lockfile changes

update lockfiles / deps bounds

.github/ISSUE_TEMPLATE/config.yml

@@ -10,6 +10,6 @@ contact_links:
   - name: Show and tell
     about: Show what you built with LangChain
     url: https://github.com/langchain-ai/langgraph/discussions/categories/show-and-tell
-  - name: Slack
-    url:  https://www.langchain.com/join-community
-    about: General community discussions
+  - name: LangChain Forum
+    url:  https://forum.langchain.com/
+    about: General community discussions and support

.github/dependabot.yml

@@ -1,11 +1,18 @@
-# Please see the documentation for all configuration options:
-# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
-# and
-# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
-
 version: 2
 updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: "weekly"
+
+  - package-ecosystem: "pip"
+    directories:
+      - "libs/checkpoint"
+      - "libs/checkpoint-postgres"
+      - "libs/checkpoint-sqlite"
+      - "libs/cli"
+      - "libs/langgraph"
+      - "libs/prebuilt"
+      - "libs/sdk-py"
+    schedule:
+      interval: "weekly"

.github/workflows/_test.yml

@@ -58,3 +58,13 @@ jobs:
           # grep will exit non-zero if the target message isn't found,
           # and `set -e` above will cause the step to fail.
           echo "$STATUS" | grep 'nothing to commit, working tree clean'
+
+      - name: Install min version of deps
+        shell: bash
+        working-directory: ${{ inputs.working-directory }}
+        run: uv sync --no-default-groups --resolution lowest-direct --no-sources --force-reinstall
+
+      - name: Run tests with min version of deps
+        shell: bash
+        working-directory: ${{ inputs.working-directory }}
+        run: make test

.github/workflows/_test_langgraph.yml

@@ -53,3 +53,13 @@ jobs:
           # grep will exit non-zero if the target message isn't found,
           # and `set -e` above will cause the step to fail.
           echo "$STATUS" | grep 'nothing to commit, working tree clean'
+
+      - name: Install min version of deps
+        shell: bash
+        working-directory: ${{ inputs.working-directory }}
+        run: uv sync --no-default-groups --resolution lowest-direct --no-sources --force-reinstall
+
+      - name: Run tests with min version of deps
+        shell: bash
+        working-directory: ${{ inputs.working-directory }}
+        run: make test

.github/workflows/ci.yml

@@ -22,6 +22,7 @@ jobs:
     outputs:
       python: ${{ steps.filter.outputs.python }}
       sdk-js: ${{ steps.filter.outputs.sdk-js }}
+      deps: ${{ steps.filter.outputs.deps }}
     steps:
       - uses: actions/checkout@v4
       - uses: dorny/paths-filter@v3
@@ -38,6 +39,9 @@ jobs:
               - 'libs/prebuilt/**'
             sdk-js:
               - 'libs/sdk-js/**'
+            deps:
+              - '**/pyproject.toml'
+              - '**/uv.lock'
 
   lint:
     needs: changes
@@ -55,7 +59,7 @@ jobs:
 
             "libs/prebuilt",
           ]
-    if: needs.changes.outputs.python == 'true'
+    if: needs.changes.outputs.python == 'true' || needs.changes.outputs.deps == 'true'
     uses: ./.github/workflows/_lint.yml
     with:
       working-directory: ${{ matrix.working-directory }}
@@ -74,7 +78,7 @@ jobs:
             "libs/checkpoint-postgres",
             "libs/prebuilt",
           ]
-    if: needs.changes.outputs.python == 'true'
+    if: needs.changes.outputs.python == 'true' || needs.changes.outputs.deps == 'true'
     uses: ./.github/workflows/_test.yml
     with:
       working-directory: ${{ matrix.working-directory }}
@@ -83,7 +87,7 @@ jobs:
   # NOTE: we're testing langgraph separately because it requires a different matrix
   test-langgraph:
     needs: changes
-    if: needs.changes.outputs.python == 'true'
+    if: needs.changes.outputs.python == 'true' || needs.changes.outputs.deps == 'true'
     name: "cd libs/langgraph"
     uses: ./.github/workflows/_test_langgraph.yml
     secrets: inherit
@@ -140,7 +144,7 @@ jobs:
 
   integration-test:
     needs: changes
-    if: needs.changes.outputs.python == 'true'
+    if: needs.changes.outputs.python == 'true' || needs.changes.outputs.deps == 'true'
     name: CLI integration test
     uses: ./.github/workflows/_integration_test.yml
     secrets: inherit

.github/workflows/uv_lock_ugprade.yml

@@ -0,0 +1,45 @@
+name: UV Lock Upgrade
+
+on:
+  schedule:
+    # run at midnight every Sunday
+    - cron: '0 0 * * 0'
+  # allow manual triggering
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  upgrade-dependencies:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/checkout@v4
+      
+      - name: Set up uv
+        uses: astral-sh/setup-uv@v6
+        with:
+          # use minimum supported Python version
+          python-version: "3.9"
+          enable-cache: true
+          cache-suffix: "uv-lock-upgrade"
+          
+      - name: Run uv lock --upgrade in all Python packages
+        run: make lock-upgrade
+          
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v6
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          commit-message: "chore: upgrade dependencies with `uv lock --upgrade`"
+          title: "chore: upgrade dependencies with `uv lock --upgrade`"
+          body: |
+            This PR updates the dependencies in all Python packages using `uv lock --upgrade`.
+            
+            This is an automated PR created by the UV Lock Upgrade workflow.
+          branch: deps/uv-lock-upgrade
+          delete-branch: true
+          labels: |
+            dependencies

Makefile

@@ -47,6 +47,16 @@ lock:
 		fi; \
 	done
 
+# Lock all projects and upgrade dependencies
+.PHONY: lock-upgrade
+lock-upgrade:
+	@for dir in $(LIBS_DIRS); do \
+		if [ -f $$dir/Makefile ]; then \
+			echo "Running lock-upgrade in $$dir"; \
+			(cd $$dir && uv lock --upgrade); \
+		fi; \
+	done
+
 # Test all projects
 .PHONY: test
 test:

README.md

@@ -63,7 +63,7 @@ LangGraph provides low-level supporting infrastructure for *any* long-running, s
 While LangGraph can be used standalone, it also integrates seamlessly with any LangChain product, giving developers a full suite of tools for building agents. To improve your LLM application development, pair LangGraph with:
 
 - [LangSmith](http://www.langchain.com/langsmith) — Helpful for agent evals and observability. Debug poor-performing LLM app runs, evaluate agent trajectories, gain visibility in production, and improve performance over time.
-- [LangGraph Platform](https://langchain-ai.github.io/langgraph/concepts/#langgraph-platform) — Deploy and scale agents effortlessly with a purpose-built deployment platform for long running, stateful workflows. Discover, reuse, configure, and share agents across teams — and iterate quickly with visual prototyping in [LangGraph Studio](https://langchain-ai.github.io/langgraph/concepts/langgraph_studio/).
+- [LangGraph Platform](https://langchain-ai.github.io/langgraph/concepts/langgraph_platform/) — Deploy and scale agents effortlessly with a purpose-built deployment platform for long running, stateful workflows. Discover, reuse, configure, and share agents across teams — and iterate quickly with visual prototyping in [LangGraph Studio](https://langchain-ai.github.io/langgraph/concepts/langgraph_studio/).
 - [LangChain](https://python.langchain.com/docs/introduction/) – Provides integrations and composable components to streamline LLM application development.
 
