From df9a9f1f833502f2df6f6fd19450cc4030d4dad6 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Tue, 28 Nov 2023 16:07:23 -0800
Subject: [PATCH 01/25] Runnable with message history

---
 langchain-core/src/callbacks/manager.ts       |   7 +
 langchain-core/src/chat_history.ts            |  34 ++++
 langchain-core/src/runnables/history.ts       | 178 ++++++++++++++++++
 .../tests/runnable_history.int.test.ts        |  44 +++++
 4 files changed, 263 insertions(+)
 create mode 100644 langchain-core/src/runnables/history.ts
 create mode 100644 langchain-core/src/runnables/tests/runnable_history.int.test.ts

diff --git a/langchain-core/src/callbacks/manager.ts b/langchain-core/src/callbacks/manager.ts
index 34fe086636a6..66e6d7edebf3 100644
--- a/langchain-core/src/callbacks/manager.ts
+++ b/langchain-core/src/callbacks/manager.ts
@@ -61,6 +61,13 @@ export interface BaseCallbackConfig {
    * Tags are passed to all callbacks, metadata is passed to handle*Start callbacks.
    */
   callbacks?: Callbacks;
+
+  /**
+   * Runtime values for attributes previously made configurable on this Runnable,
+   * or sub-Runnables.
+   */
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  configurable?: Record<string, any>;
 }
 
 export function parseCallbackConfigArg(
diff --git a/langchain-core/src/chat_history.ts b/langchain-core/src/chat_history.ts
index 6841d19e865e..7c17fc2f5423 100644
--- a/langchain-core/src/chat_history.ts
+++ b/langchain-core/src/chat_history.ts
@@ -32,3 +32,37 @@ export abstract class BaseListChatMessageHistory extends Serializable {
     return this.addMessage(new AIMessage(message));
   }
 }
+
+export class FakeChatMessageHistory extends BaseChatMessageHistory {
+  lc_namespace = ["langchain", "core", "message", "fake"];
+
+  messages: Array<BaseMessage> = [];
+
+  constructor() {
+    super();
+  }
+
+  public getMessages(): Promise<BaseMessage[]> {
+    return Promise.resolve(this.messages);
+  }
+
+  public addMessage(message: BaseMessage): Promise<void> {
+    this.messages.push(message);
+    return Promise.resolve();
+  }
+
+  public addUserMessage(message: string): Promise<void> {
+    this.messages.push(new HumanMessage(message));
+    return Promise.resolve();
+  }
+
+  public addAIChatMessage(message: string): Promise<void> {
+    this.messages.push(new AIMessage(message));
+    return Promise.resolve();
+  }
+
+  public clear(): Promise<void> {
+    this.messages = [];
+    return Promise.resolve();
+  }
+}
diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
new file mode 100644
index 000000000000..354bf91d567e
--- /dev/null
+++ b/langchain-core/src/runnables/history.ts
@@ -0,0 +1,178 @@
+import { BaseChatMessageHistory } from "../chat_history.js";
+import {
+  AIMessage,
+  BaseMessage,
+  HumanMessage,
+  isBaseMessage,
+} from "../messages/index.js";
+import { Run } from "../tracers/base.js";
+import {
+  Runnable,
+  RunnableBinding,
+  RunnableBindingArgs,
+  RunnableLambda,
+} from "./base.js";
+import { RunnableConfig } from "./config.js";
+import { RunnablePassthrough } from "./passthrough.js";
+
+type GetSessionHistoryCallable = (
+  ...args: Array<any>
+) => BaseChatMessageHistory;
+
+export class RunnableWithMessageHistory<
+  RunInput,
+  RunOutput,
+  CallOptions extends RunnableConfig
+> extends RunnableBinding<RunInput, RunOutput, CallOptions> {
+  runnable: Runnable<RunInput, RunOutput>;
+
+  inputMessagesKey = "input";
+
+  outputMessagesKey = "output";
+
+  historyMessagesKey = "history";
+
+  getMessageHistory: GetSessionHistoryCallable;
+
+  constructor(
+    fields: RunnableBindingArgs<RunInput, RunOutput, CallOptions> & {
+      runnable: Runnable<RunInput, RunOutput>;
+      getMessageHistory: GetSessionHistoryCallable;
+      inputMessagesKey?: string;
+      outputMessagesKey?: string;
+      historyMessagesKey?: string;
+    }
+  ) {
+    super(fields);
+    this.runnable = fields.runnable;
+    this.getMessageHistory = fields.getMessageHistory;
+    this.inputMessagesKey = fields.inputMessagesKey ?? this.inputMessagesKey;
+    this.outputMessagesKey = fields.outputMessagesKey ?? this.outputMessagesKey;
+    this.historyMessagesKey =
+      fields.historyMessagesKey ?? this.historyMessagesKey;
+
+    let historyChain: Runnable = new RunnableLambda({
+      func: (input: any) => (config: CallOptions) =>
+        this._enterHistory(input, config),
+    }).withConfig({ runName: "load_history" });
+
+    const messages_key =
+      (fields.historyMessagesKey ?? this.historyMessagesKey) ||
+      (fields.inputMessagesKey ?? this.inputMessagesKey);
+    if (messages_key) {
+      historyChain = RunnablePassthrough.assign({
+        [messages_key]: historyChain,
+      }).withConfig({ runName: "insert_history" });
+    }
+
+    // const bound = historyChain
+    //   .pipe(fields.runnable)
+    //   .withConfig({ runName: "RunnableWithMessageHistory" })
+
+    // this.bound = bound;
+  }
+
+  _getInputMessages(
+    inputValue: string | BaseMessage | Array<BaseMessage>
+  ): Array<BaseMessage> {
+    if (typeof inputValue === "string") {
+      return [new HumanMessage(inputValue)];
+    } else if (Array.isArray(inputValue)) {
+      return inputValue;
+    } else {
+      return [inputValue];
+    }
+  }
+
+  _getOutputMessages(
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    outputValue: string | BaseMessage | Array<BaseMessage> | Record<string, any>
+  ): Array<BaseMessage> {
+    let newOutputValue = outputValue;
+    if (
+      !Array.isArray(outputValue) &&
+      !isBaseMessage(outputValue) &&
+      typeof outputValue !== "string"
+    ) {
+      newOutputValue = outputValue[this.outputMessagesKey];
+    }
+
+    if (typeof newOutputValue === "string") {
+      return [new AIMessage(newOutputValue)];
+    } else if (Array.isArray(newOutputValue)) {
+      return newOutputValue;
+    } else if (isBaseMessage(newOutputValue)) {
+      return [newOutputValue];
+    }
+    throw new Error(
+      `Expected a string, BaseMessage, or array of BaseMessages. Received: ${JSON.stringify(
+        newOutputValue,
+        null,
+        2
+      )}`
+    );
+  }
+
+  _enterHistory(input: any, config: CallOptions): Array<BaseMessage> {
+    // what the hell is python doin?
+    const history = config.configurable?.messageHistory;
+
+    if (this.historyMessagesKey) {
+      // from python, once again, what the??
+      // return history.messages.copy();
+      return history.messages;
+    }
+
+    const inputVal = this.inputMessagesKey
+      ? input[this.inputMessagesKey]
+      : input;
+    return [...history.messages, ...this._getInputMessages(inputVal)];
+  }
+
+  _exitHistory(run: Run, config: CallOptions): void {
+    // what the hell is python doin?
+    const history = config.configurable?.messageHistory;
+
+    // Get input messages
+    const { inputs } = run;
+    const inputValue = inputs[this.inputMessagesKey];
+    const inputMessages = this._getInputMessages(inputValue);
+    // Get output messages
+    const outputValue = run.outputs;
+    if (!outputValue) {
+      throw new Error(
+        `Output values from 'Run' undefined. Run: ${JSON.stringify(
+          run,
+          null,
+          2
+        )}`
+      );
+    }
+    const outputMessages = this._getOutputMessages(outputValue);
+
+    for (const message of [...inputMessages, ...outputMessages]) {
+      history.addMessage(message);
+    }
+  }
+
+  _mergeConfigs(...configs: Array<CallOptions | undefined>) {
+    const config = super._mergeConfig(...configs);
+    // Extract sessionId
+    if (!config.configurable || !config.configurable.sessionId) {
+      const exampleInput = {
+        [this.inputMessagesKey]: "foo",
+      };
+      const exampleConfig = { configurable: { sessionId: "123" } };
+      throw new Error(
+        `session_id is required. Pass it in as part of the config argument to .invoke() or .stream()\n` +
+          `eg. chain.invoke(${JSON.stringify(exampleInput)}, ${JSON.stringify(
+            exampleConfig
+          )})`
+      );
+    }
+    // attach messageHistory
+    const { sessionId } = config.configurable;
+    config.configurable.messageHistory = this.getMessageHistory(sessionId);
+    return config;
+  }
+}
diff --git a/langchain-core/src/runnables/tests/runnable_history.int.test.ts b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
new file mode 100644
index 000000000000..70680e574acb
--- /dev/null
+++ b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
@@ -0,0 +1,44 @@
+import { HumanMessage, isBaseMessage } from "../../messages/index.js";
+import { RunnableLambda } from "../base.js";
+import { RunnableConfig } from "../config.js";
+import { RunnableWithMessageHistory } from "../history.js";
+import {
+  BaseChatMessageHistory,
+  FakeChatMessageHistory,
+} from "../../chat_history.js";
+
+function getGetSessionHistory(): (sessionId: string) => BaseChatMessageHistory {
+  const chatHistoryStore: { [key: string]: BaseChatMessageHistory } = {};
+
+  function getSessionHistory(sessionId: string): BaseChatMessageHistory {
+    if (!(sessionId in chatHistoryStore)) {
+      chatHistoryStore[sessionId] = new FakeChatMessageHistory();
+    }
+    return chatHistoryStore[sessionId];
+  }
+
+  return getSessionHistory;
+}
+
+test("Runnable with message history", async () => {
+  const runnable = new RunnableLambda({
+    func: (messages: HumanMessage[]) =>
+      `you said: ${messages
+        .filter((m) => isBaseMessage(m))
+        .map((m) => m.content)
+        .join("\n")}`,
+  });
+  const getSessionHistory = getGetSessionHistory();
+  const withHistory = new RunnableWithMessageHistory({
+    runnable,
+    bound: runnable,
+    kwargs: {},
+    config: {},
+    getMessageHistory: getSessionHistory,
+  });
+  const config: RunnableConfig = { configurable: { session_id: "1" } };
+  let output = await withHistory.invoke([new HumanMessage("hello")], config);
+  expect(output).toBe("you said: hello");
+  output = await withHistory.invoke([new HumanMessage("good bye")], config);
+  expect(output).toBe("you said: hello\ngood bye");
+});

From a22855ef1dff7d8b1eac1117af65b16313644e82 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Tue, 28 Nov 2023 16:09:26 -0800
Subject: [PATCH 02/25] cr

---
 langchain-core/src/runnables/history.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 354bf91d567e..4a298f573226 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -16,6 +16,7 @@ import { RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   ...args: Array<any>
 ) => BaseChatMessageHistory;
 
@@ -52,6 +53,7 @@ export class RunnableWithMessageHistory<
       fields.historyMessagesKey ?? this.historyMessagesKey;
 
     let historyChain: Runnable = new RunnableLambda({
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       func: (input: any) => (config: CallOptions) =>
         this._enterHistory(input, config),
     }).withConfig({ runName: "load_history" });
@@ -113,13 +115,12 @@ export class RunnableWithMessageHistory<
     );
   }
 
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   _enterHistory(input: any, config: CallOptions): Array<BaseMessage> {
-    // what the hell is python doin?
     const history = config.configurable?.messageHistory;
 
     if (this.historyMessagesKey) {
-      // from python, once again, what the??
-      // return history.messages.copy();
+      // todo: this is def not right brace!
       return history.messages;
     }
 
@@ -130,7 +131,6 @@ export class RunnableWithMessageHistory<
   }
 
   _exitHistory(run: Run, config: CallOptions): void {
-    // what the hell is python doin?
     const history = config.configurable?.messageHistory;
 
     // Get input messages

From add083febb7af7dda5c317ab6100060358685582 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Tue, 28 Nov 2023 17:34:53 -0800
Subject: [PATCH 03/25] cr

