# E2B Stack

In the [AI Enablement Stack](/docs/introduction/ai-enablement-stack), **Blekline is Layer 4** and **E2B is Layer 1** (Firecracker microVM sandboxes for AI agents).

| Layer | Product | Role |
|-------|---------|------|
| **L4** | Blekline | Mask prompts, classify risk, govern MCP tool calls, audit |
| **L1** | E2B | Isolated code interpreter, desktop sandboxes, MCP tools |

## Wiring

1. Connect `@blekline/mcp-proxy` — [MCP proxy](/docs/mcp/proxy)
2. Set `BLEKLINE_DOWNSTREAM_MCP_COMMAND` to E2B MCP server
3. Provide `E2B_API_KEY`

```bash
export BLEKLINE_DOWNSTREAM_MCP_COMMAND="npx,-y,@e2b/mcp-server"
export BLEKLINE_DOWNSTREAM_SERVER=e2b
export E2B_API_KEY=...
```

**Flow:** L5 Agent → L4 Blekline proxy → L1 E2B MCP → sandbox.

See [E2B documentation](https://e2b.dev/docs) for SDK and MCP server setup.

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**Next steps:** [Sandbox providers](/docs/integrations/sandbox-providers) · [AI Enablement Stack](/docs/introduction/ai-enablement-stack) · [MCP Cursor setup](/docs/mcp/cursor) · [Open workspace](https://app.blekline.com)