Developer API Updated Mar 2026

Sending SMS via API

Complete guide to sending SMS programmatically using the REST API.

apisendsmsrestendpointmessagescurl

POST /api/v1/messages

Send SMS to one or many recipients via a single API call.

Request Parameters

campaignName (string, required) — Internal tracking name
senderId (string, required) — Approved sender ID (max 11 chars)
message (string, required) — SMS text content
manualNumbers (string) — Comma-separated phone numbers
groupIds (string[]) — Contact group IDs to send to
scheduledAt (ISO 8601) — Schedule for future delivery

Response

A successful response (200) returns:

campaignId — Unique ID for tracking the campaign
totalRecipients — Number of recipients
cost — Credits consumed
status — SENT, SCHEDULED, or QUEUED

Phone Number Format

Numbers must be in international format without the + prefix: 255712345678. The system auto-corrects common formats (0712345678 -> 255712345678).

Credit Check: The API will return a 402 Insufficient Credits error if your balance cannot cover the campaign cost. Always check your balance before sending large campaigns.

Related in Developer API

API Authentication

How to authenticate your API requests with Bearer tokens.

Webhooks & Callbacks

Receive real-time delivery notifications and event callbacks.

SDKs & Libraries

Quick-start code examples in Node.js, Python, PHP, and Java.

Rate Limits & API Best Practices

Understand rate limits and build resilient API integrations.

Back to Knowledge Base