Function generateViaAgent

packages/core/src/agent.ts:963–1580

(
  input: GenerateInput,
  deps: GenerateViaAgentDeps = {},
)

 * tool calls, and file updates while preserving the GenerateOutput boundary.
 */
export async function generateViaAgent(
  input: GenerateInput,
  deps: GenerateViaAgentDeps = {},
): Promise<GenerateOutput> {
  const log = input.logger ?? NOOP_LOGGER;
  const ctx = {
    provider: input.model.provider,
    modelId: input.model.modelId,
  } as const;

  if (!input.prompt.trim()) {
    throw new CodesignError('Prompt cannot be empty', ERROR_CODES.INPUT_EMPTY_PROMPT);
  }
  const initialApiKey = input.apiKey.trim();
  if (initialApiKey.length === 0 && input.allowKeyless !== true) {
    throw new CodesignError('Missing API key', ERROR_CODES.PROVIDER_AUTH_MISSING);
  }
  if (!input.systemPrompt && input.mode && input.mode !== 'create') {
    throw new CodesignError(
      'generateViaAgent() built-in prompt only supports mode "create".',
      ERROR_CODES.INPUT_UNSUPPORTED_MODE,
    );
  }

  log.info('[generate] step=resolve_model', ctx);
  const resolveStart = Date.now();
  const piModel = buildPiModel(
    input.model,
    input.wire,
    input.baseUrl,
    input.httpHeaders,
    initialApiKey,
  );
  log.info('[generate] step=resolve_model.ok', { ...ctx, ms: Date.now() - resolveStart });

  log.info('[generate] step=build_request', ctx);
  const buildStart = Date.now();
  const resourceState = cloneResourceState(input.initialResourceState);
  const trackedFs = deps.fs ? trackFsMutations(deps.fs, resourceState) : undefined;
  let doneRepairLimitReached = false;
  const skillsBuiltinDir = input.templatesRoot
    ? path.join(input.templatesRoot, 'skills')
    : undefined;
  const resourceResult = input.systemPrompt
    ? {
        sections: [] as string[],
        warnings: [] as string[],
        skillCount: 0,
        scaffoldCount: 0,
        brandCount: 0,
      }
    : await collectResourceManifest({
        log,
        providerId: input.model.provider,
        templatesRoot: input.templatesRoot,
      });
  const preflightTitle = isAutoDesignName(input.currentDesignName)
    ? autoTitleFromPrompt(input.prompt)