Authenticated Fetch

Use a saved login session to fetch pages behind a login. Browserbase stores this login state in a context, and the API refers to it with contextId.

Fetching with a context

Pass a contextId to fetch pages that require a login. Browserbase calls the saved login state a context. Fetch sends only the cookies saved in that context. It follows normal browser cookie rules: each cookie goes only to the domains and paths it belongs to, including across redirects, and Fetch drops expired cookies.

Node.js
Python
cURL

Node.js

const response = await bb.fetchAPI.create({
  url: "https://example.com/account/orders",
  contextId: "<context-id>",
});

Python

response = bb.fetch_api.create(
    url="https://example.com/account/orders",
    context_id="<context-id>",
)

cURL

curl -X POST https://api.browserbase.com/v1/fetch \
  -H "Content-Type: application/json" \
  -H "X-BB-API-Key: $BROWSERBASE_API_KEY" \
  -d '{"url": "https://example.com/account/orders", "contextId": "<context-id>"}'

How it works:

Fetch uses the cookies saved when the browser session ends. Log in with a browser session that uses the context with persist: true.
Fetch is read-only. Fetch doesn’t write cookies the site sets during a request back to the context.
Fetch requires a context saved on or after September 1, 2026. To use an older context, run one browser session with that context and persist: true. The context works with Fetch after that session ends.
Bring-your-own-storage uses your existing role. If your project stores contexts in your own S3 bucket, Fetch reads them with the role you configured for it. Fetch only needs s3:GetObject on your contexts bucket, which the BYOS setup guide already grants.

Errors specific to fetching with a context:

Status	Message starts with	Meaning
`400`	`Context ID not found`	The context doesn’t exist or belongs to another project.
`404`	`context_cookies_unavailable`	The context has no saved cookies yet, or was last saved before September 1, 2026. Run a browser session with the context and `persist: true`, then retry.
`400`	`context_storage_access_denied`	Browserbase couldn’t assume your BYOS role, or your KMS key refused to decrypt the context. Check the role’s trust policy, external ID, and KMS key policy.
`400`	`Fetching with a context is not supported for this project`	Your project uses an older context configuration that Fetch can’t read. Contact support to enable it.

Some sites authenticate data requests with tokens that the page’s JavaScript creates per session, such as an Authorization header. Fetch only sends cookies, so it can’t authenticate those requests. Use a browser session with the saved login for those sites.

Proxies

Route Fetch requests through Browserbase’s proxy network or target a specific location.

Fetch

Return page content without an interactive browser session.

Welcome

Platform

Use cases

Optimization

Account

Fetching with a context

Proxies

Fetch

​Fetching with a context

Proxies

Fetch

Fetching with a context