Intelligent Customer Support Upgrade

Automatically assign models based on question complexity, balancing experience, cost, and stability. 4ALL API model switching only requires changing the model field; layered routing can be implemented in business logic with just a few lines of code.

Layered Routing Strategy

Tier	Scenario	Recommended Models
L1 Quick Answers	Greetings, FAQ, order lookup	gpt-5.4-mini, gemini-3.5-flash
L2 Standard	Multi-turn consultations, after-sales handling	gpt-5.5, claude-haiku-4-5
L3 Complex	Complaints, complex policy explanations	claude-sonnet-5, gpt-5.5-high

def pick_model(question, history):
    if is_faq(question):
        return "gpt-5.4-mini"
    if needs_escalation(question, history):
        return "claude-sonnet-5"
    return "gpt-5.5"

Implementation Notes

• All models use the same Chat Completions interface, so switching requires no changes; see Chat Completions;
• Use streaming output to reduce time to first byte; the difference in customer support experience is significant;
• Create a separate token for the customer support system and set a quota cap to facilitate cost accounting and loss prevention; see Authentication and Keys;
• When the upstream service experiences occasional instability, follow Error Codes and Retries for fallback (for example, downgrade from L3 to an L2 model as backup).