, outbound | The direction of the fax. |
data.payload.fax_id |
uuid | Identifies the fax. |
data.payload.original_media_url |
string | The original URL to the PDF used for the fax's media. |
data.payload.media_name |
string | The media_name used for the fax's media. |
data.payload.to |
string | The phone number, in E.164 format, the fax will be sent to or SIP URI |
data.payload.from |
string | The phone number, in E.164 format, the fax will be sent from. |
data.payload.user_id |
uuid | Identifier of the user to whom the fax belongs |
data.payload.status |
enum: sending | The status of the fax. |
data.payload.client_state |
string | State received from a command. |
meta.attempt |
integer | The delivery attempt number. |
meta.delivered_to |
uri | The URL the webhook was delivered to. |