The five model providers ResponseCX routes to, the default model per provider, and how to pick per agent.
ResponseCX is provider-agnostic: every agent carries a model field, and the platform routes the
request to the matching provider. Leave it unset and the provider’s default applies.
Providers and defaults
Provider
Default model
Character
Anthropic
claude-sonnet-4-5-20250929
The default choice for customer-facing agents — strong instruction-following under long policies
OpenAI
gpt-4o
General-purpose; also the family behind realtime voice
Google
gemini-2.0-flash
Fast and inexpensive for high-volume, low-stakes turns
Groq (Llama)
llama-3.1-8b-instant
Lowest latency; good for classification and routing steps
Any model identifier the provider accepts is passed through, so a newer model is available the day
the provider ships it — no platform release needed.
Match the model to the step, not the agent fleet. A common shape: a fast, cheap model
(llama-3.1-8b-instant or gemini-2.0-flash) for intent classification, and a stronger model for
the customer-facing reply. The classification step runs on every message; the strong model only on
the ones that need it.
What the model does not decide
Model choice affects fluency, latency, and cost. It does not decide what the agent is allowed to
do — that is Settings, Rules,
and, for consequential actions, the decision gate.
Upgrading a model is a behaviour change. A stronger model follows your policies differently — often
better, occasionally in a new wrong way. Run your
evaluations against the new model before switching production traffic.
