Capability Checks

Check RCS capability

Check whether a recipient address (phone number) supports RCS messaging.

address must be an E.164 phone number. RCS has no email addressing, so an email is rejected with a 400 rather than attempted.

A 200 means the check ran and the answer is about the recipient. A 503 means the check could not produce an answer because of a fault on the sender line — 4004 (RCS not turned on for the line), 4009 (line has no RCS account), or 4010 (the check could not run). Treat all three as "unknown", never as "the recipient does not support RCS", and do not cache them as a negative result.

post/v3/capability/check_rcs

Request

  • Base URL: https://api.linqapp.com/api/partner
  • URL: https://api.linqapp.com/api/partner/v3/capability/check_rcs
  • Auth: HTTP bearer

Request body

addressstring required

The recipient address to check. check_imessage accepts an E.164 phone number or an email address; check_rcs accepts an E.164 phone number only and rejects an email with a 400, since RCS has no email addressing.

fromstring

Optional sender phone number. If omitted, an available phone from your pool is used automatically.

Example request

{
  "address": "+15551234567",
  "from": "+15559876543"
}

Response

RCS capability check completed

addressstring required

The recipient address that was checked

availableboolean required

Whether the recipient supports the checked messaging service

reason'not_supported'

Why available is false. Only present on a negative result.

not_supported is the only value returned with a 200, and it means the check completed and the recipient is genuinely not reachable over this service. On check_rcs, sender-side faults do not return 200 — they return 503 with a specific error code. check_imessage does not use this mapping.

selected_servicestring

The service that would actually carry a message to this address right now, which is not always the service you checked — a recipient without RCS resolves to SMS. Absent when the check could not determine one.

Example response

{
  "address": "+15551234567",
  "available": true,
  "reason": "not_supported",
  "selected_service": "SMS"
}

Changes

No recorded changes to this operation across all 1 revision of this API.