# Fly.io Sprites

Persistent Firecracker microVMs for agents and dev environments that pause when idle, billed for CPU time and memory actually used plus storage.

- Operated by: Fly.io, Inc.
- Status: Active [1]
- Website: https://fly.io/sprites
- Categories: Agent sandboxes, Devboxes
- Checked: 31 Oct 2026

## Sprites (Agent sandboxes)

- Price: $0.0385 /vCPU-h (+ $0.0219 per GB-hour)
- 1-hour session: ≥ $0.164 (2 vCPU / 4 GB · rank 12 of 26)
- Fleet month: ≥ $1,448 (50 × 8 h × 22 days)
- Billed on: Active CPU (increment unknown)
- Isolation: Firecracker microVM (max session unknown)

What to know:

- Active-CPU billing: Only CPU in use is billed, so idle time costs less; the light-use column shows how much.

### Plans

- Pay-as-you-go: Free; Usage at standard rates; 10 Sprite creations a minute; community support [1]
- Adventurer: unknown (Price not on the current pages; the 2026-01-22 release notes listed 'Level 20 (Adventurer) - $20/mo'); 60 Sprite creations a minute; community support [1]
- Veteran: unknown (Named in the Sprites FAQ; price not published); Community support [1]
- Hero: $100 /month; 1,200 CPU-hours, 4,800 RAM GB-hours, 150 GB storage; 100 running and 100 warm Sprites; standard email support [1]
- Champion: unknown (Named in the Sprites FAQ; price not published); Standard email support [1]
- Legend: unknown (Price not on the current pages; the 2026-01-22 release notes listed 'Level 200 (Legend) - $200/mo'); Standard email support [1]
- Epic: unknown (Named in the Sprites FAQ; price not published); Premium email support [1]
- Mythic: $2,000 /month; 28,000 RAM GB-hours; 240 Sprite creations a minute; premium email support [1]

### Billing

- Payment: Metered: usage billed afterwards [1]
- Plan minimum: None [1]
- Billing increment: unknown (Sprites page says resources are 'billed hourly, based on actual usage'; the docs overview says 'billed by the second') [1]
- Minimum charge: unknown (Not published) [1]
- Per-job fee: None [1]

### Runtime

- Billed on: Active CPU [1]
- Isolation: Firecracker microVM [1]
- Max session: unknown (No maximum published; a Sprite runs while active and pauses about 30 seconds after activity stops (Tasks hold it active, 1 hour per task, renewable)) [1]
- Concurrent sandboxes: unknown (Not published for pay-as-you-go; Hero allows 100 running and 100 warm Sprites, cold Sprites unlimited) [1]
- Largest vCPU: 8 [1]
- Largest memory: unknown (Memory is managed and autoscaled by the platform; no fixed figure published) [1]

### Lifecycle

- Survives a stop: Disk [2]
- Snapshots: Yes [2]
- Pause and resume: Yes [2]
- Fork: No [2]
- Compute billed while stopped: No [2]
- Auto-stop: unknown (Pauses about 30 seconds after activity stops; the field holds whole minutes) [2]
- Start time (vendor claim): 2 s [2]

### Capabilities

- GPU: No [3]
- Desktop: None [3]
- Coding agents installed: Claude Code, Gemini CLI, Codex, Cursor [3]
- Agent prompt API: No [3]
- SSH: Yes [3]
- Docker inside: unknown (Not documented on the Sprites pages) [3]
- SDKs: TypeScript, Python, Go, CLI, REST, MCP [3]
- SOC 2: Yes [3]

### Storage and network

- Disk included: None [4]
- Extra disk: $0.02 per GB-month [4]
- Snapshot storage: unknown (Checkpoint storage is not priced separately on the pricing pages) [4]
- Egress: Free [4]

### Platform

- Regions: unknown (No region list or region choice published for Sprites) [2]
- Your cloud (BYOC): No [2]
- Self-host: No [2]

### Free allowance

- Minutes a month: None [1]
- Credit a month: None [1]
- One-time credit: $30 [1]

### Prices

| Resource | Price | Per hour |
|---|---|---|
| per vCPU | $0.0385 /h [1] | $0.0385 |
| per GB of memory | $0.0219 /h [1] | $0.0219 |

- CPU is billed on cumulative CPU time (cpu.stat) and memory on actual memory used, both only while the Sprite is running; warm and cold (paused) Sprites are not billed for compute.
- Storage is billed on bytes used, up to a 100 GB volume per Sprite. Cold storage is $0.000027/GB-hour (about $0.02/GB-month) for as long as data exists; hot storage adds $0.000683/GB-hour (about $0.50/GB-month) while the Sprite is awake.
- Bandwidth is not metered for Sprites.
- Each Sprite has 8 vCPUs; memory is assigned and scaled by the platform.
- A warm wake keeps processes in memory (vendor claim 100-500 ms); a cold wake keeps only the filesystem (vendor claim 1-2 s).
- Checkpoints snapshot the whole writable filesystem copy-on-write (vendor claim "about a second") and are taken automatically; restoring rewinds files in the same Sprite.
- Plans bundle CPU-hours, RAM GB-hours and storage; usage above the allowance bills at the standard rates. Fly.io credits pay for usage, not the plan fee.
- SSH works through `sprite proxy --ssh` as a ProxyCommand once you run an SSH server in the Sprite; `sprite console` is the built-in shell. Elixir SDK too; remote MCP server at sprites.dev/mcp.

## Sources

[1] https://fly.io/sprites (checked 31 Oct 2026)
[2] https://docs.fly.io/sprites/concepts/lifecycle.md (checked 31 Oct 2026)
[3] https://docs.fly.io/sprites/working-with-sprites.md (checked 31 Oct 2026)
[4] https://fly.io/pricing.md (checked 31 Oct 2026)