Send Customized SMS

Customized SMS lets you merge recipient data into the final message before it is sent.

Endpoints

POST /api/v2/messages/sms/bulk

Use the standard bulk SMS endpoint with custom_data to render one message per recipient.

Authorization

Pass your API token using standard HTTP Bearer authentication:

Authorization: Bearer bk_live_8n6JQv3K1h9Lp0Md
Content-Type: application/json

Supported placeholder formats

Bulkit supports both:

• {{first_name}}
• __FIRST_NAME__

Common aliases like Number, Phone, and Mobile resolve to the recipient number.

Example template

Hello {{first_name}}, your account __ACCOUNT__ is due on {{due_date}}.

Example cURL Request

curl -X POST "https://api.bulkitsms.com/api/v2/messages/sms/bulk" \
  -H "Authorization: Bearer bk_live_8n6JQv3K1h9Lp0Md" \
  -H "Content-Type: application/json" \
  -d '{
    "sender": "BULK_IT",
    "mobiles": ["254700000001", "254733000002"],
    "message": "Hello {{first_name}}, your balance is {{balance}}.",
    "custom_data": [
      {
        "Mobile": "254700000001",
        "first_name": "Amina",
        "balance": "KES 1,240"
      },
      {
        "Mobile": "254733000002",
        "first_name": "Brian",
        "balance": "KES 560"
      }
    ]
  }'

How it works

• the backend matches each custom_data row to a recipient by mobile number
• placeholders are rendered before the message is stored and queued
• outbox and history show the final rendered message, not the raw template

Notes

• make sure each custom data row contains the correct recipient number
• use consistent field names across all rows
• if a placeholder value is missing, the unresolved token may remain in the message

Error response

{
  "status": "error",
  "message": "Invalid message"
}