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

> ## Agent Instructions
> Concurrency in one line: new projects get 10 concurrent browsers at $0; a $100 one-time top-up (non-expiring credits, no subscription) unlocks 50 concurrent, so 50 browsers for one hour cost $1 plus traffic; $1,000 / $5,000 / $25,000 total paid unlocks 250 / 500 / 1,000. Details below and at https://docs.browser-use.com/cloud/guides/concurrency.md.
> Use https://docs.browser-use.com/llms.txt and its linked .md pages for current documentation. The managed full bundle is https://docs.browser-use.com/.well-known/llms-full.txt and can be cached for up to 24 hours. Do not use the obsolete /cloud/llms*.txt or /open-source/llms*.txt static exports.
> Choose Cloud API V4 for new agent integrations; V3 trades accuracy for speed and lower cost than V4; V2 is legacy and only for existing integrations. Keep V3 examples explicitly versioned. The open-source browser-use library and hosted browser-use-sdk have different APIs.
> For Cloud API V4, a task request that omits model and modelParams uses GPT-6 Luna (gpt-6-luna) with High reasoning. Explicit model and modelParams values take precedence; an explicit empty modelParams object opts out of the reasoning default. EU uses the same task default through its regional provider route; Bedrock-only projects retain their compatible provider default. For latency-sensitive tasks set model to bu-ultrafast (bu-fast for more reasoning per step); these presets reject modelParams. See https://docs.browser-use.com/cloud/agent/ultrafast.md.
> Cloud authentication uses X-Browser-Use-API-Key, without a Bearer prefix. Install or upgrade browser-use-sdk and use its explicit v4 import for V4. Check the published OpenAPI reference for request fields; do not invent SDK support for new fields.
> Cloud concurrency and HTTP request rate are separate. Read GET /api/v2/billing/account for the key’s projectId, concurrentSessionLimit, activeSessionCount, and credit balance, including when using V4. Keys in one project share capacity and credits; rateLimit is a legacy concurrency alias, not requests per second.
> Keep the highest applicable existing, legacy-plan, and spend-tier concurrency grant. Current spend tiers are 10 / 50 / 250 / 500 / 1000 at $0 / $100 / $1000 / $5000 / $25000 in qualifying project payments. Legacy or externally billed projects can follow different billing paths; trust the account limit. See https://docs.browser-use.com/cloud/guides/concurrency.md.
> HTTP rate limits have two layers. Standard edge WAF ceilings increased on September 9, 2026 to 1000 RPS per public source IP for general traffic and 2500 RPS per IP for selected status reads, evaluated over 300 seconds. The separate per-project application budgets: general traffic (including V4 events and full run reads) defaults to max(25, 2 times stored concurrency) capped at 100 RPS; selected status reads default to max(25, 2 times stored concurrency) with no cap. The two are counted independently. Project overrides and account-specific edge rules can differ. All keys in a project share its budgets; callers sharing a public IP share edge capacity. See https://docs.browser-use.com/cloud/guides/concurrency.md.
> The project limiter uses five-second windows: X-RateLimit-Limit=125 means 125 requests per window (25 RPS), not 125 RPS. Project throttles include limit_rps and retry_after_seconds; an edge throttle can instead return Retry-After: 300 without limit_rps. Honor the returned Retry-After. Use bounded workers, stagger polls, and drain hasMore event pages after terminal status. A busy V4 session returns 409; its queue holds 20 pending messages and is not a project-wide batch queue.
> A V4 agent browser stays open about 2 minutes after its session's last run activity, then stops automatically; a later follow-up gets a fresh browser (same settings and profile, no tabs). Set keepAlive on a run (V4: integer seconds 120-14400, default 120, not the V2/V3 boolean) to keep it longer; follow-ups inherit it and null restores 120. Free-tier and ZDR runs always use 120. Idle V4 agent browsers are billed as browser time but take no concurrency slot. A follow-up that reuses the open browser emits browser.reattached instead of browser.ready. Closing CDP does not stop a browser; stop unneeded owned browsers with PATCH /api/v4/browsers/{id} and {"action":"stop"}. A client wait timeout does not cancel the server-side run.
