Everything you need
to ship agents.
Real Linux microVMs with fast boot, socket-reused exec, fork-trees, hibernation, org controls, and open-source deployment paths.
Run commands without paying handshake tax.
Use REST for simple jobs, PTY for interactive shells, and one WebSocket for high-frequency agent loops.
Multiplexed WebSocket exec
Upgrade once at GET /v1/sandboxes/{id}/exec/ws, then tag each command with an id. Keepalive pings hold the socket open; cancel frames stop runaway work.
client → { "id": "lint", "cmd": "pnpm lint", "timeout_seconds": 60 }
client → { "id": "test", "cmd": "pnpm test" }
client → { "id": "test", "cancel": true }
server → { "id": "lint", "stream": "stdout", "data": "ok" }
server → { "id": "lint", "exit": 0 }
server → { "id": "test", "error": "cancelled" }REST exec
POST commands for simple one-shot jobs, CI probes, and SDK defaults.
PTY shell
Interactive terminals with resize events for IDEs and human handoff.
File uploads
Stream source trees, artifacts, and prompt bundles into a running microVM.
Agents are tree search. Now they branch on the world.
Fork the sandbox N ways in half a second, try a different approach in each in parallel, keep the winner — losers reaped automatically. Best-of-N over real execution, not re-sampled tokens. Only possible on sub-second copy-on-write forks.
winner = result.winner // the fixed workspace, already independent
result = sandbox.explore(
[patch("guard-zero", fix_a),
patch("try-except", fix_b),
patch("or-1", fix_c)],
score_fn=lambda sb, o:
1.0 if o.value.exit_code == 0
else 0.0,
)
winner = result.winnerFast when hot. Cheap when idle.
Cold start, TTL, hibernation, wake, and volumes are designed for long-running agents that pause between turns.
Sub-75ms boot
Every create restores from a baked snapshot with streamed memory — ~49ms p50 (n=50 prod, June 2026).
Idle hibernation
Default 5-minute TTL writes memory + disk state and stops active compute billing.
Persistent volumes
Attach named volumes for caches, repos, model shards, and user state.
Every pull request gets a live URL.
Connect a repo, open a PR, and PandaStack builds it inside a fresh Firecracker microVM — then drops the preview link right in the PR. Encrypted env, scoped secrets, and scale-to-zero included.
- 01Open a PRpush commits to a branch
- 02Build in a microVMclone · detect · install · build
- 03Live preview URLisolated, per-PR environment
- 04Posted on the PRsticky comment, updates on push
- 05Auto torn downon merge / close / @pandastack delete
Serverless code with real microVM isolation.
Deploy Python or Node.js functions, expose them over HTTP, and automate invocations with cron schedules.
Functions & Schedules
Deploy Python/Node functions in isolated microVMs. Schedule them with cron. Public HTTPS endpoints.
pandastack function deploy handler.py --name my-fn --runtime python --public
pandastack schedule create --name my-fn --fn <function-id> --cron "0 9 * * *"A control plane for real teams.
Personal orgs are auto-provisioned on first /v1/me. Teams add members, invites, roles, and Stripe-metered invoices.
Orgs
orgs, org_members, org_invites, and user_current_org live in shared Postgres.
Roles
owner > admin > member permissions, with dashboard pages for team and org switching.
Metered billing
Agents emit pending_meter_events; a 60s edge worker posts Stripe Meter Events idempotently.
Move sandboxes without breaking identity.
Snapshot restore keeps starts low; snapshot migration lets the scheduler rebalance across hosts and regions.
Multi-region seeds
Template snapshots replicated by region for consistent p50s near users.
Cross-host migration
Snapshots carry baked NATID so restores keep the same external identity.
Preview URL ACLs
Share demos and interview prompts with path-level access controls.
Meet agents where they already run.
Use PandaStack from SDKs, the CLI, webhooks, or any MCP client that can call tools.
MCP server
Claude, Cursor, and other clients can spin up sandboxes and execute commands with tool calls.
Auth + org switch
API tokens, JWT requests, X-Pandastack-Org, and X-Fcs-Workspace resolver middleware.
Open source
Apache-2.0 core, self-hostable on your machines or available as a managed cloud.
Templates
Use public stacks or bake Dockerfiles and live snapshots into reusable templates.
TypeScript SDK
Create, exec, fork, forkTree, promote, upload, and expose ports.
Python SDK
The same sandbox primitives for agents, notebooks, and evaluation harnesses.
CLI + webhooks
Script sandboxes from CI and subscribe to lifecycle / hibernation events.
Ship on the millisecond cloud.
Free tier with $5.40/mo usage credit. No card. Apache-2.0.