{
  response: MessageType,   // The assistant's response message
  usage: {
    promptTokens: number,
    completionTokens: number,
    totalTokens: number,
  },
  toolCalls?: ToolCallType[],  // If the model requested tool calls
}

{
  response: string,    // The text chunk
  usage?: {            // Only present in the final chunk
    promptTokens: number,
    completionTokens: number,
    totalTokens: number,
  },
  toolCalls?: ToolCallType[],  // Only present in the final chunk
}

{
  embeddings: number[][],  // Array of embedding vectors
  usage: {
    promptTokens: number,
    totalTokens: number,
  },
}

import { GatewayError } from "@adaline/gateway";

try {
  const response = await gateway.completeChat({ ... });
} catch (error) {
  if (error instanceof GatewayError) {
    console.error(error.message);
    console.error(error.cause);   // Original provider error
  }
}