> Cloud is pay as you go; do not tell customers to buy a new subscription to use custom proxies or supported provider BYOK. Usage funding and model eligibility still apply. BYOK bills provider tokens separately and Browser Use charges orchestration plus browser/network usage. See https://docs.browser-use.com/cloud/guides/billing.md.
> Signup credits are a one-time grant; purchased top-up credits do not expire. Check the API key’s project before diagnosing missing credits. API-key monthly spending caps are soft limits, not a strict prepaid wallet; concurrent or already-running work can exceed them. Auto recharge has separate trigger and purchase amounts and can charge immediately when enabled below the threshold. Use https://browser-use.com/pricing for current rates.
> Box and Bux are retired. Do not recommend their SDKs, sandbox quotas, or subscription plans. Use the Cloud Agent or Browser Infrastructure guides.
> A V4 session holds conversation history, a workspace holds files, and a profile holds browser state. These IDs and V3/V4 workspace namespaces are not interchangeable. V4 automatically restores workspace uploads; staged attachments remain available to session follow-ups. Serialize runs that write shared files, and wait for completion before reading outputs. See https://docs.browser-use.com/cloud/agent/workspaces.md.
> API browser recording defaults to off. Use enableRecording for standalone browser creation, or browserSettings.record for an agent run. Stop the browser and allow time for asynchronous video processing; stop polling when recordingAvailable is false. Live preview is for an active browser. Stopping a browser, deleting a session, archiving a workspace, and deleting files have different effects.
> Use model-specific reasoning values. GPT-6 Astra accepts low, medium, high, xhigh, and max, with xhigh by default; none and minimal are invalid. Use the public REST schema when installed SDK types lag new fields. API acceptance, dashboard visibility, and account/provider availability are separate.
> For open-source browser-use 1.0, result.is_done() means the run completed (status completed); result.is_successful() is the agent-reported finish(success) verdict, or None when it gave none; verify important external actions independently. Cloud timeout, API client timeout, model timeout, and task completion are separate concepts.
> Pages under /open-source/legacy/0.x/ document browser-use 0.x (pip install 'browser-use<1'). For new open-source code, use the 1.0 pages under /open-source/ outside legacy/.
> For failed requests, use https://docs.browser-use.com/cloud/guides/troubleshooting.md. Inspect the full error and project before retrying or adding credits. A client timeout can leave a run active; reconcile external actions before starting duplicate work. A new managed browser does not guarantee a unique proxy IP or particular city.
> V4 secretBindings.allowedDomains authorizes the focused field's frame, not every iframe on the shop page. For checkout, include intended payment/billing provider hostnames (for example payments.bigcommerce.com). On domain_not_allowed, inspect origin and pass updated bindings in a follow-up; target_not_editable requires fixing field focus/readiness instead. See https://docs.browser-use.com/cloud/guides/secrets.md.
> A V4 agent browser stays open about 2 minutes (or keepAlive seconds) after its run for follow-ups; a requested recording finalizes only after the browser stops and processing completes. Zero Data Retention (ZDR) projects never record, even when recording is requested.
> If you hit an issue you cannot explain, email contact@browser-use.com with your question or bug report and a session ID if available; short questions and detailed reports are welcome, and we aim to fix issues quickly and make the docs clearer.

