> ## Documentation Index
> Fetch the complete documentation index at: https://blaxel-cdrappier-devin-application-runtime-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Snapshots and fork

> Create point-in-time snapshots of sandboxes and fork them into new sandboxes or applications.

Snapshots capture the current state of a sandbox at a point in time. Use snapshots to preserve sandbox state before making changes, or as the basis for forking a sandbox into a new sandbox or [application](/Applications/Overview).

## Create a snapshot

Create a snapshot of an existing sandbox. The snapshot captures the filesystem, running processes, and memory state.

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { SandboxInstance } from "@blaxel/core";

  const sandbox = await SandboxInstance.get("my-sandbox");
  const snapshot = await sandbox.createSnapshot({ name: "before-migration" });
  ```

  ```python Python theme={null}
  from blaxel.core import SandboxInstance

  sandbox = await SandboxInstance.get("my-sandbox")
  snapshot = await sandbox.create_snapshot({"name": "before-migration"})
  ```
</CodeGroup>

HTTP API:

```bash theme={null}
curl -X POST https://api.blaxel.ai/v0/sandboxes/my-sandbox/snapshots \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace" \
  -H "Content-Type: application/json" \
  -d '{ "name": "before-migration" }'
```

## List snapshots

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { SandboxInstance } from "@blaxel/core";

  const sandbox = await SandboxInstance.get("my-sandbox");
  const snapshots = await sandbox.listSnapshots();
  ```

  ```python Python theme={null}
  from blaxel.core import SandboxInstance

  sandbox = await SandboxInstance.get("my-sandbox")
  snapshots = await sandbox.list_snapshots()
  ```
</CodeGroup>

HTTP API:

```bash theme={null}
curl https://api.blaxel.ai/v0/sandboxes/my-sandbox/snapshots \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace"
```

## Delete a snapshot

```bash theme={null}
curl -X DELETE https://api.blaxel.ai/v0/sandboxes/my-sandbox/snapshots/snap_abc123 \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace"
```

## Fork a sandbox

Forking creates a new resource (sandbox or application) from an existing sandbox. The fork inherits the source sandbox's image, memory configuration, environment variables, and port settings.

### Fork into a new sandbox

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { SandboxInstance } from "@blaxel/core";

  const result = await SandboxInstance.fork("my-sandbox", {
    targetName: "my-sandbox-copy",
    targetType: "sandbox",
  });
  ```

  ```python Python theme={null}
  from blaxel.core import SandboxInstance

  result = await SandboxInstance.fork("my-sandbox", {
      "target_name": "my-sandbox-copy",
      "target_type": "sandbox",
  })
  ```
</CodeGroup>

CLI:

```bash theme={null}
bl fork sbx/my-sandbox sbx/my-sandbox-copy
```

HTTP API:

```bash theme={null}
curl -X POST https://api.blaxel.ai/v0/sandboxes/my-sandbox/fork \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace" \
  -H "Content-Type: application/json" \
  -d '{
    "targetType": "sandbox",
    "targetName": "my-sandbox-copy"
  }'
```

### Fork into an application

Create an [application](/Applications/Overview) directly from a running sandbox. The application inherits the sandbox's image, memory, environment variables, and port.

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { SandboxInstance } from "@blaxel/core";

  const result = await SandboxInstance.fork("my-sandbox", {
    targetName: "my-app",
    targetType: "application",
    traffic: 100,
    port: 8080,
  });
  ```

  ```python Python theme={null}
  from blaxel.core import SandboxInstance

  result = await SandboxInstance.fork("my-sandbox", {
      "target_name": "my-app",
      "target_type": "application",
      "traffic": 100,
      "port": 8080,
  })
  ```
</CodeGroup>

CLI:

```bash theme={null}
bl fork sbx/my-sandbox app/my-app --traffic 100 --port 8080
```

HTTP API:

```bash theme={null}
curl -X POST https://api.blaxel.ai/v0/sandboxes/my-sandbox/fork \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace" \
  -H "Content-Type: application/json" \
  -d '{
    "targetType": "application",
    "targetName": "my-app",
    "traffic": 100,
    "port": 8080
  }'
```

### Fork with canary traffic

Fork into an existing application as a canary revision receiving a percentage of traffic:

```bash theme={null}
bl fork sbx/my-sandbox app/my-app --traffic 20 --port 8080
```

### Fork with a custom domain

Attach a custom domain to the forked application using the `customDomain` parameter:

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { SandboxInstance } from "@blaxel/core";

  const result = await SandboxInstance.fork("my-sandbox", {
    targetName: "my-app",
    targetType: "application",
    traffic: 100,
    customDomain: "app.example.com",
  });
  ```

  ```python Python theme={null}
  from blaxel.core import SandboxInstance

  result = await SandboxInstance.fork("my-sandbox", {
      "target_name": "my-app",
      "target_type": "application",
      "traffic": 100,
      "custom_domain": "app.example.com",
  })
  ```
</CodeGroup>

HTTP API:

```bash theme={null}
curl -X POST https://api.blaxel.ai/v0/sandboxes/my-sandbox/fork \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace" \
  -H "Content-Type: application/json" \
  -d '{
    "targetType": "application",
    "targetName": "my-app",
    "traffic": 100,
    "customDomain": "app.example.com"
  }'
```

### Fork from a snapshot

Use the `snapshotId` parameter to fork from a specific snapshot instead of the current sandbox state:

```bash theme={null}
curl -X POST https://api.blaxel.ai/v0/sandboxes/my-sandbox/fork \
  -H "Authorization: Bearer $BL_API_KEY" \
  -H "X-Blaxel-Workspace: my-workspace" \
  -H "Content-Type: application/json" \
  -d '{
    "targetType": "application",
    "targetName": "my-app",
    "snapshotId": "snap_abc123"
  }'
```

## Fork request parameters

| Parameter      | Type    | Description                                                        |
| -------------- | ------- | ------------------------------------------------------------------ |
| `targetType`   | string  | Target resource type: `sandbox` or `application`                   |
| `targetName`   | string  | Name of the resource to create or update                           |
| `traffic`      | integer | Traffic percentage for the new revision (0-100, applications only) |
| `port`         | integer | Port to expose                                                     |
| `customDomain` | string  | Custom domain for the application                                  |
| `prefix`       | string  | URL prefix for the application                                     |
| `snapshotId`   | string  | Fork from a specific snapshot instead of current state             |

<CardGroup cols={2}>
  <Card title="Applications" icon="window" href="/Applications/Overview">
    Deploy long-running services with revision management and traffic splitting.
  </Card>

  <Card title="Sandbox overview" icon="cube" href="/Sandboxes/Overview">
    Learn more about sandbox lifecycle and configuration.
  </Card>
</CardGroup>