agsamantha/node_modules/@langchain/community/dist/chat_models/yandex.js
2024-10-02 15:15:21 -05:00

131 lines
4.5 KiB
JavaScript

import { AIMessage } from "@langchain/core/messages";
import { BaseChatModel } from "@langchain/core/language_models/chat_models";
import { getEnvironmentVariable } from "@langchain/core/utils/env";
const apiUrl = "https://llm.api.cloud.yandex.net/llm/v1alpha/chat";
function _parseChatHistory(history) {
const chatHistory = [];
let instruction = "";
for (const message of history) {
if (typeof message.content !== "string") {
throw new Error("ChatYandexGPT does not support non-string message content.");
}
if ("content" in message) {
if (message._getType() === "human") {
chatHistory.push({ role: "user", text: message.content });
}
else if (message._getType() === "ai") {
chatHistory.push({ role: "assistant", text: message.content });
}
else if (message._getType() === "system") {
instruction = message.content;
}
}
}
return [chatHistory, instruction];
}
/**
* @deprecated Prefer @langchain/yandex
* @example
* ```typescript
* const chat = new ChatYandexGPT({});
* // The assistant is set to translate English to French.
* const res = await chat.call([
* new SystemMessage(
* "You are a helpful assistant that translates English to French."
* ),
* new HumanMessage("I love programming."),
* ]);
* console.log(res);
* ```
*/
export class ChatYandexGPT extends BaseChatModel {
constructor(fields) {
super(fields ?? {});
Object.defineProperty(this, "apiKey", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "iamToken", {
enumerable: true,
configurable: true,
writable: true,
value: void 0
});
Object.defineProperty(this, "temperature", {
enumerable: true,
configurable: true,
writable: true,
value: 0.6
});
Object.defineProperty(this, "maxTokens", {
enumerable: true,
configurable: true,
writable: true,
value: 1700
});
Object.defineProperty(this, "model", {
enumerable: true,
configurable: true,
writable: true,
value: "general"
});
const apiKey = fields?.apiKey ?? getEnvironmentVariable("YC_API_KEY");
const iamToken = fields?.iamToken ?? getEnvironmentVariable("YC_IAM_TOKEN");
if (apiKey === undefined && iamToken === undefined) {
throw new Error("Please set the YC_API_KEY or YC_IAM_TOKEN environment variable or pass it to the constructor as the apiKey or iamToken field.");
}
this.apiKey = apiKey;
this.iamToken = iamToken;
this.maxTokens = fields?.maxTokens ?? this.maxTokens;
this.temperature = fields?.temperature ?? this.temperature;
this.model = fields?.model ?? this.model;
}
_llmType() {
return "yandexgpt";
}
_combineLLMOutput() {
return {};
}
/** @ignore */
async _generate(messages, options, _) {
const [messageHistory, instruction] = _parseChatHistory(messages);
const headers = { "Content-Type": "application/json", Authorization: "" };
if (this.apiKey !== undefined) {
headers.Authorization = `Api-Key ${this.apiKey}`;
}
else {
headers.Authorization = `Bearer ${this.iamToken}`;
}
const bodyData = {
model: this.model,
generationOptions: {
temperature: this.temperature,
maxTokens: this.maxTokens,
},
messages: messageHistory,
instructionText: instruction,
};
const response = await fetch(apiUrl, {
method: "POST",
headers,
body: JSON.stringify(bodyData),
signal: options?.signal,
});
if (!response.ok) {
throw new Error(`Failed to fetch ${apiUrl} from YandexGPT: ${response.status}`);
}
const responseData = await response.json();
const { result } = responseData;
const { text } = result.message;
const totalTokens = result.num_tokens;
const generations = [
{ text, message: new AIMessage(text) },
];
return {
generations,
llmOutput: { totalTokens },
};
}
}