A sandbox per user

How it fits together

• A template. Install your stack once in a sandbox and save it: froog snapshot base --name web-stack. Every user's sandbox starts from it, house rules for the agents (AGENTS.md, CLAUDE.md, skills, MCP servers) included.
• A scoped key for your backend. froog api-key create backend --preset ci can create, start, fork and delete only what it created, and can't touch billing or other keys. A key can also be limited to one user's sandbox.
• Nothing of yours in user sandboxes. Create them with "environment": false and pass each one only its own variables: the user's API key, a tenant id.
• Know when it's ready. Creating answers 202 at once; the sandbox is usable when its state is running, or take the sandbox.running webhook.
• Run the agent. POST /v1/sandboxes/{name}/prompt runs one of seven coding agents with the user's keys.
• Show the result. POST /v1/sandboxes/{name}/urls with a port gives a preview URL; embed the desktop in an iframe if the user should watch.

POST https://api.froog.tech/v1/sandboxes
Authorization: Bearer $FROOG_API_KEY

{"name": "user-42", "from": "web-stack", "environment": false,
 "env": {"TENANT_ID": "42", "ANTHROPIC_API_KEY": "<the user's key>"}}

Patterns and cost

Running time is billed per second, only while a sandbox runs, and a stopped sandbox costs no running time.

• Always on, one sandbox per user or project: $20 a month for a default one (4 vCPU, 8 GB).
• Stop when unused: its auto-stop timer stops it (push it back while the user works) and you start the sandbox when the user returns, in about 15 seconds. A user who works two hours a day costs a twelfth of one who keeps it on. The disk is kept 14 days, longer with a saved snapshot.
• Disposable per task: start from the template, run, read the output, delete. 20 runs of 2 hours each on default cost $1.10.

Keep only what you must

Turn monitoring off to keep no command history, or use zero data retention to erase each sandbox when it stops. Details in the data controls and the platform guide.

Questions

Do the terms allow reselling sandboxes to my users?

Yes. froog's terms allow building a product that gives your users sandboxes. See the platform guide.

How fast does a user's sandbox start?

A new sandbox from a template is ready in about a minute; starting a stopped one takes about 15–30 seconds, and about a second within 10 minutes of a stop, when the paused VM resumes with its programs still running.

Can each user's sandbox have its own secrets?

Yes. Create it with "environment": false so none of your account's variables or files go in, and pass that user's keys in env.