Before you start<\/h2>\n\n- Create a free account at fast2sms.com<\/a> and copy your API key from the Dev API section.<\/li>\n
- Connect a WhatsApp Business number (new, or your existing app number). Free, no setup fee. Steps in the Cloud API guide<\/a>.<\/li>\n
- Get a template approved (marketing, utility, or authentication). Every approved template gets its own ready-made API.<\/li>\n<\/ol>\n
\n ![\"API](\"https:\/\/www.fast2sms.com\/help\/wp-content\/uploads\/2026\/03\/Screenshot-2026-03-27-at-10.42.38-PM.png\")
Your API key goes in the Authorization header of every request.<\/figcaption><\/figure>\nSend a template message<\/h2>\n
One GET request sends an approved template to any WhatsApp number:<\/p>\n
curl \"https:\/\/www.fast2sms.com\/dev\/whatsapp?message_id=9&phone_number_id=579519398574288&numbers=9999999999&variables_values=Rahul|1234\" \\\n -H \"Authorization: YOUR_API_KEY\"<\/code><\/pre>\nThe parameters:<\/p>\n
\nmessage_id<\/code> \u2014 the ID of your approved template (shown in your panel).<\/li>\nphone_number_id<\/code> \u2014 your WhatsApp Business number’s ID.<\/li>\nnumbers<\/code> \u2014 recipient’s 10-digit Indian mobile number.<\/li>\nvariables_values<\/code> \u2014 values for template variables, separated by a pipe, like Rahul|1234<\/code>.<\/li>\nmedia_url<\/code> \u2014 optional, for templates with an image or PDF header.<\/li>\ndocument_filename<\/code> \u2014 optional, the file name the customer sees on a PDF.<\/li>\n<\/ul>\nSuccess response:<\/p>\n
{\n \"status\": true,\n \"message\": \"Message sent successfully\",\n \"request_id\": \"6a3b2c1d\"\n}<\/code><\/pre>\nKeep the request_id<\/code>. It traces the message in delivery reports.<\/p>\nEvery template comes with a ready API<\/h2>\n
You do not have to build requests by hand. The panel generates the exact API call for each approved template, and you can download all of them as a sheet.<\/p>\n\n ![\"Sheet](\"https:\/\/www.fast2sms.com\/help\/wp-content\/uploads\/2026\/03\/Screenshot-2026-03-27-at-10.45.22-PM.png\")
Ready APIs for every approved template. Copy, add values, send.<\/figcaption><\/figure>\nMore than templates<\/h2>\n\n- Session messages.<\/strong> Reply free-form within the 24-hour customer service window.<\/li>\n
- Authentication templates.<\/strong> Purpose-built OTP messages. Pair with Smart OTP<\/a> for SMS fallback.<\/li>\n
- Media, carousel and flows templates.<\/strong> Rich formats for offers and forms.<\/li>\n
- Template management by API.<\/strong> Create, edit, delete and list templates programmatically.<\/li>\n<\/ul>\n
Webhooks: know what happened<\/h2>\n
Create a WhatsApp webhook and Fast2SMS calls your URL with delivery events, so your database always knows if a message was sent, delivered or failed. Webhook endpoints exist for SMS and OTP events too, plus a logs API for pulling history. All documented at docs.fast2sms.com<\/a>.<\/p>\nFrequently asked questions<\/h2>\nWhat does the WhatsApp API cost?<\/h3>\n
Access is free with no monthly fee. Messages are billed per delivered message: INR 0.25 for utility and authentication, INR 0.95 for marketing. Failed messages are refunded automatically.<\/p>\n
Which numbers can receive messages?<\/h3>\n
Any WhatsApp user. Sending is set up for Indian businesses, and recipient numbers are Indian 10-digit numbers.<\/p>\n
Do I need Meta developer approval myself?<\/h3>\n
No. Connect your number through the Fast2SMS panel with Facebook login, get templates approved there, and use the simple REST API above. Fast2SMS handles the Meta side.<\/p>\n
Can I send bulk campaigns through the API?<\/h3>\n
Yes, loop your list with one request per number, or use the panel broadcast. See how to send bulk WhatsApp messages<\/a>.<\/p>\nIs there an SMS API too?<\/h3>\n
