Connect over CDP

Opens a WebSocket that speaks the Chrome DevTools Protocol for this session only, so Playwright (`chromium.connectOverCDP`), Puppeteer (`puppeteer.connect`) or any CDP client can drive the browser. The proxy exposes only the session's own targets. It refuses `SystemInfo.*`, `Tethering.*`, `Extensions.*`, `Cast.*`, and `Browser.*` except the methods Playwright and Puppeteer need to drive a browser (`getVersion`, the permission methods, window bounds, `setDownloadBehavior` and `cancelDownload`); host file access (`DOM.setFileInputFiles`, file drags); downloads to host paths (they land in the session's own directory, wiped with the browser); and navigation to anything but `http:`, `https:` and `about:blank` (`file:`, `chrome:`, `chrome-extension:`, `view-source:`, `devtools:`, `data:`). These answer `cdp_method_blocked` in the CDP error (`error.data.code`). `Target.createBrowserContext` with `proxyServer`, `proxyBypassList` or `originsWithUniversalNetworkAccess` answers `forbidden` (403): every context of a session uses the session's egress. Authenticate with the `Authorization` header or a ticket from `POST /v1/vision/sessions/{session_id}/ticket`. A client that falls more than a few MB behind is disconnected, and so is one that sends a message over 32 MiB. A message with a repeated member (two `method`s, say) answers the JSON-RPC parse error `-32700`.

GET /v1/vision/sessions/{session_id}/cdp

Authentication

Bearer Token (b3os_sk_ API key or b3os_pat_ token) API Key (cookie: __Host-b3os_session) API Key (query: ticket)

Path Parameters

session_id string required path

The session ID (`brs_…`).

Example: "brs_01m5t3y30wcksxf22t9gwk9fwb"

Query Parameters

ticket string optional query

A single-use stream ticket from the resource's `POST …/ticket` operation, for clients that cannot set headers (browser `WebSocket` and `EventSource`); see the `ticket` security scheme. WebSocket clients may send it as a subprotocol instead: `Sec-WebSocket-Protocol: b3os.v1, b3os.ticket.<ticket>`. Query strings are redacted from logs.

Responses

101 Switching protocols. Messages are CDP JSON in text frames.

No response body

400 The request failed validation (`invalid_request`, `invalid_url`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

401 Missing, malformed, expired or revoked credentials (`unauthorized`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

403 Authenticated but not allowed (`forbidden`, `egress_denied`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

404 No such browser session in this project (`session_not_found`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

409 The session already closed (`session_closed`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

429 A rate, concurrency or quota limit applies (`rate_limited`, `concurrency_limited`, `quota_exceeded`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

500 Something failed inside B3OS (`internal`). Retry with backoff.

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

503 The node or the product is not available right now (`node_unavailable`, `product_unavailable`, `capacity_unavailable`).

application/problem+json

type string (uri) REQUIRED

`https://docs.beta.b3os.org/errors#<code>`.

title string REQUIRED

Short summary of the problem type.

status integer REQUIRED

The HTTP status code, repeated for convenience.

code string REQUIRED

Stable machine-readable error code from the errors catalog.

detail string REQUIRED

Explanation of this occurrence. Never contains secrets.

instance string

The request ID (`req_…`) of the request that failed. Include it when you contact support.

errors object[]

Validation problems, one per field (`invalid_request` and the other codes that list `errors`).

Array of:

pointer string REQUIRED

Where the problem is: a JSON pointer into the request body (`/url`, `/steps/0/uses`), or `#query/<name>`, `#path/<name>` or `#header/<name>` for parameters.

detail string REQUIRED

What is wrong there.

reason string

Finer-grained cause for codes that document one (`unauthorized`, `forbidden`, `egress_denied`, `upstream_unreachable`, …).

required_scope string

The scope that was missing (`forbidden` with `reason: scope`).

retry_after_s integer

Same value as the `Retry-After` header, for clients that only read the body.

limit object

The limit an error refers to. IDs and current values are listed by `GET /v1/limits`.

id string REQUIRED

Limit ID, such as `vision.scrape.rpm` or `sandboxes.concurrent`.

limit number REQUIRED

The limit's value.

