This drops the service from ~876 to ~283 lines with zero public API changes. Adding a new provider becomes a 1-5 line config entry instead of a switch case + method copy-paste. TypeScript enforces exhaustiveness — if a new provider is added to the union type without a config entry, it's a compile error.

TL;DR

Replace the redundant fetchXxxModels() methods and switch statement with a declarative registry and a single dispatch function to simplify adding new LLM providers.

Guidance

• Identify the ChatHubModelsService class and locate the 14 private fetchXxxModels() methods and the 16-case switch statement.
• Replace these methods with a Record<ChatHubLLMProvider, LLMProviderFetchConfig> registry to store configuration data for each provider.
• Implement a single fetchLLMProviderModels() function to handle all config types, reducing code duplication and improving maintainability.
• Verify that the new implementation does not introduce any public API changes and that TypeScript enforces exhaustiveness for new provider additions.

Example

const llmProviderRegistry: Record<ChatHubLLMProvider, LLMProviderFetchConfig> = {
  // Example entry for a provider
  ProviderA: { /* config data */ },
  ProviderB: { /* config data */ },
  // ...
};

function fetchLLMProviderModels(provider: ChatHubLLMProvider) {
  const config = llmProviderRegistry[provider];
  // Handle config and dispatch to DynamicNodeParametersService
}

Notes

This solution assumes that the ChatHubLLMProvider union type is up-to-date and includes all existing providers. If new providers are added to the union type without a corresponding config entry, TypeScript will raise a compile error.

Recommendation

Apply the proposed workaround by replacing the redundant methods and switch statement with a declarative registry and a single dispatch function, as it simplifies the code and improves maintainability.