core[minor]: Standardize tool calling (langchain-ai#5019)

* Beef up tool message support

* Fix build

* Relax types

* Plumb in partner packages

* Fix lint

* Lint

* Add new tool calling agent

* Fix build

* Fix build

* Coerce OpenAI request params from input tool messages

* Few shotting support

* Remove log

* Only populate tool params if sensible

* Fix agent flows

Author: jacoblee93

docs/core_docs/.gitignore

@@ -57,12 +57,6 @@ docs/use_cases/query_analysis/quickstart.md
 docs/use_cases/query_analysis/quickstart.mdx
 docs/use_cases/query_analysis/index.md
 docs/use_cases/query_analysis/index.mdx
-docs/use_cases/extraction/quickstart.md
-docs/use_cases/extraction/quickstart.mdx
-docs/use_cases/extraction/index.md
-docs/use_cases/extraction/index.mdx
-docs/use_cases/extraction/guidelines.md
-docs/use_cases/extraction/guidelines.mdx
 docs/use_cases/graph/semantic.md
 docs/use_cases/graph/semantic.mdx
 docs/use_cases/graph/quickstart.md
@@ -73,18 +67,14 @@ docs/use_cases/graph/mapping.md
 docs/use_cases/graph/mapping.mdx
 docs/use_cases/graph/index.md
 docs/use_cases/graph/index.mdx
-docs/use_cases/query_analysis/techniques/structuring.md
-docs/use_cases/query_analysis/techniques/structuring.mdx
-docs/use_cases/query_analysis/techniques/step_back.md
-docs/use_cases/query_analysis/techniques/step_back.mdx
-docs/use_cases/query_analysis/techniques/routing.md
-docs/use_cases/query_analysis/techniques/routing.mdx
-docs/use_cases/query_analysis/techniques/hyde.md
-docs/use_cases/query_analysis/techniques/hyde.mdx
-docs/use_cases/query_analysis/techniques/expansion.md
-docs/use_cases/query_analysis/techniques/expansion.mdx
-docs/use_cases/query_analysis/techniques/decomposition.md
-docs/use_cases/query_analysis/techniques/decomposition.mdx
+docs/use_cases/graph/construction.md
+docs/use_cases/graph/construction.mdx
+docs/use_cases/extraction/quickstart.md
+docs/use_cases/extraction/quickstart.mdx
+docs/use_cases/extraction/index.md
+docs/use_cases/extraction/index.mdx
+docs/use_cases/extraction/guidelines.md
+docs/use_cases/extraction/guidelines.mdx
 docs/use_cases/query_analysis/how_to/no_queries.md
 docs/use_cases/query_analysis/how_to/no_queries.mdx
 docs/use_cases/query_analysis/how_to/multiple_retrievers.md
@@ -97,6 +87,18 @@ docs/use_cases/query_analysis/how_to/few_shot.md
 docs/use_cases/query_analysis/how_to/few_shot.mdx
 docs/use_cases/query_analysis/how_to/constructing_filters.md
 docs/use_cases/query_analysis/how_to/constructing_filters.mdx
+docs/use_cases/query_analysis/techniques/structuring.md
+docs/use_cases/query_analysis/techniques/structuring.mdx
+docs/use_cases/query_analysis/techniques/step_back.md
+docs/use_cases/query_analysis/techniques/step_back.mdx
+docs/use_cases/query_analysis/techniques/routing.md
+docs/use_cases/query_analysis/techniques/routing.mdx
+docs/use_cases/query_analysis/techniques/hyde.md
+docs/use_cases/query_analysis/techniques/hyde.mdx
+docs/use_cases/query_analysis/techniques/expansion.md
+docs/use_cases/query_analysis/techniques/expansion.mdx
+docs/use_cases/query_analysis/techniques/decomposition.md
+docs/use_cases/query_analysis/techniques/decomposition.mdx
 docs/use_cases/extraction/how_to/parse.md
 docs/use_cases/extraction/how_to/parse.mdx
 docs/use_cases/extraction/how_to/handle_long_text.md
@@ -105,12 +107,12 @@ docs/use_cases/extraction/how_to/handle_files.md
 docs/use_cases/extraction/how_to/handle_files.mdx
 docs/use_cases/extraction/how_to/examples.md
 docs/use_cases/extraction/how_to/examples.mdx
-docs/modules/memory/chat_messages/custom.md
-docs/modules/memory/chat_messages/custom.mdx
 docs/modules/model_io/output_parsers/custom.md
 docs/modules/model_io/output_parsers/custom.mdx
 docs/modules/model_io/chat/function_calling.md
 docs/modules/model_io/chat/function_calling.mdx
+docs/modules/memory/chat_messages/custom.md
+docs/modules/memory/chat_messages/custom.mdx
 docs/modules/data_connection/vectorstores/custom.md
 docs/modules/data_connection/vectorstores/custom.mdx
 docs/modules/model_io/output_parsers/types/openai_tools.md

