Development Update — May 1

Skywire: Per-Transport Latency End-to-End

PR #2401 plumbs measured latency through every layer that touches a transport:

Visor → TPD — the visor’s transport-level ping result (the new mechanism from PR #2317 that replaced RSN-based latency) is included in the transport register call. TPD persists the latency on the entry alongside type, label, and timing.

TPD storage — latency lives in the transport entry, queryable via the GET /transports/edge:{pk} endpoint and surfaced through the DHT mirror.

Discovery API — cli tp ls, the hypervisor’s transport table, and route calc all read latency from the entry directly.

--mux 0 = unlimited — the multiplex pool flag was previously a positive integer; 0 is now an explicit “no cap” mode for benchmarks and for visors that genuinely want to keep every available route alive.

Net effect: an operator looking at cli tp ls sees real RTT per transport without the visor having to re-measure on demand. Route calculation can finally sort by latency, not just by hop count.

Skywire: DMSG Servers — Live Confbs + Disk Cache

2403 dmsg_servers: refresh embedded list, live confbs response, visor-side disk cache — three changes to the dmsg-servers bootstrap path:

• Refreshed embedded list — the baked-in dmsg-servers list (used when the visor can’t reach the config service yet) is updated to the current production keyring. Pre-fix visors carrying the older embedded list would fail their first dmsg connect for ~30s while they waited for confbs.
• Live confbs response — config service now serves the dmsg-servers field from a live snapshot of the dmsg-discovery’s servers set instead of from a static config field. New servers added to the deployment are reachable by fresh visors immediately, without redeploying conf-service.
• Visor-side disk cache — the visor persists the last-good dmsg-servers list to ~/.skywire/dmsg-servers.json and reads it on next boot before reaching out to confbs. A visor that booted offline (laptop on a plane) now still has a usable dmsg-servers set from its last online run.

Skywire: httputil WriteJSON Panic Fix + errors.Is Sweep

2402 httputil: fix WriteJSON panic on slow clients; sweep err.Error() string matches → errors.Is — two unrelated cleanups in one PR:

WriteJSON panic — the helper would panic when the HTTP response writer’s Write returned an error (slow or disconnected client) because the panic message used a format verb without checking the err type. Race-clean E2E test had been intermittently failing on this for two weeks.

err.Error() string matches — twelve sites across the codebase were comparing error messages by string equality. Standard Go idiom is errors.Is/errors.As. The sweep converts them all: transport.ErrNotFound, routing.ErrRuleNotFound, dmsg’s various NotFound errors. Errors stay comparable across version boundaries even when their formatted text changes.

Skywire: Misc

• The --mux 0 = unlimited knob is documented in the transport CLI help.
• TPD’s /uptimes response now includes the latency field on each entry; the existing TPD-aggregator clients pick it up automatically.