Agent sandboxes / Buddy Sandboxes alternative

A Buddy Sandboxes alternative for a growing agent computer

Buddy Sandboxes already retains installed packages, system configuration, files, and database contents across restarts. For a returning agent, compare its fixed disk, process restart rules, and CI-oriented account model with automatic RootFS growth and files accessible during compute pauses.

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Reviewed 2026-10-18 · Published by the Sandbox0 team

When Buddy Sandboxes fits

Buddy fits teams that want agent workspaces, application previews, and sandbox automation beside existing Buddy pipelines. Its supervised apps, repository permissions, endpoints, snapshots, CLI, SDK, and MCP integrate that workflow.

When to consider Sandbox0

Consider Sandbox0 when each user needs a persistent Linux environment whose entire writable RootFS can grow automatically while the agent runs. Supported Files API access during pause also lets the application inspect or edit persistent state without starting compute.

Capabilities

Buddy Sandboxes and Sandbox0: what persists?

Feature comparison with documentation and verification status
Environment and runtime lifetimeBuddy SandboxesBuddy describes no lifetime cap unless configured; optional inactivity stopping needs appropriate activity for unattended tasks.View evidence ↗Sandbox0ttl and hard_ttl default to 0 (disabled). Configure idle pause and deletion policies for the same persistent sandbox identity; an idle running sandbox still accrues compute charges.Read documentation →
Persistent filesBuddy SandboxesThe disk survives stop/restart, including installed packages, database files, and build caches.View evidence ↗Sandbox0The writable RootFS survives successful checkpoints, including software, system configuration, dependencies, and user data.Read documentation →
Whole RootFSBuddy SandboxesPersistent machine disk includes software, files, and system configuration.View evidence ↗Sandbox0Persistence extends beyond /workspace to paths such as /usr/local, /etc, and /home. Runtime tmpfs and virtual filesystems are excluded.Read documentation →
Release compute, keep stateBuddy SandboxesStop retains disk and starts configured apps again at boot; it does not retain live processes.View evidence ↗Sandbox0Pause compute between tasks; resume on available capacity. Default resume starts fresh processes from the saved filesystem.Read documentation →
Memory and process stateBuddy SandboxesBuddy explicitly states that memory does not survive stop; processes are restarted.View evidence ↗Sandbox0Experimental memory checkpoints can preserve compatible process state. Use memory: true on both pause and resume on a compatible deployment. A filesystem checkpoint alone does not preserve running processes.Read documentation →

Online RootFS growth

On growth-enabled images, Sandbox0 automatically expands the writable RootFS as free space runs low, within a configured sparse logical ceiling up to 64 TiB. Agent processes keep running. Growth is enabled in the qualified Cloud region; confirm activation for other regions. Existing images and snapshots retain their captured storage geometry. The ceiling is logical capacity, not preallocated host disk.

Buddy’s configuration guide states that disk capacity is always 50 GB and is not configurable. This is a meaningful difference from automatic online expansion of a growth-enabled Sandbox0 RootFS.

Files while compute is paused

Sandbox0's Files API reads persistent files without resuming compute. Filesystem-only pauses also permit edits; retained-memory pauses are read-only and reject mutations with 409. SSH, SFTP, file watching, and runtime-only mounts require running compute.

See paused file operations →

A retained disk does not keep a manually started process alive

Buddy keeps the disk through stop and restart, but terminates processes. Configured apps restart at boot; commands launched manually do not. An idle timeout is optional, and an attached terminal or SSH session can keep a long task active. Design startup and reconnect logic around those rules.

Source 1 ↗Source 2 ↗

Prepared snapshots and a fixed disk solve different needs

Buddy snapshots capture installed and configured filesystem state, can seed new sandboxes, and survive deletion of the source. The configuration guide fixes the disk at 50 GB with no size control. Retaining that disk does not make its capacity expand as dependencies and outputs accumulate.

