# Send SMS with Java

Source: https://jointextkit.com/docs/send-with-java
Index: https://jointextkit.com/llms.txt

Send your first text from Java with the JDK's HttpClient and TextKit's REST API. No dependency to add.

## Prompt for your AI agent

Paste this into Claude Code, Cursor or any coding agent to have it do the
integration:

```text
Add SMS sending to this Java project with TextKit.

- Docs for this stack: https://jointextkit.com/docs/send-with-java.md
- API: POST https://api.jointextkit.com/v1/messages with `Authorization: Bearer
  <key>` and a JSON body `{"to": "+1...", "body": "..."}`.
- There is no Java SDK: POST JSON to https://api.jointextkit.com/v1/messages
  with java.net.http.HttpClient.
- Read the key from the `TEXTKIT_API_KEY` environment variable. Never hardcode
  it or send it to the browser.
- Phone numbers are E.164 and US or Canada only (`+1` followed by 10 digits).
- A test key (`ssms_sk_test_`) simulates: `+15005550006` always ends `delivered`
  and no phone gets a text.
- Errors are JSON: `{"error": {"code", "message", "param"}}` with a 4xx status.
  On `429`, wait `Retry-After` seconds and retry.
- Send only from server code that runs after a real event (a signup, an order).
  Never expose an endpoint that texts any number a visitor types.
```

## Before you start

- **An API key.** [Create a free account](/signup) and copy the test key
  (`ssms_sk_test_...`) from Home in the console. It works at once, no card.
- **Java 17 or later (the example uses a text block and runs as a single file).**
- Put the key in an environment variable:

```bash
export TEXTKIT_API_KEY=ssms_sk_test_...
```

## 1. Send an SMS

Create `SendSms.java`:

```java
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class SendSms {
    public static void main(String[] args) throws Exception {
        String json = """
            {"to": "+15005550006", "body": "Hello from TextKit"}
            """;

        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create("https://api.jointextkit.com/v1/messages"))
            .header("Authorization", "Bearer " + System.getenv("TEXTKIT_API_KEY"))
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(json))
            .build();

        HttpResponse<String> response = HttpClient.newHttpClient()
            .send(request, HttpResponse.BodyHandlers.ofString());

        if (response.statusCode() >= 400) {
            System.err.println(response.statusCode() + " " + response.body());
            System.exit(1);
        }
        System.out.println(response.body());
    }
}
```

## 2. Run it

```bash
java SendSms.java
```

It prints the message as JSON, with its `id` (`msg_...`) and `"status": "delivered"`.
Parse it with the JSON library your project already uses (Jackson, Gson).

## What the test key did

`+15005550006` is a sandbox number: the send comes back `delivered` and no
phone gets a text (the response says `"simulated": true`). Put your own
verified phone in `to` and the test key texts it for real. See
[Sandbox & test numbers](/docs/sandbox).

## Handle errors

The program above already stops on an error and prints the body. A failed request returns a 4xx status and a JSON body
`{"error": {"code": "...", "message": "...", "param": "..."}}`. On `429
rate_limited`, wait the `Retry-After` seconds and try again. Send an
`Idempotency-Key` header (any unique string per message) and a retried request
returns the first result instead of sending twice.

| Status | Code | What to do |
| --- | --- | --- |
| 400 | `invalid_request` | A field is missing or malformed; `param` names it. |
| 401 | `invalid_api_key` | The key is missing, revoked or mistyped. |
| 402 | `insufficient_credits` | Add credits; nothing was sent or charged. |
| 403 | `recipient_opted_out` | They texted STOP. Do not retry. |
| 429 | `rate_limited` | Wait `Retry-After` seconds, then retry. |

Every code is in [Errors](/docs/errors).

## Go live

1. **Add a number** in the [console](/console).
2. **Register your use case.** We file your 10DLC registration; toll-free
   numbers use a guided verification form. Until carriers approve it, the number
   texts only your verified numbers. See [Compliance & registration](/docs/compliance).
3. **Swap in a live key** (`ssms_sk_live_...`). The code stays the same.

## Next steps

- [Webhooks](/docs/webhooks): delivery receipts and replies, pushed to your server.
- [Verify](/docs/verify): one-time codes in two calls, billed only when verified.
- [Send an SMS](/docs/api/messages/send): every field the endpoint takes.
- [All quickstarts](/docs/quickstarts): the same guide for other languages and frameworks.