Send an SMS message
POST
/v1/sms/messages
curl -X POST "https://us1.platform.bird.com/v1/sms/messages" \
-H "Authorization: Bearer $TOKEN" \
-H "Content-Type: application/json" \
-d '{
"to": "+15551234567",
"from": "+15557654321",
"text": "Your verification code is 123456.",
"category": "authentication"
}'Sends a single SMS message to one recipient. The 202 response is returned only after the message is durably accepted for delivery; actual delivery happens asynchronously, and you track it with the get-message and list-events endpoints or with webhooks. category is required and controls opt-out (STOP) policy, quiet hours, and per-country compliance. A body exceeding the 12-segment cap is rejected with a 422, as are field-level validation failures and sends that cannot be afforded by the workspace balance.
Response Payload
id
string
required
Message ID.
direction
string
required
Whether the message was sent from a Bird sender (outbound) or received from a subscriber (inbound).
status
object
required
to
string
required
Recipient phone number in E.164 format.
from
string
required
Sender the message was sent from — an E.164 number, an alphanumeric sender ID, or a short code.
text
string
required
Message body.
category
nullable string
Content classification supplied on the send. Null for inbound messages.
segments
object
required
Segment breakdown for the body.
Show child attributes
segments.count
integer
required
Number of segments the body is split into. Each segment is a billable unit.
segments.encoding
string
required
Encoding used for the body. GSM_7BIT fits 160 characters in a single segment (153 per part when multi-segment); UCS2 is used when the body contains any character outside the GSM 03.38 alphabet (emoji, CJK, some accented characters) and fits 70 characters in a single segment (67 per part when multi-segment).
segments.characters
integer
required
Character count of the body under the selected encoding.
cost
nullable object
Cost of the message. Null until the message has been priced.
Show child attributes
cost.currency_code
string
ISO 4217 currency code for the cost amount. Omitted when the cost is not denominated in a currency (for example a zero-priced internal send).
cost.amount
string
required
Total cost as a decimal string — the per-segment rate multiplied by the segment count, plus any surcharges.
cost.breakdown
object
Per-component cost breakdown. Returned on single-message reads; omitted from list rows.
Show child attributes
cost.breakdown.per_segment
string
required
Per-segment price as a decimal string.
cost.breakdown.segments
integer
required
Number of billable segments.
cost.breakdown.country_code
string
required
ISO 3166-1 alpha-2 destination country the price was resolved for.
cost.breakdown.carrier_surcharge
string
required
Carrier surcharge component as a decimal string (for example US 10DLC fees). 0.0000 when none applies.
tags
array of object
Structured {name, value} filter labels applied to this message.
Show child attributes
tags.name
string
required
Tag name. ASCII letters, digits, underscore, and hyphen only. Case-sensitive. Maximum 32 characters.
tags.value
string
required
Tag value. ASCII letters, digits, underscore, and hyphen only. Case-sensitive. Maximum 64 characters.
metadata
object
Arbitrary JSON metadata stored on the message and echoed in webhook payloads.
validity_period
integer
How long, in seconds, Bird keeps trying to deliver before the message transitions to expired.
carrier
nullable string
Carrier that handled the message, when known. Populated once a delivery receipt identifies it.
mcc_mnc
nullable string
Mobile country code and mobile network code of the carrier, when known.
last_error
nullable object
Failure detail on a terminally failed or rejected message. Null otherwise.
Show child attributes
last_error.code
string
required
Bird-stable failure reason. invalid_destination — the number is not assigned, ported out, or malformed. unreachable — handset off or out of coverage. blocked_by_carrier — the carrier filtered the message. blocked_by_recipient — the recipient device blocked the sender. landline_unreachable — the destination is a landline that does not accept SMS. content_rejected — the carrier rejected the content. sender_unregistered — the sender is not registered for the destination. recipient_opted_out — the recipient is on a suppression list. provider_unavailable — an upstream failure after retries. unknown — an unmapped failure.
last_error.description
string
required
Human-readable explanation of the failure.
last_error.carrier_error_code
nullable string
Raw carrier-supplied error code, when available, for low-level debugging.
last_error.occurred_at
string
required
When the failure occurred.
created_at
string
required
When the message was accepted (outbound) or received (inbound).
sent_at
nullable string
When the message was handed to the carrier. Null until then.
delivered_at
nullable string
When delivery was confirmed. Null until then.