---
 langchain-core/src/runnables/history.ts       | 85 ++++++++++---------
 .../tests/runnable_history.int.test.ts        | 28 ++++--
 2 files changed, 65 insertions(+), 48 deletions(-)

diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 4a298f573226..c88a2f1f35e2 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -1,3 +1,4 @@
+import { BaseCallbackConfig } from "../callbacks/manager.js";
 import { BaseChatMessageHistory } from "../chat_history.js";
 import {
   AIMessage,
@@ -12,31 +13,29 @@ import {
   RunnableBindingArgs,
   RunnableLambda,
 } from "./base.js";
-import { RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   ...args: Array<any>
-) => BaseChatMessageHistory;
+) => Promise<BaseChatMessageHistory>;
 
 export class RunnableWithMessageHistory<
   RunInput,
-  RunOutput,
-  CallOptions extends RunnableConfig
-> extends RunnableBinding<RunInput, RunOutput, CallOptions> {
+  RunOutput
+> extends RunnableBinding<RunInput, RunOutput, BaseCallbackConfig> {
   runnable: Runnable<RunInput, RunOutput>;
 
-  inputMessagesKey = "input";
+  inputMessagesKey?: string;
 
-  outputMessagesKey = "output";
+  outputMessagesKey?: string;
 
-  historyMessagesKey = "history";
+  historyMessagesKey?: string;
 
   getMessageHistory: GetSessionHistoryCallable;
 
   constructor(
-    fields: RunnableBindingArgs<RunInput, RunOutput, CallOptions> & {
+    fields: RunnableBindingArgs<RunInput, RunOutput, BaseCallbackConfig> & {
       runnable: Runnable<RunInput, RunOutput>;
       getMessageHistory: GetSessionHistoryCallable;
       inputMessagesKey?: string;
@@ -47,31 +46,30 @@ export class RunnableWithMessageHistory<
     super(fields);
     this.runnable = fields.runnable;
     this.getMessageHistory = fields.getMessageHistory;
-    this.inputMessagesKey = fields.inputMessagesKey ?? this.inputMessagesKey;
-    this.outputMessagesKey = fields.outputMessagesKey ?? this.outputMessagesKey;
-    this.historyMessagesKey =
-      fields.historyMessagesKey ?? this.historyMessagesKey;
+    this.inputMessagesKey = fields.inputMessagesKey;
+    this.outputMessagesKey = fields.outputMessagesKey;
+    this.historyMessagesKey = fields.historyMessagesKey;
 
     let historyChain: Runnable = new RunnableLambda({
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      func: (input: any) => (config: CallOptions) =>
-        this._enterHistory(input, config),
-    }).withConfig({ runName: "load_history" });
-
-    const messages_key =
-      (fields.historyMessagesKey ?? this.historyMessagesKey) ||
-      (fields.inputMessagesKey ?? this.inputMessagesKey);
-    if (messages_key) {
+      func: (input: any) => {
+        console.log("HISTORY CHAIN CALLED", input);
+        return this._enterHistory(input, {});
+      },
+    }).withConfig({ runName: "loadHistory" });
+
+    const messagesKey = fields.historyMessagesKey || fields.inputMessagesKey;
+    if (messagesKey) {
       historyChain = RunnablePassthrough.assign({
-        [messages_key]: historyChain,
-      }).withConfig({ runName: "insert_history" });
+        [messagesKey]: historyChain,
+      }).withConfig({ runName: "insertHistory" });
     }
 
-    // const bound = historyChain
-    //   .pipe(fields.runnable)
-    //   .withConfig({ runName: "RunnableWithMessageHistory" })
+    const bound = historyChain
+      .pipe(fields.runnable)
+      .withConfig({ runName: "RunnableWithMessageHistory" });
 
-    // this.bound = bound;
+    this.bound = bound;
   }
 
   _getInputMessages(
@@ -96,7 +94,7 @@ export class RunnableWithMessageHistory<
       !isBaseMessage(outputValue) &&
       typeof outputValue !== "string"
     ) {
-      newOutputValue = outputValue[this.outputMessagesKey];
+      newOutputValue = outputValue[this.outputMessagesKey ?? "output"];
     }
 
     if (typeof newOutputValue === "string") {
@@ -116,26 +114,33 @@ export class RunnableWithMessageHistory<
   }
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  _enterHistory(input: any, config: CallOptions): Array<BaseMessage> {
+  _enterHistory(input: any, config: BaseCallbackConfig): Array<BaseMessage> {
+    console.log("Running _enterHistory");
     const history = config.configurable?.messageHistory;
 
+    // @TODO I think this is broken
     if (this.historyMessagesKey) {
-      // todo: this is def not right brace!
       return history.messages;
     }
 
-    const inputVal = this.inputMessagesKey
-      ? input[this.inputMessagesKey]
-      : input;
-    return [...history.messages, ...this._getInputMessages(inputVal)];
+    const inputVal =
+      input ||
+      (this.inputMessagesKey ? input[this.inputMessagesKey] : undefined);
+    const historyMessages = history ? history.messages : [];
+    const returnType = [
+      ...historyMessages,
+      ...this._getInputMessages(inputVal),
+    ];
+    console.log("returning", returnType);
+    return returnType;
   }
 
-  _exitHistory(run: Run, config: CallOptions): void {
+  async _exitHistory(run: Run, config: BaseCallbackConfig): Promise<void> {
     const history = config.configurable?.messageHistory;
 
     // Get input messages
     const { inputs } = run;
-    const inputValue = inputs[this.inputMessagesKey];
+    const inputValue = inputs[this.inputMessagesKey ?? "input"];
     const inputMessages = this._getInputMessages(inputValue);
     // Get output messages
     const outputValue = run.outputs;
@@ -150,17 +155,17 @@ export class RunnableWithMessageHistory<
     }
     const outputMessages = this._getOutputMessages(outputValue);
 
-    for (const message of [...inputMessages, ...outputMessages]) {
-      history.addMessage(message);
+    for await (const message of [...inputMessages, ...outputMessages]) {
+      await history.addMessage(message);
     }
   }
 
-  _mergeConfigs(...configs: Array<CallOptions | undefined>) {
+  _mergeConfig(...configs: Array<BaseCallbackConfig | undefined>) {
     const config = super._mergeConfig(...configs);
     // Extract sessionId
     if (!config.configurable || !config.configurable.sessionId) {
       const exampleInput = {
-        [this.inputMessagesKey]: "foo",
+        [this.inputMessagesKey ?? "input"]: "foo",
       };
       const exampleConfig = { configurable: { sessionId: "123" } };
       throw new Error(
diff --git a/langchain-core/src/runnables/tests/runnable_history.int.test.ts b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
index 70680e574acb..111f9cfcf3fb 100644
--- a/langchain-core/src/runnables/tests/runnable_history.int.test.ts
+++ b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
@@ -7,12 +7,19 @@ import {
   FakeChatMessageHistory,
 } from "../../chat_history.js";
 
-function getGetSessionHistory(): (sessionId: string) => BaseChatMessageHistory {
+async function getGetSessionHistory(): Promise<
+  (sessionId: string) => Promise<BaseChatMessageHistory>
+> {
   const chatHistoryStore: { [key: string]: BaseChatMessageHistory } = {};
 
-  function getSessionHistory(sessionId: string): BaseChatMessageHistory {
+  async function getSessionHistory(
+    sessionId: string
+  ): Promise<BaseChatMessageHistory> {
     if (!(sessionId in chatHistoryStore)) {
+      console.log("not in store");
       chatHistoryStore[sessionId] = new FakeChatMessageHistory();
+    } else {
+      console.log("in store", await chatHistoryStore[sessionId].getMessages());
     }
     return chatHistoryStore[sessionId];
   }
@@ -22,21 +29,26 @@ function getGetSessionHistory(): (sessionId: string) => BaseChatMessageHistory {
 
 test("Runnable with message history", async () => {
   const runnable = new RunnableLambda({
-    func: (messages: HumanMessage[]) =>
-      `you said: ${messages
+    func: (messages: HumanMessage[]) => {
+      console.log("runnin", messages);
+      const messagesArr: HumanMessage[] = !Array.isArray(messages)
+        ? Object.values(messages)
+        : messages;
+      return `you said: ${messagesArr
         .filter((m) => isBaseMessage(m))
         .map((m) => m.content)
-        .join("\n")}`,
+        .join("\n")}`;
+    },
   });
-  const getSessionHistory = getGetSessionHistory();
+  const getMessageHistory = await getGetSessionHistory();
   const withHistory = new RunnableWithMessageHistory({
     runnable,
     bound: runnable,
     kwargs: {},
     config: {},
-    getMessageHistory: getSessionHistory,
+    getMessageHistory,
   });
-  const config: RunnableConfig = { configurable: { session_id: "1" } };
+  const config: RunnableConfig = { configurable: { sessionId: "1" } };
   let output = await withHistory.invoke([new HumanMessage("hello")], config);
   expect(output).toBe("you said: hello");
   output = await withHistory.invoke([new HumanMessage("good bye")], config);

From 05b71eae994a819438aa18ee353388628e3b818c Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 12:03:53 -0800
Subject: [PATCH 04/25] adds withListeners method to runnables/callbacks

---
 langchain-core/src/callbacks/manager.ts     |  26 +++-
 langchain-core/src/runnables/base.ts        | 134 +++++++++++++++++---
 langchain-core/src/runnables/config.ts      |  74 +++++++++++
 langchain-core/src/tracers/root_listener.ts |  63 +++++++++
 langchain/tsconfig.json                     |   2 +-
 5 files changed, 276 insertions(+), 23 deletions(-)
 create mode 100644 langchain-core/src/tracers/root_listener.ts

diff --git a/langchain-core/src/callbacks/manager.ts b/langchain-core/src/callbacks/manager.ts
index 34fe086636a6..1bb20acf30b8 100644
--- a/langchain-core/src/callbacks/manager.ts
+++ b/langchain-core/src/callbacks/manager.ts
@@ -484,9 +484,9 @@ export class CallbackManager
   extends BaseCallbackManager
   implements BaseCallbackManagerMethods
 {
-  handlers: BaseCallbackHandler[];
+  handlers: BaseCallbackHandler[] = [];
 
-  inheritableHandlers: BaseCallbackHandler[];
+  inheritableHandlers: BaseCallbackHandler[] = [];
 
   tags: string[] = [];
 
@@ -500,10 +500,26 @@ export class CallbackManager
 
   private readonly _parentRunId?: string;
 
-  constructor(parentRunId?: string) {
+  constructor(
+    parentRunId?: string,
+    options?: {
+      handlers?: BaseCallbackHandler[];
+      inheritableHandlers?: BaseCallbackHandler[];
+      tags?: string[];
+      inheritableTags?: string[];
+      metadata?: Record<string, unknown>;
+      inheritableMetadata?: Record<string, unknown>;
+    }
+  ) {
     super();
-    this.handlers = [];
-    this.inheritableHandlers = [];
+    this.handlers = options?.handlers ?? this.handlers;
+    this.inheritableHandlers =
+      options?.inheritableHandlers ?? this.inheritableHandlers;
+    this.tags = options?.tags ?? this.tags;
+    this.inheritableTags = options?.inheritableTags ?? this.inheritableTags;
+    this.metadata = options?.metadata ?? this.metadata;
+    this.inheritableMetadata =
+      options?.inheritableMetadata ?? this.inheritableMetadata;
     this._parentRunId = parentRunId;
   }
 
diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 0403b91486bb..c8c3d9d91b7c 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -12,8 +12,14 @@ import {
 } from "../tracers/log_stream.js";
 import { Serializable } from "../load/serializable.js";
 import { IterableReadableStream } from "../utils/stream.js";
-import { RunnableConfig, getCallbackMangerForConfig } from "./config.js";
+import {
+  RunnableConfig,
+  getCallbackMangerForConfig,
+  mergeConfigs,
+} from "./config.js";
 import { AsyncCaller } from "../utils/async_caller.js";
+import { Run } from "../tracers/base.js";
+import { RootListenersTracer } from "../tracers/root_listener.js";
 
 export type RunnableFunc<RunInput, RunOutput> = (
   input: RunInput
@@ -549,6 +555,44 @@ export abstract class Runnable<
   static isRunnable(thing: any): thing is Runnable {
     return thing ? thing.lc_runnable : false;
   }
+
+  /**
+   * Bind lifecycle listeners to a Runnable, returning a new Runnable.
+   * The Run object contains information about the run, including its id,
+   * type, input, output, error, startTime, endTime, and any tags or metadata
+   * added to the run.
+   *
+   * @param {Object} params - The object containing the callback functions.
+   * @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
+   * @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
+   * @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
+   */
+  withListeners({
+    onStart,
+    onEnd,
+    onError,
+  }: {
+    onStart?: (run: Run) => void;
+    onEnd?: (run: Run) => void;
+    onError?: (run: Run) => void;
+  }): Runnable<RunInput, RunOutput, CallOptions> {
+    // eslint-disable-next-line @typescript-eslint/no-use-before-define
+    return new RunnableBinding<RunInput, RunOutput, CallOptions>({
+      bound: this,
+      config: {},
+      configFactories: [
+        () => ({
+          callbacks: [
+            new RootListenersTracer({
+              onStart,
+              onEnd,
+              onError,
+            }),
+          ],
+        }),
+      ],
+    });
+  }
 }
 
 export type RunnableBindingArgs<
@@ -557,8 +601,9 @@ export type RunnableBindingArgs<
   CallOptions extends RunnableConfig
 > = {
   bound: Runnable<RunInput, RunOutput, CallOptions>;
-  kwargs: Partial<CallOptions>;
+  kwargs?: Partial<CallOptions>;
   config: RunnableConfig;
+  configFactories?: Array<() => RunnableConfig>;
 };
 