unit string REQUIRED

What the limit counts, such as `requests`, `sandboxes`, `vcpu` or `MiB`.

window_s integer

Window length in seconds for rate limits and quotas.

current number

Current usage against the limit, when known.

current_status string

The object's current status, for state conflicts such as `sandbox_not_running`.

upstream_status integer

The HTTP status the upstream returned (`upstream_error`, `action_output_invalid`).

step string

The failed step, as a step ID (routines), an index (`act`) or a path such as `beats/2/do/0` (render).

pack_error object

The error a pack's error mapping chose (`upstream_error` from pack actions).

code string REQUIRED

message string REQUIRED

retryable boolean REQUIRED

curl -X GET 'https://beta-api.b3os.org/v1/vision/sessions/brs_01m5t3y30wcksxf22t9gwk9fwb/cdp' \  -H 'Authorization: Bearer YOUR_API_TOKEN'

const response = await fetch('https://beta-api.b3os.org/v1/vision/sessions/brs_01m5t3y30wcksxf22t9gwk9fwb/cdp', {  method: 'GET',  headers: {      "Authorization": "Bearer YOUR_API_TOKEN"  }});const data = await response.json();console.log(data);

import requestsheaders = {    'Authorization': 'Bearer YOUR_API_TOKEN'}response = requests.get('https://beta-api.b3os.org/v1/vision/sessions/brs_01m5t3y30wcksxf22t9gwk9fwb/cdp', headers=headers)print(response.json())

400 Response

{  "type": "https://docs.beta.b3os.org/errors#invalid_request",  "title": "Invalid request",  "status": 400,  "code": "invalid_request",  "detail": "1 field failed validation",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "errors": [    {      "pointer": "/url",      "detail": "must be an absolute http or https URL"    }  ]}

401 Response

{  "type": "https://docs.beta.b3os.org/errors#unauthorized",  "title": "Unauthorized",  "status": 401,  "code": "unauthorized",  "detail": "API key checksum does not match; check that the whole key was copied",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "reason": "malformed"}

403 Response

{  "type": "https://docs.beta.b3os.org/errors#forbidden",  "title": "Forbidden",  "status": 403,  "code": "forbidden",  "detail": "This key lacks the scope sandboxes:write",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "reason": "scope",  "required_scope": "sandboxes:write"}

404 Response

{  "type": "https://docs.beta.b3os.org/errors#session_not_found",  "title": "Browser session not found",  "status": 404,  "code": "session_not_found",  "detail": "No browser session brs_01m5t3y30wcksxf22t9gwk9fwb in this project",  "instance": "req_01m5t4yg394wegr3j4y01qb363"}

409 Response

{  "type": "https://docs.beta.b3os.org/errors#session_closed",  "title": "Browser session closed",  "status": 409,  "code": "session_closed",  "detail": "brs_01m5t3y30wcksxf22t9gwk9fwb reached its 600 s timeout and was closed",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "current_status": "expired"}

429 Response

{  "type": "https://docs.beta.b3os.org/errors#rate_limited",  "title": "Rate limited",  "status": 429,  "code": "rate_limited",  "detail": "60 scrapes per minute allowed; retry in 12 seconds",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "retry_after_s": 12,  "limit": {    "id": "vision.scrape.rpm",    "limit": 60,    "unit": "requests",    "window_s": 60,    "current": 60  }}

500 Response

{  "type": "https://docs.beta.b3os.org/errors#internal",  "title": "Internal error",  "status": 500,  "code": "internal",  "detail": "internal error",  "instance": "req_01m5t4yg394wegr3j4y01qb363"}

503 Response

{  "type": "https://docs.beta.b3os.org/errors#node_unavailable",  "title": "Node unavailable",  "status": 503,  "code": "node_unavailable",  "detail": "Node n1 is not reachable; retry in 5 seconds",  "instance": "req_01m5t4yg394wegr3j4y01qb363",  "retry_after_s": 5}

GET /v1/vision/sessions/{session_id}/cdp

Base URL

Bearer Token

Path Parameters

session_id string required

Query Parameters

ticket string

Response

Was this page helpful?

Previous Run browser actions

Next Create a stream ticket