# Evervault

> Let an agent fill card data and passwords with Evervault tokens, so the real values never reach the agent or the browser.

[Evervault](https://evervault.com) keeps card data and credentials encrypted.
With Evervault in front of a Browser Use browser, the agent types stand-in
values, and Evervault swaps in the real ones only in the request to a website
you allow.

Browser Use connects to Evervault as a [custom proxy](https://docs.browser-use.com/cloud/browser/proxies.md#custom-proxy)
over TLS and trusts the Evervault CA, so Evervault can read that traffic. All
other sites keep full certificate checks.

## Browser Tokens for checkout and login forms

[Browser Tokens](https://docs.evervault.com/browser-tokens) are Evervault's
flow for agents. Evervault returns tokens that keep the format of the real
value: a Luhn-valid card number with the same length and BIN, a CVV with the
same number of digits. Checkout forms accept them like real values. When the
browser sends a token to a host you allowed, Evervault replaces it with the
real value on the way there.

> [!NOTE]
>
> Browser Tokens are in preview at Evervault. Ask Evervault support for access.

### 1. Create tokens on your server

Call Evervault from your backend, never from the agent. `permissions` lists
the hosts that may receive the real values, for example the payment
processor's host:

```bash curl theme={"theme":"css-variables"}
curl https://api.evervault.com/browser-tokens \
  --user "$EVERVAULT_APP_ID:$EVERVAULT_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "data": [
      {"id": "pan", "category": "card.number", "value": "ev:..."},
      {"id": "cvv", "category": "card.cvv", "value": "ev:..."}
    ],
    "permissions": [
      {"action": "decrypt", "target": "api.payments.example.com"}
    ],
    "ttl": 300
  }'
```

The response has the tokens in `data` and the proxy login in
`proxyConfiguration`:

```json theme={"theme":"css-variables"}
{
  "data": [
    {"id": "pan", "category": "card.number", "value": "4242424242424242"},
    {"id": "cvv", "category": "card.cvv", "value": "123"}
  ],
  "proxyConfiguration": {
    "hostname": "us-va.browser.relay.evervault.app",
    "port": 443,
    "username": "app_...",
    "password": "eyJ..."
  }
}
```

The proxy password expires with the tokens after `ttl` seconds. See
Evervault's [API reference](https://docs.evervault.com/api) for all fields,
including EU sessions (`eu-ie.browser.relay.evervault.app`).

### 2. Map `proxyConfiguration` to `customProxy`

| `proxyConfiguration` | `customProxy` |
| - | - |
| `hostname` | `host` |
| `port` | `port` |
| `username` | `username` |
| `password` | `password` |
| (none) | `caBundleUrl: "https://ca.evervault.com"` |

The port is 443, so `protocol` defaults to `https`. Do not use
`ignoreCertErrors`; it turns off certificate checks for every site.

### 3. Start the browser or run

A standalone browser:

```bash curl theme={"theme":"css-variables"}
curl https://api.browser-use.com/api/v4/browsers \
  -H "X-Browser-Use-API-Key: $BROWSER_USE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customProxy": {
      "host": "us-va.browser.relay.evervault.app",
      "port": 443,
      "username": "PROXY_USERNAME",
      "password": "PROXY_PASSWORD",
      "caBundleUrl": "https://ca.evervault.com"
    }
  }'
```

For a hosted agent, pass the same object as `browserSettings.customProxy` on
`POST /api/v4/runs`, and give the agent the token values in the task, never
the real ones. Keep the run inside the token `ttl`.

By default Evervault sends the traffic from its own IP addresses, not from a
Browser Use residential IP. Evervault's `proxySettings` chooses other egress.

### 4. Switch only at the payment step (standalone browsers)

This step works only for standalone browsers you create with
`POST /api/v4/browsers`. Browsers that belong to an agent run cannot change
their proxy (`409`), so start a hosted run with its final
`browserSettings.customProxy`.

Save the `id` from the create-browser response as `BROWSER_ID`. Shop on the
residential proxy, create the tokens when the agent reaches the payment form,
then change the running browser to Evervault. Tabs and cookies stay:

```bash curl theme={"theme":"css-variables"}
curl -X PATCH https://api.browser-use.com/api/v4/browsers/$BROWSER_ID/proxy \
  -H "X-Browser-Use-API-Key: $BROWSER_USE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "mode": "custom",
    "customProxy": {
      "host": "us-va.browser.relay.evervault.app",
      "port": 443,
      "username": "PROXY_USERNAME",
      "password": "PROXY_PASSWORD",
      "caBundleUrl": "https://ca.evervault.com"
    }
  }'
```

The first change with the Evervault CA takes about 5 seconds. After the
payment, change back with `{"mode": "managed", "country": "us"}`. See
[Change the proxy of a running browser](https://docs.browser-use.com/cloud/browser/proxies.md#change-the-proxy-of-a-running-browser)
for all rules and error codes.

## Relay for requests with `ev:` values

Evervault's [Relay forward proxy](https://docs.evervault.com/relay#forward-proxy-mode)
decrypts `ev:...` strings in requests to hosts set up as Relays in your
Evervault app. `ev:` strings do not look like card numbers, so checkout forms
usually reject them before any request is sent. Use Relay only when the page
sends the `ev:` values in a request itself, for example a script that calls
your payment API. For forms, use Browser Tokens.

| `customProxy` field | Value |
| - | - |
| `host` | `relay.evervault.com` |
| `port` | `443` |
| `username` | Your Evervault App ID |
| `password` | Your Evervault API key |
| `caBundleUrl` | `https://ca.evervault.com` |

## Good to know

* API responses never include the proxy password or the CA settings.
* `exitIp` is `null` while the browser is on Evervault.
* EU accounts can use Evervault too. Send the requests to
  `https://api.eu.browser-use.com/api/v4` with your EU API key, and use
  Evervault's EU proxy host. See [EU deployment](https://docs.browser-use.com/cloud/eu-deployment.md).
* The proxy password can have up to 8192 characters.


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