API reference

Base URL: https://api.99billingsolutions.com. Every request is authenticated with your API key in the x-api-key header — see Authentication. Requests and responses are JSON with snake_case field names.

Response envelope

// success
{ "status": "success", "message": "…", "data": { … } }

// list
{ "status": "success", "message": "…", "data": { "items": [ … ], "cursor": "…", "has_more": true } }

// error
{ "status": "error", "message": "…", "error_code": "invalid_phone_number", "data": { "field": "to_number" } }

Endpoints

Method	Path	Purpose
POST	/v1/messages/send	Send one SMS
POST	/v1/messages/bulk-send	Send the same SMS to up to 500 numbers
GET	/v1/messages	List messages (cursor paginated)
GET	/v1/messages/{id}	One message with its event timeline
POST	/v1/messages/batch-status	Status of up to 100 messages
GET/POST	/v1/campaigns	Personalised sends with {{variables}}
GET/POST/PUT/DELETE	/v1/contacts	Contacts, tags and opt-outs
GET/POST/PUT/DELETE	/v1/templates	Reusable message templates
GET/POST/PUT/DELETE	/v1/webhooks	Webhook endpoints and delivery log
GET	/v1/devices	Paired phones and their status
GET	/v1/analytics/overview	Sent / received / delivery-rate totals

Conventions

Phone numbers are E.164: a plus sign, country code and number, no spaces (+15551234567).
Timestamps are ISO 8601 with a UTC offset. Fields whose value is null are left out of responses.
Idempotency: pass request_id when sending; a repeat with the same value returns 409 duplicate_request with the original message id instead of sending twice.
Pagination: pass the cursor from the previous page; limit is 1–100 (default 25).
Rate limits return 429 with a Retry-After header — see Rate limits.
Message text is removed from our database 30 minutes after a message is sent or received, and the whole record after 24 hours. Store anything you need to keep on your side (webhooks are the easiest way).

Try it

Build a request in the API playground, or start with the quickstart.