app/node_modules/@langchain/core/dist/tracers/console.js

import styles from "ansi-styles";
import { BaseTracer } from "./base.js";
function wrap(style, text) {
    return `${style.open}${text}${style.close}`;
}
function tryJsonStringify(obj, fallback) {
    try {
        return JSON.stringify(obj, null, 2);
    }
    catch (err) {
        return fallback;
    }
}
function formatKVMapItem(value) {
    if (typeof value === "string") {
        return value.trim();
    }
    if (value === null || value === undefined) {
        return value;
    }
    return tryJsonStringify(value, value.toString());
}
function elapsed(run) {
    if (!run.end_time)
        return "";
    const elapsed = run.end_time - run.start_time;
    if (elapsed < 1000) {
        return `${elapsed}ms`;
    }
    return `${(elapsed / 1000).toFixed(2)}s`;
}
const { color } = styles;
/**
 * A tracer that logs all events to the console. It extends from the
 * `BaseTracer` class and overrides its methods to provide custom logging
 * functionality.
 * @example
 * ```typescript
 *
 * const llm = new ChatAnthropic({
 *   temperature: 0,
 *   tags: ["example", "callbacks", "constructor"],
 *   callbacks: [new ConsoleCallbackHandler()],
 * });
 *
 * ```
 */
export class ConsoleCallbackHandler extends BaseTracer {
    constructor() {
        super(...arguments);
        Object.defineProperty(this, "name", {
            enumerable: true,
            configurable: true,
            writable: true,
            value: "console_callback_handler"
        });
    }
    /**
     * Method used to persist the run. In this case, it simply returns a
     * resolved promise as there's no persistence logic.
     * @param _run The run to persist.
     * @returns A resolved promise.
     */
    persistRun(_run) {
        return Promise.resolve();
    }
    // utility methods
    /**
     * Method used to get all the parent runs of a given run.
     * @param run The run whose parents are to be retrieved.
     * @returns An array of parent runs.
     */
    getParents(run) {
        const parents = [];
        let currentRun = run;
        while (currentRun.parent_run_id) {
            const parent = this.runMap.get(currentRun.parent_run_id);
            if (parent) {
                parents.push(parent);
                currentRun = parent;
            }
            else {
                break;
            }
        }
        return parents;
    }
    /**
     * Method used to get a string representation of the run's lineage, which
     * is used in logging.
     * @param run The run whose lineage is to be retrieved.
     * @returns A string representation of the run's lineage.
     */
    getBreadcrumbs(run) {
        const parents = this.getParents(run).reverse();
        const string = [...parents, run]
            .map((parent, i, arr) => {
            const name = `${parent.execution_order}:${parent.run_type}:${parent.name}`;
            return i === arr.length - 1 ? wrap(styles.bold, name) : name;
        })
            .join(" > ");
        return wrap(color.grey, string);
    }
    // logging methods
    /**
     * Method used to log the start of a chain run.
     * @param run The chain run that has started.
     * @returns void
     */
    onChainStart(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.green, "[chain/start]")} [${crumbs}] Entering Chain run with input: ${tryJsonStringify(run.inputs, "[inputs]")}`);
    }
    /**
     * Method used to log the end of a chain run.
     * @param run The chain run that has ended.
     * @returns void
     */
    onChainEnd(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.cyan, "[chain/end]")} [${crumbs}] [${elapsed(run)}] Exiting Chain run with output: ${tryJsonStringify(run.outputs, "[outputs]")}`);
    }
    /**
     * Method used to log any errors of a chain run.
     * @param run The chain run that has errored.
     * @returns void
     */
    onChainError(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.red, "[chain/error]")} [${crumbs}] [${elapsed(run)}] Chain run errored with error: ${tryJsonStringify(run.error, "[error]")}`);
    }
    /**
     * Method used to log the start of an LLM run.
     * @param run The LLM run that has started.
     * @returns void
     */
    onLLMStart(run) {
        const crumbs = this.getBreadcrumbs(run);
        const inputs = "prompts" in run.inputs
            ? { prompts: run.inputs.prompts.map((p) => p.trim()) }
            : run.inputs;
        console.log(`${wrap(color.green, "[llm/start]")} [${crumbs}] Entering LLM run with input: ${tryJsonStringify(inputs, "[inputs]")}`);
    }
    /**
     * Method used to log the end of an LLM run.
     * @param run The LLM run that has ended.
     * @returns void
     */
    onLLMEnd(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.cyan, "[llm/end]")} [${crumbs}] [${elapsed(run)}] Exiting LLM run with output: ${tryJsonStringify(run.outputs, "[response]")}`);
    }
    /**
     * Method used to log any errors of an LLM run.
     * @param run The LLM run that has errored.
     * @returns void
     */
    onLLMError(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.red, "[llm/error]")} [${crumbs}] [${elapsed(run)}] LLM run errored with error: ${tryJsonStringify(run.error, "[error]")}`);
    }
    /**
     * Method used to log the start of a tool run.
     * @param run The tool run that has started.
     * @returns void
     */
    onToolStart(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.green, "[tool/start]")} [${crumbs}] Entering Tool run with input: "${formatKVMapItem(run.inputs.input)}"`);
    }
    /**
     * Method used to log the end of a tool run.
     * @param run The tool run that has ended.
     * @returns void
     */
    onToolEnd(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.cyan, "[tool/end]")} [${crumbs}] [${elapsed(run)}] Exiting Tool run with output: "${formatKVMapItem(run.outputs?.output)}"`);
    }
    /**
     * Method used to log any errors of a tool run.
     * @param run The tool run that has errored.
     * @returns void
     */
    onToolError(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.red, "[tool/error]")} [${crumbs}] [${elapsed(run)}] Tool run errored with error: ${tryJsonStringify(run.error, "[error]")}`);
    }
    /**
     * Method used to log the start of a retriever run.
     * @param run The retriever run that has started.
     * @returns void
     */
    onRetrieverStart(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.green, "[retriever/start]")} [${crumbs}] Entering Retriever run with input: ${tryJsonStringify(run.inputs, "[inputs]")}`);
    }
    /**
     * Method used to log the end of a retriever run.
     * @param run The retriever run that has ended.
     * @returns void
     */
    onRetrieverEnd(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.cyan, "[retriever/end]")} [${crumbs}] [${elapsed(run)}] Exiting Retriever run with output: ${tryJsonStringify(run.outputs, "[outputs]")}`);
    }
    /**
     * Method used to log any errors of a retriever run.
     * @param run The retriever run that has errored.
     * @returns void
     */
    onRetrieverError(run) {
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.red, "[retriever/error]")} [${crumbs}] [${elapsed(run)}] Retriever run errored with error: ${tryJsonStringify(run.error, "[error]")}`);
    }
    /**
     * Method used to log the action selected by the agent.
     * @param run The run in which the agent action occurred.
     * @returns void
     */
    onAgentAction(run) {
        const agentRun = run;
        const crumbs = this.getBreadcrumbs(run);
        console.log(`${wrap(color.blue, "[agent/action]")} [${crumbs}] Agent selected action: ${tryJsonStringify(agentRun.actions[agentRun.actions.length - 1], "[action]")}`);
    }
}