URL shapes that reach the server
idle—shapes arriving
Runs first: everything below is meaningless if a filter is matching on the path. One shape deliberately contains the word “probe” as a known-bad canary.
Measure this network
The gate for Phase 0 is whether held HTTPS requests survive here. Run the suite from every network that matters — office proxy, hotel wifi, phone on carrier data — and submit each result.
Checks
pass
degraded
fail
Path & protocol
idle—negotiated
Compares what the browser negotiated against what the server received. A mismatch means a terminating proxy.
Held request ceiling
idle—longest hold
The headline measurement. Long-poll defaults to a 25 s hold; this finds where the network cuts one.
SSE streaming
idle—to first event
A buffering proxy leaves the connection looking healthy while nothing arrives. The padded hello is how we catch it.
Upload ceiling
idle—largest intact
Phase 2 uses 4 MB file chunks. Verified by digest, so a rewritten body shows up as well as a truncated one.
Binary fidelity
idle—octet-stream
The screen segment's content type, checked byte for byte. Only Phase 3 depends on this one.
End to end · long-poll
idle—median delivery
Two devices, one room. Proves the cursor is right, not just that the network carries — this is the architecture under test.
End to end · SSE
idle—median delivery
Same room, same cursor, tier one forced.
End to end · short-poll
idle—median delivery
The floor. If this fails, nothing works here.
Submit this run
Runs are stored server-side as JSONL. Telemetry from the networks you are actually on beats any amount of reasoning about middleboxes.
Cross-device smoke test
no roomCreate a room here, then open the same link on another device on a different network. Messages are plaintext — encryption lands in Phase 1; this panel exists only to watch the cursor work between two real devices.