 /**
@@ -581,31 +626,21 @@ export class RunnableBinding<
 
   config: RunnableConfig;
 
-  protected kwargs: Partial<CallOptions>;
+  protected kwargs?: Partial<CallOptions>;
+
+  configFactories?: Array<() => RunnableConfig>;
 
   constructor(fields: RunnableBindingArgs<RunInput, RunOutput, CallOptions>) {
     super(fields);
     this.bound = fields.bound;
     this.kwargs = fields.kwargs;
     this.config = fields.config;
+    this.configFactories = fields.configFactories;
   }
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   _mergeConfig(options?: Record<string, any>) {
-    // eslint-disable-next-line @typescript-eslint/no-explicit-any
-    const copy: Record<string, any> = { ...this.config };
-    if (options) {
-      for (const key of Object.keys(options)) {
-        if (key === "metadata") {
-          copy[key] = { ...copy[key], ...options[key] };
-        } else if (key === "tags") {
-          copy[key] = (copy[key] ?? []).concat(options[key] ?? []);
-        } else {
-          copy[key] = options[key] ?? copy[key];
-        }
-      }
-    }
-    return copy as Partial<CallOptions>;
+    return mergeConfigs<CallOptions>(this.config, options);
   }
 
   bind(
@@ -721,6 +756,45 @@ export class RunnableBinding<
   ): thing is RunnableBinding<any, any, any> {
     return thing.bound && Runnable.isRunnable(thing.bound);
   }
+
+  /**
+   * Bind lifecycle listeners to a Runnable, returning a new Runnable.
+   * The Run object contains information about the run, including its id,
+   * type, input, output, error, startTime, endTime, and any tags or metadata
+   * added to the run.
+   *
+   * @param {Object} params - The object containing the callback functions.
+   * @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
+   * @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
+   * @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
+   */
+  withListeners({
+    onStart,
+    onEnd,
+    onError,
+  }: {
+    onStart?: (run: Run) => void;
+    onEnd?: (run: Run) => void;
+    onError?: (run: Run) => void;
+  }): Runnable<RunInput, RunOutput, CallOptions> {
+    //
+    return new RunnableBinding<RunInput, RunOutput, CallOptions>({
+      bound: this.bound,
+      kwargs: this.kwargs,
+      config: this.config,
+      configFactories: [
+        () => ({
+          callbacks: [
+            new RootListenersTracer({
+              onStart,
+              onEnd,
+              onError,
+            }),
+          ],
+        }),
+      ],
+    });
+  }
 }
 
 /**
@@ -789,6 +863,32 @@ export class RunnableEach<
       this._patchConfig(config, runManager?.getChild())
     );
   }
+
+  /**
+   * Bind lifecycle listeners to a Runnable, returning a new Runnable.
+   * The Run object contains information about the run, including its id,
+   * type, input, output, error, startTime, endTime, and any tags or metadata
+   * added to the run.
+   *
+   * @param {Object} params - The object containing the callback functions.
+   * @param {(run: Run) => void} params.onStart - Called before the runnable starts running, with the Run object.
+   * @param {(run: Run) => void} params.onEnd - Called after the runnable finishes running, with the Run object.
+   * @param {(run: Run) => void} params.onError - Called if the runnable throws an error, with the Run object.
+   */
+  withListeners({
+    onStart,
+    onEnd,
+    onError,
+  }: {
+    onStart?: (run: Run) => void;
+    onEnd?: (run: Run) => void;
+    onError?: (run: Run) => void;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  }): Runnable<any, any, CallOptions> {
+    return new RunnableEach<RunInputItem, RunOutputItem, CallOptions>({
+      bound: this.bound.withListeners({ onStart, onEnd, onError }),
+    });
+  }
 }
 
 /**
diff --git a/langchain-core/src/runnables/config.ts b/langchain-core/src/runnables/config.ts
index d70cbeb328bc..5473834748b1 100644
--- a/langchain-core/src/runnables/config.ts
+++ b/langchain-core/src/runnables/config.ts
@@ -14,3 +14,77 @@ export async function getCallbackMangerForConfig(config?: RunnableConfig) {
     config?.metadata
   );
 }
+
+export function mergeConfigs<CallOptions extends RunnableConfig>(
+  config: RunnableConfig,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  options?: Record<string, any>
+): Partial<CallOptions> {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const copy: Record<string, any> = { ...config };
+  const base: RunnableConfig = {};
+  if (options) {
+    for (const key of Object.keys(options)) {
+      if (key === "metadata") {
+        copy[key] = { ...copy[key], ...options[key] };
+      } else if (key === "tags") {
+        copy[key] = (copy[key] ?? []).concat(options[key] ?? []);
+      } else if (key === "callbacks") {
+        const baseCallbacks = base.callbacks;
+        const theseCallbacks = options.callbacks ?? config.callbacks;
+        // callbacks can be either undefined, Array<handler> or manager
+        // so merging two callbacks values has 6 cases
+        if (Array.isArray(theseCallbacks)) {
+          if (!baseCallbacks) {
+            base.callbacks = theseCallbacks;
+          } else if (Array.isArray(baseCallbacks)) {
+            base.callbacks = baseCallbacks.concat(theseCallbacks);
+          } else {
+            // baseCallbacks is a manager
+            const manager = baseCallbacks.copy();
+            for (const callback of theseCallbacks) {
+              manager.addHandler(callback, true);
+            }
+            base.callbacks = manager;
+          }
+        } else if (theseCallbacks) {
+          // theseCallbacks is a manager
+          if (!baseCallbacks) {
+            base.callbacks = theseCallbacks;
+          } else if (Array.isArray(baseCallbacks)) {
+            const manager = theseCallbacks.copy();
+            for (const callback of baseCallbacks) {
+              manager.addHandler(callback, true);
+            }
+            base.callbacks = manager;
+          } else {
+            // baseCallbacks is also a manager
+            base.callbacks = new CallbackManager(theseCallbacks.parentRunId, {
+              handlers: baseCallbacks.handlers.concat(theseCallbacks.handlers),
+              inheritableHandlers: baseCallbacks.inheritableHandlers.concat(
+                theseCallbacks.inheritableHandlers
+              ),
+              tags: Array.from(
+                new Set(baseCallbacks.tags.concat(theseCallbacks.tags))
+              ),
+              inheritableTags: Array.from(
+                new Set(
+                  baseCallbacks.inheritableTags.concat(
+                    theseCallbacks.inheritableTags
+                  )
+                )
+              ),
+              metadata: {
+                ...baseCallbacks.metadata,
+                ...theseCallbacks.metadata,
+              },
+            });
+          }
+        }
+      } else {
+        copy[key] = options[key] ?? copy[key];
+      }
+    }
+  }
+  return copy as Partial<CallOptions>;
+}
diff --git a/langchain-core/src/tracers/root_listener.ts b/langchain-core/src/tracers/root_listener.ts
new file mode 100644
index 000000000000..2c9990bf880c
--- /dev/null
+++ b/langchain-core/src/tracers/root_listener.ts
@@ -0,0 +1,63 @@
+import { BaseTracer, Run } from "./base.js";
+
+export class RootListenersTracer extends BaseTracer {
+  name = "RootListenersTracer";
+
+  /** The Run's ID. Type UUID */
+  rootId?: string;
+
+  argOnStart?: (run: Run) => void;
+
+  argOnEnd?: (run: Run) => void;
+
+  argOnError?: (run: Run) => void;
+
+  constructor({
+    onStart,
+    onEnd,
+    onError,
+  }: {
+    onStart?: (run: Run) => void;
+    onEnd?: (run: Run) => void;
+    onError?: (run: Run) => void;
+  }) {
+    super();
+    this.argOnStart = onStart;
+    this.argOnEnd = onEnd;
+    this.argOnError = onError;
+  }
+
+  /**
+   * This is a legacy method only called once for an entire run tree
+   * therefore not useful here
+   * @param {Run} _ Not used
+   */
+  persistRun(_: Run): Promise<void> {
+    return Promise.resolve();
+  }
+
+  onRunCreate(run: Run) {
+    if (this.rootId) {
+      return;
+    }
+
+    this.rootId = run.id;
+
+    if (this.argOnStart) {
+      this.argOnStart(run);
+    }
+  }
+
+  onRunUpdate(run: Run) {
+    if (run.id !== this.rootId) {
+      return;
+    }
+    if (!run.error) {
+      if (this.argOnEnd) {
+        this.argOnEnd(run);
+      }
+    } else if (this.argOnError) {
+      this.argOnError(run);
+    }
+  }
+}
diff --git a/langchain/tsconfig.json b/langchain/tsconfig.json
index ffc49dde54a6..54680cab2458 100644
--- a/langchain/tsconfig.json
+++ b/langchain/tsconfig.json
@@ -24,7 +24,7 @@
   },
   "include": [
     "src/**/*"
-  ],
+, "../langchain-core/src/tracers/root_listener.ts"  ],
   "exclude": [
     "node_modules",
     "dist",

From 2cf91d5811ee059585b9e24ed35c2ae39ec6600a Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 12:23:46 -0800
Subject: [PATCH 05/25] added entrypoint for root listener file

---
 langchain-core/.gitignore                    | 3 +++
 langchain-core/package.json                  | 8 ++++++++
 langchain-core/scripts/create-entrypoints.js | 1 +
 langchain-core/src/load/import_map.ts        | 1 +
 4 files changed, 13 insertions(+)

diff --git a/langchain-core/.gitignore b/langchain-core/.gitignore
index 62c193054dc8..88d036cfea5a 100644
--- a/langchain-core/.gitignore
+++ b/langchain-core/.gitignore
@@ -82,6 +82,9 @@ tracers/initialize.d.ts
 tracers/log_stream.cjs
 tracers/log_stream.js
 tracers/log_stream.d.ts
+tracers/root_listener.cjs
+tracers/root_listener.js
+tracers/root_listener.d.ts
 tracers/run_collector.cjs
 tracers/run_collector.js
 tracers/run_collector.d.ts
diff --git a/langchain-core/package.json b/langchain-core/package.json
index a81b5c30a5c7..e3a5df236610 100644
--- a/langchain-core/package.json
+++ b/langchain-core/package.json
@@ -219,6 +219,11 @@
       "import": "./tracers/log_stream.js",
       "require": "./tracers/log_stream.cjs"
     },
+    "./tracers/root_listener": {
+      "types": "./tracers/root_listener.d.ts",
+      "import": "./tracers/root_listener.js",
+      "require": "./tracers/root_listener.cjs"
+    },
     "./tracers/run_collector": {
       "types": "./tracers/run_collector.d.ts",
       "import": "./tracers/run_collector.js",
@@ -367,6 +372,9 @@
     "tracers/log_stream.cjs",
     "tracers/log_stream.js",
     "tracers/log_stream.d.ts",
+    "tracers/root_listener.cjs",
+    "tracers/root_listener.js",
+    "tracers/root_listener.d.ts",
     "tracers/run_collector.cjs",
     "tracers/run_collector.js",
     "tracers/run_collector.d.ts",
diff --git a/langchain-core/scripts/create-entrypoints.js b/langchain-core/scripts/create-entrypoints.js
index 31e99061c5b7..728d18c0b2d2 100644
--- a/langchain-core/scripts/create-entrypoints.js
+++ b/langchain-core/scripts/create-entrypoints.js
@@ -36,6 +36,7 @@ const entrypoints = {
   "tracers/console": "tracers/console",
   "tracers/initialize": "tracers/initialize",
   "tracers/log_stream": "tracers/log_stream",
+  "tracers/root_listener": "tracers/root_listener",
   "tracers/run_collector": "tracers/run_collector",
   "tracers/tracer_langchain_v1": "tracers/tracer_langchain_v1",
   "tracers/tracer_langchain": "tracers/tracer_langchain",
diff --git a/langchain-core/src/load/import_map.ts b/langchain-core/src/load/import_map.ts
index 512144832529..d4fd7d3c14b5 100644
--- a/langchain-core/src/load/import_map.ts
+++ b/langchain-core/src/load/import_map.ts
@@ -27,6 +27,7 @@ export * as tracers__base from "../tracers/base.js";
 export * as tracers__console from "../tracers/console.js";
 export * as tracers__initialize from "../tracers/initialize.js";
 export * as tracers__log_stream from "../tracers/log_stream.js";
+export * as tracers__root_listener from "../tracers/root_listener.js";
 export * as tracers__run_collector from "../tracers/run_collector.js";
 export * as tracers__tracer_langchain_v1 from "../tracers/tracer_langchain_v1.js";
 export * as tracers__tracer_langchain from "../tracers/tracer_langchain.js";

