Skip to main content
POST
Send a fax

Authorizations

Authorization
string
header
required

Dashboard JWT token from Clerk

Headers

Idempotency-Key
string

Stripe-style idempotency token. Pass a stable, client-generated value (1-255 chars) to dedupe retries on transient timeouts. The same key+credential+path replays the original response for 24h on 2xx (5min on 4xx, 30s on 5xx). Returns 409 if a concurrent request with the same key is already in flight; replayed responses include the Idempotency-Replay: true response header.

Required string length: 1 - 255
X-Test-Mode
enum<string>

Sandbox opt-in for Clerk-session-authenticated requests. Set to true to route the call through the test-mode pipeline: no real provider delivery, no credits deducted, response meta.test_mode: true. Ignored for live API keys (dv_live_sk_*) — server-to-server clients must use a test-prefixed key (dv_test_sk_*) to exercise sandbox. Test-prefixed keys unconditionally enable sandbox regardless of this header.

Available options:
true,
false

Body

application/json
to
string
required

Recipient fax number (E.164).

Pattern: ^\+[1-9]\d{1,14}$
media_url
string<uri>
required

Public URL of the document to fax (PDF or TIFF).

from
string

Sender fax number (E.164).

Pattern: ^\+[1-9]\d{1,14}$
quality
enum<string>
default:normal

Fax transmission quality forwarded to Telnyx. Defaults to normal. Equivalent to setting metadata.quality; an explicit metadata.quality takes precedence if both are sent.

Available options:
normal,
high,
very_high
webhook_url
string
Maximum string length: 2048
metadata
object

Response

Message accepted for delivery (fax)

Message accepted for delivery (fax)

data
object
meta
object