 > [!NOTE]

docs/docs/cloud/deployment/self_hosted_control_plane.md

@@ -3,7 +3,7 @@
 Before deploying, review the [conceptual guide for the Self-Hosted Control Plane](../../concepts/langgraph_self_hosted_control_plane.md) deployment option.
 
 !!! info "Important"
-    The Self-Hosted Control Plane deployment option is currently in beta stage and requires an [Enterprise](../../concepts/plans.md) plan.
+    The Self-Hosted Control Plane deployment option requires an [Enterprise](../../concepts/plans.md) plan.
 
 ## Prerequisites
 

docs/docs/cloud/deployment/self_hosted_data_plane.md

@@ -3,7 +3,7 @@
 Before deploying, review the [conceptual guide for the Self-Hosted Data Plane](../../concepts/langgraph_self_hosted_data_plane.md) deployment option.
 
 !!! info "Important"
-    The Self-Hosted Data Plane deployment option is currently in beta stage and requires an [Enterprise](../../concepts/plans.md) plan.
+    The Self-Hosted Data Plane deployment option requires an [Enterprise](../../concepts/plans.md) plan.
 
 ## Prerequisites
 

docs/docs/cloud/how-tos/use_stream_react.md

@@ -1,4 +1,4 @@
-How to integrate LangGraph into your React application# How to integrate LangGraph into your React application
+# How to integrate LangGraph into your React application
 
 !!! info "Prerequisites"
 
