Keep LLM Model Selection Out of Business Logic

#ai #api #architecture #llm

Changing an LLM model should not require editing business logic. A service should ask for a task, such as “summarize this ticket,” instead of choosing a provider-specific model name.

The request boundary can then resolve the route, timeout, retry policy, and usage record. It should return the result together with the model used, latency, token usage when available, and failure state.

This separation also makes retries safer. A read-only summary may tolerate one bounded retry. A request that sends an email or changes a database record needs idempotency and explicit workflow state.

VectorNode is one implementation option for this model-access boundary. Its public product description covers access to multiple AI models through one API key, unified credits, transparent pricing, and usage logs: https://www.vectronode.com

Disclosure: VectorNode is our product and is included as a technical implementation example.

The practical test is simple: can you change the model route without editing the support-ticket service? If not, the boundary is still leaking.