diff --git a/libs/checkpoint/pyproject.toml b/libs/checkpoint/pyproject.toml
index 8ed0bd3b5..da2012a17 100644
--- a/libs/checkpoint/pyproject.toml
+++ b/libs/checkpoint/pyproject.toml
@@ -45,6 +45,9 @@ dev = [
   "pycryptodome>=3.23.0",
 ]
 
+[tool.uv.sources]
+langchain-core = { git = "https://github.com/langchain-ai/langchain", branch = "cb/chat-model-updates", subdirectory = "libs/core" }
+
 [tool.hatch.build.targets.wheel]
 include = ["langgraph"]
 
diff --git a/libs/checkpoint/uv.lock b/libs/checkpoint/uv.lock
index 86e7e3c7a..5ad419455 100644
--- a/libs/checkpoint/uv.lock
+++ b/libs/checkpoint/uv.lock
@@ -267,10 +267,11 @@ wheels = [
 
 [[package]]
 name = "langchain-core"
-version = "1.2.28"
-source = { registry = "https://pypi.org/simple" }
+version = "1.3.2"
+source = { git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates#aee50839376e379891c99fcbe6d5264f66dedc68" }
 dependencies = [
     { name = "jsonpatch" },
+    { name = "langchain-protocol" },
     { name = "langsmith" },
     { name = "packaging" },
     { name = "pydantic" },
@@ -279,9 +280,17 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/f8/a4/317a1a3ac1df33a64adb3670bf88bbe3b3d5baa274db6863a979db472897/langchain_core-1.2.28.tar.gz", hash = "sha256:271a3d8bd618f795fdeba112b0753980457fc90537c46a0c11998516a74dc2cb", size = 846119, upload-time = "2026-04-08T18:19:34.867Z" }
+
+[[package]]
+name = "langchain-protocol"
+version = "0.0.14"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "typing-extensions" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/05/bf/efb5e2ed832e4d6d45590e25a9e5191986b291b543bc6a807b48bee070b0/langchain_protocol-0.0.14.tar.gz", hash = "sha256:bc1e8553122e6ede310280462d5813023a172ff2785ccbbdec54d43f3a15e5f2", size = 5862, upload-time = "2026-04-29T16:40:18.657Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/a8/92/32f785f077c7e898da97064f113c73fbd9ad55d1e2169cf3a391b183dedb/langchain_core-1.2.28-py3-none-any.whl", hash = "sha256:80764232581eaf8057bcefa71dbf8adc1f6a28d257ebd8b95ba9b8b452e8c6ac", size = 508727, upload-time = "2026-04-08T18:19:32.823Z" },
+    { url = "https://files.pythonhosted.org/packages/c2/e9/06c47ecb2aff08f83dfa30058da3bf86be64862c19569043ed5331bbeecd/langchain_protocol-0.0.14-py3-none-any.whl", hash = "sha256:ffc35089779bd8ca217015180cef5e660fc3b074efdaa0f2e95df73583f1a047", size = 6984, upload-time = "2026-04-29T16:40:17.841Z" },
 ]
 
 [[package]]
@@ -330,7 +339,7 @@ test = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=0.2.38" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "ormsgpack", specifier = ">=1.12.0" },
 ]
 
diff --git a/libs/langgraph/pyproject.toml b/libs/langgraph/pyproject.toml
index d8664c6b6..f272f2def 100644
--- a/libs/langgraph/pyproject.toml
+++ b/libs/langgraph/pyproject.toml
@@ -81,6 +81,7 @@ dev = [
 
 
 [tool.uv.sources]
+langchain-core = { git = "https://github.com/langchain-ai/langchain", branch = "cb/chat-model-updates", subdirectory = "libs/core" }
 langgraph-prebuilt = { path = "../prebuilt", editable = true }
 langgraph-checkpoint = { path = "../checkpoint", editable = true }
 langgraph-checkpoint-sqlite = { path = "../checkpoint-sqlite", editable = true }
diff --git a/libs/langgraph/uv.lock b/libs/langgraph/uv.lock
index 9a3ca4cb7..ea47c3f50 100644
--- a/libs/langgraph/uv.lock
+++ b/libs/langgraph/uv.lock
@@ -1349,7 +1349,7 @@ wheels = [
 [[package]]
 name = "langchain-core"
 version = "1.3.2"
-source = { registry = "https://pypi.org/simple" }
+source = { git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates#aee50839376e379891c99fcbe6d5264f66dedc68" }
 dependencies = [
     { name = "jsonpatch" },
     { name = "langchain-protocol" },
@@ -1361,21 +1361,17 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/a8/03/7219502e8ca728d65eb44d7a3eb60239230742a70dbfc9241b9bfd61c4ab/langchain_core-1.3.2.tar.gz", hash = "sha256:fd7a50b2f28ba561fd9d7f5d2760bc9e06cf00cdf820a3ccafe88a94ffa8d5b7", size = 911813, upload-time = "2026-04-24T15:49:23.699Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/7d/d5/8fa4431007cbb7cfed7590f4d6a5dea3ad724f4174d248f6642ef5ce7d05/langchain_core-1.3.2-py3-none-any.whl", hash = "sha256:d44a66127f9f8db735bdfd0ab9661bccb47a97113cfd3f2d89c74864422b7274", size = 542390, upload-time = "2026-04-24T15:49:21.991Z" },
-]
 