@@ -503,6 +503,74 @@ const handleSubmit = (text: string) => {
 };
 ```
 
+### Cached Thread Display
+
+Use the `initialValues` option to display cached thread data immediately while the history is being loaded from the server. This improves user experience by showing cached data instantly when navigating to existing threads.
+
+```tsx
+import { useStream } from "@langchain/langgraph-sdk/react";
+
+const CachedThreadExample = ({ threadId, cachedThreadData }) => {
+  const stream = useStream({
+    apiUrl: "http://localhost:2024",
+    assistantId: "agent",
+    threadId,
+    // Show cached data immediately while history loads
+    initialValues: cachedThreadData?.values,
+    messagesKey: "messages",
+  });
+
+  return (
+    <div>
+      {stream.messages.map((message) => (
+        <div key={message.id}>{message.content as string}</div>
+      ))}
+    </div>
+  );
+};
+```
+
+### Optimistic Thread Creation
+
+Use the `threadId` option in `submit` function to enable optimistic UI patterns where you need to know the thread ID before the thread is actually created.
+
+```tsx
+import { useState } from "react";
+import { useStream } from "@langchain/langgraph-sdk/react";
+
+const OptimisticThreadExample = () => {
+  const [threadId, setThreadId] = useState<string | null>(null);
+  const [optimisticThreadId] = useState(() => crypto.randomUUID());
+
+  const stream = useStream({
+    apiUrl: "http://localhost:2024",
+    assistantId: "agent",
+    threadId,
+    onThreadId: setThreadId, // (3) Updated after thread has been created.
+    messagesKey: "messages",
+  });
+
+  const handleSubmit = (text: string) => {
+    // (1) Perform a soft navigation to /threads/${optimisticThreadId}
+    // without waiting for thread creation.
+    window.history.pushState({}, "", `/threads/${optimisticThreadId}`);
+
+    // (2) Submit message to create thread with the predetermined ID.
+    stream.submit(
+      { messages: [{ type: "human", content: text }] },
+      { threadId: optimisticThreadId }
+    );
+  };
+
+  return (
+    <div>
+      <p>Thread ID: {threadId ?? optimisticThreadId}</p>
+      {/* Rest of component */}
+    </div>
+  );
+};
+```
+
 ### TypeScript
 
 The `useStream()` hook is friendly for apps written in TypeScript and you can specify types for the state to get better type safety and IDE support.

docs/docs/cloud/reference/cli.md

@@ -395,7 +395,7 @@ The LangGraph CLI requires a JSON configuration file that follows this [schema](
 
 === "Python"
 
-    Start LangGraph API server. For local testing, requires a LangSmith API key with access to LangGraph Platform closed beta. Requires a license key for production use.
+    Start LangGraph API server. For local testing, requires a LangSmith API key with access to LangGraph Platform. Requires a license key for production use.
 
     **Usage**
 
@@ -422,7 +422,7 @@ The LangGraph CLI requires a JSON configuration file that follows this [schema](
 
 === "JS"
 
-    Start LangGraph API server. For local testing, requires a LangSmith API key with access to LangGraph Platform closed beta. Requires a license key for production use.
+    Start LangGraph API server. For local testing, requires a LangSmith API key with access to LangGraph Platform. Requires a license key for production use.
 
     **Usage**
 

docs/docs/concepts/application_structure.md

@@ -48,7 +48,7 @@ Below are examples of directory structures for Python and JavaScript application
     │   ├── utils # utilities for your graph
     │   │   ├── __init__.py
     │   │   ├── tools.py # tools for your graph
-    │   │   ├── nodes.py # node functions for you graph
+    │   │   ├── nodes.py # node functions for your graph
     │   │   └── state.py # state definition of your graph
     │   ├── __init__.py
     │   └── agent.py # code for constructing your graph
@@ -64,7 +64,7 @@ Below are examples of directory structures for Python and JavaScript application
     ├── src # all project code lies within here
     │   ├── utils # optional utilities for your graph
     │   │   ├── tools.ts # tools for your graph
-    │   │   ├── nodes.ts # node functions for you graph
+    │   │   ├── nodes.ts # node functions for your graph
     │   │   └── state.ts # state definition of your graph
     │   └── agent.ts # code for constructing your graph
     ├── package.json # package dependencies

docs/docs/concepts/deployment_options.md

@@ -18,9 +18,9 @@ There are 4 main options for deploying with the [LangGraph Platform](langgraph_p
 
 1. [Cloud SaaS](#cloud-saas)
 
-1. [Self-Hosted Data Plane<sup>(Beta)</sup>](#self-hosted-data-plane)
+1. [Self-Hosted Data Plane](#self-hosted-data-plane)
 
-1. [Self-Hosted Control Plane<sup>(Beta)</sup>](#self-hosted-control-plane)
+1. [Self-Hosted Control Plane](#self-hosted-control-plane)
 
 1. [Standalone Container](#standalone-container)
 
@@ -50,7 +50,7 @@ For more information, please see:
 ## Self-Hosted Data Plane
 
 !!! info "Important"
-    The Self-Hosted Data Plane deployment option is currently in beta stage and requires an [Enterprise](../concepts/plans.md) plan.
+    The Self-Hosted Data Plane deployment option requires an [Enterprise](../concepts/plans.md) plan.
 
 The [Self-Hosted Data Plane](./langgraph_self_hosted_data_plane.md) deployment option is a "hybrid" model for deployment where we manage the [control plane](./langgraph_control_plane.md) in our cloud and you manage the [data plane](./langgraph_data_plane.md) in your cloud. This option provides a way to securely manage your data plane infrastructure, while offloading control plane management to us.
 
@@ -66,7 +66,7 @@ For more information, please see:
 ## Self-Hosted Control Plane
 
 !!! info "Important"
-    The Self-Hosted Control Plane deployment option is currently in beta stage and requires an [Enterprise](../concepts/plans.md) plan.
+    The Self-Hosted Control Plane deployment option requires an [Enterprise](../concepts/plans.md) plan.
 
 The [Self-Hosted Control Plane](./langgraph_self_hosted_control_plane.md) deployment option is a fully self-hosted model for deployment where you manage the [control plane](./langgraph_control_plane.md) and [data plane](./langgraph_data_plane.md) in your cloud. This option gives you full control and responsibility of the control plane and data plane infrastructure.
 

docs/docs/concepts/faq.md

@@ -47,7 +47,7 @@ LangGraph is a stateful, orchestration framework that brings added control to ag
 
 No. LangGraph Platform is proprietary software.
 
-There is a free, self-hosted version of LangGraph Platform with access to basic features. The Cloud SaaS deployment option is free while in beta, but will eventually be a paid service. We will always give ample notice before charging for a service and reward our early adopters with preferential pricing. The Self-Hosted deployment options are paid services. [Contact our sales team](https://www.langchain.com/contact-sales) to learn more.
+There is a free, self-hosted version of LangGraph Platform with access to basic features. The Cloud SaaS deployment option and the Self-Hosted deployment options are paid services. [Contact our sales team](https://www.langchain.com/contact-sales) to learn more.
 
 For more information, see our [LangGraph Platform pricing page](https://www.langchain.com/pricing-langgraph-platform).
 

docs/docs/concepts/langgraph_self_hosted_control_plane.md

@@ -3,7 +3,7 @@
 There are two versions of the self-hosted deployment: [Self-Hosted Data Plane](./deployment_options.md#self-hosted-data-plane) and [Self-Hosted Control Plane](./deployment_options.md#self-hosted-control-plane).
 
 !!! info "Important"
-    The Self-Hosted Control Plane deployment option is currently in beta stage and requires an [Enterprise](plans.md) plan.
+    The Self-Hosted Control Plane deployment option requires an [Enterprise](plans.md) plan.
 
 ## Requirements
 

docs/docs/concepts/langgraph_self_hosted_data_plane.md

@@ -8,7 +8,7 @@ search:
 There are two versions of the self-hosted deployment: [Self-Hosted Data Plane](./deployment_options.md#self-hosted-data-plane) and [Self-Hosted Control Plane](./deployment_options.md#self-hosted-control-plane).
 
 !!! info "Important"
-    The Self-Hosted Data Plane deployment option is currently in beta stage and requires an [Enterprise](plans.md) plan.
+    The Self-Hosted Data Plane deployment option requires an [Enterprise](plans.md) plan.
 
 ## Requirements
 

docs/mkdocs.yml

@@ -289,6 +289,7 @@ nav:
     - Case studies: adopters.md
     - concepts/faq.md
     - llms.txt: llms-txt-overview.md
+    - LangChain Forum: https://forum.langchain.com/
     - Troubleshooting:
         - Errors:
           - troubleshooting/errors/index.md

libs/checkpoint-postgres/pyproject.toml

@@ -12,7 +12,7 @@ readme = "README.md"
 license = "MIT"
 license-files = ['LICENSE']
 dependencies = [
-  "langgraph-checkpoint>=2.0.21",
+  "langgraph-checkpoint>=2.0.21,<3.0.0",
   "orjson>=3.10.1",
   "psycopg>=3.2.0",
   "psycopg-pool>=3.2.0",

libs/checkpoint-sqlite/pyproject.toml

@@ -12,7 +12,7 @@ readme = "README.md"
 license = "MIT"
 license-files = ['LICENSE']
 dependencies = [
-    "langgraph-checkpoint>=2.0.21",
+    "langgraph-checkpoint>=2.0.21,<3.0.0",
     "aiosqlite>=0.20",
     "sqlite-vec>=0.1.6",
 ]

libs/cli/langgraph_cli/cli.py

@@ -208,7 +208,7 @@ def up(
 ):
     click.secho("Starting LangGraph API server...", fg="green")
     click.secho(
-        """For local dev, requires env var LANGSMITH_API_KEY with access to LangGraph Platform closed beta.
+        """For local dev, requires env var LANGSMITH_API_KEY with access to LangGraph Platform.
 For production use, requires a license key in env var LANGGRAPH_CLOUD_LICENSE_KEY.""",
     )
     with Runner() as runner, Progress(message="Pulling...") as set:

libs/cli/pyproject.toml

@@ -18,8 +18,8 @@ dependencies = [
 
 [project.optional-dependencies]
 inmem = [
-    "langgraph-api>=0.2.67 ; python_version >= '3.11'",
-    "langgraph-runtime-inmem>=0.3.0 ; python_version >= '3.11'",
+    "langgraph-api>=0.2.67,<0.3.0 ; python_version >= '3.11'",
+    "langgraph-runtime-inmem>=0.3.0,<0.4.0 ; python_version >= '3.11'",
     "python-dotenv>=0.8.0",
 ]
 

libs/cli/uv.lock

@@ -530,8 +530,8 @@ dev = [
 [package.metadata]
 requires-dist = [
     { name = "click", specifier = ">=8.1.7" },
-    { name = "langgraph-api", marker = "python_full_version >= '3.11' and extra == 'inmem'", specifier = ">=0.2.67" },
-    { name = "langgraph-runtime-inmem", marker = "python_full_version >= '3.11' and extra == 'inmem'", specifier = ">=0.3.0" },
+    { name = "langgraph-api", marker = "python_full_version >= '3.11' and extra == 'inmem'", specifier = ">=0.2.67,<0.3.0" },
+    { name = "langgraph-runtime-inmem", marker = "python_full_version >= '3.11' and extra == 'inmem'", specifier = ">=0.3.0,<0.4.0" },
     { name = "langgraph-sdk", marker = "python_full_version >= '3.11'", specifier = ">=0.1.0" },
     { name = "python-dotenv", marker = "extra == 'inmem'", specifier = ">=0.8.0" },
 ]

libs/langgraph/README.md

@@ -63,7 +63,7 @@ LangGraph provides low-level supporting infrastructure for *any* long-running, s
 While LangGraph can be used standalone, it also integrates seamlessly with any LangChain product, giving developers a full suite of tools for building agents. To improve your LLM application development, pair LangGraph with:
 
 - [LangSmith](http://www.langchain.com/langsmith) — Helpful for agent evals and observability. Debug poor-performing LLM app runs, evaluate agent trajectories, gain visibility in production, and improve performance over time.
-- [LangGraph Platform](https://langchain-ai.github.io/langgraph/concepts/#langgraph-platform) — Deploy and scale agents effortlessly with a purpose-built deployment platform for long running, stateful workflows. Discover, reuse, configure, and share agents across teams — and iterate quickly with visual prototyping in [LangGraph Studio](https://langchain-ai.github.io/langgraph/concepts/langgraph_studio/).
+- [LangGraph Platform](https://langchain-ai.github.io/langgraph/concepts/langgraph_platform/) — Deploy and scale agents effortlessly with a purpose-built deployment platform for long running, stateful workflows. Discover, reuse, configure, and share agents across teams — and iterate quickly with visual prototyping in [LangGraph Studio](https://langchain-ai.github.io/langgraph/concepts/langgraph_studio/).
 - [LangChain](https://python.langchain.com/docs/introduction/) – Provides integrations and composable components to streamline LLM application development.
 
 > [!NOTE]

libs/langgraph/pyproject.toml

@@ -13,11 +13,12 @@ license = "MIT"
 license-files = ['LICENSE']
 dependencies = [
     "langchain-core>=0.1",
-    "langgraph-checkpoint>=2.1.0",
-    "langgraph-sdk>=0.1.42",
-    "langgraph-prebuilt>=0.5.0",
+    "langgraph-checkpoint>=2.1.0,<3.0.0",
+    "langgraph-sdk>=0.1.42,<0.2.0",
+    "langgraph-prebuilt>=0.5.0,<0.6.0",
     "xxhash>=3.5.0",
-    "pydantic>=2.7.4",
+    "pydantic>=2.7.4; python_version < '3.13'",
+    "pydantic>=2.0.0; python_version >= '3.13'",
 ]
 
 [project.urls]

libs/langgraph/uv.lock

@@ -1246,7 +1246,8 @@ requires-dist = [
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-prebuilt", editable = "../prebuilt" },
     { name = "langgraph-sdk", editable = "../sdk-py" },
-    { name = "pydantic", specifier = ">=2.7.4" },
+    { name = "pydantic", marker = "python_full_version < '3.13'", specifier = ">=2.7.4" },
+    { name = "pydantic", marker = "python_full_version >= '3.13'", specifier = ">=2.0.0" },
     { name = "xxhash", specifier = ">=3.5.0" },
 ]
 

libs/prebuilt/pyproject.toml

@@ -12,7 +12,7 @@ readme = "README.md"
 license = "MIT"
 license-files = ['LICENSE']
 dependencies = [
-    "langgraph-checkpoint>=2.1.0",
+    "langgraph-checkpoint>=2.1.0,<3.0.0",
     "langchain-core>=0.3.67",
 ]
 

libs/prebuilt/uv.lock

@@ -2,7 +2,8 @@ version = 1
 revision = 2
 requires-python = ">=3.9"
 resolution-markers = [
-    "python_full_version >= '3.12.4'",
+    "python_full_version >= '3.13'",
+    "python_full_version >= '3.12.4' and python_full_version < '3.13'",
     "python_full_version < '3.12.4'",
 ]
 
@@ -337,7 +338,8 @@ requires-dist = [
     { name = "langgraph-checkpoint", editable = "../checkpoint" },
     { name = "langgraph-prebuilt", editable = "." },
     { name = "langgraph-sdk", editable = "../sdk-py" },
-    { name = "pydantic", specifier = ">=2.7.4" },
+    { name = "pydantic", marker = "python_full_version < '3.13'", specifier = ">=2.7.4" },
+    { name = "pydantic", marker = "python_full_version >= '3.13'", specifier = ">=2.0.0" },
     { name = "xxhash", specifier = ">=3.5.0" },
 ]
 

libs/sdk-js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@langchain/langgraph-sdk",
-  "version": "0.0.87",
+  "version": "0.0.89",
   "description": "Client library for interacting with the LangGraph API",
   "type": "module",
   "packageManager": "yarn@1.22.19",

libs/sdk-js/src/client.ts

@@ -1014,8 +1014,8 @@ export class RunsClient<
     const stream: ReadableStream<{ event: any; data: any }> = (
       response.body || new ReadableStream({ start: (ctrl) => ctrl.close() })
     )
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     yield* IterableReadableStream.fromReadableStream(stream);
   }
@@ -1318,8 +1318,8 @@ export class RunsClient<
     const stream: ReadableStream<{ event: string; data: any }> = (
       response.body || new ReadableStream({ start: (ctrl) => ctrl.close() })
     )
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     yield* IterableReadableStream.fromReadableStream(stream);
   }

libs/sdk-js/src/react/stream.tsx

@@ -31,7 +31,7 @@ import type {
 } from "../types.stream.js";
 
 import {
-  type MutableRefObject,
+  type RefObject,
   useCallback,
   useEffect,
   useMemo,
@@ -316,8 +316,8 @@ function fetchHistory<StateType extends Record<string, unknown>>(