From 21ce187a2876641d2c325553a6884e3bc376811e Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 12:34:39 -0800
Subject: [PATCH 06/25] cr

---
 langchain-core/.gitignore                    | 3 ---
 langchain-core/package.json                  | 8 --------
 langchain-core/scripts/create-entrypoints.js | 1 -
 langchain-core/src/load/import_map.ts        | 1 -
 langchain/tsconfig.json                      | 2 +-
 5 files changed, 1 insertion(+), 14 deletions(-)

diff --git a/langchain-core/.gitignore b/langchain-core/.gitignore
index 88d036cfea5a..62c193054dc8 100644
--- a/langchain-core/.gitignore
+++ b/langchain-core/.gitignore
@@ -82,9 +82,6 @@ tracers/initialize.d.ts
 tracers/log_stream.cjs
 tracers/log_stream.js
 tracers/log_stream.d.ts
-tracers/root_listener.cjs
-tracers/root_listener.js
-tracers/root_listener.d.ts
 tracers/run_collector.cjs
 tracers/run_collector.js
 tracers/run_collector.d.ts
diff --git a/langchain-core/package.json b/langchain-core/package.json
index e3a5df236610..a81b5c30a5c7 100644
--- a/langchain-core/package.json
+++ b/langchain-core/package.json
@@ -219,11 +219,6 @@
       "import": "./tracers/log_stream.js",
       "require": "./tracers/log_stream.cjs"
     },
-    "./tracers/root_listener": {
-      "types": "./tracers/root_listener.d.ts",
-      "import": "./tracers/root_listener.js",
-      "require": "./tracers/root_listener.cjs"
-    },
     "./tracers/run_collector": {
       "types": "./tracers/run_collector.d.ts",
       "import": "./tracers/run_collector.js",
@@ -372,9 +367,6 @@
     "tracers/log_stream.cjs",
     "tracers/log_stream.js",
     "tracers/log_stream.d.ts",
-    "tracers/root_listener.cjs",
-    "tracers/root_listener.js",
-    "tracers/root_listener.d.ts",
     "tracers/run_collector.cjs",
     "tracers/run_collector.js",
     "tracers/run_collector.d.ts",
diff --git a/langchain-core/scripts/create-entrypoints.js b/langchain-core/scripts/create-entrypoints.js
index 728d18c0b2d2..31e99061c5b7 100644
--- a/langchain-core/scripts/create-entrypoints.js
+++ b/langchain-core/scripts/create-entrypoints.js
@@ -36,7 +36,6 @@ const entrypoints = {
   "tracers/console": "tracers/console",
   "tracers/initialize": "tracers/initialize",
   "tracers/log_stream": "tracers/log_stream",
-  "tracers/root_listener": "tracers/root_listener",
   "tracers/run_collector": "tracers/run_collector",
   "tracers/tracer_langchain_v1": "tracers/tracer_langchain_v1",
   "tracers/tracer_langchain": "tracers/tracer_langchain",
diff --git a/langchain-core/src/load/import_map.ts b/langchain-core/src/load/import_map.ts
index d4fd7d3c14b5..512144832529 100644
--- a/langchain-core/src/load/import_map.ts
+++ b/langchain-core/src/load/import_map.ts
@@ -27,7 +27,6 @@ export * as tracers__base from "../tracers/base.js";
 export * as tracers__console from "../tracers/console.js";
 export * as tracers__initialize from "../tracers/initialize.js";
 export * as tracers__log_stream from "../tracers/log_stream.js";
-export * as tracers__root_listener from "../tracers/root_listener.js";
 export * as tracers__run_collector from "../tracers/run_collector.js";
 export * as tracers__tracer_langchain_v1 from "../tracers/tracer_langchain_v1.js";
 export * as tracers__tracer_langchain from "../tracers/tracer_langchain.js";
diff --git a/langchain/tsconfig.json b/langchain/tsconfig.json
index 54680cab2458..ffc49dde54a6 100644
--- a/langchain/tsconfig.json
+++ b/langchain/tsconfig.json
@@ -24,7 +24,7 @@
   },
   "include": [
     "src/**/*"
-, "../langchain-core/src/tracers/root_listener.ts"  ],
+  ],
   "exclude": [
     "node_modules",
     "dist",

From a8b2dbd3978899640bd0ac3cef6402b81777a660 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 14:26:45 -0800
Subject: [PATCH 07/25] cr

---
 langchain-core/src/runnables/config.ts | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/langchain-core/src/runnables/config.ts b/langchain-core/src/runnables/config.ts
index 5473834748b1..6491d38ac25f 100644
--- a/langchain-core/src/runnables/config.ts
+++ b/langchain-core/src/runnables/config.ts
@@ -22,7 +22,6 @@ export function mergeConfigs<CallOptions extends RunnableConfig>(
 ): Partial<CallOptions> {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const copy: Record<string, any> = { ...config };
-  const base: RunnableConfig = {};
   if (options) {
     for (const key of Object.keys(options)) {
       if (key === "metadata") {
@@ -30,36 +29,36 @@ export function mergeConfigs<CallOptions extends RunnableConfig>(
       } else if (key === "tags") {
         copy[key] = (copy[key] ?? []).concat(options[key] ?? []);
       } else if (key === "callbacks") {
-        const baseCallbacks = base.callbacks;
+        const baseCallbacks = copy.callbacks;
         const theseCallbacks = options.callbacks ?? config.callbacks;
         // callbacks can be either undefined, Array<handler> or manager
         // so merging two callbacks values has 6 cases
         if (Array.isArray(theseCallbacks)) {
           if (!baseCallbacks) {
-            base.callbacks = theseCallbacks;
+            copy.callbacks = theseCallbacks;
           } else if (Array.isArray(baseCallbacks)) {
-            base.callbacks = baseCallbacks.concat(theseCallbacks);
+            copy.callbacks = baseCallbacks.concat(theseCallbacks);
           } else {
             // baseCallbacks is a manager
             const manager = baseCallbacks.copy();
             for (const callback of theseCallbacks) {
               manager.addHandler(callback, true);
             }
-            base.callbacks = manager;
+            copy.callbacks = manager;
           }
         } else if (theseCallbacks) {
           // theseCallbacks is a manager
           if (!baseCallbacks) {
-            base.callbacks = theseCallbacks;
+            copy.callbacks = theseCallbacks;
           } else if (Array.isArray(baseCallbacks)) {
             const manager = theseCallbacks.copy();
             for (const callback of baseCallbacks) {
               manager.addHandler(callback, true);
             }
-            base.callbacks = manager;
+            copy.callbacks = manager;
           } else {
             // baseCallbacks is also a manager
-            base.callbacks = new CallbackManager(theseCallbacks.parentRunId, {
+            copy.callbacks = new CallbackManager(theseCallbacks.parentRunId, {
               handlers: baseCallbacks.handlers.concat(theseCallbacks.handlers),
               inheritableHandlers: baseCallbacks.inheritableHandlers.concat(
                 theseCallbacks.inheritableHandlers

From 48e1f7e0049c700b53c2e102cad638d82ef5a37f Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 15:00:44 -0800
Subject: [PATCH 08/25] cr

---
 langchain-core/src/runnables/base.ts | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index c8c3d9d91b7c..7beef6aa56d0 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -576,6 +576,7 @@ export abstract class Runnable<
     onEnd?: (run: Run) => void;
     onError?: (run: Run) => void;
   }): Runnable<RunInput, RunOutput, CallOptions> {
+    console.log("gets called");
     // eslint-disable-next-line @typescript-eslint/no-use-before-define
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
       bound: this,
@@ -603,7 +604,7 @@ export type RunnableBindingArgs<
   bound: Runnable<RunInput, RunOutput, CallOptions>;
   kwargs?: Partial<CallOptions>;
   config: RunnableConfig;
-  configFactories?: Array<() => RunnableConfig>;
+  configFactories?: Array<(config: RunnableConfig) => RunnableConfig>;
 };
 
 /**
@@ -628,7 +629,7 @@ export class RunnableBinding<
 
   protected kwargs?: Partial<CallOptions>;
 
-  configFactories?: Array<() => RunnableConfig>;
+  configFactories?: Array<(config: RunnableConfig) => RunnableConfig>;
 
   constructor(fields: RunnableBindingArgs<RunInput, RunOutput, CallOptions>) {
     super(fields);
@@ -639,8 +640,15 @@ export class RunnableBinding<
   }
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  _mergeConfig(options?: Record<string, any>) {
-    return mergeConfigs<CallOptions>(this.config, options);
+  _mergeConfig(options?: Record<string, any>): Partial<CallOptions> {
+    const config = mergeConfigs(this.config, options);
+    return mergeConfigs(
+      config,
+      ...(this.configFactories
+        ? this.configFactories.map((f) => f(config))
+        : [])
+    );
+    // return mergeConfigs<CallOptions>(this.config, options);
   }
 
   bind(

From a56cd19142ac00348448b6b8646205c22f1f6e18 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 15:01:01 -0800
Subject: [PATCH 09/25] cr

---
 langchain-core/src/runnables/base.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 7beef6aa56d0..2d3bc6a95f53 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -576,7 +576,6 @@ export abstract class Runnable<
     onEnd?: (run: Run) => void;
     onError?: (run: Run) => void;
   }): Runnable<RunInput, RunOutput, CallOptions> {
-    console.log("gets called");
     // eslint-disable-next-line @typescript-eslint/no-use-before-define
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
       bound: this,
@@ -648,7 +647,6 @@ export class RunnableBinding<
         ? this.configFactories.map((f) => f(config))
         : [])
     );
-    // return mergeConfigs<CallOptions>(this.config, options);
   }
 
   bind(

From 89d689d1b2089406b4beb5433c2848837e91fedc Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 15:01:18 -0800
Subject: [PATCH 10/25] cr

---
 langchain/src/schema/tests/runnable.test.ts | 31 ++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/langchain/src/schema/tests/runnable.test.ts b/langchain/src/schema/tests/runnable.test.ts
index ffd78a2c50c7..4093814050d0 100644
--- a/langchain/src/schema/tests/runnable.test.ts
+++ b/langchain/src/schema/tests/runnable.test.ts
@@ -2,7 +2,7 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import { z } from "zod";
-import { test } from "@jest/globals";
+import { jest, test } from "@jest/globals";
 import { createChatMessageChunkEncoderStream } from "../../chat_models/base.js";
 import {
   ChatPromptTemplate,
@@ -28,6 +28,7 @@ import {
   FakeStreamingLLM,
   FakeSplitIntoListParser,
 } from "./lib.js";
+import { FakeListChatModel } from "../../chat_models/fake.js";
 
 test("Test batch", async () => {
   const llm = new FakeLLM({});
@@ -247,3 +248,31 @@ test("Runnable withConfig", async () => {
   expect(chunks[0]?.tags).toEqual(["a-tag", "b-tag"]);
   expect(chunks[0]?.metadata).toEqual({ a: "updated", b: "c" });
 });
+
+test("Listeners work", async () => {
+  // implement
+  const prompt = ChatPromptTemplate.fromMessages([
+    SystemMessagePromptTemplate.fromTemplate("You are a nice assistant."),
+    ["human", "{question}"],
+  ]);
+  const model = new FakeListChatModel({
+    responses: ["foo"],
+  });
+  const chain = prompt.pipe(model);
+
+  const mockStart = jest.fn();
+  const mockEnd = jest.fn();
+
+  await chain
+    .withListeners({
+      onStart: mockStart,
+      onEnd: mockEnd,
+    })
+    .invoke({ question: "What is the meaning of life?" });
+
+  expect(mockStart).toHaveBeenCalledTimes(1);
+  expect((mockStart.mock.calls[0][0] as { name: string }).name).toBe(
+    "RunnableSequence"
+  );
+  expect(mockEnd).toHaveBeenCalledTimes(1);
+});

From be79ae6d056e0c46d139cd2694cde6413f60c982 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 15:20:14 -0800
Subject: [PATCH 11/25] support async listeners

