From 5a1d2ab2045a9ff993f132c7fcc21c452541435a Mon Sep 17 00:00:00 2001
From: slience1213 <2503404258gl@gmail.com>
Date: Tue, 21 Oct 2025 12:53:57 +0800
Subject: [PATCH 1/2] fix(chat): enhance model name parsing to preserve full
 model name with multiple colons

---
 .../src/chat_models/tests/universal.int.test.ts  | 16 ++++++++++++++++
 libs/langchain/src/chat_models/universal.ts      |  6 +++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/libs/langchain/src/chat_models/tests/universal.int.test.ts b/libs/langchain/src/chat_models/tests/universal.int.test.ts
index 944b9994c725..37912e001f53 100644
--- a/libs/langchain/src/chat_models/tests/universal.int.test.ts
+++ b/libs/langchain/src/chat_models/tests/universal.int.test.ts
@@ -807,3 +807,19 @@ describe("Can be initialized without `modelProvider`", () => {
     expect(modelResult.content.length).toBeGreaterThan(0);
   });
 });
+
+describe.skip("Model name parsing with multiple colons preserves full model name", () => {
+  test.each([
+    "ollama:qwen2.5:14b",
+    "ollama:llama3:8b",
+    "ollama:deepseek-r1:1.5b",
+  ])("for %s", async (modelName) => {
+    const model = await initChatModel(modelName, {
+      temperature: 0,
+    });
+
+    const modelResult = await model.invoke("what's your name");
+    expect(modelResult).toBeDefined();
+    expect(modelResult.content.length).toBeGreaterThan(0);
+  });
+});
diff --git a/libs/langchain/src/chat_models/universal.ts b/libs/langchain/src/chat_models/universal.ts
index c80fc286113e..e3679e9301cc 100644
--- a/libs/langchain/src/chat_models/universal.ts
+++ b/libs/langchain/src/chat_models/universal.ts
@@ -855,7 +855,11 @@ export async function initChatModel<
     ...(fields ?? {}),
   };
   if (modelProvider === undefined && model?.includes(":")) {
-    const modelComponents = model.split(":", 2);
+    const [provider, ...remainingParts] = model.split(":");
+    const modelComponents =
+      remainingParts.length === 0
+        ? [provider]
+        : [provider, remainingParts.join(":")];
     if (SUPPORTED_PROVIDERS.includes(modelComponents[0] as ChatModelProvider)) {
       // eslint-disable-next-line no-param-reassign
       [modelProvider, model] = modelComponents;

From 272119c5f5437ed15375d5b9aa727bfe15ffa998 Mon Sep 17 00:00:00 2001
From: Hunter Lovell <40191806+hntrl@users.noreply.github.com>
Date: Tue, 21 Oct 2025 09:04:20 -0700
Subject: [PATCH 2/2] Create wicked-teachers-brake.md

---
 .changeset/wicked-teachers-brake.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/wicked-teachers-brake.md

diff --git a/.changeset/wicked-teachers-brake.md b/.changeset/wicked-teachers-brake.md
new file mode 100644
index 000000000000..14db019c6767
--- /dev/null
+++ b/.changeset/wicked-teachers-brake.md
@@ -0,0 +1,5 @@
+---
+"langchain": patch
+---
+
+preserve full model name when deciding model provider