js: infer gpt-5 on init (#1206)

depends on langchain-ai/langchainjs#9294

Author: mdrxy

src/oss/javascript/migrate/langchain-v1.mdx

@@ -539,7 +539,7 @@ In v1, messages gain provider-agnostic standard content blocks. Access them via
 ```typescript v1 (new)
 import { initChatModel } from "langchain";
 
-const model = await initChatModel("openai:gpt-5-nano");
+const model = await initChatModel("gpt-5-nano");
 const response = await model.invoke("Explain AI");
 
 for (const block of response.contentBlocks) {
@@ -623,7 +623,7 @@ export LC_OUTPUT_VERSION=v1
 ```typescript
 import { initChatModel } from "langchain";
 
-const model = await initChatModel("openai:gpt-5-nano", {
+const model = await initChatModel("gpt-5-nano", {
   outputVersion: "v1",
 });
 ```

src/oss/langchain/agents.mdx

@@ -85,7 +85,7 @@ agent = create_agent(
 import { createAgent } from "langchain";
 
 const agent = createAgent({
-  model: "openai:gpt-5",
+  model: "gpt-5",
   tools: []
 });
 ```

src/oss/langchain/messages.mdx

@@ -40,7 +40,7 @@ response = model.invoke(messages)  # Returns AIMessage
 ```typescript
 import { initChatModel, HumanMessage, SystemMessage } from "langchain";
 
-const model = await initChatModel("openai:gpt-5-nano");
+const model = await initChatModel("gpt-5-nano");
 
 const systemMsg = new SystemMessage("You are a helpful assistant.");
 const humanMsg = new HumanMessage("Hello, how are you?");
@@ -441,7 +441,7 @@ response.usage_metadata
 ```typescript
 import { initChatModel } from "langchain";
 
-const model = await initChatModel("openai:gpt-5-nano");
+const model = await initChatModel("gpt-5-nano");
 
 const response = await model.invoke("Hello!");
 console.log(response.usage_metadata);
@@ -833,7 +833,7 @@ inference provider of your choice.
     import { initChatModel } from "langchain";
 
     const model = await initChatModel(
-      "openai:gpt-5-nano",
+      "gpt-5-nano",
       { outputVersion: "v1" }
     );
     ```

src/oss/langchain/rag.mdx

@@ -170,7 +170,7 @@ const retrieve = tool(
   }
 );
 
-const agent = createAgent({ model: "openai:gpt-5", tools: [retrieve] });
+const agent = createAgent({ model: "gpt-5", tools: [retrieve] });
 ```
 ```typescript
 let inputMessage = `What is Task Decomposition?`;
@@ -572,7 +572,7 @@ const systemPrompt = new SystemMessage(
     "Use the tool to help answer user queries."
 )
 
-const agent = createAgent({ model: "openai:gpt-5", tools, systemPrompt });
+const agent = createAgent({ model: "gpt-5", tools, systemPrompt });
 ```
 :::
 

src/oss/langchain/short-term-memory.mdx

@@ -160,7 +160,7 @@ const stateExtensionMiddleware = createMiddleware({
 
 const checkpointer = new MemorySaver();
 const agent = createAgent({
-    model: "openai:gpt-5",
+    model: "gpt-5",
     tools: [],
     middleware: [stateExtensionMiddleware] as const,  // [!code highlight]
     checkpointer,
@@ -290,7 +290,7 @@ const stateModifier = async (state: AgentState) => {
 
 const checkpointer = new MemorySaver();
 const agent = createAgent({
-    model: "openai:gpt-5",
+    model: "gpt-5",
     tools: [],
     preModelHook: stateModifier,
     checkpointer,
@@ -437,7 +437,7 @@ const deleteMessages = (state: AgentState) => {
 };
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [],
     prompt: "Please be concise and to the point.",
     postModelHook: deleteMessages,
@@ -631,7 +631,7 @@ const getUserInfo = tool(
 );
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [getUserInfo],
     stateSchema,
 });
@@ -860,7 +860,7 @@ const getWeather = tool(
 );
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [getWeather],
     contextSchema,
     prompt: (state, config) => {
@@ -1021,7 +1021,7 @@ const trimMessageHistory = createMiddleware({
 });
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [],
     middleware: [trimMessageHistory],
 });
@@ -1104,7 +1104,7 @@ const validateResponse = createMiddleware({
 });
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [],
     middleware: [validateResponse],
 });

src/oss/langchain/sql-agent.mdx

@@ -642,7 +642,7 @@ Now, create an agent with the model, tools, and prompt:
 import { createAgent } from "langchain";
 
 const agent = createAgent({
-  model: "openai:gpt-5",
+  model: "gpt-5",
   tools: [executeSql],
   systemPrompt: getSystemPrompt,
 });
@@ -803,7 +803,7 @@ Rules:
 `);
 
 export const agent = createAgent({
-  model: "openai:gpt-5",
+  model: "gpt-5",
   tools: [executeSql],
   systemPrompt: getSystemPrompt,
 });

src/oss/langchain/streaming.mdx

@@ -90,7 +90,7 @@ const getWeather = tool(
 );
 
 const agent = createAgent({
-    model: "openai:gpt-5-nano",
+    model: "gpt-5-nano",
     tools: [getWeather],
 });
 

src/oss/langchain/structured-output.mdx

@@ -226,7 +226,7 @@ LangChain automatically uses `ProviderStrategy` when you pass a schema type dire
     });
 
     const agent = createAgent({
-        model: "openai:gpt-5",
+        model: "gpt-5",
         tools: tools,
         responseFormat: providerStrategy(ContactInfo)
     });
@@ -254,7 +254,7 @@ LangChain automatically uses `ProviderStrategy` when you pass a schema type dire
     }
 
     const agent = createAgent({
-        model: "openai:gpt-5",
+        model: "gpt-5",
         tools: tools,
         responseFormat: providerStrategy(contactInfoSchema)
     });
@@ -581,7 +581,7 @@ function toolStrategy<StructuredResponseT>(
     });
 
     const agent = createAgent({
-        model: "openai:gpt-5",
+        model: "gpt-5",
         tools: tools,
         responseFormat: toolStrategy(ProductReview)
     })
@@ -622,7 +622,7 @@ function toolStrategy<StructuredResponseT>(
     }
 
     const agent = createAgent({
-        model: "openai:gpt-5",
+        model: "gpt-5",
         tools: tools,
         responseFormat: toolStrategy(productReviewSchema)
     });
@@ -652,7 +652,7 @@ function toolStrategy<StructuredResponseT>(
     });
 
     const agent = createAgent({
-        model: "openai:gpt-5",
+        model: "gpt-5",
         tools: tools,
         responseFormat: toolStrategy([ProductReview, CustomerComplaint])
     });
@@ -681,7 +681,7 @@ const MeetingAction = z.object({
 });
 
 const agent = createAgent({
-    model: "openai:gpt-5",
+    model: "gpt-5",
     tools: [],
     responseFormat: toolStrategy(MeetingAction, {
         toolMessageContent: "Action item captured and added to meeting notes!"
@@ -812,7 +812,7 @@ const EventDetails = z.object({
 });
 
 const agent = createAgent({
-    model: "openai:gpt-5",
+    model: "gpt-5",
     tools: [],
     responseFormat: toolStrategy([ContactInfo, EventDetails]),
 });
@@ -1002,7 +1002,7 @@ const ProductRating = z.object({
 });
 
 const agent = createAgent({
-    model: "openai:gpt-5",
+    model: "gpt-5",
     tools: [],
     responseFormat: toolStrategy(ProductRating),
 });