---
 langchain-core/src/runnables/base.ts        | 53 ++++++++++++---------
 langchain-core/src/tracers/root_listener.ts | 22 ++++-----
 langchain/src/schema/tests/runnable.test.ts | 46 ++++++++++++++++--
 3 files changed, 85 insertions(+), 36 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 2d3bc6a95f53..1592bda8df13 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -572,9 +572,9 @@ export abstract class Runnable<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void;
-    onEnd?: (run: Run) => void;
-    onError?: (run: Run) => void;
+    onStart?: (run: Run) => void | Promise<void>;
+    onEnd?: (run: Run) => void | Promise<void>;
+    onError?: (run: Run) => void | Promise<void>;
   }): Runnable<RunInput, RunOutput, CallOptions> {
     // eslint-disable-next-line @typescript-eslint/no-use-before-define
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
@@ -628,7 +628,9 @@ export class RunnableBinding<
 
   protected kwargs?: Partial<CallOptions>;
 
-  configFactories?: Array<(config: RunnableConfig) => RunnableConfig>;
+  configFactories?: Array<
+    (config: RunnableConfig) => RunnableConfig | Promise<RunnableConfig>
+  >;
 
   constructor(fields: RunnableBindingArgs<RunInput, RunOutput, CallOptions>) {
     super(fields);
@@ -639,12 +641,16 @@ export class RunnableBinding<
   }
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  _mergeConfig(options?: Record<string, any>): Partial<CallOptions> {
+  async _mergeConfig(
+    options?: Record<string, any>
+  ): Promise<Partial<CallOptions>> {
     const config = mergeConfigs(this.config, options);
     return mergeConfigs(
       config,
       ...(this.configFactories
-        ? this.configFactories.map((f) => f(config))
+        ? await Promise.all(
+            this.configFactories.map(async (f) => await f(config))
+          )
         : [])
     );
   }
@@ -686,7 +692,7 @@ export class RunnableBinding<
   ): Promise<RunOutput> {
     return this.bound.invoke(
       input,
-      this._mergeConfig({ ...options, ...this.kwargs })
+      await this._mergeConfig({ ...options, ...this.kwargs })
     );
   }
 
@@ -714,13 +720,16 @@ export class RunnableBinding<
     batchOptions?: RunnableBatchOptions
   ): Promise<(RunOutput | Error)[]> {
     const mergedOptions = Array.isArray(options)
-      ? options.map((individualOption) =>
-          this._mergeConfig({
-            ...individualOption,
-            ...this.kwargs,
-          })
+      ? await Promise.all(
+          options.map(
+            async (individualOption) =>
+              await this._mergeConfig({
+                ...individualOption,
+                ...this.kwargs,
+              })
+          )
         )
-      : this._mergeConfig({ ...options, ...this.kwargs });
+      : await this._mergeConfig({ ...options, ...this.kwargs });
     return this.bound.batch(inputs, mergedOptions, batchOptions);
   }
 
@@ -730,7 +739,7 @@ export class RunnableBinding<
   ) {
     yield* this.bound._streamIterator(
       input,
-      this._mergeConfig({ ...options, ...this.kwargs })
+      await this._mergeConfig({ ...options, ...this.kwargs })
     );
   }
 
@@ -740,7 +749,7 @@ export class RunnableBinding<
   ): Promise<IterableReadableStream<RunOutput>> {
     return this.bound.stream(
       input,
-      this._mergeConfig({ ...options, ...this.kwargs })
+      await this._mergeConfig({ ...options, ...this.kwargs })
     );
   }
 
@@ -751,7 +760,7 @@ export class RunnableBinding<
   ): AsyncGenerator<RunOutput> {
     yield* this.bound.transform(
       generator,
-      this._mergeConfig({ ...options, ...this.kwargs })
+      await this._mergeConfig({ ...options, ...this.kwargs })
     );
   }
 
@@ -779,9 +788,9 @@ export class RunnableBinding<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void;
-    onEnd?: (run: Run) => void;
-    onError?: (run: Run) => void;
+    onStart?: (run: Run) => void | Promise<void>;
+    onEnd?: (run: Run) => void | Promise<void>;
+    onError?: (run: Run) => void | Promise<void>;
   }): Runnable<RunInput, RunOutput, CallOptions> {
     //
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
@@ -886,9 +895,9 @@ export class RunnableEach<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void;
-    onEnd?: (run: Run) => void;
-    onError?: (run: Run) => void;
+    onStart?: (run: Run) => void | Promise<void>;
+    onEnd?: (run: Run) => void | Promise<void>;
+    onError?: (run: Run) => void | Promise<void>;
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
   }): Runnable<any, any, CallOptions> {
     return new RunnableEach<RunInputItem, RunOutputItem, CallOptions>({
diff --git a/langchain-core/src/tracers/root_listener.ts b/langchain-core/src/tracers/root_listener.ts
index 2c9990bf880c..cabb4a9dba74 100644
--- a/langchain-core/src/tracers/root_listener.ts
+++ b/langchain-core/src/tracers/root_listener.ts
@@ -6,20 +6,20 @@ export class RootListenersTracer extends BaseTracer {
   /** The Run's ID. Type UUID */
   rootId?: string;
 
-  argOnStart?: (run: Run) => void;
+  argOnStart?: (run: Run) => void | Promise<void>;
 
-  argOnEnd?: (run: Run) => void;
+  argOnEnd?: (run: Run) => void | Promise<void>;
 
-  argOnError?: (run: Run) => void;
+  argOnError?: (run: Run) => void | Promise<void>;
 
   constructor({
     onStart,
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void;
-    onEnd?: (run: Run) => void;
-    onError?: (run: Run) => void;
+    onStart?: (run: Run) => void | Promise<void>;
+    onEnd?: (run: Run) => void | Promise<void>;
+    onError?: (run: Run) => void | Promise<void>;
   }) {
     super();
     this.argOnStart = onStart;
@@ -36,7 +36,7 @@ export class RootListenersTracer extends BaseTracer {
     return Promise.resolve();
   }
 
-  onRunCreate(run: Run) {
+  async onRunCreate(run: Run) {
     if (this.rootId) {
       return;
     }
@@ -44,20 +44,20 @@ export class RootListenersTracer extends BaseTracer {
     this.rootId = run.id;
 
     if (this.argOnStart) {
-      this.argOnStart(run);
+      await this.argOnStart(run);
     }
   }
 
-  onRunUpdate(run: Run) {
+  async onRunUpdate(run: Run) {
     if (run.id !== this.rootId) {
       return;
     }
     if (!run.error) {
       if (this.argOnEnd) {
-        this.argOnEnd(run);
+        await this.argOnEnd(run);
       }
     } else if (this.argOnError) {
-      this.argOnError(run);
+      await this.argOnError(run);
     }
   }
 }
diff --git a/langchain/src/schema/tests/runnable.test.ts b/langchain/src/schema/tests/runnable.test.ts
index 4093814050d0..223e5710ce0e 100644
--- a/langchain/src/schema/tests/runnable.test.ts
+++ b/langchain/src/schema/tests/runnable.test.ts
@@ -250,7 +250,6 @@ test("Runnable withConfig", async () => {
 });
 
 test("Listeners work", async () => {
-  // implement
   const prompt = ChatPromptTemplate.fromMessages([
     SystemMessagePromptTemplate.fromTemplate("You are a nice assistant."),
     ["human", "{question}"],
@@ -265,8 +264,49 @@ test("Listeners work", async () => {
 
   await chain
     .withListeners({
-      onStart: mockStart,
-      onEnd: mockEnd,
+      onStart: (run) => {
+        mockStart(run);
+      },
+      onEnd: (run) => {
+        mockEnd(run);
+      },
+    })
+    .invoke({ question: "What is the meaning of life?" });
+
+  expect(mockStart).toHaveBeenCalledTimes(1);
+  expect((mockStart.mock.calls[0][0] as { name: string }).name).toBe(
+    "RunnableSequence"
+  );
+  expect(mockEnd).toHaveBeenCalledTimes(1);
+});
+
+test("Listeners work with async handlers", async () => {
+  const prompt = ChatPromptTemplate.fromMessages([
+    SystemMessagePromptTemplate.fromTemplate("You are a nice assistant."),
+    ["human", "{question}"],
+  ]);
+  const model = new FakeListChatModel({
+    responses: ["foo"],
+  });
+  const chain = prompt.pipe(model);
+
+  const mockStart = jest.fn();
+  const mockEnd = jest.fn();
+
+  await chain
+    .withListeners({
+      // eslint-disable-next-line @typescript-eslint/no-misused-promises
+      onStart: async (run) => {
+        const promise = new Promise((resolve) => setTimeout(resolve, 2000));
+        await promise;
+        mockStart(run);
+      },
+      // eslint-disable-next-line @typescript-eslint/no-misused-promises
+      onEnd: async (run) => {
+        const promise = new Promise((resolve) => setTimeout(resolve, 2000));
+        await promise;
+        mockEnd(run);
+      },
     })
     .invoke({ question: "What is the meaning of life?" });
 

From b71e30da8ff0cd57e8f59fb586def3a884db0c1d Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 15:46:55 -0800
Subject: [PATCH 12/25] allow for run or run and config as args to listener
 funcs

---
 langchain-core/src/runnables/base.ts        | 51 ++++++++++++++-----
 langchain-core/src/tracers/root_listener.ts | 54 +++++++++++++++++----
 2 files changed, 85 insertions(+), 20 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 1592bda8df13..2f02c0543025 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -572,18 +572,28 @@ export abstract class Runnable<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void | Promise<void>;
-    onEnd?: (run: Run) => void | Promise<void>;
-    onError?: (run: Run) => void | Promise<void>;
+    onStart?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onEnd?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onError?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
   }): Runnable<RunInput, RunOutput, CallOptions> {
     // eslint-disable-next-line @typescript-eslint/no-use-before-define
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
       bound: this,
       config: {},
       configFactories: [
-        () => ({
+        (config) => ({
           callbacks: [
             new RootListenersTracer({
+              config,
               onStart,
               onEnd,
               onError,
@@ -788,9 +798,18 @@ export class RunnableBinding<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void | Promise<void>;
-    onEnd?: (run: Run) => void | Promise<void>;
-    onError?: (run: Run) => void | Promise<void>;
+    onStart?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onEnd?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onError?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
   }): Runnable<RunInput, RunOutput, CallOptions> {
     //
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
@@ -798,9 +817,10 @@ export class RunnableBinding<
       kwargs: this.kwargs,
       config: this.config,
       configFactories: [
-        () => ({
+        (config) => ({
           callbacks: [
             new RootListenersTracer({
+              config,
               onStart,
               onEnd,
               onError,
@@ -895,9 +915,18 @@ export class RunnableEach<
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void | Promise<void>;
-    onEnd?: (run: Run) => void | Promise<void>;
-    onError?: (run: Run) => void | Promise<void>;
+    onStart?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onEnd?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onError?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
   }): Runnable<any, any, CallOptions> {
     return new RunnableEach<RunInputItem, RunOutputItem, CallOptions>({
diff --git a/langchain-core/src/tracers/root_listener.ts b/langchain-core/src/tracers/root_listener.ts
index cabb4a9dba74..486bd59e6b07 100644
--- a/langchain-core/src/tracers/root_listener.ts
+++ b/langchain-core/src/tracers/root_listener.ts
@@ -1,3 +1,4 @@
+import { RunnableConfig } from "../runnables/config.js";
 import { BaseTracer, Run } from "./base.js";
 
 export class RootListenersTracer extends BaseTracer {
@@ -6,22 +7,45 @@ export class RootListenersTracer extends BaseTracer {
   /** The Run's ID. Type UUID */
   rootId?: string;
 
-  argOnStart?: (run: Run) => void | Promise<void>;
+  config: RunnableConfig;
 
-  argOnEnd?: (run: Run) => void | Promise<void>;
+  argOnStart?: {
+    (run: Run): void | Promise<void>;
+    (run: Run, config: RunnableConfig): void | Promise<void>;
+  };
 
-  argOnError?: (run: Run) => void | Promise<void>;
+  argOnEnd?: {
+    (run: Run): void | Promise<void>;
+    (run: Run, config: RunnableConfig): void | Promise<void>;
+  };
+
+  argOnError?: {
+    (run: Run): void | Promise<void>;
+    (run: Run, config: RunnableConfig): void | Promise<void>;
+  };
 
   constructor({
+    config,
     onStart,
     onEnd,
     onError,
   }: {
-    onStart?: (run: Run) => void | Promise<void>;
-    onEnd?: (run: Run) => void | Promise<void>;
-    onError?: (run: Run) => void | Promise<void>;
+    config: RunnableConfig;
+    onStart?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onEnd?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
+    onError?: {
+      (run: Run): void | Promise<void>;
+      (run: Run, config: RunnableConfig): void | Promise<void>;
+    };
   }) {
     super();
+    this.config = config;
     this.argOnStart = onStart;
     this.argOnEnd = onEnd;
     this.argOnError = onError;
@@ -44,7 +68,11 @@ export class RootListenersTracer extends BaseTracer {
     this.rootId = run.id;
 
     if (this.argOnStart) {
-      await this.argOnStart(run);
+      if (this.argOnStart.length === 1) {
+        await this.argOnStart(run);
+      } else if (this.argOnStart.length === 2) {
+        await this.argOnStart(run, this.config);
+      }
     }
   }
 
