HTTP API Messaging
A clean, well-documented RESTful SMS API that integrates into any application or technology stack in minutes — with the tooling, sandbox, and developer experience your team expects.
Easy Integration
Our HTTP SMS API is built for teams that want to add SMS to their application without weeks of integration work. The API follows REST principles, uses standard JSON for all requests and responses, and requires nothing more than an API key for authentication. There is no SDK required — any language that can make an HTTP POST request can send SMS within minutes.
Delivery receipts arrive via webhook with a simple HTTP POST to your endpoint, eliminating the need to poll for status. Inbound (MO) messages are forwarded the same way, making two-way SMS workflows straightforward to implement. We have built-in idempotency key support so retry logic in your application will never result in duplicate sends, even if a network timeout occurs between your request and our response.
View API DocumentationKey Capabilities
- Single REST endpoint for sending — POST /messages
- API key authentication, no OAuth complexity
- JSON request and response throughout
- Delivery receipt webhooks with full status data
- Inbound (MO) message webhooks for two-way SMS
- Comprehensive, machine-readable error codes
- Idempotency keys for safe retries
- Rate limit headers in every response
Developer-Ready
Good API documentation is not optional — it is how developers evaluate whether they can trust an API before committing to an integration. Our documentation covers every endpoint, every parameter, every response code, and every edge case, with real examples in multiple languages. We publish an OpenAPI specification so you can generate client libraries in any language and import the spec into your existing tooling.
Our sandbox environment lets you test the full send-and-receive flow, including webhook delivery, without touching real networks or incurring costs. Test numbers simulate real delivery and failure scenarios so your application can handle edge cases before going live. The developer portal gives your team a single place for API credentials, live request logs, webhook event history, usage metrics, and spend tracking — reducing time spent on account management and debugging.
View API DocumentationKey Capabilities
- Complete API reference documentation with examples
- SDKs for PHP, Python, Node.js, Ruby, Java, and Go
- Sandbox environment with simulated delivery and failures
- Live request log in developer portal
- Webhook event history and replay tool
- Usage metrics and spend dashboards
- OpenAPI 3.0 specification for tooling integration
- Code examples for the most common use cases
Built for Developers Across Every Industry
Any application that needs to communicate with users via SMS can integrate our HTTP API — from indie developers to global enterprises.
From API Key to First Send in Minutes
No complex setup, no lengthy onboarding. If you can make an HTTP request, you can send SMS with our API.
Get your API key
Sign up or contact our team. API credentials are provisioned immediately. Your key is ready to use in the sandbox within minutes of account creation.
Send your first message
A single HTTP POST with your API key, destination number, and message text. Our API responds with a message ID and queued status within milliseconds.
Receive delivery confirmation
When the message is delivered to the handset, we fire a webhook to your endpoint with the full delivery receipt, including carrier and timestamp data.
HTTP API — Frequently Asked Questions
What is an SMS HTTP API and how does it work?
An SMS HTTP API is a web service that allows your application to send and receive SMS messages by making standard HTTP requests. Your application sends a POST request to our API endpoint with the message content, destination number, and your API key. Our gateway routes the message through carrier networks to the recipient's handset, and sends a delivery receipt back to your specified webhook URL when delivery is confirmed.
How do I get started with your SMS API?
Contact our team or submit an enquiry via our contact page. We will provision your account and API credentials, usually within one business day. You can start testing immediately in our sandbox environment, and our documentation provides ready-to-run code examples in multiple languages so you can make your first API call within minutes of receiving your credentials.
Which programming languages and frameworks are supported?
Our HTTP API is language-agnostic — any language capable of making HTTP POST requests can integrate with it. We provide native SDKs for PHP, Python, Node.js, Ruby, Java, and Go, as well as code examples for frameworks including Laravel, Django, Express, Rails, and Spring. We also publish an OpenAPI 3.0 specification that can be used to auto-generate client libraries in any language.
How do delivery receipt webhooks work?
When you send a message, you include a webhook URL in your request (or set a default in your account settings). When the message status changes — delivered, failed, or expired — we send an HTTP POST request to your webhook URL with a JSON payload containing the message ID, status, timestamp, and carrier data. Your endpoint should respond with a 200 HTTP status to acknowledge receipt. We retry failed webhook deliveries automatically.
Is there a sandbox environment for testing?
Yes. Our sandbox environment is a full simulation of the production API, including send, delivery receipt, and inbound message flows. Sandbox messages are not sent to real networks, so you can test freely without cost or risk. We provide a set of test numbers that simulate different delivery scenarios including successful delivery, handset unreachable, and invalid number responses, allowing you to test your error handling logic before going live.
What are the API rate limits?
Rate limits depend on your account tier. Standard accounts support up to 100 messages per second. Higher limits are available for enterprise accounts and can be configured based on your expected volumes. Rate limit status is communicated via standard HTTP response headers (X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset) in every API response, allowing your application to implement compliant throttling. Contact our team to discuss limits appropriate for your use case.
Start Building with Our SMS API.
Get your API credentials today and start sending in minutes. Full documentation, sandbox environment, and developer support included.