[Coframe] Disabled via URL parameter

https://yoursite.com/landing?coframe_variant_id=var_abc123

https://yoursite.com/landing?coframe_variant_id=var_abc123,var_def456

https://yoursite.com/landing?coframe_variant_id=var_abc123&coframe_should_send_events=true

// View SDK log history
window.Coframe.debug.logs

// Check whether events would be sent right now
window.Coframe.debug.shouldSendEvents()

// Flush pending events immediately
window.Coframe.debug.flushQueuedEvents()

# Preview & Debugging

URL parameters and tools for previewing variants and debugging the SDK

This page covers the URL parameters and in-browser utilities available for
development and QA workflows. None of these mechanisms are intended for
production use with real visitors.

## Disable Coframe (?cf_disabled)

The generated installation snippet includes an early-exit guard that runs before
the SDK loads. When the page URL matches the regex `/cf_disable/`, the snippet
logs a warning and returns immediately — the SDK is never fetched or executed:


PLAINTEXT



```
[Coframe] Disabled via URL parameter
```




The regex matches any URL that contains the string `cf_disable`, so both
`?cf_disable` and `?cf_disabled` work. This guard lives in the install-script
IIFE itself; it is not handled by the edge worker or the browser SDK.


Practical use — clean LCP measurement. Because the SDK is never loaded,
adding `?cf_disabled` to a page URL gives you a baseline page-load measurement
with zero Coframe overhead. Use this when benchmarking Core Web Vitals or
comparing your page’s Largest Contentful Paint with and without the SDK active.


For a step-by-step guide to verifying your integration before go-live, see
[Testing and Validation](../docs/testing-and-validation.html).

## Preview specific variants (?cf_variant_id)

Append `coframe_variant_id` as a query parameter to force the SDK into preview
mode for one or more variants:


PLAINTEXT



```
https://yoursite.com/landing?coframe_variant_id=var_abc123
```




To preview multiple variants at once, supply a comma-separated list:


PLAINTEXT



```
https://yoursite.com/landing?coframe_variant_id=var_abc123,var_def456
```




Two things happen when this parameter is present:



- Edge: `extractVariantIdsFromUrl` reads `coframe_variant_id` from the
resolved `config.currentUrl` and builds a preview project from KV instead of
the live project data.


- Browser SDK: `resolveConfig` reads `coframe_variant_id` from
`window.location` and sets `isPreviewVariant = true`, which suppresses event
sending so preview sessions do not pollute experiment data.

## Force event sending in preview (coframe_should_send_events)

When you are using `coframe_variant_id` to preview a variant but also need to
verify that analytics hooks fire correctly, add the override parameter:


PLAINTEXT



```
https://yoursite.com/landing?coframe_variant_id=var_abc123&coframe_should_send_events=true
```




The value must be the string `true`. When set, `resolveConfig` calls
`setForceSendEvents(true)`, which causes the event-gate check to return `true`
regardless of `isPreviewVariant`. This lets you exercise the full
`bulkCallbackV2` → analytics pipeline against a preview variant without
affecting live experiment traffic.


Note: use this in a controlled QA environment. Events sent this way are
delivered normally and will appear in your project’s event stream.

## Debug logging

Coframe.debug utilities
`window.Coframe.debug` is an object of debugging utilities. It is populated
during SDK initialisation and is not part of the public API. Available utilities:





Utility | 
Description | 





`logs` | 
SDK warning/error log history (`LogEntry[]`). | 



`project` | 
Resolved project payload received from the edge. | 



`frames` | 
Active frames after audience/URL filtering. | 



`laneClaims` | 
Mutual-exclusion lane assignments for this visitor. | 



`getSelector(el)` | 
Compute a UniversalSelector for a DOM element. | 



`getElement(sel)` | 
Resolve a UniversalSelector back to a DOM element. | 



`getElementUniversal(sel)` | 
Broader element resolver. | 



`waitForCmd(predicate)` | 
Await a CFQ command interactively from the console. | 



`flushQueuedEvents()` | 
Manually flush the pending event batch. | 



`queuedEvents` | 
Reference to the pending events array. | 



`shouldSendEvents()` | 
Check the current event-gate state. | 



`querySelector(sel)` | 
SDK DOM query wrapper. | 








Open your browser DevTools console and inspect `window.Coframe.debug` to
access these. For example:


JS



```
// View SDK log history
window.Coframe.debug.logs

// Check whether events would be sent right now
window.Coframe.debug.shouldSendEvents()

// Flush pending events immediately
window.Coframe.debug.flushQueuedEvents()
```




Checking the network for cf.js
The SDK is delivered as a single script response from the edge worker (the
`cf.js` request). In the browser DevTools Network tab, filter for `cf.js`
or `cf-static` to find this request. A successful response includes both the
baked-in project JSON and the compiled SDK bundle in one HTTP response,
eliminating a separate fetch round-trip. Inspect the response body to confirm
the project data is present and the status code is `200`.



See also:
[Coframe Global](../docs/coframe-global.html) — full reference for
`window.Coframe` properties and `Coframe.debug` utilities.
[Debug Checklist](../docs/debug-checklist.html) — step-by-step
checklist for diagnosing SDK and integration issues.