Messaging capability
Check which messaging service is currently available for an E.164 phone number. This is a read-only lookup and does not require an agent identity or an existing conversation.
Check messaging capability GET
GET /check-messaging-capability
Query parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
number | string | Yes | Recipient phone number in E.164 format |
URL-encode the leading + as %2B when you place the number in the query string:
bashUse an admin API key or claimed agent key. Unclaimed (mid-signup) agent keys are rejected.
Response (200)
The response body is a JSON string—not an object—and is always one of iMessage, SMS, or RCS:
JSONCheck capability close to the time you intend to message the recipient because service availability can change.
Error responses
| Status | Description |
|---|---|
| 401 | Authentication is missing or invalid |
| 403 | The credential is valid but is not permitted to perform capability lookups |
| 422 | number is missing or is not a valid phone number |
| 502 | Capability information is temporarily unavailable |