Function buildProviderOptions

src/common/utils/ai/providerOptions.ts:219–532

(
  modelString: string,
  thinkingLevel: ThinkingLevel,
  messages?: MuxMessage[],
  _lostResponseIds?: (id: string) => boolean,
  muxProviderOptions?: MuxProviderOptions,
  workspaceId?: string, // Optional for non-OpenAI providers
  openaiTruncationMode?: OpenAIResponsesProviderOptions["truncation"],
  providersConfig?: ProvidersConfigMap | null,
  routeProvider?: ProviderName,
  promptCacheScope?: string
)

 * @returns Provider options object for AI SDK
 */
export function buildProviderOptions(
  modelString: string,
  thinkingLevel: ThinkingLevel,
  messages?: MuxMessage[],
  _lostResponseIds?: (id: string) => boolean,
  muxProviderOptions?: MuxProviderOptions,
  workspaceId?: string, // Optional for non-OpenAI providers
  openaiTruncationMode?: OpenAIResponsesProviderOptions["truncation"],
  providersConfig?: ProvidersConfigMap | null,
  routeProvider?: ProviderName,
  promptCacheScope?: string
): ProviderOptions {
  // Caller is responsible for enforcing thinking policy before calling this function.
  // agentSession.ts is the canonical enforcement point.
  const effectiveThinking = thinkingLevel;
  // Parse origin from normalized model string
  const normalizedModel = normalizeToCanonical(modelString);
  const [origin, modelName] = normalizedModel.split(":", 2);

  if (!origin || !modelName) {
    log.debug("buildProviderOptions: No origin or model name found, returning empty");
    return {};
  }

  const providerOptionsNamespaceKey = resolveProviderOptionsNamespaceKey(origin, routeProvider);

  // SDK payload-family selection: passthrough gateways use origin payloads,
  // while transforming gateways use the route provider's payload schema.
  const formatProvider =
    providerOptionsNamespaceKey === origin ? origin : (routeProvider ?? origin);

  // Resolve aliases to their base model for capability detection while keeping
  // the original modelString for provider routing and metadata lookups.
  const capabilityModel = resolveModelForMetadata(normalizedModel, providersConfig ?? null);
  const [, resolvedCapabilityModelName] = capabilityModel.split(":", 2);
  const capModelName = resolvedCapabilityModelName || modelName;

  log.debug("buildProviderOptions", {
    modelString,
    origin,
    routeProvider,
    providerOptionsNamespaceKey,
    formatProvider,
    modelName,
    capabilityModel,
    capModelName,
    thinkingLevel,
  });

  // Build Anthropic-specific options
  if (formatProvider === "anthropic") {
    // Anthropic prompt caching is already applied on Mux's manual cache markers
    // (cached system message, conversation tail, last tool) deeper in the
    // request pipeline. Do not also send top-level cacheControl here: the SDK
    // serializes it to a top-level cache_control block, which adds an extra
    // breakpoint on direct Anthropic requests.

    // Opus 4.5+, Sonnet 4.6, and Sonnet 5 use the effort parameter for reasoning control.