Tenki Sandbox
Full Linux VMs for agents from the Tenki CI-runner company, booting from Ceph-backed disks in under a second (claimed), with pause, memory snapshots, forks and volumes at per-second rates. A sensible per-second VM sandbox from a CI vendor with real infrastructure, provided you can live with the undocumented hypervisor and region list.
Overview
Tenki Sandbox is the agent-VM product of Tenki Cloud, a Seattle company founded in 2024 and owned by Luxor Technology, better known for its CI runners. Each session is a fresh, single-tenant Linux VM with its own kernel (the hypervisor is not named) whose disk mounts directly from a Ceph cluster so nothing is copied before boot; the site claims sub-second starts. Defaults are 2 vCPU, 4,096 MB and a 5 GiB root disk, configurable at creation, with Docker, root and systemd available. SDKs exist for TypeScript, Python and Go alongside a CLI, and Claude Code and Codex are listed as supported harnesses.
Sessions can be paused (memory and durable files kept, billing stops), snapshotted with memory and forked, and attached to persistent volumes; sticky sessions run until terminated while others pause at their maximum duration. Pricing is per second for vCPU, memory and disk, with a free Starter tier carrying a $100 credit and a Team plan with $100 of monthly credits. Compliance leans on the parent company's SOC 2 Type II programme. Structured data on the page gives a software version of "2026.11", and most of the testimonials on the product page concern the runner product rather than the sandbox.
Notable
- Tenki Cloud founded 2024 in Seattle; parent company Luxor Technology; "Built In Seattle — Featured Startup".
- Pricing page shows the Team plan at $200/month (annual) while the FAQ gives $250/month or $200/month billed yearly.
- Tenki for Startups offers $10K in free credits and up to $40K in matching grants across Tenki products.
Tenki Sandbox specifications
| Attribute | Details |
|---|---|
| Isolation | Hardware-isolated single-tenant VM with its own kernel; hypervisor not named; disks mount from a Ceph cluster |
| Deployment | Hosted platform |
| Open source | No |
| SDKs and interfaces | JavaScript/TypeScript, Python, Go, CLI |
| Cold start (vendor claim) | Website: "Isolated VMs that start in under a second" and "Your custom image, running in under a second" (vendor claims) |
| Max session length | Maximum duration is set per session (default not stated); non-sticky sessions pause automatically at their maximum; sticky sessions run until terminated |
| Persistence | Pause preserves memory and durable files (/home/tenki and volumes; /tmp survives a pause but is cleared on snapshot) and stops compute charges; snapshots capture disk and memory and can be forked; persistent volumes keep data across sessions |
| GPU | Not documented |
| Networking | Inbound and outbound networking on by default and fixed at create time; outbound allowlists up to 256 domains and 64 IPv4 CIDRs; expose_port creates authenticated, tunnelled preview URLs with optional TTL; no public IPs |
| Pricing | Per second: vCPU $0.000014 ($0.0504/hour), memory $0.0000045 per GiB ($0.0162/GiB-hour), disk $0.00000003 per GiB ($0.000108/GiB-hour, first 5 GiB free), kept storage $0.000000076 per GiB-second. Starter $0; Team $250/month ($200/month billed yearly) with $100 monthly credits, up to 100 concurrent sessions and 16 cores/64 GB; Enterprise custom |
| Free tier | Starter: $100 one-time credit (granted when a payment method is added), up to 5 concurrent sessions, 4 cores/8 GB, 100 GiB storage |
| Compliance | SOC 2 Type II through parent Luxor Technology's programme (report under NDA); compute in SOC 2-attested and ISO 27001-certified data centres; GDPR alignment with certification on the roadmap |
| Regions | Multi-region availability mentioned; regions not listed (preview URL example uses a "us" subdomain) |
Facts from Tenki Sandbox’s public documentation, verified November 9, 2026. Performance numbers are vendor claims.
Strengths and trade-offs
Strengths
- You want a full VM with Docker and systemd rather than a container-shaped sandbox.
- You need pause-and-resume with memory kept and no charge while paused.
- You want Go support alongside TypeScript and Python SDKs.
- You are already using Tenki runners and want one credit balance.
Trade-offs
- Hypervisor, regions, default session duration and maximum VM sizes are not documented.
- Compliance is inherited from the parent company rather than attested for the sandbox product.
- Networking policy is fixed at creation time and cannot be changed on a running session.
- The product page mixes sandbox and CI-runner claims and reviews.
Good fit for: Coding agents that need a full Linux VM with Docker and systemd, pausable between tasks, at per-second rates.
How Tenki Sandbox compares
| Sandbox | Isolation | Open source | Self-host / BYOC | Cold start (vendor) | Max session | Snapshots / pause | GPU | SDKs |
|---|---|---|---|---|---|---|---|---|
| Tenki Sandbox | Single-tenant VM | No | No / No | <1 s (claim) | Configurable; sticky = unlimited | Yes / Yes | Not documented | JavaScript/TypeScript, Python, Go, CLI |
| E2B | Firecracker microVM | Yes | Yes / Yes | Not documented | 1 h / 24 h (Pro) | Yes / Yes | No | Python, JavaScript/TypeScript |
| Daytona | Containers or VMs | No | Not documented / Yes | <90 ms | Unlimited | Yes / Yes | Yes | Python, TypeScript, Ruby, Go, Java |
| Superserve | Firecracker microVM | No | No / Yes | Not documented | Unlimited | Yes / Yes | Not documented | Python, JavaScript/TypeScript, CLI, REST API, MCP server |
| Runtime | Firecracker microVM | No | No / No | Not documented | No limit documented | Yes / Yes | Not documented | JavaScript/TypeScript, Python, Go, Ruby, Java, CLI, REST API, MCP server |
| InstaVM | Firecracker microVM | No | No / No | <200 ms (claim) | Configurable | Yes / Yes | Not documented | Python, JavaScript/TypeScript, CLI, REST API |
| Namespace | KVM virtual machine | No | No / No | Not documented | Deadline-based; Devbox 3-24 h | Yes / Yes | Not documented | JavaScript/TypeScript, Go, CLI, MCP server, gRPC/Connect API |
Frequently asked questions
What is Tenki Sandbox?
How does Tenki Sandbox isolate code?
Is Tenki Sandbox open source?
How much does Tenki Sandbox cost?
What are the alternatives to Tenki Sandbox?
Sources
Cite this page
Agent Sandboxes. (2026). Tenki Sandbox. agentsandboxes.org. Last reviewed November 9, 2026. https://agentsandboxes.org/sandboxes/tenki-sandbox/
Found an error or a missing sandbox? Submit a correction — every entry links to the sources it relies on.