--- title: CodeSandbox SDK slug: codesandbox-sdk url: "https://toolweight.com/options/codesandbox-sdk" homepage: "https://codesandbox.io/docs/sdk" categories: sandbox-providers last_verified: 2026-01-15 license: CC-BY-4.0 --- # CodeSandbox SDK > Firecracker VMs with memory snapshots, from the online IDE, now owned by Together AI. CodeSandbox spent years making browser-based development environments resume instantly, and the SDK sells that infrastructure directly: microVMs that hibernate to a memory snapshot, resume with processes intact, and fork cheaply from any snapshot. Together AI acquired the company in 2025. The snapshot-and-fork model is the most mature in this roster, and pricing is credit-based rather than hourly. ## Identity | | | | --- | --- | | Name | CodeSandbox SDK | | Company | Together AI | | One-liner | Firecracker VMs with memory snapshots, from the online IDE, now owned by Together AI. | | Site | https://codesandbox.io/docs/sdk | | Docs | https://codesandbox.io/docs/sdk | | Founded | 2017 | | Funding | Acquired | | Brand | https://toolweight.com/vendors/CodeSandbox | | Compared in | 1 | ## Where it is compared ### [Sandbox providers](https://toolweight.com/compare/sandbox-providers) Ranked **#8 of 20** on default weights. | Field | Value | Confidence | Verified | Source | Note | | --- | --- | --- | --- | --- | --- | | Cold start | 1.2 s | Inferred | - | - | Estimate for a cold create. The vendor's ~1 s figure is a different operation, resuming an existing hibernated VM, so the near-parity between the two columns here is the least defensible estimate on the page: every other provider whose claim describes a snapshot restore lands 2-20× above it. Flagged rather than adjusted, because moving the number to fit the pattern would be inventing one. The harness settles this row first. | | Cold start (claimed) | 1 s | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | Marketed as resuming a hibernated VM in about a second, processes intact. | | Isolation | microvm | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | Firecracker. | | Root in guest | ● | Inferred | - | - | - | | Egress control | open | Inferred | - | - | - | | Max runtime | 1440 min | Inferred | - | - | VMs hibernate on an inactivity timeout rather than hitting a hard runtime cap. | | Persistent FS | ● | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | Disk and memory both persist across hibernation. | | Snapshot & fork | ● | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | The most mature memory-snapshot-and-fork implementation in this roster. | | Custom images | ● | Inferred | - | - | Docker-based environment definitions. | | GPU | ○ | Inferred | - | - | - | | Runtimes | python, javascript-typescript, bash, any-oci-image | Inferred | - | - | - | | Preview URLs | ● | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | - | | Browser inside | ◐ | Inferred | - | - | - | | File up/download | ● | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | - | | Sydney region | ○ | Inferred | - | - | US and EU clusters. | | Concurrent limit | 100 sandboxes | Inferred | - | - | Tier-dependent; approximate. | | MCP server | ○ | Inferred | - | - | - | | SDKs | typescript, python | Inferred | - | - | - | | Streaming output | ● | Vendor-claimed | 2026-01-15 | https://codesandbox.io/docs/sdk | - | | Price / hour | - | Unknown | - | - | Credit-based pricing per VM tier rather than a published hourly rate for a given vCPU/RAM shape. Historically among the cheaper options; model it against your own session profile. | | Meter | per-second | Inferred | - | - | Credits are consumed while a VM is awake. | | Idle cost | storage-only | Inferred | - | - | Hibernated VMs stop consuming compute credits. | | GitHub stars | 13,000 | Community-reported | - | - | codesandbox/codesandbox-client, rounded, the IDE, not the SDK. | | Funding | acquired | Community-reported | - | - | Acquired by Together AI in 2025. | | Shipped | 2024 | Inferred | - | - | - | | Positioning | The VM infrastructure behind CodeSandbox, sold as an SDK. | Inferred | - | - | - | **Verdict.** If your workload branches, try five patches from one prepared state, this is the best-engineered snapshot implementation available, because CodeSandbox spent years being punished for slow resumes. The open question is roadmap: it is now a component of Together AI's stack rather than a company's whole product. ## Alternatives - [ascii](https://toolweight.com/options/ascii), Agent orchestration over Telegram, running on box's VM infrastructure. - [Blaxel](https://toolweight.com/options/blaxel), Agent-first cloud claiming ~25 ms microVM boots from snapshots. - [box](https://toolweight.com/options/box), Persistent Linux VMs with SSH, per-VM IPv4 and disk-level forking, priced flat. - [Cloudflare Sandbox](https://toolweight.com/options/cloudflare-sandbox), Container sandboxes driven from a Worker, addressed through Durable Objects. - [Daytona](https://toolweight.com/options/daytona), Sub-second container sandboxes for agent workloads, from a team that built a dev-env manager. - [Self-hosted Firecracker](https://toolweight.com/options/diy-firecracker), The baseline: Firecracker on your own metal, plus every hard part you now own. - [E2B](https://toolweight.com/options/e2b), Open-source Firecracker sandboxes with Python and TypeScript SDKs for AI agents. - [exe.dev](https://toolweight.com/options/exe-dev), Persistent VMs you SSH into, with root, apt and systemd, on a flat monthly plan. - [Fly.io Machines](https://toolweight.com/options/fly-machines), Raw Firecracker microVMs with a REST API, durable volumes and 35+ regions. - [Freestyle](https://toolweight.com/options/freestyle), Run untrusted JavaScript and full dev servers, with git hosting and domains built in. - [GitHub Codespaces](https://toolweight.com/options/github-codespaces), Devcontainer-backed cloud VMs built for humans, occasionally repurposed for agents. - [Islo](https://toolweight.com/options/islo), Per-agent isolated cloud sandboxes with enterprise policy controls, from Incredibuild. ## Licence and attribution Data from toolweight (https://toolweight.com), licensed CC-BY-4.0. - Licence: [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/) - Canonical HTML: https://toolweight.com/options/codesandbox-sdk - Machine-readable: https://toolweight.com/options/codesandbox-sdk.md · https://toolweight.com/api/v1 · https://toolweight.com/mcp - toolweight takes no affiliate revenue and sells no placements. Corrections: https://toolweight.com/suggest