About Runtime

Runtime is a cloud built for AI agents. Its first product is sandboxes: Linux microVMs with their own kernel, which an agent creates, drives and stops by API, CLI, MCP or SDK.

What it runs

Each sandbox is a Firecracker microVM on servers Runtime runs itself, with Python, Node, Bun, git, a compiler and sudo. Measured on 25 September 2026: 243 ms median creation, 391 ms median from the create request through the first Python result, and 981 ms at the 95th percentile. 20 sequential public API runs, zero errors, 2 vCPUs, 4 GiB RAM and 4 GiB disk.

20 products are available today: Sandboxes, Code interpreter, Network rules, Secrets, Images, Volumes, Snapshots, Previews, Desktop, Metrics, Webhooks, OpenTelemetry, Bucket mounts, MCP servers, Custom domains, TCP ports, Dedicated addresses, Private networks, Identity tokens and Single sign-on. One account, one API, one CLI and one SDK reach all of them, and new products join the same shape as they launch (your account and its products).

What it costs

Runtime charges $0.025 per active vCPU-hour and $0.0075 per reserved GiB-hour of memory, with no plan fee, 100 free hours to start and no card, which makes it 42% to 88% cheaper than fourteen other sandbox providers for an agent that spends most of its time waiting on a model. Pricing has every rate and the comparison.

How an agent starts

• llms.txt is the quickstart: connect, run a first command, switch a project from another provider and report the saving, with no other page.
• MCP: remote clients add https://api.withruntime.com/mcp and sign in through the browser. Local clients run npx -y withruntime mcp.
• SDKs: npm i withruntime and pip install withruntime. The HTTP API is at https://api.withruntime.com/v1, described by /v1/openapi.json.
• Code written for E2B, Daytona or Vercel Sandbox runs by changing one import (switching).

Trust

• Security: isolation, keys, secrets sandboxes never see, network rules and single sign-on.
• Status: the API checked from outside every two minutes, and a real sandbox started and stopped every ten.
• Terms, privacy, data processing, subprocessors and acceptable use.

Company

Runtime is made by Runtime LLC, 1500 N Grant St Ste N, Denver, CO 80203, United States. For help, ask in the console, run runtime feedback, or write to support@withruntime.com (feedback and support). What changed and when is in the changelog.