# Limits & quotas

Every number on this page is enforced server-side and reported live by `GET /v1/sandboxes/limits` (or `Sandbox.limits()` in the SDKs) for the calling token's tier. When in doubt, trust the API over this page - it is the same source the enforcement reads.

> **The three tiers**
>
> **Free** - a verified email, no card. **Pay as you go** - a card on file; compute is metered past the one-time trial credit. **Enterprise** - contract accounts with dedicated capacity. The tier is a property of the account, not a subscription you pick - adding a card moves you to pay as you go.

## Per-tier limits

| Limit | Free | Pay as you go | Enterprise |
| --- | --- | --- | --- |
| Sandbox sizes | small only | small, medium, large | small, medium, large |
| Concurrent RAM budget | 2 GB (~2 small) | 32 GB | 128 GB |
| Max sandbox lifetime | 30 minutes | 24 hours | 24 hours |
| Paused sandboxes held at once | 1 | 10 | 50 |
| Paused snapshot retention | 7 days | 30 days | no expiry |
| Custom templates | 1 | 15 | 50 |
| Persistent volumes | 1 | 10 | 50 |
| Total provisioned volume storage | 10 GB | 200 GB | 2 TB |
| Custom egress allowlist | yes | yes | yes |
| Public preview URLs | no | yes | yes |

## Sandbox sizes

| Size | vCPU | Memory | Availability |
| --- | --- | --- | --- |
| small | 1 vCPU | 1 GB RAM | default size |
| medium | 2 vCPU | 4 GB RAM | paid tiers |
| large | 4 vCPU | 8 GB RAM | paid tiers |

The concurrent RAM budget is the real concurrency gate: a create is refused once the sum of your live (non-paused) sandboxes' memory plus the new one would exceed it. Paused sandboxes free their RAM, so parking sessions raises how many you can hold.

## Fixed limits (all tiers)

- **Sandbox lifetime**: 10 seconds to 24 hours per create, capped by your tier's `max_timeout_seconds`. Default 600 seconds.
- **Per-exec timeout**: 1 to 3600 seconds, default 60. A timed-out command leaves the sandbox alive.
- **File transfers**: 16 MiB per read or write request (base64 over HTTPS). For bigger data, generate it inside the sandbox or stage it on a [volume](https://orkestr.eu/docs/sandboxes/volumes).
- **Metadata**: 16 keys per sandbox, 256 characters per value.
- **Volume size**: 10 GB default, 100 GB max per volume; billed on provisioned size as GB-month.
- **List page size**: 50 by default, 200 max.

## Compute trial and billing

Compute is not a monthly grant. Every account gets a **one-time trial credit in EUR** - the current amounts are shown on the [product page](https://orkestr.eu/sandboxes) and in `trial_credit_eur` from the limits API. Compute is metered per second at the public rates and drawn against the credit; it never resets. On the free tier the credit is also time-limited and ends in a hard wall; with a card on file, usage past the credit simply meters as pay as you go under your spend cap. Paused sandboxes stop the compute meter; snapshots, templates, and volumes meter as storage (GB-month).

## Rate limiting

There are currently no per-request rate limits on the sandbox API. The enforced gates are the ones above - the concurrent RAM budget, the trial credit or spend cap, and the per-tier object caps. When a request is refused, the `429` or `409` response carries a machine-readable `code` (for example `trial_exhausted`, `spend_cap_reached`, `snapshot_cap_reached`) - dispatch on that rather than retrying blindly.

## Need more?

The enterprise tier's envelope is a default, not a ceiling - dedicated capacity and custom limits are arranged per contract. [Talk to us](https://orkestr.eu/contact).