@@ -54,10 +82,18 @@ export class RootListenersTracer extends BaseTracer {
     }
     if (!run.error) {
       if (this.argOnEnd) {
-        await this.argOnEnd(run);
+        if (this.argOnEnd.length === 1) {
+          await this.argOnEnd(run);
+        } else if (this.argOnEnd.length === 2) {
+          await this.argOnEnd(run, this.config);
+        }
       }
     } else if (this.argOnError) {
-      await this.argOnError(run);
+      if (this.argOnError.length === 1) {
+        await this.argOnError(run);
+      } else if (this.argOnError.length === 2) {
+        await this.argOnError(run, this.config);
+      }
     }
   }
 }

From e8432ac578a79504a66f38e8f73b91c444b7cd32 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 17:02:02 -0800
Subject: [PATCH 13/25] cr

---
 langchain-core/src/runnables/history.ts       | 47 ++++++++++---------
 .../tests/runnable_history.int.test.ts        | 17 ++-----
 2 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index c88a2f1f35e2..39222e144558 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -35,7 +35,10 @@ export class RunnableWithMessageHistory<
   getMessageHistory: GetSessionHistoryCallable;
 
   constructor(
-    fields: RunnableBindingArgs<RunInput, RunOutput, BaseCallbackConfig> & {
+    fields: Omit<
+      RunnableBindingArgs<RunInput, RunOutput, BaseCallbackConfig>,
+      "bound"
+    > & {
       runnable: Runnable<RunInput, RunOutput>;
       getMessageHistory: GetSessionHistoryCallable;
       inputMessagesKey?: string;
@@ -43,19 +46,9 @@ export class RunnableWithMessageHistory<
       historyMessagesKey?: string;
     }
   ) {
-    super(fields);
-    this.runnable = fields.runnable;
-    this.getMessageHistory = fields.getMessageHistory;
-    this.inputMessagesKey = fields.inputMessagesKey;
-    this.outputMessagesKey = fields.outputMessagesKey;
-    this.historyMessagesKey = fields.historyMessagesKey;
-
     let historyChain: Runnable = new RunnableLambda({
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      func: (input: any) => {
-        console.log("HISTORY CHAIN CALLED", input);
-        return this._enterHistory(input, {});
-      },
+      func: (input: any) => this._enterHistory(input, {}),
     }).withConfig({ runName: "loadHistory" });
 
     const messagesKey = fields.historyMessagesKey || fields.inputMessagesKey;
@@ -66,10 +59,23 @@ export class RunnableWithMessageHistory<
     }
 
     const bound = historyChain
-      .pipe(fields.runnable)
+      .pipe(
+        fields.runnable.withListeners({
+          // eslint-disable-next-line @typescript-eslint/no-misused-promises
+          onEnd: (run, config) => this._exitHistory(run, config),
+        })
+      )
       .withConfig({ runName: "RunnableWithMessageHistory" });
 
-    this.bound = bound;
+    super({
+      ...fields,
+      bound,
+    });
+    this.runnable = fields.runnable;
+    this.getMessageHistory = fields.getMessageHistory;
+    this.inputMessagesKey = fields.inputMessagesKey;
+    this.outputMessagesKey = fields.outputMessagesKey;
+    this.historyMessagesKey = fields.historyMessagesKey;
   }
 
   _getInputMessages(
@@ -115,10 +121,8 @@ export class RunnableWithMessageHistory<
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   _enterHistory(input: any, config: BaseCallbackConfig): Array<BaseMessage> {
-    console.log("Running _enterHistory");
-    const history = config.configurable?.messageHistory;
+    const history = config?.configurable?.messageHistory;
 
-    // @TODO I think this is broken
     if (this.historyMessagesKey) {
       return history.messages;
     }
@@ -131,7 +135,6 @@ export class RunnableWithMessageHistory<
       ...historyMessages,
       ...this._getInputMessages(inputVal),
     ];
-    console.log("returning", returnType);
     return returnType;
   }
 
@@ -160,8 +163,8 @@ export class RunnableWithMessageHistory<
     }
   }
 
-  _mergeConfig(...configs: Array<BaseCallbackConfig | undefined>) {
-    const config = super._mergeConfig(...configs);
+  async _mergeConfig(...configs: Array<BaseCallbackConfig | undefined>) {
+    const config = await super._mergeConfig(...configs);
     // Extract sessionId
     if (!config.configurable || !config.configurable.sessionId) {
       const exampleInput = {
@@ -177,7 +180,9 @@ export class RunnableWithMessageHistory<
     }
     // attach messageHistory
     const { sessionId } = config.configurable;
-    config.configurable.messageHistory = this.getMessageHistory(sessionId);
+    config.configurable.messageHistory = await this.getMessageHistory(
+      sessionId
+    );
     return config;
   }
 }
diff --git a/langchain-core/src/runnables/tests/runnable_history.int.test.ts b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
index 111f9cfcf3fb..bb7da5e47847 100644
--- a/langchain-core/src/runnables/tests/runnable_history.int.test.ts
+++ b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
@@ -16,10 +16,7 @@ async function getGetSessionHistory(): Promise<
     sessionId: string
   ): Promise<BaseChatMessageHistory> {
     if (!(sessionId in chatHistoryStore)) {
-      console.log("not in store");
       chatHistoryStore[sessionId] = new FakeChatMessageHistory();
-    } else {
-      console.log("in store", await chatHistoryStore[sessionId].getMessages());
     }
     return chatHistoryStore[sessionId];
   }
@@ -29,22 +26,16 @@ async function getGetSessionHistory(): Promise<
 
 test("Runnable with message history", async () => {
   const runnable = new RunnableLambda({
-    func: (messages: HumanMessage[]) => {
-      console.log("runnin", messages);
-      const messagesArr: HumanMessage[] = !Array.isArray(messages)
-        ? Object.values(messages)
-        : messages;
-      return `you said: ${messagesArr
+    func: (messages: HumanMessage[]) =>
+      `you said: ${messages
         .filter((m) => isBaseMessage(m))
         .map((m) => m.content)
-        .join("\n")}`;
-    },
+        .join("\n")}`,
   });
+
   const getMessageHistory = await getGetSessionHistory();
   const withHistory = new RunnableWithMessageHistory({
     runnable,
-    bound: runnable,
-    kwargs: {},
     config: {},
     getMessageHistory,
   });

From 00ab504b2c74cf8c426134f85055a37c82026aa1 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Wed, 29 Nov 2023 17:03:26 -0800
Subject: [PATCH 14/25] chore: lint files

---
 .../src/runnables/tests/runnable_history.int.test.ts         | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/langchain-core/src/runnables/tests/runnable_history.int.test.ts b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
index bb7da5e47847..cceba6e73ea8 100644
--- a/langchain-core/src/runnables/tests/runnable_history.int.test.ts
+++ b/langchain-core/src/runnables/tests/runnable_history.int.test.ts
@@ -6,7 +6,10 @@ import {
   BaseChatMessageHistory,
   FakeChatMessageHistory,
 } from "../../chat_history.js";
-
+/**
+ * @TODO Move this to `langchain` and replace real llm with fake.
+ * Only reason it's here is so I don't have to rebuild every time I make a change.
+ */
 async function getGetSessionHistory(): Promise<
   (sessionId: string) => Promise<BaseChatMessageHistory>
 > {

From 08698aa33511d0c1a32cb587cec5b98d4e8dc086 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Thu, 30 Nov 2023 11:10:40 -0800
Subject: [PATCH 15/25] cr

---
 langchain-core/src/runnables/base.ts                  |  5 +++--
 langchain-core/src/runnables/history.ts               |  5 +++--
 ...e_history.int.test.ts => runnable_history.test.ts} | 11 ++++-------
 3 files changed, 10 insertions(+), 11 deletions(-)
 rename langchain-core/src/runnables/tests/{runnable_history.int.test.ts => runnable_history.test.ts} (81%)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 2f02c0543025..7c3ec1c02850 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -22,7 +22,8 @@ import { Run } from "../tracers/base.js";
 import { RootListenersTracer } from "../tracers/root_listener.js";
 
 export type RunnableFunc<RunInput, RunOutput> = (
-  input: RunInput
+  input: RunInput,
+  options?: Record<string, unknown>
 ) => RunOutput | Promise<RunOutput>;
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -1526,7 +1527,7 @@ export class RunnableLambda<RunInput, RunOutput> extends Runnable<
     config?: Partial<BaseCallbackConfig>,
     runManager?: CallbackManagerForChainRun
   ) {
-    let output = await this.func(input);
+    let output = await this.func(input, config);
     if (output && Runnable.isRunnable(output)) {
       output = await output.invoke(
         input,
diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 39222e144558..fe5dc945f9b5 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -48,7 +48,8 @@ export class RunnableWithMessageHistory<
   ) {
     let historyChain: Runnable = new RunnableLambda({
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      func: (input: any) => this._enterHistory(input, {}),
+      func: (input: any, options?: Record<string, unknown>) =>
+        this._enterHistory(input, options ?? {}),
     }).withConfig({ runName: "loadHistory" });
 
     const messagesKey = fields.historyMessagesKey || fields.inputMessagesKey;
@@ -172,7 +173,7 @@ export class RunnableWithMessageHistory<
       };
       const exampleConfig = { configurable: { sessionId: "123" } };
       throw new Error(
-        `session_id is required. Pass it in as part of the config argument to .invoke() or .stream()\n` +
+        `sessionId is required. Pass it in as part of the config argument to .invoke() or .stream()\n` +
           `eg. chain.invoke(${JSON.stringify(exampleInput)}, ${JSON.stringify(
             exampleConfig
           )})`
diff --git a/langchain-core/src/runnables/tests/runnable_history.int.test.ts b/langchain-core/src/runnables/tests/runnable_history.test.ts
similarity index 81%
rename from langchain-core/src/runnables/tests/runnable_history.int.test.ts
rename to langchain-core/src/runnables/tests/runnable_history.test.ts
index cceba6e73ea8..c6e5d1822e63 100644
--- a/langchain-core/src/runnables/tests/runnable_history.int.test.ts
+++ b/langchain-core/src/runnables/tests/runnable_history.test.ts
@@ -1,4 +1,4 @@
-import { HumanMessage, isBaseMessage } from "../../messages/index.js";
+import { BaseMessage, HumanMessage } from "../../messages/index.js";
 import { RunnableLambda } from "../base.js";
 import { RunnableConfig } from "../config.js";
 import { RunnableWithMessageHistory } from "../history.js";
@@ -6,10 +6,7 @@ import {
   BaseChatMessageHistory,
   FakeChatMessageHistory,
 } from "../../chat_history.js";
-/**
- * @TODO Move this to `langchain` and replace real llm with fake.
- * Only reason it's here is so I don't have to rebuild every time I make a change.
- */
+
 async function getGetSessionHistory(): Promise<
   (sessionId: string) => Promise<BaseChatMessageHistory>
 > {
@@ -29,9 +26,9 @@ async function getGetSessionHistory(): Promise<
 
 test("Runnable with message history", async () => {
   const runnable = new RunnableLambda({
-    func: (messages: HumanMessage[]) =>
+    func: (messages: BaseMessage[]) =>
       `you said: ${messages
-        .filter((m) => isBaseMessage(m))
+        .filter((m) => m._getType() === "human")
         .map((m) => m.content)
         .join("\n")}`,
   });

From b05533729d5b93ce0be7598ec3108e7430c0213e Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Thu, 30 Nov 2023 11:16:19 -0800
Subject: [PATCH 16/25] cr

