core[minor]: Add ID

langchain-core/src/messages/base.ts

@@ -5,6 +5,8 @@ export interface StoredMessageData {
   content: string;
   role: string | undefined;
   name: string | undefined;
+  /** An optional unique identifier for the message. */
+  id: string | undefined;
   tool_call_id: string | undefined;
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   additional_kwargs?: Record<string, any>;
@@ -98,6 +100,11 @@ export interface ToolCall {
 export type BaseMessageFields = {
   content: MessageContent;
   name?: string;
+  /**
+   * An optional unique identifier for the message. This should ideally be
+   * provided by the provider/model which created the message.
+   */
+  id?: string;
   additional_kwargs?: {
     function_call?: FunctionCall;
     tool_calls?: ToolCall[];
@@ -164,6 +171,12 @@ export abstract class BaseMessage
   /** The name of the message sender in a multi-user chat. */
   name?: string;
 
+  /**
+   * An optional unique identifier for the message. This should ideally be
+   * provided by the provider/model which created the message.
+   */
+  id?: string;
+
   /** Additional keyword arguments */
   additional_kwargs: NonNullable<BaseMessageFields["additional_kwargs"]>;
 
@@ -195,7 +208,12 @@ export abstract class BaseMessage
       // eslint-disable-next-line no-param-reassign
       fields.response_metadata = {};
     }
+    if (!fields.id) {
+      // eslint-disable-next-line no-param-reassign
+      fields.id = undefined;
+    }
     super(fields);
+    this.id = fields.id;
     this.name = fields.name;
     this.content = fields.content;
     this.additional_kwargs = fields.additional_kwargs;

langchain-core/src/messages/tests/base_message.test.ts

@@ -107,3 +107,31 @@ test("Deserialisation and serialisation of tool_call_id", async () => {
   const deserialized: ToolMessage = await load(JSON.stringify(message), config);
   expect(deserialized).toEqual(message);
 });
+
+test("Deserialisation and serialisation of id", async () => {
+  const config = {
+    importMap: { messages: { AIMessage } },
+    optionalImportEntrypoints: [],
+    optionalImportsMap: {},
+    secretsMap: {},
+  };
+
+  const message = new AIMessage({
+    content: "I am a message 1",
+    id: "my-cool-id",
+  });
+
+  const deserialized: AIMessage = await load(JSON.stringify(message), config);
+  expect(deserialized).toEqual(message);
+
+  // Ensure it works if you mutate the id after creation
+  const newMessage = new AIMessage({
+    content: "I am a message 2",
+  });
+  newMessage.id = "my-other-cool-id";
+  const deserializedNew: AIMessage = await load(
+    JSON.stringify(newMessage),
+    config
+  );
+  expect(deserializedNew.id).toEqual(newMessage.id);
+});

langchain-core/src/messages/utils.ts

@@ -97,6 +97,7 @@ function mapV1MessageToStoredMessage(
         role: v1Message.role,
         name: undefined,
         tool_call_id: undefined,
+        id: undefined,
       },
     };
   }

langchain-core/src/prompts/tests/chat.test.ts

@@ -33,15 +33,6 @@ function createChatPromptTemplate() {
     template: "I'm a generic message. I'm {foo}. I'm {bar}.",
     inputVariables: ["foo", "bar"],
   });
-  // return new ChatPromptTemplate({
-  //   promptMessages: [
-  //     new SystemMessagePromptTemplate(systemPrompt),
-  //     new HumanMessagePromptTemplate(userPrompt),
-  //     new AIMessagePromptTemplate({ prompt: aiPrompt }),
-  //     new ChatMessagePromptTemplate(genericPrompt, "test"),
-  //   ],
-  //   inputVariables: ["context", "foo", "bar"],
-  // });
   return ChatPromptTemplate.fromMessages<{
     foo: string;
     bar: string;