 function useThreadHistory<StateType extends Record<string, unknown>>(
   threadId: string | undefined | null,
   client: Client,
-  clearCallbackRef: MutableRefObject<(() => void) | undefined>,
-  submittingRef: MutableRefObject<boolean>,
+  clearCallbackRef: RefObject<(() => void) | undefined>,
+  submittingRef: RefObject<boolean>,
 ) {
   const [history, setHistory] = useState<ThreadState<StateType>[]>([]);
 
@@ -511,6 +511,31 @@ export interface UseStreamOptions<
    */
   onDebugEvent?: (data: DebugStreamEvent["data"]) => void;
 
+  /**
+   * Callback that is called when the stream is stopped by the user.
+   * Provides a mutate function to update the stream state immediately
+   * without requiring a server roundtrip.
+   *
+   * @example
+   * ```typescript
+   * onStop: ({ mutate }) => {
+   *   mutate((prev) => ({
+   *     ...prev,
+   *     ui: prev.ui?.map(component =>
+   *       component.props.isLoading
+   *         ? { ...component, props: { ...component.props, stopped: true, isLoading: false }}
+   *         : component
+   *     )
+   *   }));
+   * }
+   * ```
+   */
+  onStop?: (options: {
+    mutate: (
+      update: Partial<StateType> | ((prev: StateType) => Partial<StateType>),
+    ) => void;
+  }) => void;
+
   /**
    * The ID of the thread to fetch history and current values from.
    */
@@ -523,6 +548,17 @@ export interface UseStreamOptions<
 
   /** Will reconnect the stream on mount */
   reconnectOnMount?: boolean | (() => RunMetadataStorage);
+
+  /**
+   * Initial values to display immediately when loading a thread.
+   * Useful for displaying cached thread data while official history loads.
+   * These values will be replaced when official thread data is fetched.
+   *
+   * Note: UI components from initialValues will render immediately if they're
+   * predefined in LoadExternalComponent's components prop, providing instant
+   * cached UI display without server fetches.
+   */
+  initialValues?: StateType | null;
 }
 
 interface RunMetadataStorage {
@@ -656,6 +692,61 @@ interface SubmitOptions<
    */
   streamSubgraphs?: boolean;
   streamResumable?: boolean;
+  /**
+   * The ID to use when creating a new thread. When provided, this ID will be used
+   * for thread creation when threadId is `null` or `undefined`.
+   * This enables optimistic UI updates where you know the thread ID
+   * before the thread is actually created.
+   */
+  threadId?: string;
+}
+
+function useStreamValuesState<StateType extends Record<string, unknown>>() {
+  type Kind = "stream" | "stop";
+  type Values = StateType | null;
+  type Update = Values | ((prev: Values, kind?: Kind) => Values);
+  type Mutate = Partial<StateType> | ((prev: StateType) => Partial<StateType>);
+
+  const [values, setValues] = useState<[values: StateType, kind: Kind] | null>(
+    null,
+  );
+
+  const setStreamValues = useCallback(
+    (values: Update, kind: Kind = "stream") => {
+      if (typeof values === "function") {
+        setValues((prevTuple) => {
+          const [prevValues, prevKind] = prevTuple ?? [null, "stream"];
+          const next = values(prevValues, prevKind);
+
+          if (next == null) return null;
+          return [next, kind] as [StateType, Kind];
+        });
+
+        return;
+      }
+
+      if (values == null) setValues(null);
+      setValues([values, kind] as [StateType, Kind]);
+    },
+    [],
+  );
+
+  const mutate = useCallback(
+    (kind: Kind, serverValues: StateType) => (update: Mutate) => {
+      setStreamValues((clientValues) => {
+        const prev = { ...serverValues, ...clientValues };
+        const next = typeof update === "function" ? update(prev) : update;
+        return { ...prev, ...next };
+      }, kind);
+    },
+    [setStreamValues],
+  );
+
+  return [values?.[0] ?? null, setStreamValues, mutate] as [
+    Values,
+    (update: Update, kind?: Kind) => void,
+    (kind: Kind, serverValues: StateType) => (update: Mutate) => void,
+  ];
 }
 
 export function useStream<
@@ -721,7 +812,8 @@ export function useStream<
   const [isLoading, setIsLoading] = useState(false);
 
   const [streamError, setStreamError] = useState<unknown>(undefined);
-  const [streamValues, setStreamValues] = useState<StateType | null>(null);
+  const [streamValues, setStreamValues, getMutateFn] =
+    useStreamValuesState<StateType>();
 
   const messageManagerRef = useRef(new MessageTupleManager());
   const submittingRef = useRef(false);
@@ -792,7 +884,9 @@ export function useStream<
   );
 
   const threadHead: ThreadState<StateType> | undefined = flatHistory.at(-1);
-  const historyValues = threadHead?.values ?? ({} as StateType);
+  const historyValues =
+    threadHead?.values ?? options.initialValues ?? ({} as StateType);
+
   const historyError = (() => {
     const error = threadHead?.tasks?.at(-1)?.error;
     if (error == null) return undefined;
@@ -857,6 +951,8 @@ export function useStream<
       if (runId) client.runs.cancel(threadId, runId);
       runMetadataStorage.removeItem(`lg:stream:${threadId}`);
     }
+
+    options?.onStop?.({ mutate: getMutateFn("stop", historyValues) });
   };
 
   async function consumeStream(
@@ -889,15 +985,7 @@ export function useStream<
         if (event === "updates") options.onUpdateEvent?.(data);
         if (event === "custom")
           options.onCustomEvent?.(data, {
-            mutate: (update) =>
-              setStreamValues((prev) => {
-                // should not happen
-                if (prev == null) return prev;
-                return {
-                  ...prev,
-                  ...(typeof update === "function" ? update(prev) : update),
-                };
-              }),
+            mutate: getMutateFn("stream", historyValues),
           });
         if (event === "metadata") options.onMetadataEvent?.(data);
         if (event === "events") options.onLangChainEvent?.(data);
@@ -939,8 +1027,11 @@ export function useStream<
 
       // TODO: stream created checkpoints to avoid an unnecessary network request
       const result = await run.onSuccess();
-
-      setStreamValues(null);
+      setStreamValues((values, kind) => {
+        // Do not clear out the user values set on `stop`.
+        if (kind === "stop") return values;
+        return null;
+      });
       if (streamError != null) throw streamError;
 
       const lastHead = result.at(0);
@@ -1003,26 +1094,24 @@ export function useStream<
 
       if (newPath != null) setBranch(newPath ?? "");
 
-      // Assumption: we're setting the initial value
-      // Used for instant feedback
       setStreamValues(() => {
-        const values = { ...historyValues };
-
         if (submitOptions?.optimisticValues != null) {
           return {
-            ...values,
+            ...historyValues,
             ...(typeof submitOptions.optimisticValues === "function"
-              ? submitOptions.optimisticValues(values)
+              ? submitOptions.optimisticValues(historyValues)
               : submitOptions.optimisticValues),
           };
         }
 
-        return values;
+        return { ...historyValues };
       });
 
       let usableThreadId = threadId;
       if (!usableThreadId) {
-        const thread = await client.threads.create();
+        const thread = await client.threads.create({
+          threadId: submitOptions?.threadId,
+        });
         onThreadId(thread.thread_id);
         usableThreadId = thread.thread_id;
       }

libs/sdk-js/src/tests/sse.test.ts

@@ -20,7 +20,7 @@ describe("BytesLineDecoder", () => {
 
   test("handles single line with newline", async () => {
     const input = createStream([textEncoder.encode("hello\n")]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(1);
@@ -29,7 +29,7 @@ describe("BytesLineDecoder", () => {
 
   test("handles multiple lines", async () => {
     const input = createStream([textEncoder.encode("line1\nline2\nline3\n")]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(3);
@@ -44,7 +44,7 @@ describe("BytesLineDecoder", () => {