Yes, same account and same key. See the bulk SMS API guide<\/a>.<\/p>\nWhere are the full docs?<\/h3>\n
docs.fast2sms.com<\/a> covers every endpoint: messages, templates, webhooks, logs and wallet balance.<\/p>\nGet your API key<\/h2>\n
Create your free account, connect your WhatsApp number, and send your first API message today.<\/p>\n
Send a template message<\/h2>\n
One GET request sends an approved template to any WhatsApp number:<\/p>\n
curl \"https:\/\/www.fast2sms.com\/dev\/whatsapp?message_id=9&phone_number_id=579519398574288&numbers=9999999999&variables_values=Rahul|1234\" \\\n -H \"Authorization: YOUR_API_KEY\"<\/code><\/pre>\nThe parameters:<\/p>\n
\nmessage_id<\/code> \u2014 the ID of your approved template (shown in your panel).<\/li>\nphone_number_id<\/code> \u2014 your WhatsApp Business number’s ID.<\/li>\nnumbers<\/code> \u2014 recipient’s 10-digit Indian mobile number.<\/li>\nvariables_values<\/code> \u2014 values for template variables, separated by a pipe, like Rahul|1234<\/code>.<\/li>\nmedia_url<\/code> \u2014 optional, for templates with an image or PDF header.<\/li>\ndocument_filename<\/code> \u2014 optional, the file name the customer sees on a PDF.<\/li>\n<\/ul>\nSuccess response:<\/p>\n
{\n \"status\": true,\n \"message\": \"Message sent successfully\",\n \"request_id\": \"6a3b2c1d\"\n}<\/code><\/pre>\nKeep the request_id<\/code>. It traces the message in delivery reports.<\/p>\nEvery template comes with a ready API<\/h2>\n
You do not have to build requests by hand. The panel generates the exact API call for each approved template, and you can download all of them as a sheet.<\/p>\n\n Ready APIs for every approved template. Copy, add values, send.<\/figcaption><\/figure>\nMore than templates<\/h2>\n\n- Session messages.<\/strong> Reply free-form within the 24-hour customer service window.<\/li>\n
- Authentication templates.<\/strong> Purpose-built OTP messages. Pair with Smart OTP<\/a> for SMS fallback.<\/li>\n
- Media, carousel and flows templates.<\/strong> Rich formats for offers and forms.<\/li>\n
- Template management by API.<\/strong> Create, edit, delete and list templates programmatically.<\/li>\n<\/ul>\n
Webhooks: know what happened<\/h2>\n
Create a WhatsApp webhook and Fast2SMS calls your URL with delivery events, so your database always knows if a message was sent, delivered or failed. Webhook endpoints exist for SMS and OTP events too, plus a logs API for pulling history. All documented at docs.fast2sms.com<\/a>.<\/p>\nFrequently asked questions<\/h2>\nWhat does the WhatsApp API cost?<\/h3>\n
Access is free with no monthly fee. Messages are billed per delivered message: INR 0.25 for utility and authentication, INR 0.95 for marketing. Failed messages are refunded automatically.<\/p>\n
Which numbers can receive messages?<\/h3>\n
Any WhatsApp user. Sending is set up for Indian businesses, and recipient numbers are Indian 10-digit numbers.<\/p>\n
Do I need Meta developer approval myself?<\/h3>\n
No. Connect your number through the Fast2SMS panel with Facebook login, get templates approved there, and use the simple REST API above. Fast2SMS handles the Meta side.<\/p>\n
Can I send bulk campaigns through the API?<\/h3>\n
Yes, loop your list with one request per number, or use the panel broadcast. See how to send bulk WhatsApp messages<\/a>.<\/p>\nIs there an SMS API too?<\/h3>\n
Yes, same account and same key. See the bulk SMS API guide<\/a>.<\/p>\nWhere are the full docs?<\/h3>\n
docs.fast2sms.com<\/a> covers every endpoint: messages, templates, webhooks, logs and wallet balance.<\/p>\nGet your API key<\/h2>\n
Create your free account, connect your WhatsApp number, and send your first API message today.<\/p>\n