feat(docs): sandbox agent sdk + e2b usage docs

docs.json

@@ -56,6 +56,7 @@
               "docs/agents/amp",
               "docs/agents/claude-code",
               "docs/agents/codex",
+              "docs/agents/sandbox-agent-sdk",
               {
                 "group": "OpenClaw",
                 "icon": "https://mintlify.s3.us-west-1.amazonaws.com/e2b-openclaw-icon/images/icons/openclaw.svg",

docs/agents/sandbox-agent-sdk.mdx

@@ -0,0 +1,102 @@
+---
+title: "Sandbox Agent SDK"
+description: "Run Sandbox Agent inside an E2B sandbox and control it from a local Node.js script."
+---
+
+This guide shows how to run [Sandbox Agent](https://github.com/rivet-dev/sandbox-agent) inside an E2B sandbox and control it with the [Sandbox Agent SDK](https://sandboxagent.dev/docs/sdk-overview).
+
+Sandbox Agent lets you run coding agents in sandboxes and control them from your own backend over HTTP.
+
+- **Universal Agent API** - A single interface to manage Claude Code, Codex, OpenCode, Cursor, Amp, and Pi with full feature coverage across every supported agent.
+- **Universal Session Schema** - A standardized schema that normalizes all agent event formats into a consistent structure for storage and replay.
+- **Server or SDK Mode** - Run as a standalone HTTP server or integrate natively using the TypeScript SDK.
+
+## Workflow overview
+
+- A local Node.js script starts an E2B sandbox and boots the Sandbox Agent server inside it.
+- The script opens a session, sends a prompt to an agent (Claude in this example), and prints the response.
+- When the script exits, the sandbox is destroyed.
+
+## Prerequisites
+
+- `E2B_API_KEY`
+- At least one provider key: `OPENAI_API_KEY`, `CODEX_API_KEY`, or `ANTHROPIC_API_KEY`
+
+## Setup
+
+Install dependencies:
+
+```bash
+npm install sandbox-agent dotenv tsx @e2b/code-interpreter
+```
+
+Create a `.env` file:
+
+```bash
+E2B_API_KEY=your_e2b_api_key
+ANTHROPIC_API_KEY=your_anthropic_api_key
+# OPENAI_API_KEY=your_openai_api_key
+```
+
+Create `index.ts` with the snippets below, then run:
+
+```bash
+node --import tsx index.ts
+```
+
+## Code snippets
+
+Forward your provider credentials into the sandbox:
+
+```ts
+import "dotenv/config";
+const envs: Record<string, string> = {};
+if (process.env.ANTHROPIC_API_KEY) envs.ANTHROPIC_API_KEY = process.env.ANTHROPIC_API_KEY;
+if (process.env.OPENAI_API_KEY) envs.OPENAI_API_KEY = process.env.OPENAI_API_KEY;
+```
+
+Start Sandbox Agent with the E2B provider:
+
+```ts
+import { SandboxAgent } from 'sandbox-agent';
+import { e2b } from 'sandbox-agent/e2b';
+
+const sdk = await SandboxAgent.start({
+  sandbox: e2b({
+    create: { envs },
+  })
+});
+
+// The printed inspector URL is where you can open
+// the Sandbox Agent inspector UI.
+console.log(`Inspector URL: ${sdk.inspectorUrl}`);
+```
+
+Send a prompt, and stream events:
+
+```ts
+const session = await sdk.createSession({ agent: 'claude' });
+const off = session.onEvent((event) => {
+    console.log(`[event] from ${event.sender}`, event.payload);
+});
+await session.prompt([
+  { type: 'text', text: 'Summarize this repository' }
+]);
+off();
+```
+
+Read more about [Sessions and Events](https://sandboxagent.dev/docs/agent-sessions).
+
+Finally, once done, destroy the sandbox:
+
+```ts
+await sdk.destroySandbox();
+```
+
+## Customize the agent
+
+To use a different agent, update the `agent` value in `createSession` (for example, `codex`) and ensure the corresponding provider credentials are available in the environment.
+
+## Full example
+
+See the complete project here in the [e2b-cookbook repo](https://github.com/rivet-dev/e2b-cookbook/tree/main/examples/sandbox-agent-sdk).