       textEncoder.encode("ne1\nli"),
       textEncoder.encode("ne2\n"),
     ]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(2);
@@ -54,7 +54,7 @@ describe("BytesLineDecoder", () => {
 
   test("handles CR LF line endings", async () => {
     const input = createStream([textEncoder.encode("line1\r\nline2\r\n")]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(2);
@@ -67,7 +67,7 @@ describe("BytesLineDecoder", () => {
       textEncoder.encode("line1\r"),
       textEncoder.encode("\nline2\r\n"),
     ]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(2);
@@ -77,7 +77,7 @@ describe("BytesLineDecoder", () => {
 
   test("handles stale line", async () => {
     const input = createStream([textEncoder.encode("hello")]);
-    const decoded = input.pipeThrough(new BytesLineDecoder());
+    const decoded = input.pipeThrough(BytesLineDecoder());
     const results = await gather(decoded);
 
     expect(results.length).toBe(1);
@@ -99,8 +99,8 @@ describe("SSEDecoder", () => {
       "\n",
     ]);
     const decoded = input
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     const results = await gather(decoded);
     expect(results.length).toBe(1);
@@ -117,8 +117,8 @@ describe("SSEDecoder", () => {
       'data: {"message": "hello"}\n',
     ]);
     const decoded = input
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     const results = await gather(decoded);
     expect(results.length).toBe(1);
@@ -138,8 +138,8 @@ describe("SSEDecoder", () => {
       "\n",
     ]);
     const decoded = input
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     const results = await gather(decoded);
     expect(results.length).toBe(2);
@@ -156,8 +156,8 @@ describe("SSEDecoder", () => {
   test("end event without data", async () => {
     const input = createStream(["event: test\n"]);
     const decoded = input
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     const results = await gather(decoded);
     expect(results.length).toBe(1);
@@ -170,8 +170,8 @@ describe("SSEDecoder", () => {
   test("end event without newline", async () => {
     const input = createStream(["event: end"]);
     const decoded = input
-      .pipeThrough(new BytesLineDecoder())
-      .pipeThrough(new SSEDecoder());
+      .pipeThrough(BytesLineDecoder())
+      .pipeThrough(SSEDecoder());
 
     const results = await gather(decoded);
     expect(results.length).toBe(1);

libs/sdk-js/src/tests/stream.test.tsx

@@ -6,15 +6,15 @@ import { userEvent } from "@testing-library/user-event";
 import { setupServer } from "msw/node";
 import { http } from "msw";
 import { useStream } from "../react/stream.js";
+import type { Message } from "../types.messages.js";
 
 import { StateGraph, MessagesAnnotation, START } from "@langchain/langgraph";
 import { MemorySaver } from "@langchain/langgraph-checkpoint";
 import { FakeStreamingChatModel } from "@langchain/core/utils/testing";
-import { AIMessage, BaseMessageLike } from "@langchain/core/messages";
-
-import { Hono } from "hono";
-import { logger } from "hono/logger";
+import { AIMessage } from "@langchain/core/messages";
 import { createEmbedServer } from "@langchain/langgraph-api/experimental/embed";
+import { randomUUID } from "node:crypto";
+import { useState } from "react";
 
 const threads = (() => {
   const THREADS: Record<
@@ -40,17 +40,14 @@ const checkpointer = new MemorySaver();
 
 const model = new FakeStreamingChatModel({ responses: [new AIMessage("Hey")] });
 const agent = new StateGraph(MessagesAnnotation)
-  .addNode("agent", async (state: { messages: BaseMessageLike[] }) => {
+  .addNode("agent", async (state: { messages: Message[] }) => {
     const response = await model.invoke(state.messages);
     return { messages: [response] };
   })
   .addEdge(START, "agent")
   .compile();
 
-const app = new Hono();
-app.use(logger());
-app.route("/", createEmbedServer({ graph: { agent }, checkpointer, threads }));
-
+const app = createEmbedServer({ graph: { agent }, checkpointer, threads });
 const server = setupServer(http.all("*", (ctx) => app.fetch(ctx.request)));
 
 function TestChatComponent() {
@@ -138,4 +135,316 @@ describe("useStream", () => {
       expect(screen.getByTestId("loading")).toHaveTextContent("Not loading");
     });
   });
+
+  it("displays initial values immediately and clears them when submitting", async () => {
+    const user = userEvent.setup();
+
+    function TestCachedComponent() {
+      const { messages, values, submit } = useStream<{
+        messages: Message[];
+      }>({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        initialValues: {
+          messages: [
+            { id: "cached-1", type: "human", content: "Cached user message" },
+            { id: "cached-2", type: "ai", content: "Cached AI response" },
+          ],
+        },
+      });
+
+      return (
+        <div>
+          <div data-testid="messages">
+            {messages.map((msg, i) => (
+              <div
+                key={msg.id ?? i}
+                data-testid={
+                  msg.id?.includes("cached")
+                    ? `message-cached-${i}`
+                    : `message-${i}`
+                }
+              >
+                {typeof msg.content === "string"
+                  ? msg.content
+                  : JSON.stringify(msg.content)}
+              </div>
+            ))}
+          </div>
+          <div data-testid="values">{JSON.stringify(values)}</div>
+          <button
+            data-testid="submit"
+            onClick={() =>
+              submit({ messages: [{ content: "Hello", type: "human" }] })
+            }
+          >
+            Submit
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestCachedComponent />);
+
+    // Should immediately show cached messages
+    expect(screen.getByTestId("message-cached-0")).toHaveTextContent(
+      "Cached user message",
+    );
+    expect(screen.getByTestId("message-cached-1")).toHaveTextContent(
+      "Cached AI response",
+    );
+
+    // Values should include initial values
+    expect(screen.getByTestId("values")).toHaveTextContent(
+      "Cached user message",
+    );
+
+    // Submitting should clear out the cached messages
+    await user.click(screen.getByTestId("submit"));
+
+    // Wait for messages to appear
+    await waitFor(() => {
+      expect(screen.getByTestId("message-0")).toHaveTextContent("Hello");
+      expect(screen.getByTestId("message-1")).toHaveTextContent("Hey");
+    });
+  });
+
+  it("accepts newThreadId option without errors", async () => {
+    const user = userEvent.setup();
+
+    const spy = vi.fn();
+    const predeterminedThreadId = randomUUID();
+
+    // Test that newThreadId option can be passed without causing errors
+    function TestNewThreadComponent() {
+      const stream = useStream<{ messages: Message[] }>({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        threadId: null, // Start with no thread
+        onThreadId: spy, // Mock callback
+      });
+
+      return (
+        <div>
+          <div data-testid="loading">
+            {stream.isLoading ? "Loading..." : "Not loading"}
+          </div>
+          <div data-testid="thread-id">
+            {stream.client ? "Client ready" : "No client"}
+          </div>
+          <button
+            data-testid="submit"
+            onClick={() =>
+              stream.submit({}, { threadId: predeterminedThreadId })
+            }
+          >
+            Submit
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestNewThreadComponent />);
+
+    // Should render without errors
+    expect(screen.getByTestId("loading")).toHaveTextContent("Not loading");
+    expect(screen.getByTestId("thread-id")).toHaveTextContent("Client ready");
+
+    await user.click(screen.getByTestId("submit"));
+    expect(spy).toHaveBeenCalledWith(predeterminedThreadId);
+    expect(await threads.get(predeterminedThreadId)).toEqual({
+      thread_id: predeterminedThreadId,
