Kedge’s billing guide describes public preview with limited trial credit. Its displayed resource rates are estimates for future paid service and may change. Read the source ↗

Agent sandboxes / Kedge alternative

A Kedge sandbox alternative for a durable, growing agent computer

Kedge has two relevant execution paths: an ephemeral eval sandbox destroyed after each run, and a persistent coding-agent workspace. The latter already keeps the complete writable filesystem. Compare the intended path and preview terms before evaluating storage growth or retained state.

Start buildingCompare capabilities ↓

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

When Kedge fits

Kedge fits teams that want its app deployment stack, coding-agent workspaces, local-style persistent volumes, and measured resource billing. Ephemeral evals provide a separate path for small scripts that should leave no retained machine.

When to consider Sandbox0

Consider Sandbox0 when the product primarily needs a per-user sandbox runtime with durable RootFS storage separated from compute, online automatic disk growth, and supported paused file operations. Port application-platform features separately where they are required.

Capabilities

Kedge and Sandbox0: what persists?

Feature comparison with documentation and verification status
Environment and runtime lifetimeKedgeNot established in this reviewSandbox0ttl 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 filesKedgePersistent volumes keep workspace data; ephemeral evals are destroyed after a run.View evidence ↗Sandbox0The writable RootFS survives successful checkpoints, including software, system configuration, dependencies, and user data.Read documentation →
Whole RootFSKedgeAgent workspaces explicitly retain the complete writable filesystem across restarts and host moves.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 stateKedgeWorkspaces support idle suspend and resume; this is distinct from the one-shot eval path.View evidence ↗Sandbox0Pause compute between tasks; resume on available capacity. Default resume starts fresh processes from the saved filesystem.Read documentation →
Memory and process stateKedgeApp initialization snapshots and workspace continuity do not establish a universal arbitrary live-memory checkpoint contract here.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.

Kedge workspaces already retain the complete writable filesystem on a volume. Volume size is described as a sparse logical limit; the reviewed guides do not establish the same automatic online free-space-triggered RootFS growth contract as Sandbox0.

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 →

Ephemeral evals and workspaces retain different state

Kedge eval runs start an isolated VM and destroy it afterward, with no deployed or persisted state. Its workspace guide instead keeps sessions, tools and the complete writable filesystem across restarts and host moves. Select the persistent workspace path when the agent needs to return to accumulated state across tasks.

Source 1 ↗Source 2 ↗

Workspace deletion can leave a separately billed volume

Kedge uses a persistent volume for a workspace’s writable filesystem. Sleeping stops compute usage but retained data remains billable; deleting a workspace can leave an orphaned volume until explicitly removed. Retain or delete that data deliberately when migrating agent environments.

Source 1 ↗Source 2 ↗

The published rates are preview estimates

Kedge’s billing page says its public preview includes a limited free trial and that listed rates estimate future paid service. CPU measures scheduled time, memory uses recently touched pages with a resident-memory fallback, and sparse storage measures written data. Those are not allocated-resource machine quotes or confirmed future production prices.

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.

Kedge

Pricing reviewed 2026-10-18

Estimated future CPU rate
$15 per vCPU-month
730 vCPU-hours per month; the page also quotes approximately $0.0205/vCPU-hour.
Rate source ↗
Estimated future memory rate
$5 per GiB-month
Recently touched pages, or resident memory when working-set measurement is unavailable; approximately $0.0068/GiB-hour.
Rate source ↗
Estimated future stored data rate
$0.05 per GiB-month
Rate source ↗
Estimated future egress rate
$0.01 per GiB
Rate source ↗

These are explicitly estimates for future paid service during public preview, not a guaranteed live commercial rate card. The page lists a $5 monthly resource allowance and a separate coding-model allowance. CPU/memory stop accruing while scaled to zero or idle-suspended; stored data remains chargeable under the published model.

Check current Kedge 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 Kedge

  1. Identify ephemeral evals versus persistent workspaces, attached volumes, app configuration, agent sessions, and retained data after deletion.
  2. Export required files and port commands, credentials, tools, network access, and deployment-specific integrations into a Sandbox0-backed application.
  3. Test system changes across tasks, RootFS growth, idle behavior, paused file access, and a real workload estimate after confirming current commercial terms.

Common questions

Is Sandbox0 a drop-in Kedge 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 ↗kedge.dev/docs/sandboxes ↗kedge.dev/docs/agents.md ↗kedge.dev/docs/volumes.md ↗kedge.dev/docs/billing ↗kedge.dev/docs/runtime.md ↗Sandbox0 RootFS capacity →

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