> ## Documentation Index
> Fetch the complete documentation index at: https://docs-preview.webcompute.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Limits and retention

> Design browser jobs around documented limits, account-specific quotas, artifact size caps, and cleanup.

Limits keep browser jobs predictable. Some limits are source-defined and public. Others can vary by account or deployment.

## Public limits to design around

| Area                           | Current guidance                                                                              |
| ------------------------------ | --------------------------------------------------------------------------------------------- |
| Browser duration               | Pass `maxDuration` when creating browsers that should expire sooner than the default.         |
| Browser-code execution timeout | Keep snippets bounded. SDK and MCP surfaces cap execution timeout.                            |
| Staged files                   | The SDK rejects staged file uploads above its file size limit.                                |
| Downloads                      | Use `maxBytes` when saving or reading downloads.                                              |
| MCP tool calls                 | `run_web_agent` accepts `maxTurns`, `maxToolCalls`, and `toolTimeoutMs` on the agent surface. |
| Recordings and artifacts       | Store IDs you need, and close browsers when the workflow is done.                             |

Use the [limits reference](/reference/limits) for exact current values that are documented publicly.

## Account-specific limits

Concurrency, rate limits, retention windows, and cost controls may depend on your account or deployment. Your application should handle `429`, `413`, timeout, and resource-limit errors explicitly.

## Cost controls

Public source does not define a universal billing-control API in these docs. Treat cost as an application concern:

* Set browser `maxDuration` for job-scoped browsers.
* Set agent `maxTurns`, `maxToolCalls`, `timeoutMs`, and `toolTimeoutMs`.
* Cap downloads, uploads, observations, and returned data.
* Close browsers when a job is complete.
* Log usage metadata when `web.agent()` returns it.

## Cleanup checklist

* Close browsers created for one job.
* Store only the artifact IDs and summaries your app needs.
* Avoid logging signed Debug UI or CDP URLs.
* Put file size caps on download reads and saves.
* Use policy to constrain uploads and downloads.

Reference: [observability](/production/observability), [SDK resources reference](/reference/sdk-resources-reference), [proxy reference](/reference/proxy-reference), [environment variables](/reference/environment-variables), and [limits](/reference/limits).