+      metadata: {
+        graph_id: "agent",
+        assistant_id: "agent",
+      },
+    });
+  });
+
+  it("onStop callback is called when stop is called", async () => {
+    const user = userEvent.setup();
+    const onStopCallback = vi.fn();
+
+    function TestComponent() {
+      const { submit, stop } = useStream({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        onStop: onStopCallback,
+      });
+
+      return (
+        <div>
+          <button data-testid="submit" onClick={() => submit({})}>
+            Send
+          </button>
+          <button data-testid="stop" onClick={stop}>
+            Stop
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestComponent />);
+
+    // Start a stream and stop it
+    await user.click(screen.getByTestId("submit"));
+    await user.click(screen.getByTestId("stop"));
+
+    // Verify onStop was called with mutate function
+    expect(onStopCallback).toHaveBeenCalledTimes(1);
+    expect(onStopCallback).toHaveBeenCalledWith(
+      expect.objectContaining({
+        mutate: expect.any(Function),
+      }),
+    );
+  });
+
+  it("onStop mutate function updates stream values immediately", async () => {
+    const user = userEvent.setup();
+
+    function TestComponent() {
+      const [stopped, setStopped] = useState(false);
+      const { submit, stop, messages } = useStream<{ messages: Message[] }>({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        onStop: ({ mutate }) => {
+          setStopped(true);
+          mutate((prev) => ({
+            ...prev,
+            messages: [
+              ...(prev.messages ?? []),
+              { type: "ai", content: "Stream stopped" },
+            ],
+          }));
+        },
+      });
+
+      return (
+        <div>
+          <div data-testid="stopped-status">
+            {stopped ? "Stopped" : "Not stopped"}
+          </div>
+          <div data-testid="messages">
+            {messages.map((msg, i) => (
+              <div key={msg.id ?? i} data-testid={`message-${i}`}>
+                {typeof msg.content === "string"
+                  ? msg.content
+                  : JSON.stringify(msg.content)}
+              </div>
+            ))}
+          </div>
+          <button data-testid="submit" onClick={() => submit({})}>
+            Send
+          </button>
+          <button data-testid="stop" onClick={stop}>
+            Stop
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestComponent />);
+
+    // Initial state
+    expect(screen.getByTestId("stopped-status")).toHaveTextContent(
+      "Not stopped",
+    );
+
+    // Start and stop stream
+    await user.click(screen.getByTestId("submit"));
+    await user.click(screen.getByTestId("stop"));
+
+    // Verify state was updated immediately
+    await waitFor(() => {
+      expect(screen.getByTestId("stopped-status")).toHaveTextContent("Stopped");
+      expect(screen.getByTestId("message-0")).toHaveTextContent(
+        "Stream stopped",
+      );
+    });
+  });
+
+  it("onStop handles functional updates correctly", async () => {
+    const user = userEvent.setup();
+
+    function TestComponent() {
+      const { submit, stop, values } = useStream({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        initialValues: {
+          counter: 5,
+          items: ["item1", "item2"],
+        },
+        onStop: ({ mutate }) => {
+          mutate((prev: any) => ({
+            ...prev,
+            counter: (prev.counter || 0) + 10,
+            items: [...(prev.items || []), "stopped"],
+          }));
+        },
+      });
+
+      return (
+        <div>
+          <div data-testid="counter">{(values as any).counter}</div>
+          <div data-testid="items">{(values as any).items?.join(", ")}</div>
+          <button data-testid="submit" onClick={() => submit({})}>
+            Send
+          </button>
+          <button data-testid="stop" onClick={stop}>
+            Stop
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestComponent />);
+
+    // Initial state
+    expect(screen.getByTestId("counter")).toHaveTextContent("5");
+    expect(screen.getByTestId("items")).toHaveTextContent("item1, item2");
+
+    // Start and stop stream
+    await user.click(screen.getByTestId("submit"));
+    await user.click(screen.getByTestId("stop"));
+
+    // Verify functional update was applied correctly
+    await waitFor(() => {
+      expect(screen.getByTestId("counter")).toHaveTextContent("15");
+      expect(screen.getByTestId("items")).toHaveTextContent(
+        "item1, item2, stopped",
+      );
+    });
+  });
+
+  it("onStop is not called when stream completes naturally", async () => {
+    const user = userEvent.setup();
+
+    const onStopCallback = vi.fn();
+
+    function TestComponent() {
+      const { submit } = useStream({
+        assistantId: "agent",
+        apiKey: "test-api-key",
+        onStop: onStopCallback,
+      });
+
+      return (
+        <div>
+          <button data-testid="submit" onClick={() => submit({})}>
+            Send
+          </button>
+        </div>
+      );
+    }
+
+    render(<TestComponent />);
+
+    // Start a stream and let it complete naturally
+    await user.click(screen.getByTestId("submit"));
+
+    // Wait for stream to complete naturally
+    await waitFor(() => {
+      expect(onStopCallback).not.toHaveBeenCalled();
+    });
+  });
 });

libs/sdk-js/src/types.messages.ts

@@ -13,16 +13,22 @@ type MessageContent = string | MessageContentComplex[];
  */
 type MessageAdditionalKwargs = Record<string, unknown>;
 
-export type HumanMessage = {
-  type: "human";
-  id?: string | undefined;
+type BaseMessage = {
+  additional_kwargs?: MessageAdditionalKwargs | undefined;
   content: MessageContent;
+  id?: string | undefined;
+  name?: string | undefined;
+  response_metadata?: Record<string, unknown> | undefined;
 };
 
-export type AIMessage = {
+export type HumanMessage = BaseMessage & {
+  type: "human";
+  example?: boolean | undefined;
+};
+
+export type AIMessage = BaseMessage & {
   type: "ai";
-  id?: string | undefined;
-  content: MessageContent;
+  example?: boolean | undefined;
   tool_calls?:
     | {
         name: string;
@@ -57,19 +63,12 @@ export type AIMessage = {
           | undefined;
       }
     | undefined;
-  additional_kwargs?: MessageAdditionalKwargs | undefined;
-  response_metadata?: Record<string, unknown> | undefined;
 };
 
-export type ToolMessage = {
+export type ToolMessage = BaseMessage & {
   type: "tool";
-  name?: string | undefined;
-  id?: string | undefined;
-  content: MessageContent;
   status?: "error" | "success" | undefined;
   tool_call_id: string;
-  additional_kwargs?: MessageAdditionalKwargs | undefined;
-  response_metadata?: Record<string, unknown> | undefined;
   /**
    * Artifact of the Tool execution which is not meant to be sent to the model.
    *
@@ -81,22 +80,16 @@ export type ToolMessage = {
   artifact?: any;
 };
 
-export type SystemMessage = {
+export type SystemMessage = BaseMessage & {
   type: "system";
-  id?: string | undefined;
-  content: MessageContent;
 };
 
-export type FunctionMessage = {
+export type FunctionMessage = BaseMessage & {
   type: "function";
-  id?: string | undefined;
-  content: MessageContent;
 };
 
-export type RemoveMessage = {
+export type RemoveMessage = BaseMessage & {
   type: "remove";
-  id: string;
-  content: MessageContent;
 };
 
 export type Message =

libs/sdk-js/src/utils/sse.ts

@@ -6,90 +6,88 @@ const SPACE = " ".charCodeAt(0);
 
 const TRAILING_NEWLINE = [CR, LF];
 
-export class BytesLineDecoder extends TransformStream<Uint8Array, Uint8Array> {
-  constructor() {
-    let buffer: Uint8Array[] = [];
-    let trailingCr = false;
+export function BytesLineDecoder() {
+  let buffer: Uint8Array[] = [];
+  let trailingCr = false;
 
-    super({
-      start() {
-        buffer = [];
+  return new TransformStream<Uint8Array, Uint8Array>({
+    start() {
+      buffer = [];
