Install & Run

Get a running Atmosphere app in seconds — no Maven, no project setup, no boilerplate.

Install the CLI

Pick whichever package manager you already have:

curl

curl -fsSL https://raw.githubusercontent.com/Atmosphere/atmosphere/main/cli/install.sh | sh

The installer checks for Java 21+, downloads the atmosphere script to /usr/local/bin, and creates ~/.atmosphere/ for caching.

Homebrew (macOS, Linux)

brew install Atmosphere/tap/atmosphere

SDKMAN (macOS, Linux, WSL)

sdk install atmosphere

SDKMAN manages JDKs, Gradle, Maven, and now Atmosphere side-by-side. Switch versions with sdk use atmosphere <version> and list releases with sdk list atmosphere. If you haven’t installed SDKMAN yet, see sdkman.io.

npx (zero install, scaffolding only)

No Java CLI needed — scaffold a project straight from npm:

npx create-atmosphere-app my-chat-app
npx create-atmosphere-app my-ai-app --template ai-chat

npx gives you atmosphere new functionality without a local install, but running samples still needs the full CLI (curl, brew, or sdk above).

Run Your First App

atmosphere run spring-boot-chat

That’s it. The CLI downloads a pre-built JAR from GitHub Releases, caches it in ~/.atmosphere/cache/, and starts a WebSocket chat app on http://localhost:8080. Open it in your browser — you have a working real-time chat.

Try an AI Chat

atmosphere run spring-boot-ai-chat --env LLM_API_KEY=your-key

This starts an AI streaming chat that connects to Gemini, GPT, Claude, or Ollama — configured via environment variables. Without an API key, it runs in demo mode with simulated streaming.

Browse All Samples

atmosphere install

The interactive picker shows every sample grouped by category. Pick one, then choose to run it or install its source code into your current directory:

  Atmosphere Samples

  CHAT
    1) spring-boot-chat                Real-time WebSocket chat with Spring Boot
    2) quarkus-chat                    Real-time WebSocket chat with Quarkus
    3) embedded-jetty-websocket-chat   Embedded Jetty WebSocket chat (no framework)

  AI
    4) spring-boot-ai-chat             AI streaming with conversation memory and structured events
    5) spring-boot-ai-classroom        Multiple clients share streaming AI responses
    6) spring-boot-ai-tools            Framework-agnostic @AiTool tool calling
    7) spring-boot-koog-chat           Kotlin-based Koog agent chat
    ...

  Pick a sample:

If fzf is installed, you get fuzzy-search instead of numbered menus.

Filter by Category or Tag

atmosphere install --tag ai          # AI samples only
atmosphere install --category tools  # Tool-calling samples
atmosphere list                      # List all samples without the picker
atmosphere info spring-boot-ai-chat  # Show details about a specific sample

Create a New Project

When you’re ready to write your own code:

atmosphere new my-app
atmosphere new my-ai-app --template ai-chat
atmosphere new my-rag-app --template rag

This scaffolds a complete Spring Boot + Atmosphere project with pom.xml, source code, and a frontend. Run it with ./mvnw spring-boot:run.

Available Templates

atmosphere new sparse-clones the matching sample from cli/samples.json and rewrites the cloned pom.xml so its parent resolves from Maven Central — the result compiles standalone with plain mvn compile.

Template	Source sample	What you get
`chat`	`spring-boot-chat`	WebSocket chat with Broadcaster and `@ManagedService`
`ai-chat`	`spring-boot-ai-chat`	`@AiEndpoint` with streaming, conversation memory, configurable LLM backend
`ai-tools`	`spring-boot-ai-tools`	`@AiTool` tool calling, approval gates
`mcp-server`	`spring-boot-mcp-server`	MCP tools, resources, and prompts
`rag`	`spring-boot-rag-chat`	RAG chat with Spring AI vector store + embeddings
`agent`	`spring-boot-dentist-agent`	Single agent with `@Agent` / `@Command` + skill file
`koog`	`spring-boot-koog-chat`	JetBrains Koog runtime (Kotlin)
`semantic-kernel`	`spring-boot-semantic-kernel-chat`	Microsoft Semantic Kernel runtime
`multi-agent`	`spring-boot-multi-agent-startup-team`	5-agent `@Coordinator` fleet with A2A specialists
`classroom`	`spring-boot-ai-classroom`	Multi-room shared AI (Spring Boot + Expo React Native client)

Pass --skill-file <path> to auto-select the agent template with your skill file wired in.

npx Alternative (Zero Install)

No Java CLI needed — scaffold from npm:

npx create-atmosphere-app my-chat-app
npx create-atmosphere-app my-ai-app --template ai-chat

create-atmosphere-app is a thin shim over the same atmosphere new CLI — it delegates to the installed binary, so the template list is always in sync.

Sample Catalog

Chat

Sample	Description	Port
`spring-boot-chat`	Real-time WebSocket chat with Spring Boot	8080
`quarkus-chat`	Real-time WebSocket chat with Quarkus	8080
`embedded-jetty-websocket-chat`	Embedded Jetty, no framework	8080

AI Streaming & Tools

Sample	Description	Port
`spring-boot-ai-chat`	Conversation memory, structured events, capability validation	8080
`spring-boot-ai-classroom`	Multiple clients share streaming AI responses	8080
`spring-boot-ai-tools`	Framework-agnostic `@AiTool` tool calling	8080
`spring-boot-koog-chat`	Kotlin-based Koog agent chat	8080
`spring-boot-rag-chat`	RAG with Spring AI vector store	8080

Agents & Coordination

Sample	Description	Port
`spring-boot-dentist-agent`	Single-agent workflow with `@Agent` / `@Command`	8080
`spring-boot-multi-agent-startup-team`	Multi-agent coordinator with `@Coordinator` and `@Fleet`	8080
`spring-boot-orchestration-demo`	Orchestration primitives (handoffs, routing, judges)	8080
`spring-boot-a2a-agent`	Agent-to-agent (A2A) protocol	8080
`spring-boot-checkpoint-agent`	Agent with checkpoint/recovery	8080

Infrastructure

Sample	Description	Port
`spring-boot-mcp-server`	MCP tools, resources, and prompts for AI agents	8080
`spring-boot-otel-chat`	OpenTelemetry tracing with Jaeger	8080
`spring-boot-durable-sessions`	Session persistence with SQLite	8080
`spring-boot-channels-chat`	Channels API for pub/sub routing	8080
`spring-boot-agui-chat`	AgUI real-time agent UI	8080
`grpc-chat`	Mixed WebSocket + gRPC transport	8080

Run atmosphere list for the full, current sample catalog.

Environment Variables

All AI samples accept the same environment variables:

Variable	Description	Default
`LLM_API_KEY`	API key for your LLM provider	(none — runs in demo mode)
`LLM_MODEL`	Model name	`gemini-2.5-flash`
`LLM_BASE_URL`	Override API endpoint	(auto-detected from model name)
`LLM_MODE`	`remote` or `local` (Ollama)	`remote`

Pass them via --env:

atmosphere run spring-boot-ai-chat \
  --env LLM_API_KEY=your-key \
  --env LLM_MODEL=gpt-4o

Requirements

Requirement	Version	How to install
Java	21+	`brew install openjdk@21` or SDKMAN
fzf	(optional)	`brew install fzf` — for fuzzy-search sample picker

What’s Next

Once you have a running sample, you’re ready to understand the code. Start with Chapter 1: Introduction for the architecture, or jump straight to Chapter 2: Getting Started to build your first app from scratch.