---
 langchain-core/src/runnables/history.ts     |  6 +++---
 langchain/src/schema/tests/runnable.test.ts | 10 +++++-----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index fe5dc945f9b5..178549ac66c5 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -13,6 +13,7 @@ import {
   RunnableBindingArgs,
   RunnableLambda,
 } from "./base.js";
+import { RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (
@@ -47,7 +48,6 @@ export class RunnableWithMessageHistory<
     }
   ) {
     let historyChain: Runnable = new RunnableLambda({
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       func: (input: any, options?: Record<string, unknown>) =>
         this._enterHistory(input, options ?? {}),
     }).withConfig({ runName: "loadHistory" });
@@ -62,8 +62,8 @@ export class RunnableWithMessageHistory<
     const bound = historyChain
       .pipe(
         fields.runnable.withListeners({
-          // eslint-disable-next-line @typescript-eslint/no-misused-promises
-          onEnd: (run, config) => this._exitHistory(run, config),
+          onEnd: (run: Run, config: RunnableConfig = {}) =>
+            this._exitHistory(run, config),
         })
       )
       .withConfig({ runName: "RunnableWithMessageHistory" });
diff --git a/langchain/src/schema/tests/runnable.test.ts b/langchain/src/schema/tests/runnable.test.ts
index 223e5710ce0e..8011d2e922ba 100644
--- a/langchain/src/schema/tests/runnable.test.ts
+++ b/langchain/src/schema/tests/runnable.test.ts
@@ -29,6 +29,7 @@ import {
   FakeSplitIntoListParser,
 } from "./lib.js";
 import { FakeListChatModel } from "../../chat_models/fake.js";
+import { Run } from "../../callbacks/index.js";
 
 test("Test batch", async () => {
   const llm = new FakeLLM({});
@@ -264,10 +265,10 @@ test("Listeners work", async () => {
 
   await chain
     .withListeners({
-      onStart: (run) => {
+      onStart: (run: Run) => {
         mockStart(run);
       },
-      onEnd: (run) => {
+      onEnd: (run: Run) => {
         mockEnd(run);
       },
     })
@@ -295,14 +296,13 @@ test("Listeners work with async handlers", async () => {
 
   await chain
     .withListeners({
-      // eslint-disable-next-line @typescript-eslint/no-misused-promises
-      onStart: async (run) => {
+      onStart: async (run: Run) => {
         const promise = new Promise((resolve) => setTimeout(resolve, 2000));
         await promise;
         mockStart(run);
       },
       // eslint-disable-next-line @typescript-eslint/no-misused-promises
-      onEnd: async (run) => {
+      onEnd: async (run: Run) => {
         const promise = new Promise((resolve) => setTimeout(resolve, 2000));
         await promise;
         mockEnd(run);

From 8e23d5db3dfc155f66970001ad28a9be0e6e0f6f Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Thu, 30 Nov 2023 15:11:45 -0800
Subject: [PATCH 17/25] eslint disbale any

---
 langchain-core/src/runnables/base.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 2f02c0543025..5387a19bef24 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -650,8 +650,8 @@ export class RunnableBinding<
     this.configFactories = fields.configFactories;
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   async _mergeConfig(
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     options?: Record<string, any>
   ): Promise<Partial<CallOptions>> {
     const config = mergeConfigs(this.config, options);

From 670f4f1308d831301b6c9f1be5201bca9399b67e Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 09:10:23 -0800
Subject: [PATCH 18/25] update types

---
 langchain-core/src/runnables/base.ts        | 45 +++++----------------
 langchain-core/src/tracers/root_listener.ts | 15 ++-----
 2 files changed, 12 insertions(+), 48 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 5387a19bef24..cffccc316e8e 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -572,18 +572,9 @@ export abstract class Runnable<
     onEnd,
     onError,
   }: {
-    onStart?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onEnd?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onError?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
+    onStart?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onEnd?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onError?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
   }): Runnable<RunInput, RunOutput, CallOptions> {
     // eslint-disable-next-line @typescript-eslint/no-use-before-define
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
@@ -798,18 +789,9 @@ export class RunnableBinding<
     onEnd,
     onError,
   }: {
-    onStart?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onEnd?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onError?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
+    onStart?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onEnd?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onError?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
   }): Runnable<RunInput, RunOutput, CallOptions> {
     //
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
@@ -915,18 +897,9 @@ export class RunnableEach<
     onEnd,
     onError,
   }: {
-    onStart?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onEnd?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onError?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
+    onStart?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onEnd?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onError?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
   }): Runnable<any, any, CallOptions> {
     return new RunnableEach<RunInputItem, RunOutputItem, CallOptions>({
diff --git a/langchain-core/src/tracers/root_listener.ts b/langchain-core/src/tracers/root_listener.ts
index 486bd59e6b07..222c307f531f 100644
--- a/langchain-core/src/tracers/root_listener.ts
+++ b/langchain-core/src/tracers/root_listener.ts
@@ -31,18 +31,9 @@ export class RootListenersTracer extends BaseTracer {
     onError,
   }: {
     config: RunnableConfig;
-    onStart?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onEnd?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
-    onError?: {
-      (run: Run): void | Promise<void>;
-      (run: Run, config: RunnableConfig): void | Promise<void>;
-    };
+    onStart?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onEnd?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
+    onError?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
   }) {
     super();
     this.config = config;

From cec10acf9b14f0b32e3de50f322ea792e32b0e1e Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 10:03:55 -0800
Subject: [PATCH 19/25] cr

---
 examples/src/chains/retrieval_qa.ts                            | 2 +-
 examples/src/guides/expression_language/cookbook_retriever.ts  | 2 +-
 examples/src/models/chat/integration_llama_cpp_stream_multi.ts | 2 +-
 langchain-core/src/runnables/base.ts                           | 3 ++-
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/examples/src/chains/retrieval_qa.ts b/examples/src/chains/retrieval_qa.ts
index 2e8706b1f4fd..803ea724a6b2 100644
--- a/examples/src/chains/retrieval_qa.ts
+++ b/examples/src/chains/retrieval_qa.ts
@@ -39,7 +39,7 @@ const prompt = ChatPromptTemplate.fromMessages(messages);
 
 const chain = RunnableSequence.from([
   {
-    context: vectorStoreRetriever.pipe(formatDocumentsAsString),
+    context: vectorStoreRetriever.pipe((docs) => formatDocumentsAsString(docs)),
     question: new RunnablePassthrough(),
   },
   prompt,
diff --git a/examples/src/guides/expression_language/cookbook_retriever.ts b/examples/src/guides/expression_language/cookbook_retriever.ts
index 800e0d810c41..c2f33280702c 100644
--- a/examples/src/guides/expression_language/cookbook_retriever.ts
+++ b/examples/src/guides/expression_language/cookbook_retriever.ts
@@ -26,7 +26,7 @@ Question: {question}`);
 
 const chain = RunnableSequence.from([
   {
-    context: retriever.pipe(formatDocumentsAsString),
+    context: retriever.pipe((docs) => formatDocumentsAsString(docs)),
     question: new RunnablePassthrough(),
   },
   prompt,
diff --git a/examples/src/models/chat/integration_llama_cpp_stream_multi.ts b/examples/src/models/chat/integration_llama_cpp_stream_multi.ts
index 6277ac69b52b..35633c6b83fe 100644
--- a/examples/src/models/chat/integration_llama_cpp_stream_multi.ts
+++ b/examples/src/models/chat/integration_llama_cpp_stream_multi.ts
@@ -3,7 +3,7 @@ import { SystemMessage, HumanMessage } from "langchain/schema";
 
 const llamaPath = "/Replace/with/path/to/your/model/gguf-llama2-q4_0.bin";
 
-const model = new ChatLlamaCpp({ modelPath: llamaPath, temperature: 0.7 });
+const llamaCpp = new ChatLlamaCpp({ modelPath: llamaPath, temperature: 0.7 });
 
 const stream = await llamaCpp.stream([
   new SystemMessage(
diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index e4184f5ce218..2614726dee51 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -23,7 +23,8 @@ import { RootListenersTracer } from "../tracers/root_listener.js";
 
 export type RunnableFunc<RunInput, RunOutput> = (
   input: RunInput,
-  options?: Record<string, unknown>
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  options?: any
 ) => RunOutput | Promise<RunOutput>;
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any

From c9d340284052e186dcb80103e4ed4ad49a7653f5 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 10:17:51 -0800
Subject: [PATCH 20/25] cr

---
 examples/src/chains/retrieval_qa.ts                           | 2 +-
 examples/src/guides/expression_language/cookbook_retriever.ts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/src/chains/retrieval_qa.ts b/examples/src/chains/retrieval_qa.ts
index 803ea724a6b2..2e8706b1f4fd 100644
--- a/examples/src/chains/retrieval_qa.ts
+++ b/examples/src/chains/retrieval_qa.ts
@@ -39,7 +39,7 @@ const prompt = ChatPromptTemplate.fromMessages(messages);
 
 const chain = RunnableSequence.from([
   {
-    context: vectorStoreRetriever.pipe((docs) => formatDocumentsAsString(docs)),
+    context: vectorStoreRetriever.pipe(formatDocumentsAsString),
     question: new RunnablePassthrough(),
   },
   prompt,
diff --git a/examples/src/guides/expression_language/cookbook_retriever.ts b/examples/src/guides/expression_language/cookbook_retriever.ts
index c2f33280702c..800e0d810c41 100644
--- a/examples/src/guides/expression_language/cookbook_retriever.ts
+++ b/examples/src/guides/expression_language/cookbook_retriever.ts
@@ -26,7 +26,7 @@ Question: {question}`);
 
 const chain = RunnableSequence.from([
   {
-    context: retriever.pipe((docs) => formatDocumentsAsString(docs)),
+    context: retriever.pipe(formatDocumentsAsString),
     question: new RunnablePassthrough(),
   },
   prompt,

From b465628ee7f9f4dc492be16f7ad7562ea50a8ed2 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 16:34:43 -0800
Subject: [PATCH 21/25] cr

---
 langchain-core/src/runnables/base.ts    |  8 ++--
 langchain-core/src/runnables/config.ts  | 61 +++++++++++++------------
 langchain-core/src/runnables/history.ts |  6 +--
 3 files changed, 41 insertions(+), 34 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 2614726dee51..1aed404235eb 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -647,12 +647,14 @@ export class RunnableBinding<
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     options?: Record<string, any>
   ): Promise<Partial<CallOptions>> {
-    const config = mergeConfigs(this.config, options);
-    return mergeConfigs(
+    const config = mergeConfigs<CallOptions>(this.config, options);
+    return mergeConfigs<CallOptions>(
       config,
       ...(this.configFactories
         ? await Promise.all(
-            this.configFactories.map(async (f) => await f(config))
+            this.configFactories.map(
+              async (factoryMethod) => await factoryMethod(config)
+            )
           )
         : [])
     );
diff --git a/langchain-core/src/runnables/config.ts b/langchain-core/src/runnables/config.ts
index 6491d38ac25f..e604071a7b09 100644
--- a/langchain-core/src/runnables/config.ts
+++ b/langchain-core/src/runnables/config.ts
@@ -30,54 +30,59 @@ export function mergeConfigs<CallOptions extends RunnableConfig>(
         copy[key] = (copy[key] ?? []).concat(options[key] ?? []);
       } else if (key === "callbacks") {
         const baseCallbacks = copy.callbacks;
-        const theseCallbacks = options.callbacks ?? config.callbacks;
+        const providedCallbacks = options.callbacks ?? config.callbacks;
         // callbacks can be either undefined, Array<handler> or manager
         // so merging two callbacks values has 6 cases
-        if (Array.isArray(theseCallbacks)) {
+        if (Array.isArray(providedCallbacks)) {
           if (!baseCallbacks) {
-            copy.callbacks = theseCallbacks;
+            copy.callbacks = providedCallbacks;
           } else if (Array.isArray(baseCallbacks)) {
-            copy.callbacks = baseCallbacks.concat(theseCallbacks);
+            copy.callbacks = baseCallbacks.concat(providedCallbacks);
           } else {
             // baseCallbacks is a manager
             const manager = baseCallbacks.copy();
-            for (const callback of theseCallbacks) {
+            for (const callback of providedCallbacks) {
               manager.addHandler(callback, true);
             }
             copy.callbacks = manager;
           }
-        } else if (theseCallbacks) {
-          // theseCallbacks is a manager
+        } else if (providedCallbacks) {
+          // providedCallbacks is a manager
           if (!baseCallbacks) {
-            copy.callbacks = theseCallbacks;
+            copy.callbacks = providedCallbacks;
           } else if (Array.isArray(baseCallbacks)) {
-            const manager = theseCallbacks.copy();
+            const manager = providedCallbacks.copy();
             for (const callback of baseCallbacks) {
               manager.addHandler(callback, true);
             }
             copy.callbacks = manager;
           } else {
             // baseCallbacks is also a manager
-            copy.callbacks = new CallbackManager(theseCallbacks.parentRunId, {
-              handlers: baseCallbacks.handlers.concat(theseCallbacks.handlers),
-              inheritableHandlers: baseCallbacks.inheritableHandlers.concat(
-                theseCallbacks.inheritableHandlers
-              ),
-              tags: Array.from(
-                new Set(baseCallbacks.tags.concat(theseCallbacks.tags))
-              ),
-              inheritableTags: Array.from(
-                new Set(
-                  baseCallbacks.inheritableTags.concat(
-                    theseCallbacks.inheritableTags
+            copy.callbacks = new CallbackManager(
+              providedCallbacks.parentRunId,
+              {
+                handlers: baseCallbacks.handlers.concat(
+                  providedCallbacks.handlers
+                ),
+                inheritableHandlers: baseCallbacks.inheritableHandlers.concat(
+                  providedCallbacks.inheritableHandlers
+                ),
+                tags: Array.from(
+                  new Set(baseCallbacks.tags.concat(providedCallbacks.tags))
+                ),
+                inheritableTags: Array.from(
+                  new Set(
+                    baseCallbacks.inheritableTags.concat(
+                      providedCallbacks.inheritableTags
+                    )
                   )
-                )
-              ),
-              metadata: {
-                ...baseCallbacks.metadata,
-                ...theseCallbacks.metadata,
-              },
-            });
+                ),
+                metadata: {
+                  ...baseCallbacks.metadata,
+                  ...providedCallbacks.metadata,
+                },
+              }
+            );
           }
         }
       } else {
diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 178549ac66c5..e03a1ca37f65 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -10,10 +10,10 @@ import { Run } from "../tracers/base.js";
 import {
   Runnable,
   RunnableBinding,
-  RunnableBindingArgs,
+  type RunnableBindingArgs,
   RunnableLambda,
 } from "./base.js";
-import { RunnableConfig } from "./config.js";
+import { type RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (
@@ -52,7 +52,7 @@ export class RunnableWithMessageHistory<
         this._enterHistory(input, options ?? {}),
     }).withConfig({ runName: "loadHistory" });
 
