@langchain/community/dist/stores/message/postgres.cjs

Third-party integrations for LangChain.js

Object.defineProperty(exports, Symbol.toStringTag, { value: "Module" });
const require_runtime = require("../../_virtual/_rolldown/runtime.cjs");
let _langchain_core_messages = require("@langchain/core/messages");
let pg = require("pg");
pg = require_runtime.__toESM(pg);
let _langchain_core_chat_history = require("@langchain/core/chat_history");
//#region src/stores/message/postgres.ts
var postgres_exports = /* @__PURE__ */ require_runtime.__exportAll({ PostgresChatMessageHistory: () => PostgresChatMessageHistory });
/**
* Class for managing chat message history using a Postgres Database as a
* storage backend. Extends the BaseListChatMessageHistory class.
* @example
* ```typescript
* const chatHistory = new PostgresChatMessageHistory({
*    tableName: "langchain_chat_histories",
*    sessionId: "lc-example",
*    pool: new pg.Pool({
*      host: "127.0.0.1",
*      port: 5432,
*      user: "myuser",
*      password: "ChangeMe",
*      database: "api",
*    }),
* });
* ```
*/
var PostgresChatMessageHistory = class extends _langchain_core_chat_history.BaseListChatMessageHistory {
	lc_namespace = [
		"langchain",
		"stores",
		"message",
		"postgres"
	];
	pool;
	tableName = "langchain_chat_histories";
	sessionId;
	initialized = false;
	/**
	* Creates a new PostgresChatMessageHistory.
	* @param {PostgresChatMessageHistoryInput} fields The input fields for the PostgresChatMessageHistory.
	* @param {string} fields.tableName The name of the table name to use. Defaults to `langchain_chat_histories`.
	* @param {string} fields.sessionId The session ID to use when storing and retrieving chat message history.
	* @param {pg.Pool} fields.pool The Postgres pool to use. If provided, the PostgresChatMessageHistory will use the provided pool.
	* @param {pg.PoolConfig} fields.poolConfig The configuration object for the Postgres pool. If no pool is provided, the conig will be used to create a new pool.
	* If `pool` is provided, it will be used as the Postgres pool even if `poolConfig` is also provided.
	* @throws If neither `pool` nor `poolConfig` is provided.
	*/
	constructor(fields) {
		super(fields);
		const { tableName, sessionId, pool, poolConfig, escapeTableName } = fields;
		if (!pool && !poolConfig) throw new Error("PostgresChatMessageHistory requires either a pool instance or pool config");
		this.pool = pool ?? new pg.default.Pool(poolConfig);
		const _tableName = tableName || this.tableName;
		this.tableName = escapeTableName ? pg.default.escapeIdentifier(_tableName) : _tableName;
		this.sessionId = sessionId;
	}
	/**
	* Checks if the table has been created and creates it if it hasn't.
	* @returns Promise that resolves when the table's existence is ensured.
	*/
	async ensureTable() {
		if (this.initialized) return;
		const query = `
        CREATE TABLE IF NOT EXISTS ${this.tableName} (
            id SERIAL PRIMARY KEY,
            session_id VARCHAR(255) NOT NULL,
            message JSONB NOT NULL
        );`;
		try {
			await this.pool.query(query);
		} catch (e) {
			if (!("code" in e) || e.code !== "23505") throw e;
		}
		this.initialized = true;
	}
	async addMessage(message) {
		await this.ensureTable();
		const { data, type } = (0, _langchain_core_messages.mapChatMessagesToStoredMessages)([message])[0];
		const query = `INSERT INTO ${this.tableName} (session_id, message) VALUES ($1, $2)`;
		await this.pool.query(query, [this.sessionId, {
			...data,
			type
		}]);
	}
	async getMessages() {
		await this.ensureTable();
		const query = `SELECT message FROM ${this.tableName} WHERE session_id = $1 ORDER BY id`;
		return (0, _langchain_core_messages.mapStoredMessagesToChatMessages)((await this.pool.query(query, [this.sessionId])).rows.map((row) => {
			const { type, ...data } = row.message;
			return {
				type,
				data
			};
		}));
	}
	async clear() {
		await this.ensureTable();
		const query = `DELETE FROM ${this.tableName} WHERE session_id = $1`;
		await this.pool.query(query, [this.sessionId]);
	}
	/**
	* End the Postgres pool.
	*/
	async end() {
		await this.pool.end();
	}
};
//#endregion
exports.PostgresChatMessageHistory = PostgresChatMessageHistory;
Object.defineProperty(exports, "postgres_exports", {
	enumerable: true,
	get: function() {
		return postgres_exports;
	}
});

//# sourceMappingURL=postgres.cjs.map