Known limitations

Capture

• application/x-www-form-urlencoded GraphQL bodies aren’t captured.
• Batches, multipart uploads and WebSockets are never mocked.
• Mocks only apply while DevTools is open on the tab, and requests fired before the rules reach the page aren’t mocked. Reload to mock a page’s first requests.
• WebSocket rows can’t be compared or copied as an HTTP request.
• DevTools may swallow Mod + F, Alt + [ and Alt + ]; rebind them if so.

Shared state

• All open instances (DevTools panels and full tabs) share chrome.storage.local. History and the tab list stay in sync live; the active tab is per instance.
• History has a single writer, the background service worker, so a clear or delete in one instance can’t be undone by another. If the service worker can’t be reached, the change shows locally but isn’t saved.
• Concurrent edits to the same tab from two open instances within about 300 ms: the last writer wins, and all instances then converge on what storage holds.

Limits

Thing	Limit
Collections	50, with 2,000 items each, about 3 MB in total
Schema cache	10 endpoints, 6 MB; a schema over 3 MB isn’t cached
Traffic list	1,000 operations by default
Scripts	5 s, 50,000 characters, 20 gql.fetch calls, 5 MB per fetch