langchain-core/.gitignore

@@ -62,6 +62,10 @@ messages.cjs
 messages.js
 messages.d.ts
 messages.d.cts
+messages/tool.cjs
+messages/tool.js
+messages/tool.d.ts
+messages/tool.d.cts
 output_parsers.cjs
 output_parsers.js
 output_parsers.d.ts

langchain-core/langchain.config.js

@@ -28,6 +28,7 @@ export const config = {
     "load/serializable": "load/serializable",
     memory: "memory",
     messages: "messages/index",
+    "messages/tool": "messages/tool",
     output_parsers: "output_parsers/index",
     "output_parsers/openai_tools": "output_parsers/openai_tools/index",
     "output_parsers/openai_functions": "output_parsers/openai_functions/index",

langchain-core/package.json

@@ -237,6 +237,15 @@
       "import": "./messages.js",
       "require": "./messages.cjs"
     },
+    "./messages/tool": {
+      "types": {
+        "import": "./messages/tool.d.ts",
+        "require": "./messages/tool.d.cts",
+        "default": "./messages/tool.d.ts"
+      },
+      "import": "./messages/tool.js",
+      "require": "./messages/tool.cjs"
+    },
     "./output_parsers": {
       "types": {
         "import": "./output_parsers.d.ts",
@@ -620,6 +629,10 @@
     "messages.js",
     "messages.d.ts",
     "messages.d.cts",
+    "messages/tool.cjs",
+    "messages/tool.js",
+    "messages/tool.d.ts",
+    "messages/tool.d.cts",
     "output_parsers.cjs",
     "output_parsers.js",
     "output_parsers.d.ts",

langchain-core/src/agents.ts

@@ -1,6 +1,7 @@
 export type AgentAction = {
   tool: string;
-  toolInput: string;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  toolInput: string | Record<string, any>;
   log: string;
 };
 

langchain-core/src/language_models/chat_models.ts

@@ -28,6 +28,8 @@ import {
 } from "../callbacks/manager.js";
 import type { RunnableConfig } from "../runnables/config.js";
 import type { BaseCache } from "../caches.js";
+import { StructuredToolInterface } from "../tools.js";
+import { RunnableInterface } from "../runnables/types.js";
 
 /**
  * Represents a serialized chat model.
@@ -94,8 +96,10 @@ interface ChatModelGenerateCachedParameters<
  * provides methods for generating chat based on input messages.
  */
 export abstract class BaseChatModel<
-  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions
-> extends BaseLanguageModel<BaseMessageChunk, CallOptions> {
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  // TODO: Fix the parameter order on the next minor version.
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> extends BaseLanguageModel<OutputMessageType, CallOptions> {
   declare ParsedCallOptions: Omit<
     CallOptions,
     keyof RunnableConfig & "timeout"
@@ -123,6 +127,19 @@ export abstract class BaseChatModel<
     return [runnableConfig, callOptions as this["ParsedCallOptions"]];
   }
 
+  /**
+   * Bind tool-like objects to this chat model.
+   *
+   * @param tools A list of tool definitions to bind to this chat model.
+   * Can be a structured tool or an object matching the provider's
+   * specific tool schema.
+   * @param kwargs Any additional parameters to bind.
+   */
+  bindTools?(
+    tools: (StructuredToolInterface | Record<string, unknown>)[],
+    kwargs?: Partial<CallOptions>
+  ): RunnableInterface<BaseLanguageModelInput, OutputMessageType, CallOptions>;
+
   /**
    * Invokes the chat model with a single input.
    * @param input The input for the language model.
@@ -132,7 +149,7 @@ export abstract class BaseChatModel<
   async invoke(
     input: BaseLanguageModelInput,
     options?: CallOptions
-  ): Promise<BaseMessageChunk> {
+  ): Promise<OutputMessageType> {
     const promptValue = BaseChatModel._convertInputToPromptValue(input);
     const result = await this.generatePrompt(
       [promptValue],
@@ -141,7 +158,7 @@ export abstract class BaseChatModel<
     );
     const chatGeneration = result.generations[0][0] as ChatGeneration;
     // TODO: Remove cast after figuring out inheritance
-    return chatGeneration.message as BaseMessageChunk;
+    return chatGeneration.message as OutputMessageType;
   }
 
   // eslint-disable-next-line require-yield
@@ -156,7 +173,7 @@ export abstract class BaseChatModel<
   async *_streamIterator(
     input: BaseLanguageModelInput,
     options?: CallOptions
-  ): AsyncGenerator<BaseMessageChunk> {
+  ): AsyncGenerator<OutputMessageType> {
     // Subclass check required to avoid double callbacks with default implementation
     if (
       this._streamResponseChunks ===
@@ -203,7 +220,7 @@ export abstract class BaseChatModel<
             ...chunk.generationInfo,
             ...chunk.message.response_metadata,
           };
-          yield chunk.message;
+          yield chunk.message as OutputMessageType;
           if (!generationChunk) {
             generationChunk = chunk;
           } else {