Source 1 ↗Source 2 ↗

Keep sandbox allowances separate from pipeline usage

Buddy publishes sandbox CPU-minute and GB-hour allowances beside pipeline GB-minutes, seats and cache. Use the sandbox rows for this workload. The current price page shows EUR plan prices and dollar-denominated overage labels; confirm checkout currency and the GB-hour meter before calculating a total.

Source 1 ↗

Pricing

Compare billing models, then price your workload

CPU allocation, memory, billing minimums, disk, plan fees, and supported workload differ. These meters are not equal-performance machine quotes. Confirm region, resource units, and included allowances before estimating a total.

Buddy Sandboxes

Pricing reviewed 2026-10-18

Pro plan as displayed
EUR 29 per month
Lists 300 sandbox CPU-minutes and 7,300 sandbox GB-hours, plus other plan entitlements.
Rate source ↗
Hyper plan as displayed
EUR 99 per month
Lists 300 sandbox CPU-minutes and 14,600 sandbox GB-hours.
Rate source ↗
Sandbox CPU overage as labeled
$0.00024 per CPU-minute
Rate source ↗
Sandbox GB-hour overage as labeled
$0.00011 per GB-hour
Retains the vendor’s published meter label; confirm its resource basis and currency in account billing.
Rate source ↗

The current price page mixes EUR plan labels with dollar-denominated overage labels; no currency conversion is assumed. Its Free pricing card lists sandbox allowances, while an older plan-features guide excludes Sandboxes from Free. Verify account eligibility and included usage; do not assume a paid subscription is universally required or Free access is guaranteed.

Check current Buddy Sandboxes pricing ↗

Sandbox0

$0.015/GiB-hour compute (billed by the second at approximately $0.000004167/GiB-second), plus $0.02/GiB-month of retained incremental RootFS and memory checkpoint data. Shared base images and platform recovery retention are excluded; paused sandboxes accrue storage charges only.

Compute / GiB-hour
$0.015
Retained data / GiB-month
$0.02
Paused compute
$0.00

A 4 GiB agent, 100 running hours

$6.00 compute

4 GiB × 100 hours, billed by the second. Keeping 20 GiB of billable incremental data for a full billing month adds $0.40. CPU is derived from memory by the platform; choose a tier that fits your workload.

Understand storage billing →

Before migrating from Buddy Sandboxes

  1. Save a snapshot or export required disk files before wiping or destroying a Buddy sandbox; record its configured apps and pipeline cleanup rules.
  2. Port boot commands, repository access, variables, supervised services, and endpoints into a Sandbox0 template and application integration.
  3. Test fresh-process startup, installed-package persistence, storage growth, paused file operations, and the full plan-plus-usage bill.

Common questions

Is Sandbox0 a drop-in Buddy Sandboxes replacement?

Evaluate API compatibility and product scope. A shared sandbox category does not make SDKs, lifecycle semantics, or limits interchangeable.

Does keeping files also keep a running agent?

Filesystem state and volatile process state are separate. Sandbox0 requires explicit compatible memory checkpoints to preserve running processes; its default filesystem resume starts fresh processes.

Sources and review scope

The Boat team's Battleships directory is the discovery source. References below describe the product and plan discussed on this page. Check current availability, regional terms and billing units before migrating. Where the cited material does not establish a capability or price, the comparison identifies that uncertainty.

Battleships research record ↗buddy.works/docs/sandboxes/lifecycle ↗buddy.works/docs/sandboxes/introduction ↗buddy.works/docs/sandboxes/snapshots ↗buddy.works/docs/sandboxes/configuration ↗buddy.works/pricing ↗buddy.works/sandboxes ↗Sandbox0 RootFS capacity →

Related comparisons

Agent 37 vs Sandbox0 →AgentComputer vs Sandbox0 →ainclave vs Sandbox0 →Alibaba Cloud Agent Sandbox / FC / AgentRun vs Sandbox0 →Alibaba Cloud AgentBay vs Sandbox0 →Amika vs Sandbox0 →