# SMSBlast Developers Canonical page: https://smsblast.io/developers SMSBlast (https://smsblast.io) offers a self-serve REST API to send SMS and MMS, test your key, and opt contacts out, plus listening webhooks and native plugins for WordPress and Podio. Full request and response schemas: https://smsblast.io/openapi.json (OpenAPI 3.1). ## Ways to integrate - REST API: send SMS and MMS, test your key, and opt contacts out over HTTPS with your organization API key. - Webhooks: push events into your CRM, Zapier, n8n, Make, or any HTTPS endpoint you control. - WordPress plugin: native integration for WordPress sites. - Podio plugin: native integration for Podio workspaces. ## Self-serve API access Create a free account at https://app.smsblast.io/signup, then get or rotate your API key in the app under Settings → Integrations (APIs). No contracts and no monthly fees for messaging. Keep the key secret: anyone with it can send messages billed to your account; rotating it immediately invalidates the old one. ## Authentication Base URL: https://app.smsblast.io. Every request is authenticated with your organization API key in the Authorization header; requests without it get HTTP 401. Headers: - `Authorization: Bearer YOUR_API_KEY` - `Content-Type: application/json` (POST requests) ## Send an SMS: POST /api/v2/sms/send Send a text (or an MMS with an image) from a verified number you own to one recipient or up to 100 at once. Recipients who have opted out are skipped automatically. Request body: - `to`: phone number (string) or array of phone numbers (max 100), E.164 format. - `from`: required. Your verified phone number to send from (E.164 format, e.g. +18005551234). - `message`: SMS message content (string). Supports {{firstName}} and other placeholders, filled in per recipient from their contact. - `name`: (optional) contact name. Only applied when sending to a single recipient; sets and overwrites that contact's first and last name. - `mediaUrl`: (optional) public https image URL to send as an MMS, attached to every recipient and billed at the MMS rate. Carriers accept jpg, png, gif, or webp up to 5MB. Personalize with placeholders: add {{firstName}}, {{lastName}}, {{email}}, {{address}}, {{city}}, {{state}}, or {{zip}} to your message and each recipient gets their own version, filled from their contact record. Your own custom fields work too, for example {{acreage}}. Empty fields render blank. This works the same way as campaigns and quick blast. Opt-out text is added automatically: for compliance, every message sent through the API automatically includes "Reply STOP to unsubscribe" (it is skipped only when your text already has opt-out wording or is a one-time passcode). If you have a special use case where this should not be added, such as in-app notifications or transactional alerts, open a support ticket describing your use case and our team can review it for your account. cURL: ```bash curl -X POST https://app.smsblast.io/api/v2/sms/send -H "Authorization: Bearer YOUR_API_KEY" -H "Content-Type: application/json" -d '{"to":"+15551234567","from":"+18005551234","message":"Hello from SMSBlast API!","name":"Jane Doe"}' ``` Node.js: ```js const axios = require('axios'); axios.post('https://app.smsblast.io/api/v2/sms/send', { to: '+15551234567', from: '+18005551234', message: 'Hello from SMSBlast API!', name: 'Jane Doe' }, { headers: { 'Authorization': 'Bearer YOUR_API_KEY', 'Content-Type': 'application/json' } }) .then(response => console.log(response.data)) .catch(error => console.error(error)); ``` PHP: ```php '+15551234567', 'from' => '+18005551234', 'message' => 'Hello from SMSBlast API!', 'name' => 'Jane Doe' ]; $ch = curl_init($url); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data)); curl_setopt($ch, CURLOPT_HTTPHEADER, [ 'Authorization: Bearer ' . $apiKey, 'Content-Type: application/json' ]); $response = curl_exec($ch); $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE); curl_close($ch); $result = json_decode($response, true); print_r($result); ``` Response: ```json { "success": true, "sent": 1, "failed": 0, "totalCost": "0.0150", "results": [ { "to": "+15551234567", "status": "sent", "messageSid": "SM...", "segments": 1, "cost": 0.015 } ] } ``` `errors` is included only when some recipients could not be sent (for example opted out), each with a `to` and an `error` reason. Error responses: `401` missing or invalid API key; `400` missing "from" field, phone number not found or not verified, or invalid request body; `402` insufficient balance. ## Opt out a contact: POST /api/v2/contacts/opt-out Stop a contact from receiving further messages. Matched by phone number within your account. Idempotent. Request body: - `number`: required. The contact's phone number (E.164, e.g. +15551234567). cURL: ```bash curl -X POST https://app.smsblast.io/api/v2/contacts/opt-out -H "Authorization: Bearer YOUR_API_KEY" -H "Content-Type: application/json" -d '{"number":"+15551234567"}' ``` Node.js: ```js const axios = require('axios'); axios.post('https://app.smsblast.io/api/v2/contacts/opt-out', { number: '+15551234567' }, { headers: { 'Authorization': 'Bearer YOUR_API_KEY', 'Content-Type': 'application/json' } }) .then(response => console.log(response.data)) .catch(error => console.error(error)); ``` PHP: ```php '+15551234567'])); curl_setopt($ch, CURLOPT_HTTPHEADER, [ 'Authorization: Bearer ' . $apiKey, 'Content-Type: application/json' ]); $response = curl_exec($ch); curl_close($ch); print_r(json_decode($response, true)); ``` Response: ```json { "success": true, "optedOut": 1, "alreadyOptedOut": false, "number": "+15551234567" } ``` Returns 404 if no contact matches the number. `alreadyOptedOut` is true when the contact was already opted out. ## Account: GET /api/v2/me Returns your account info, handy for confirming an API key works and checking your balance and sender number. No cost. cURL: ```bash curl https://app.smsblast.io/api/v2/me -H "Authorization: Bearer YOUR_API_KEY" ``` Node.js: ```js const axios = require('axios'); axios.get('https://app.smsblast.io/api/v2/me', { headers: { 'Authorization': 'Bearer YOUR_API_KEY' } }) .then(response => console.log(response.data)) .catch(error => console.error(error)); ``` PHP: ```php