Messaging - Allternit Docs

Scope messaging.

Method	Path
`POST`	`/v1/messages`	Send: `{ "number_id", "to", "body" }`
`GET`	`/v1/messages`	List (cursor pagination; filters `number_id`, `account_id`, `direction`)
`GET`	`/v1/messages/{id}`	Retrieve

{ "id": "msg_9f2…", "object": "message", "account_id": "acct_7Hq…", "number_id": "6f1c…", "direction": "outbound",
  "from": "+16125550142", "to": "+14155550123", "body": "Yes, 2 pm works.", "segments": 1, "status": "sent",
  "error_code": null, "media": [], "created_at": "2026-10-04T18:20:44Z" }

status is sent, simulated (sandbox), received (inbound) or failed.

When a send is refused

`403` code	Why
`sms_not_active`	The number’s carrier registration isn’t approved yet.
`recipient_opted_out`	The person replied STOP. Only their START lifts it.
`no_consent`	The person never texted this number and has no consent recorded.

429 daily_limit means the number reached its daily sending cap. 402 spend_cap_reached means the project reached its monthly spend cap; simulated (sandbox) texts are free and never refused for it.

Receiving texts

Texts that arrive on your numbers are kept and sent to your webhooks as message.received. STOP, START and HELP are answered for you and never reach you as messages; a STOP also means future sends to that person are refused.

Billing

Each text counts as one or more sms_segment (160 characters, or 70 with emoji and other non-GSM characters; longer texts split into 153 / 67 character parts), sent and received alike. Simulated texts are free.