 [[package]]
 name = "langchain-protocol"
-version = "0.0.12"
+version = "0.0.14"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "typing-extensions" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/5c/51/1157009b6f94e6e58be58fa8b620187d657909a8b36a6bf5b0c52a2711f6/langchain_protocol-0.0.12.tar.gz", hash = "sha256:5e14c434290a705c9510fdb1a83ecf7561a5e6e0dfd053930ade80dba069269f", size = 6408, upload-time = "2026-04-25T01:05:01.489Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/05/bf/efb5e2ed832e4d6d45590e25a9e5191986b291b543bc6a807b48bee070b0/langchain_protocol-0.0.14.tar.gz", hash = "sha256:bc1e8553122e6ede310280462d5813023a172ff2785ccbbdec54d43f3a15e5f2", size = 5862, upload-time = "2026-04-29T16:40:18.657Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/95/82/3431e3061c917439589fa88a6b23c9bc0e154cba0f05d2e895a68c76ff74/langchain_protocol-0.0.12-py3-none-any.whl", hash = "sha256:402b61f42d4139692528cf37226c367bb6efc8ff8165b29380accb0abfece7b2", size = 6639, upload-time = "2026-04-25T01:05:00.487Z" },
+    { url = "https://files.pythonhosted.org/packages/c2/e9/06c47ecb2aff08f83dfa30058da3bf86be64862c19569043ed5331bbeecd/langchain_protocol-0.0.14-py3-none-any.whl", hash = "sha256:ffc35089779bd8ca217015180cef5e660fc3b074efdaa0f2e95df73583f1a047", size = 6984, upload-time = "2026-04-29T16:40:17.841Z" },
 ]
 
 [[package]]
@@ -1452,7 +1448,7 @@ test = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.2,<2" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-prebuilt", editable = "../prebuilt" },
     { name = "langgraph-sdk", editable = "../sdk-py" },
@@ -1464,7 +1460,7 @@ requires-dist = [
 dev = [
     { name = "httpx" },
     { name = "jupyter" },
-    { name = "langchain-core", specifier = ">=1.0.0" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
     { name = "langgraph-checkpoint-sqlite", editable = "../checkpoint-sqlite" },
@@ -1497,7 +1493,7 @@ lint = [
 ]
 test = [
     { name = "httpx" },
-    { name = "langchain-core", specifier = ">=1.0.0" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
     { name = "langgraph-checkpoint-sqlite", editable = "../checkpoint-sqlite" },
@@ -1570,7 +1566,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=0.2.38" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "ormsgpack", specifier = ">=1.12.0" },
 ]
 
@@ -1764,14 +1760,14 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.1" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
 ]
 
 [package.metadata.requires-dev]
 dev = [
     { name = "codespell" },
-    { name = "langchain-core" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph", editable = "." },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
@@ -1791,7 +1787,7 @@ lint = [
     { name = "ruff" },
 ]
 test = [
-    { name = "langchain-core" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph", editable = "." },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
diff --git a/libs/prebuilt/pyproject.toml b/libs/prebuilt/pyproject.toml
index ad4f5c3c1..8b67b86e2 100644
--- a/libs/prebuilt/pyproject.toml
+++ b/libs/prebuilt/pyproject.toml
@@ -62,6 +62,7 @@ dev = [
 default-groups = ['dev']
 
