Agent sandboxes / OpenReward Sandboxes alternative

An OpenReward sandboxes alternative for an independent agent runtime

OpenReward’s native sandbox is designed for hosted agentic environments, not as a general-purpose machine API independent of that platform. Its OpenReward Standard environments can also use other sandbox providers. Decide whether you need evaluation-environment hosting or a persistent computer beneath your own agent.

Start building Compare capabilities ↓

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

When OpenReward Sandboxes fits

OpenReward fits teams building or evaluating ORS environments, especially when native environment buckets, sidecar services, GPU tasks, and its environment platform are useful together.

When to consider Sandbox0

Consider Sandbox0 when your application needs a persistent per-user Linux runtime that retains system tools, configuration, and outputs across tasks and grows its RootFS automatically. ORS integration, evaluation orchestration, and GPU execution remain separate workload decisions.

Capabilities

OpenReward Sandboxes and Sandbox0: what persists?

Feature comparison with documentation and verification status
Capability	OpenReward Sandboxes	Sandbox0
Environment and runtime lifetime	OpenReward SandboxesNot established in this review	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 files	OpenReward SandboxesEnvironment bucket storage can be mounted into a sandbox; its lifecycle is separate from temporary execution.View evidence ↗	Sandbox0The writable RootFS survives successful checkpoints, including software, system configuration, dependencies, and user data.Read documentation →
Whole RootFS	OpenReward SandboxesThe reviewed native lifecycle is temporary and environment-scoped; cross-session whole-RootFS retention is not established.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 state	OpenReward SandboxesThe documented native workflow focuses on create, execute, and teardown rather than a general retained-machine pause contract.View evidence ↗	Sandbox0Pause compute between tasks; resume on available capacity. Default resume starts fresh processes from the saved filesystem.Read documentation →
Memory and process state	OpenReward SandboxesNative sandbox documentation reviewed here does not establish RAM or process checkpoints.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.

Environment bucket mounting is distinct from automatic expansion of a complete writable root filesystem. The reviewed native sandbox guides do not establish that whole-RootFS growth contract.

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 →

Native sandbox compute is tied to an environment workspace

OpenReward’s guide requires creating an environment namespace to provision native compute, even during local development. It explicitly distinguishes this from a general sandbox compute service. An ORS environment can use another provider, so changing execution does not inherently require replacing the environment standard.

Source 1 ↗Source 2 ↗

Temporary execution and retained environment files differ

The usual ORS lifecycle creates a sandbox for a session and tears it down afterward, though individual environments can scope it to a tool call. Bucket mounts provide access to environment storage. Keep durable datasets and outputs separate from assumptions about installed packages or root-disk changes after teardown.

Source 1 ↗Source 2 ↗

GPU and search rates describe additional products

OpenReward lists CPU and memory rates for environment execution and an L4 GPU rate. Its archived web search and fetch APIs have separate request prices. Match the rate to the actual evaluation workload; Sandbox0’s Linux runtime price is not a replacement quote for GPU hardware or an evaluation platform.

Source 1 ↗Source 2 ↗

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.

Same size. Lower compute cost.

2 vCPU · 4 GiB RAM · 730 running hours / month

Save $77.09 / month

The same CPU and memory allocation, with runtime aggregated across sessions. Monthly allowances and credits below are applied to this workload.

OpenReward Sandboxes

Published sandbox compute

$120.89

$0.1656/hour before monthly allowances

Sandbox0

Pay as you go · no monthly plan fee

$43.80

$0.06/hour · 63% lower in this example

CPU and memory are added together at the published per-second usage rates. GPU hardware, environment storage and model inference are additional; research grants are excluded.

Compute and stated plan fees only. Storage, network, taxes and one-time credits are excluded; hardware and throughput can differ.

Calculation and billing assumptions

OpenReward Sandboxes: $120.888 compute after 0 included vCPU-hours and 0 included GiB-hours, plus $0.00 plan fee, minus $0.00 applied monthly credit.

Sandbox0: 4 GiB × 730 hours × its published compute rate. CPU uses the Cloud allocation shown on the pricing page.

Includes compute and the selected plan. Excludes storage, network, taxes, one-time grants and negotiated discounts. Assumes this workload can use the full listed monthly allowances. CPU and memory counts do not guarantee equal hardware or throughput.

Checked 2026-10-19OpenReward Sandboxes rate source ↗Sandbox0 rates ↗

OpenReward Sandboxes

Pricing reviewed 2026-10-18

CPU: $0.0504 per vCPU-hour; Rate source ↗
Memory: $0.0162 per GiB-hour; Rate source ↗
NVIDIA L4 GPU: $1.51 per GPU-hour; GPU hardware is an additional workload capability, not part of a Sandbox0 CPU-only comparison.; Rate source ↗

The rate card states per-second usage billing. Enterprise on-premise deployments and research credits have separate terms. Confirm environment storage, sidecars, selected resources, and inference costs; archived search/fetch request prices do not price sandbox compute.

Check current OpenReward 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

Understand storage billing →

Before migrating from OpenReward Sandboxes

Separate the ORS environment definition, provider adapter, native workspace namespace, bucket data, sidecars, and any GPU requirements.
Implement the appropriate execution adapter and port images, commands, files, credentials, and network controls while keeping evaluation logic where needed.
Validate agent tasks across sessions, required system changes, growing data, paused file access, and the full evaluation-plus-compute bill.

Common questions

Is Sandbox0 a drop-in OpenReward 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 ↗docs.openreward.ai/concepts/sandboxes.md ↗docs.openreward.ai/sandboxes/openreward.md ↗openreward.ai/pricing ↗docs.openreward.ai/environments/gpu-environments.md ↗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 →