-    const messagesKey = fields.historyMessagesKey || fields.inputMessagesKey;
+    const messagesKey = fields.historyMessagesKey ?? fields.inputMessagesKey;
     if (messagesKey) {
       historyChain = RunnablePassthrough.assign({
         [messagesKey]: historyChain,

From dcbc640af32f272cb4f87bc129fef82f409d6b03 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 17:37:24 -0800
Subject: [PATCH 22/25] cr

---
 langchain-core/src/runnables/base.ts                | 11 +++++------
 langchain-core/src/runnables/history.ts             |  4 +---
 langchain-core/src/runnables/tests/runnable.test.ts |  1 +
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 1aed404235eb..1c7ee6642c0f 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -726,12 +726,11 @@ export class RunnableBinding<
   ): Promise<(RunOutput | Error)[]> {
     const mergedOptions = Array.isArray(options)
       ? await Promise.all(
-          options.map(
-            async (individualOption) =>
-              await this._mergeConfig({
-                ...individualOption,
-                ...this.kwargs,
-              })
+          options.map(async (individualOption) =>
+            this._mergeConfig({
+              ...individualOption,
+              ...this.kwargs,
+            })
           )
         )
       : await this._mergeConfig({ ...options, ...this.kwargs });
diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index e03a1ca37f65..74140d28189a 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -13,7 +13,6 @@ import {
   type RunnableBindingArgs,
   RunnableLambda,
 } from "./base.js";
-import { type RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (
@@ -62,8 +61,7 @@ export class RunnableWithMessageHistory<
     const bound = historyChain
       .pipe(
         fields.runnable.withListeners({
-          onEnd: (run: Run, config: RunnableConfig = {}) =>
-            this._exitHistory(run, config),
+          onEnd: (run, config) => this._exitHistory(run, config ?? {}),
         })
       )
       .withConfig({ runName: "RunnableWithMessageHistory" });
diff --git a/langchain-core/src/runnables/tests/runnable.test.ts b/langchain-core/src/runnables/tests/runnable.test.ts
index fd0030e4f049..149a39112c4f 100644
--- a/langchain-core/src/runnables/tests/runnable.test.ts
+++ b/langchain-core/src/runnables/tests/runnable.test.ts
@@ -2,6 +2,7 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 
 import { Run } from "langsmith";
+import { jest } from "@jest/globals";
 import { createChatMessageChunkEncoderStream } from "../../language_models/chat_models.js";
 import { BaseMessage } from "../../messages/index.js";
 import { OutputParserException } from "../../output_parsers/base.js";

From 5e113e98a0850e39ad3eaacb02bb3faa01d242a8 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 17:54:52 -0800
Subject: [PATCH 23/25] cr

---
 langchain-core/src/runnables/base.ts                 |  6 ++++--
 langchain-core/src/runnables/history.ts              | 12 +++++++-----
 .../agents/toolkits/conversational_retrieval/tool.ts |  2 +-
 langchain/src/memory/vector_store.ts                 |  2 +-
 langchain/src/tools/webbrowser.ts                    |  2 +-
 langchain/src/util/document.ts                       |  3 +--
 6 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 1c7ee6642c0f..208a97b3ff49 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -24,7 +24,9 @@ import { RootListenersTracer } from "../tracers/root_listener.js";
 export type RunnableFunc<RunInput, RunOutput> = (
   input: RunInput,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  options?: any
+  options?: Record<string, any> & {
+    config?: RunnableConfig;
+  }
 ) => RunOutput | Promise<RunOutput>;
 
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -1502,7 +1504,7 @@ export class RunnableLambda<RunInput, RunOutput> extends Runnable<
     config?: Partial<BaseCallbackConfig>,
     runManager?: CallbackManagerForChainRun
   ) {
-    let output = await this.func(input, config);
+    let output = await this.func(input, { config });
     if (output && Runnable.isRunnable(output)) {
       output = await output.invoke(
         input,
diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 74140d28189a..522e153ddd6a 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -47,8 +47,7 @@ export class RunnableWithMessageHistory<
     }
   ) {
     let historyChain: Runnable = new RunnableLambda({
-      func: (input: any, options?: Record<string, unknown>) =>
-        this._enterHistory(input, options ?? {}),
+      func: (input, options) => this._enterHistory(input, options ?? {}),
     }).withConfig({ runName: "loadHistory" });
 
     const messagesKey = fields.historyMessagesKey ?? fields.inputMessagesKey;
@@ -118,9 +117,12 @@ export class RunnableWithMessageHistory<
     );
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  _enterHistory(input: any, config: BaseCallbackConfig): Array<BaseMessage> {
-    const history = config?.configurable?.messageHistory;
+  _enterHistory(
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    input: any,
+    kwargs?: { config?: RunnableConfig }
+  ): Array<BaseMessage> {
+    const history = kwargs?.config?.configurable?.messageHistory;
 
     if (this.historyMessagesKey) {
       return history.messages;
diff --git a/langchain/src/agents/toolkits/conversational_retrieval/tool.ts b/langchain/src/agents/toolkits/conversational_retrieval/tool.ts
index cc62eb3b28a4..36a15e2ef9a1 100644
--- a/langchain/src/agents/toolkits/conversational_retrieval/tool.ts
+++ b/langchain/src/agents/toolkits/conversational_retrieval/tool.ts
@@ -19,7 +19,7 @@ export function createRetrieverTool(
       input,
       runManager?.getChild("retriever")
     );
-    return formatDocumentsAsString(docs, "\n");
+    return formatDocumentsAsString(docs);
   };
   const schema = z.object({
     input: z
diff --git a/langchain/src/memory/vector_store.ts b/langchain/src/memory/vector_store.ts
index 8cdbb4e412fb..a0ba15b781d3 100644
--- a/langchain/src/memory/vector_store.ts
+++ b/langchain/src/memory/vector_store.ts
@@ -89,7 +89,7 @@ export class VectorStoreRetrieverMemory
     return {
       [this.memoryKey]: this.returnDocs
         ? results
-        : formatDocumentsAsString(results, "\n"),
+        : formatDocumentsAsString(results),
     };
   }
 
diff --git a/langchain/src/tools/webbrowser.ts b/langchain/src/tools/webbrowser.ts
index c765d4c50492..55ec8249d8a1 100644
--- a/langchain/src/tools/webbrowser.ts
+++ b/langchain/src/tools/webbrowser.ts
@@ -267,7 +267,7 @@ export class WebBrowser extends Tool {
         undefined,
         runManager?.getChild("vectorstore")
       );
-      context = formatDocumentsAsString(results, "\n");
+      context = formatDocumentsAsString(results);
     }
 
     const input = `Text:${context}\n\nI need ${
diff --git a/langchain/src/util/document.ts b/langchain/src/util/document.ts
index 3867af470ef9..640e6fc9f949 100644
--- a/langchain/src/util/document.ts
+++ b/langchain/src/util/document.ts
@@ -9,5 +9,4 @@ import { Document } from "../document.js";
  */
 export const formatDocumentsAsString = (
   documents: Document[],
-  separator = "\n\n"
-): string => documents.map((doc) => doc.pageContent).join(separator);
+): string => documents.map((doc) => doc.pageContent).join("\n\n");

From 52ceeea7de007b95263a049ffa00a500f71484b7 Mon Sep 17 00:00:00 2001
From: Brace Sproul <braceasproul@gmail.com>
Date: Fri, 1 Dec 2023 17:56:18 -0800
Subject: [PATCH 24/25] cr

---
 langchain-core/src/runnables/history.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/langchain-core/src/runnables/history.ts b/langchain-core/src/runnables/history.ts
index 522e153ddd6a..662a1cbb4de6 100644
--- a/langchain-core/src/runnables/history.ts
+++ b/langchain-core/src/runnables/history.ts
@@ -13,6 +13,7 @@ import {
   type RunnableBindingArgs,
   RunnableLambda,
 } from "./base.js";
+import { RunnableConfig } from "./config.js";
 import { RunnablePassthrough } from "./passthrough.js";
 
 type GetSessionHistoryCallable = (

From f3f6c796522eb95040524360ba6f211511bb4a24 Mon Sep 17 00:00:00 2001
From: jacoblee93 <jacoblee93@gmail.com>
Date: Fri, 1 Dec 2023 18:49:50 -0800
Subject: [PATCH 25/25] Style

---
 langchain-core/src/chat_history.ts   | 16 ++++++----------
 langchain-core/src/runnables/base.ts |  3 +--
 langchain/src/util/document.ts       |  5 ++---
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/langchain-core/src/chat_history.ts b/langchain-core/src/chat_history.ts
index 7c17fc2f5423..979323008b3b 100644
--- a/langchain-core/src/chat_history.ts
+++ b/langchain-core/src/chat_history.ts
@@ -42,27 +42,23 @@ export class FakeChatMessageHistory extends BaseChatMessageHistory {
     super();
   }
 
-  public getMessages(): Promise<BaseMessage[]> {
-    return Promise.resolve(this.messages);
+  async getMessages(): Promise<BaseMessage[]> {
+    return this.messages;
   }
 
-  public addMessage(message: BaseMessage): Promise<void> {
+  async addMessage(message: BaseMessage): Promise<void> {
     this.messages.push(message);
-    return Promise.resolve();
   }
 
-  public addUserMessage(message: string): Promise<void> {
+  async addUserMessage(message: string): Promise<void> {
     this.messages.push(new HumanMessage(message));
-    return Promise.resolve();
   }
 
-  public addAIChatMessage(message: string): Promise<void> {
+  async addAIChatMessage(message: string): Promise<void> {
     this.messages.push(new AIMessage(message));
-    return Promise.resolve();
   }
 
-  public clear(): Promise<void> {
+  async clear(): Promise<void> {
     this.messages = [];
-    return Promise.resolve();
   }
 }
diff --git a/langchain-core/src/runnables/base.ts b/langchain-core/src/runnables/base.ts
index 208a97b3ff49..697bc59f095a 100644
--- a/langchain-core/src/runnables/base.ts
+++ b/langchain-core/src/runnables/base.ts
@@ -655,7 +655,7 @@ export class RunnableBinding<
       ...(this.configFactories
         ? await Promise.all(
             this.configFactories.map(
-              async (factoryMethod) => await factoryMethod(config)
+              async (configFactory) => await configFactory(config)
             )
           )
         : [])
@@ -798,7 +798,6 @@ export class RunnableBinding<
     onEnd?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
     onError?: (run: Run, config?: RunnableConfig) => void | Promise<void>;
   }): Runnable<RunInput, RunOutput, CallOptions> {
-    //
     return new RunnableBinding<RunInput, RunOutput, CallOptions>({
       bound: this.bound,
       kwargs: this.kwargs,
diff --git a/langchain/src/util/document.ts b/langchain/src/util/document.ts
index 640e6fc9f949..a1ee0afc5285 100644
--- a/langchain/src/util/document.ts
+++ b/langchain/src/util/document.ts
@@ -7,6 +7,5 @@ import { Document } from "../document.js";
  * @param documents
  * @returns A string of the documents page content, separated by newlines.
  */
-export const formatDocumentsAsString = (
-  documents: Document[],
-): string => documents.map((doc) => doc.pageContent).join("\n\n");
+export const formatDocumentsAsString = (documents: Document[]): string =>
+  documents.map((doc) => doc.pageContent).join("\n\n");