 [tool.uv.sources]
+langchain-core = { git = "https://github.com/langchain-ai/langchain", branch = "cb/chat-model-updates", subdirectory = "libs/core" }
 langgraph = { path = "../langgraph", editable = true }
 langgraph-checkpoint = { path = "../checkpoint", editable = true }
 langgraph-checkpoint-sqlite = { path = "../checkpoint-sqlite", editable = true }
diff --git a/libs/prebuilt/uv.lock b/libs/prebuilt/uv.lock
index b781f1176..f79aa04e0 100644
--- a/libs/prebuilt/uv.lock
+++ b/libs/prebuilt/uv.lock
@@ -250,7 +250,7 @@ wheels = [
 [[package]]
 name = "langchain-core"
 version = "1.3.2"
-source = { registry = "https://pypi.org/simple" }
+source = { git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates#aee50839376e379891c99fcbe6d5264f66dedc68" }
 dependencies = [
     { name = "jsonpatch" },
     { name = "langchain-protocol" },
@@ -262,21 +262,17 @@ dependencies = [
     { name = "typing-extensions" },
     { name = "uuid-utils" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/a8/03/7219502e8ca728d65eb44d7a3eb60239230742a70dbfc9241b9bfd61c4ab/langchain_core-1.3.2.tar.gz", hash = "sha256:fd7a50b2f28ba561fd9d7f5d2760bc9e06cf00cdf820a3ccafe88a94ffa8d5b7", size = 911813, upload-time = "2026-04-24T15:49:23.699Z" }
-wheels = [
-    { url = "https://files.pythonhosted.org/packages/7d/d5/8fa4431007cbb7cfed7590f4d6a5dea3ad724f4174d248f6642ef5ce7d05/langchain_core-1.3.2-py3-none-any.whl", hash = "sha256:d44a66127f9f8db735bdfd0ab9661bccb47a97113cfd3f2d89c74864422b7274", size = 542390, upload-time = "2026-04-24T15:49:21.991Z" },
-]
 
 [[package]]
 name = "langchain-protocol"
-version = "0.0.12"
+version = "0.0.14"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "typing-extensions" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/5c/51/1157009b6f94e6e58be58fa8b620187d657909a8b36a6bf5b0c52a2711f6/langchain_protocol-0.0.12.tar.gz", hash = "sha256:5e14c434290a705c9510fdb1a83ecf7561a5e6e0dfd053930ade80dba069269f", size = 6408, upload-time = "2026-04-25T01:05:01.489Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/05/bf/efb5e2ed832e4d6d45590e25a9e5191986b291b543bc6a807b48bee070b0/langchain_protocol-0.0.14.tar.gz", hash = "sha256:bc1e8553122e6ede310280462d5813023a172ff2785ccbbdec54d43f3a15e5f2", size = 5862, upload-time = "2026-04-29T16:40:18.657Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/95/82/3431e3061c917439589fa88a6b23c9bc0e154cba0f05d2e895a68c76ff74/langchain_protocol-0.0.12-py3-none-any.whl", hash = "sha256:402b61f42d4139692528cf37226c367bb6efc8ff8165b29380accb0abfece7b2", size = 6639, upload-time = "2026-04-25T01:05:00.487Z" },
+    { url = "https://files.pythonhosted.org/packages/c2/e9/06c47ecb2aff08f83dfa30058da3bf86be64862c19569043ed5331bbeecd/langchain_protocol-0.0.14-py3-none-any.whl", hash = "sha256:ffc35089779bd8ca217015180cef5e660fc3b074efdaa0f2e95df73583f1a047", size = 6984, upload-time = "2026-04-29T16:40:17.841Z" },
 ]
 
 [[package]]
@@ -294,7 +290,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.2,<2" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-prebuilt", editable = "." },
     { name = "langgraph-sdk", editable = "../sdk-py" },
@@ -306,7 +302,7 @@ requires-dist = [
 dev = [
     { name = "httpx" },
     { name = "jupyter" },
-    { name = "langchain-core", specifier = ">=1.0.0" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
     { name = "langgraph-checkpoint-sqlite", editable = "../checkpoint-sqlite" },
@@ -339,7 +335,7 @@ lint = [
 ]
 test = [
     { name = "httpx" },
-    { name = "langchain-core", specifier = ">=1.0.0" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
     { name = "langgraph-checkpoint-sqlite", editable = "../checkpoint-sqlite" },
@@ -374,7 +370,7 @@ dependencies = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=0.2.38" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "ormsgpack", specifier = ">=1.12.0" },
 ]
 
@@ -548,14 +544,14 @@ test = [
 
 [package.metadata]
 requires-dist = [
-    { name = "langchain-core", specifier = ">=1.3.1" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
 ]
 
 [package.metadata.requires-dev]
 dev = [
     { name = "codespell" },
-    { name = "langchain-core" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph", editable = "../langgraph" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },
@@ -575,7 +571,7 @@ lint = [
     { name = "ruff" },
 ]
 test = [
-    { name = "langchain-core" },
+    { name = "langchain-core", git = "https://github.com/langchain-ai/langchain?subdirectory=libs%2Fcore&branch=cb%2Fchat-model-updates" },
     { name = "langgraph", editable = "../langgraph" },
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-checkpoint-postgres", editable = "../checkpoint-postgres" },