# Runtime (withruntime.com)

Official pricing: https://withruntime.com/pricing  
Category: agent-sandbox · Isolation: firecracker

## Pricing regimes (raw)

- **Active CPU plus reserved RAM** (resource): $0.025/vCPU-h, $0.0075/GiB-h
- **Reserved CPU** (resource): $0.025/vCPU-h, $0.0075/GiB-h

## Features

Yes: snapshots, memory snapshots, fork/clone, pause/resume, persistent disk, whole disk survives a stop, volumes, idle auto-stop, ≥24 h sessions, custom image (Docker or snapshot), start from your own snapshot, your own Docker/OCI image, full VM (own kernel), Docker inside, root, browser, desktop GUI, computer-use API, code interpreter, browser + desktop control, preinstalled agents, SSH, public IPv4, HTTPS preview URLs, custom domains, raw TCP inbound, egress allowlist, open internet, static egress IP, private networking, SSO, Python, Node.js, wake on request, memory fork, webhooks, audit logs, scoped API keys, spend limits, MCP server, usage per sandbox (API), automatic snapshots, snapshots on demand, agent harness API, gVisor or VM (no shared kernel), inbound access rules, firewall inside (nftables), secret proxy, secret proxy for any API, extra volumes, shared volumes, FUSE mounts, kernel features (eBPF, mounts, cgroups)

No: nested virtualization, anti-bot stealth, CAPTCHA solving, residential IPs, self-hosting, BYOC, open source, SOC 2, HIPAA, GPU, arm64, Windows, macOS, HTTP method/path egress rules, live resize, live fork (no pause), EU data residency, hosted agent API (their own agent)

Unknown: everything else. Evidence (source + quote) per feature: https://battleships.dev/data/providers/withruntime.json → feature_evidence

## Company

- Ownership: independent
- Stage: unknown
- Accelerators: none found
- Total raised: unknown
- Revenue: unknown

The YC directory lists a company named 'Runtime' (batch Spring 2026, https://www.ycombinator.com/companies/runtime) described as 'AI agents for financial operations' — this is a different company from withruntime.com, which is a Firecracker-microVM sandbox/VM cloud for AI agents (per its own /about page: 'Runtime is a cloud built for AI agents. Its first product is sandboxes...'). The two are unrelated despite sharing the name 'Runtime'. withruntime.com's legal entity is 'Runtime LLC' (per its own schema.org markup); its site is very new (pricing/storage changes dated September 2026), has no team/press/careers/blog pages (all return 404), and no funding, investor, or accelerator information could be found via web search, Crunchbase-style queries, or HN. Treat funding stage and backers as unknown rather than assumed bootstrapped or VC-backed.

