Sprites

Everruns integrates with Sprites to provide persistent, hardware-isolated Linux microVMs powered by Firecracker. Unlike ephemeral sandboxes, Sprites maintain their filesystem across idle periods, support instant checkpoint/restore, and expose public HTTP endpoints.

What You Get

• Persistent Filesystem: Full ext4 filesystem survives between sessions, backed to durable object storage
• Hardware Isolation: Firecracker VM-level isolation (stronger than containers)
• Checkpoints: Snapshot filesystem state in ~300ms for safe rollback before risky operations
• HTTP Services: Each sprite gets a unique public URL for exposing web services
• Instant Wake: Sprites wake from hibernation in <1 second
• Multi-Sprite Sessions: Create and manage multiple sprites per session

Quick Start

1. Get Your API Token

1. Install the Sprites CLI: curl https://sprites.dev/install.sh | bash
2. Run sprite login to authenticate
3. Copy your token from the CLI output or dashboard

2. Connect in Everruns

1. Go to Settings > Connections
2. Find Sprites in the available providers
3. Click Connect and paste your API token

Once connected, the Sprites capability is automatically available in agent sessions.

3. Use in Sessions

Agents with the Sprites capability can use these tools:

Tool	Description
sprites_create_sprite	Create a new Firecracker microVM
sprites_exec	Execute shell commands (wakes sprite if hibernating)
sprites_read_file	Read files from sprite filesystem
sprites_write_file	Write files to sprite filesystem
sprites_list_sprites	List sprites in this session
sprites_manage_sprite	Delete sprites
sprites_checkpoint	Create a filesystem checkpoint
sprites_restore_checkpoint	Restore to a previous checkpoint
sprites_service_url	Get the public HTTP URL for a sprite

Checkpoints

Sprites support instant filesystem checkpointing — a unique capability not found in other sandbox providers:

1. Before risky operations: Call sprites_checkpoint to snapshot the current state
2. If something goes wrong: Call sprites_restore_checkpoint to roll back
3. Checkpoints are fast: ~300ms without interrupting the running sprite

This makes Sprites ideal for iterative development where agents need to experiment safely.

HTTP Services

Each sprite gets a unique public URL. To expose a web service:

1. Start a web server inside the sprite listening on port 8080
2. Call sprites_service_url to get the public URL
3. Share the URL for testing or preview

Sprite Lifecycle

Created → Running → Hibernating (idle) → Running (on next command)
                 ↘ Deleted (explicit)

• Running: Active, consuming compute resources
• Hibernating: Idle, no compute charges, filesystem preserved on durable storage
• Deleted: Permanently removed, all data lost

Sprites persist indefinitely until explicitly deleted. They hibernate automatically when idle (no compute charges while idle). Always delete sprites when done to avoid storage charges.

Pricing

Sprites bill per-second for compute and per-GB-hour for storage:

• CPU: $0.07/CPU-hour
• Memory: $0.04375/GB-hour
• Storage: $0.000027/GB-hour (persistent), $0.000683/GB-hour (hot NVMe cache)
• Idle: No compute charges (filesystem still persisted)

New users receive $30 trial credits (~500 sprite sessions).

Security

• Firecracker VMs: Hardware-level isolation between sprites
• L3 Network Policies: Domain whitelisting for outbound connections
• Encrypted Credentials: API token stored in user connections (encrypted at rest)
• Leased Resources: Sprites registered for automatic cleanup on session end