The gateway/CLI /model switch path (switch_model in agent_runtime_helpers)
built the MoAClient facade but left agent.api_mode at the value
determine_api_mode / the resolved aggregator transport produced (e.g.
codex_responses or anthropic_messages). The conversation loop dispatches on
agent.api_mode, so a non-chat_completions value made the primary/acting call
go through client.responses.create — which the MoAClient facade has no
.responses for — and fall through to the moa://local placeholder, 404 three
times, then fall back to a reference model (issues #54259, #54669).
agent_init.py already pins api_mode=chat_completions for provider==moa; mirror
that in the live switch so the primary call always routes through
MoAClient.chat.completions. The aggregator's real transport is resolved and
applied inside the reference/aggregator fan-out, not on the outer call.
