Browsers advertise a conservative SCTP max-message-size in their SDP offer
(Chrome uses 256 KiB). pion enforces the remote's advertised value on send, so
a single realtime event larger than it cannot be sent over the "oai-events"
data channel: SendText fails, the event is dropped, and the turn silently
yields no response. Some turns legitimately produce a >256 KiB JSON event —
notably tool calls with sizeable schemas or results.
Browsers advertise the value conservatively but their SCTP stacks reassemble
much larger messages, so raise the max-message-size honored for our own
server-generated events by rewriting the attribute in the offer before
SetRemoteDescription.
Assisted-by: Claude:claude-opus-4-8 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
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