+      trailingCr = false;
+    },
+
+    transform(chunk, controller) {
+      // See https://docs.python.org/3/glossary.html#term-universal-newlines
+      let text = chunk;
+
+      // Handle trailing CR from previous chunk
+      if (trailingCr) {
+        text = joinArrays([[CR], text]);
         trailingCr = false;
-      },
+      }
 
-      transform(chunk, controller) {
-        // See https://docs.python.org/3/glossary.html#term-universal-newlines
-        let text = chunk;
+      // Check for trailing CR in current chunk
+      if (text.length > 0 && text.at(-1) === CR) {
+        trailingCr = true;
+        text = text.subarray(0, -1);
+      }
 
-        // Handle trailing CR from previous chunk
-        if (trailingCr) {
-          text = joinArrays([[CR], text]);
-          trailingCr = false;
-        }
+      if (!text.length) return;
+      const trailingNewline = TRAILING_NEWLINE.includes(text.at(-1)!);
 
-        // Check for trailing CR in current chunk
-        if (text.length > 0 && text.at(-1) === CR) {
-          trailingCr = true;
-          text = text.subarray(0, -1);
-        }
+      const lastIdx = text.length - 1;
+      const { lines } = text.reduce<{ lines: Uint8Array[]; from: number }>(
+        (acc, cur, idx) => {
+          if (acc.from > idx) return acc;
 
-        if (!text.length) return;
-        const trailingNewline = TRAILING_NEWLINE.includes(text.at(-1)!);
-
-        const lastIdx = text.length - 1;
-        const { lines } = text.reduce<{ lines: Uint8Array[]; from: number }>(
-          (acc, cur, idx) => {
-            if (acc.from > idx) return acc;
-
-            if (cur === CR || cur === LF) {
-              acc.lines.push(text.subarray(acc.from, idx));
-              if (cur === CR && text[idx + 1] === LF) {
-                acc.from = idx + 2;
-              } else {
-                acc.from = idx + 1;
-              }
+          if (cur === CR || cur === LF) {
+            acc.lines.push(text.subarray(acc.from, idx));
+            if (cur === CR && text[idx + 1] === LF) {
+              acc.from = idx + 2;
+            } else {
+              acc.from = idx + 1;
             }
+          }
 
-            if (idx === lastIdx && acc.from <= lastIdx) {
-              acc.lines.push(text.subarray(acc.from));
-            }
+          if (idx === lastIdx && acc.from <= lastIdx) {
+            acc.lines.push(text.subarray(acc.from));
+          }
 
-            return acc;
-          },
-          { lines: [], from: 0 },
-        );
+          return acc;
+        },
+        { lines: [], from: 0 },
+      );
 
-        if (lines.length === 1 && !trailingNewline) {
-          buffer.push(lines[0]);
-          return;
-        }
+      if (lines.length === 1 && !trailingNewline) {
+        buffer.push(lines[0]);
+        return;
+      }
 
-        if (buffer.length) {
-          // Include existing buffer in first line
-          buffer.push(lines[0]);
-          lines[0] = joinArrays(buffer);
-          buffer = [];
-        }
+      if (buffer.length) {
+        // Include existing buffer in first line
+        buffer.push(lines[0]);
+        lines[0] = joinArrays(buffer);
+        buffer = [];
+      }
 
-        if (!trailingNewline) {
-          // If the last segment is not newline terminated,
-          // buffer it for the next chunk
-          if (lines.length) buffer = [lines.pop()!];
-        }
+      if (!trailingNewline) {
+        // If the last segment is not newline terminated,
+        // buffer it for the next chunk
+        if (lines.length) buffer = [lines.pop()!];
+      }
 
-        // Enqueue complete lines
-        for (const line of lines) {
-          controller.enqueue(line);
-        }
-      },
+      // Enqueue complete lines
+      for (const line of lines) {
+        controller.enqueue(line);
+      }
+    },
 
-      flush(controller) {
-        if (buffer.length) {
-          controller.enqueue(joinArrays(buffer));
-        }
-      },
-    });
-  }
+    flush(controller) {
+      if (buffer.length) {
+        controller.enqueue(joinArrays(buffer));
+      }
+    },
+  });
 }
 
 interface StreamPart {
@@ -98,69 +96,67 @@ interface StreamPart {
   data: unknown;
 }
 
-export class SSEDecoder extends TransformStream<Uint8Array, StreamPart> {
-  constructor() {
-    let event = "";
-    let data: Uint8Array[] = [];
-    let lastEventId = "";
-    let retry: number | null = null;
+export function SSEDecoder() {
+  let event = "";
+  let data: Uint8Array[] = [];
+  let lastEventId = "";
+  let retry: number | null = null;
 
-    const decoder = new TextDecoder();
+  const decoder = new TextDecoder();
 
-    super({
-      transform(chunk, controller) {
-        // Handle empty line case
-        if (!chunk.length) {
-          if (!event && !data.length && !lastEventId && retry == null) return;
+  return new TransformStream<Uint8Array, StreamPart>({
+    transform(chunk, controller) {
+      // Handle empty line case
+      if (!chunk.length) {
+        if (!event && !data.length && !lastEventId && retry == null) return;
 
-          const sse = {
-            id: lastEventId || undefined,
-            event,
-            data: data.length ? decodeArraysToJson(decoder, data) : null,
-          };
+        const sse = {
+          id: lastEventId || undefined,
+          event,
+          data: data.length ? decodeArraysToJson(decoder, data) : null,
+        };
 
-          // NOTE: as per the SSE spec, do not reset lastEventId
-          event = "";
-          data = [];
-          retry = null;
+        // NOTE: as per the SSE spec, do not reset lastEventId
+        event = "";
+        data = [];
+        retry = null;
 
-          controller.enqueue(sse);
-          return;
-        }
+        controller.enqueue(sse);
+        return;
+      }
 
-        // Ignore comments
-        if (chunk[0] === COLON) return;
+      // Ignore comments
+      if (chunk[0] === COLON) return;
 
-        const sepIdx = chunk.indexOf(COLON);
-        if (sepIdx === -1) return;
+      const sepIdx = chunk.indexOf(COLON);
+      if (sepIdx === -1) return;
 
-        const fieldName = decoder.decode(chunk.subarray(0, sepIdx));
-        let value = chunk.subarray(sepIdx + 1);
-        if (value[0] === SPACE) value = value.subarray(1);
+      const fieldName = decoder.decode(chunk.subarray(0, sepIdx));
+      let value = chunk.subarray(sepIdx + 1);
+      if (value[0] === SPACE) value = value.subarray(1);
 
-        if (fieldName === "event") {
-          event = decoder.decode(value);
-        } else if (fieldName === "data") {
-          data.push(value);
-        } else if (fieldName === "id") {
-          if (value.indexOf(NULL) === -1) lastEventId = decoder.decode(value);
-        } else if (fieldName === "retry") {
-          const retryNum = Number.parseInt(decoder.decode(value));
-          if (!Number.isNaN(retryNum)) retry = retryNum;
-        }
-      },
+      if (fieldName === "event") {
+        event = decoder.decode(value);
+      } else if (fieldName === "data") {
+        data.push(value);
+      } else if (fieldName === "id") {
+        if (value.indexOf(NULL) === -1) lastEventId = decoder.decode(value);
+      } else if (fieldName === "retry") {
+        const retryNum = Number.parseInt(decoder.decode(value));
+        if (!Number.isNaN(retryNum)) retry = retryNum;
+      }
+    },
 
-      flush(controller) {
-        if (event) {
-          controller.enqueue({
-            id: lastEventId || undefined,
-            event,
-            data: data.length ? decodeArraysToJson(decoder, data) : null,
-          });
-        }
-      },
-    });
-  }
+    flush(controller) {
+      if (event) {
+        controller.enqueue({
+          id: lastEventId || undefined,
+          event,
+          data: data.length ? decodeArraysToJson(decoder, data) : null,
+        });
+      }
+    },
+  });
 }
 
 function joinArrays(data: ArrayLike<number>[]) {