Merge pull request #613 from trycua/align-playground-blog-structure

Add playground blog

Author: f-trycua

blog/cua-playground-preview.md

@@ -0,0 +1,86 @@
+# Cua Playground: Agents + Sandboxes in Your Browser
+
+Building computer-use agents means constant iteration—writing code, deploying to a sandbox, testing behavior, debugging issues, then repeating the cycle. Every test requires switching between your code editor, terminal, and VNC viewer. Want to try a different prompt? Edit your code, redeploy, and wait for the agent to restart. It works, but it's slow.
+
+Today we're launching the **Cua Playground**: a browser-based environment for testing computer-use agents without writing code. Send messages to your sandboxes, watch them execute in real-time, and iterate on prompts instantly—all from your dashboard at cua.ai.
+
+![Cua Playground](https://github.com/user-attachments/assets/af1071ba-3df3-4e4b-aafb-df8c3d00b0a5)
+
+**What's new with this release:**
+
+- Instant testing—send messages to any running sandbox directly from your browser
+- Real-time execution—watch your agent work with live tool call updates and screenshots
+- Multi-model support—test with Claude Sonnet 4.5, Haiku 4.5, and more
+- Persistent chat history—conversations save automatically to local storage
+
+The Playground connects to your existing Cua sandboxes—the same ones you use with the Agent SDK. Select a running sandbox and a model, then start chatting. The agent uses computer-use tools (mouse, keyboard, bash, editor) to complete your tasks, and you see every action it takes.
+
+## Getting Started Today
+
+<div align="center">
+  <video src="https://github.com/user-attachments/assets/9fef0f30-1024-4833-8b7a-6a2c02d8eb99" width="600" controls></video>
+</div>
+
+
+Sign up at [cua.ai/signin](https://cua.ai/signin) and grab your API key from the dashboard. Then navigate to the Playground:
+
+1. Navigate to Dashboard > Playground
+2. Select a sandbox from the dropdown (must be "running" status)
+3. Choose a model (we recommend Claude Sonnet 4.5 to start)
+4. Send a message: "Take a screenshot and describe what you see"
+5. Watch the agent execute computer actions in real-time
+
+Example use cases:
+
+**Prompt Testing**
+```
+❌ "Check the website"
+✅ "Navigate to example.com in Firefox and take a screenshot of the homepage"
+```
+
+**Model Comparison**
+Run the same task with different models to compare quality, speed, and cost.
+
+**Debugging Agent Behavior**
+1. Send: "Find the login button and click it"
+2. View tool calls to see each mouse movement
+3. Check screenshots to verify the agent found the right element
+4. Adjust your prompt based on what you observe
+
+## FAQs
+
+<details>
+<summary><strong>Do I need to know how to code?</strong></summary>
+
+No. The Playground is designed for testing agent behavior without writing code. However, for production deployments, you'll need to use the Agent SDK (Python/TypeScript).
+
+</details>
+
+<details>
+<summary><strong>Does this replace the Agent SDK?</strong></summary>
+
+No. The Playground is for rapid testing and experimentation. For production deployments, scheduled tasks, or complex workflows, use the Agent SDK.
+
+</details>
+
+<details>
+<summary><strong>How much does it cost?</strong></summary>
+
+Playground requests use the same credit system as Agent SDK requests. You're charged for model inference (varies by model) and sandbox runtime (billed per hour while running).
+
+</details>
+
+<details>
+<summary><strong>Why is my sandbox not showing up?</strong></summary>
+
+The sandbox must have `status = "running"` to appear in the dropdown. Check Dashboard > Sandboxes to verify status. If stopped, click "Start" and wait ~30 seconds for it to become available.
+
+</details>
+
+## Need help?
+
+If you hit issues getting the Playground working, reach out in [Discord](https://discord.gg/cua-ai). We respond fast and fix based on what people actually use.
+
+---
+
+Get started at [cua.ai](https://cua.ai) or try the Playground at [cua.ai/dashboard/playground](https://cua.ai/dashboard/playground).