[Example] 300 — Spring Boot Real-Time Transcription with Deepgram Java SDK

examples/300-spring-boot-live-transcription-java/.env.example

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+# Deepgram — https://console.deepgram.com/
+DEEPGRAM_API_KEY=

examples/300-spring-boot-live-transcription-java/.gitignore

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+target/

examples/300-spring-boot-live-transcription-java/.mvn/wrapper/maven-wrapper.properties

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+wrapperVersion=3.3.4
+distributionType=only-script
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.9/apache-maven-3.9.9-bin.zip

examples/300-spring-boot-live-transcription-java/README.md

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+# Spring Boot Real-Time Transcription with Deepgram
+
+A Spring Boot 3 application that provides a WebSocket endpoint for real-time audio transcription using Deepgram's live STT API (Nova-3). Clients connect via WebSocket, send audio data, and receive live transcription results streamed back in real time.
+
+## What you'll build
+
+A Java Spring Boot server that accepts browser WebSocket connections, proxies raw audio to Deepgram's live STT WebSocket, and streams transcription results back to the client. Includes a built-in HTML test page for browser-based microphone capture.
+
+## Prerequisites
+
+- Java 17+
+- Maven 3.9+ (or use the included Maven wrapper)
+- Deepgram account — [get a free API key](https://console.deepgram.com/)
+
+## Environment variables
+
+| Variable | Where to find it |
+|----------|-----------------|
+| `DEEPGRAM_API_KEY` | [Deepgram console](https://console.deepgram.com/) → Settings → API Keys |
+
+## Install and run
+
+```bash
+cp .env.example .env
+# Edit .env and add your DEEPGRAM_API_KEY
+
+export $(grep -v '^#' .env | xargs)
+./mvnw spring-boot:run
+```
+
+Then open [http://localhost:8080](http://localhost:8080) in your browser, click **Start**, and speak into your microphone.
+
+## Key parameters
+
+| Parameter | Value | Description |
+|-----------|-------|-------------|
+| `model` | `nova-3` | Deepgram's highest-accuracy transcription model |
+| `smartFormat` | `true` | Formats numbers, dates, currencies automatically |
+| `interimResults` | `true` | Returns partial results as audio streams in |
+| `tag` | `deepgram-examples` | Tags API usage for Deepgram console analytics |
+
+## How it works
+
+1. Browser opens a WebSocket connection to `/ws/transcribe`
+2. Spring Boot handler opens a corresponding Deepgram live STT WebSocket (Nova-3)
+3. Browser captures microphone audio via `getUserMedia`, converts to 16-bit PCM, and sends binary frames
+4. Handler forwards raw audio bytes to Deepgram in real time
+5. Deepgram returns interim and final transcription results
+6. Handler forwards transcript JSON back to the browser
+7. On disconnect, handler sends `CloseStream` to Deepgram and cleans up
+
+## Health check
+
+Spring Boot Actuator exposes a health endpoint at `GET /actuator/health`.
+
+## Starter templates
+
+[deepgram-starters](https://github.com/orgs/deepgram-starters/repositories)