## Caveats

- Public list pricing. Active CPU has absolute 0.05-vCPU floor per sandbox, not a fixed utilization percentage. Memory is reserved, not utilization. Decimal GB is explicit for snapshots and egress; rates converted to GiB with 1.073741824.
- Features set to null were not verified. No sandbox was purchased or tested; feature/performance statements are documentation claims. Null maximums are unknown unless a cited note explicitly states unlimited.
- A complete monthly bill requires known snapshot/egress/plan limits; do not silently treat missing ancillary charges as free.
- Disk: a running sandbox's first 10 GiB is included; past it, the blocks its disk alone holds are billed at the paused-storage rate, $0.08 per decimal GB per 30-day month, measured every 30 s (llms-full.txt, 2026-10-14; sandboxes made before 5 October 2026 keep their old terms). The engine bills provisioned disk past 10 GiB, so it overcounts a disk that is mostly empty. A stopped sandbox keeps its disk "billed as paused storage"; the engine still subtracts the 10 GiB there, a small undercount. persistent: true no longer has its own disk rate ("its disk is billed as any sandbox's"). Largest disk is 400 GiB with credit, 10 GiB without.
- Desktop: "Start a Linux desktop in any sandbox and drive it with clicks, keys and screenshots, or watch it live"; first start installs it (~90 s, ~1 GB disk) and a browser follows (~1 min, ~0.5 GB). Desktop recordings to MP4 are supported.
- Default idle pause is 60 seconds (configurable 10–86,400 or disabled). Compute stops at pause; the saved disk+memory blocks then cost $0.08/decimal-GB-month. Paid retention defaults 30 days and is configurable 1–365; trial retention is 7 days. Resize (memoryMiB) is possible only while paused.
- Free usage is a resource bucket (100 GiB-hours of memory + 25 vCPU-hours of active CPU, ~$1.38 at list rates), not a USD credit, so the card's free-dollar fields cannot represent it. It is once in the first 30 days, then monthly once the account has paid; the monthly renewal is not modelled.
- Paid network cap is 500 GiB/day in+out per sandbox. Trial has 5 GiB/day total in+out. Egress billing itself is account-wide: first 100 GiB/month free, then $0.02 per decimal GB.
- Storage charging began 2026-09-23. The first 3 images and first 10 GiB of volumes made under the trial remain free even after adding credit; snapshots are excluded.
- Volume backup is $0.02 per decimal GB-month ("Volume backup | $0.02 per decimal GB per 30-day month; one made before this price keeps $0.012 until 7 November 2026", pricing.md 2026-10-14); the card uses the new $0.02.
- Agent harnesses: the AI SDK harness adapter was verified only against a fake Runtime API; Runtime's own page says "No bridge harness (Claude Code, Codex) has run on Runtime yet."

## How this provider charges


As of 2026-09-28. Prices are USD unless explicitly labelled otherwise. Source type: official published list/promo or unknown, never a fabricated quote.

Public list pricing. Active CPU has absolute 0.05-vCPU floor per sandbox, not a fixed utilization percentage. Memory is reserved, not utilization. Decimal GB is explicit for snapshots and egress; rates converted to GiB with 1.073741824.

| Regime | When it applies | How billed / numbers | Source |
|---|---|---|---|
| Active CPU | Default | max(0.05, provisioned vCPU×CPU util)×$0.025/h; allocated RAM $0.0075/GiB-h. | https://withruntime.com/pricing |
| Reserved CPU | Full-core workloads | $0.025/provisioned vCPU-h + same RAM. | https://withruntime.com/pricing |
| Retained state | Paused VM, snapshot or custom image | $0.08/decimal GB/30-day month; unique blocks. | https://withruntime.com/pricing |
| Volumes | Allocated capacity | About $0.11/GiB/30-day month; backups $0.012/decimal GB. | https://withruntime.com/pricing |

## Gotchas

- Public list pricing. Active CPU has absolute 0.05-vCPU floor per sandbox, not a fixed utilization percentage. Memory is reserved, not utilization. Decimal GB is explicit for snapshots and egress; rates converted to GiB with 1.073741824.
- Features set to null were not verified. No sandbox was purchased or tested; feature/performance statements are documentation claims. Null maximums are unknown unless a cited note explicitly states unlimited.
- A complete monthly bill requires known snapshot/egress/plan limits; do not silently treat missing ancillary charges as free.

## Worked workload

4 vCPU / 8 GiB; 50 simultaneous instances × 8 h/day × 22 days = **8,800 instance-hours**, **35,200 vCPU-hours**, **70,400 GiB-hours**. At 30% observed CPU:10,560 active-vCPU-hours only where the meter actually uses utilization. Assume one start/instance/day:1,100starts. Retain50GiB snapshots for a month;100GiB outbound. Active disk capacity was not specified.

At 30% CPU: 8,800×(max(0.05,4×0.30)×0.025+8×0.0075) = $792. 50 GiB snapshots = 50×1.073741824×0.08 = $4.294967296 per 30-day month. 100 GiB egress is within free quota. Subtotal $796.294967296, excluding runtime disk/volumes, IPv4 and any extra state. C=50 consumes exactly 200 vCPU/400 GiB; quota check required.

## Sources

- https://withruntime.com/pricing
- https://withruntime.com/llms-full.txt