Function resolveRole

src/llm/role-resolver.ts:58–102

(
  role: RoleName,
  config: QodexConfig,
  explicitModel?: string,
)

 * @param explicitModel optional per-call override — e.g. the `task` tool's model arg
 */
export function resolveRole(
  role: RoleName,
  config: QodexConfig,
  explicitModel?: string,
): ResolvedRole {
  // 1. Explicit per-call wins. We have to infer the provider from the model id
  //    because callers (`task` tool) only pass the model string.
  if (explicitModel) {
    return {
      provider: inferProvider(explicitModel),
      model: explicitModel,
      source: 'explicit',
    };
  }

  // 2. Session override (from `/subagent-model <id>` or `/role-model <name> <id>`)
  const session = _sessionOverrides.get(role);
  if (session) {
    return { provider: session.provider, model: session.model, source: 'session-override' };
  }

  // 3. Config-level role binding — try exact role first
  const rolesMap = (config as any).roles as Record<string, { provider: ResolvedRole['provider']; model: string } | undefined> | undefined;
  const roleConfig = rolesMap?.[role];
  if (roleConfig?.model) {
    return { provider: roleConfig.provider, model: roleConfig.model, source: 'config-role' };
  }

  // 4. Fall back to roles.subagent if a different role was requested but unconfigured.
  //    This makes "I asked for vision but didn't set it up" gracefully degrade rather
  //    than silently using the parent model (which probably isn't vision-capable).
  if (role !== 'subagent') {
    const subagentConfig = rolesMap?.['subagent'];
    if (subagentConfig?.model) {
      return { provider: subagentConfig.provider, model: subagentConfig.model, source: 'config-role' };
    }
  }

  // 5. Last resort: parent default
  return {
    provider: config.defaults.provider,
    model: config.defaults.model,
    source: 'parent-default',
  };
}

/**
 * Infer provider from model id. Heuristic — used when a caller passes only a model