index

Base stream interface shared by all stream types.

Contains core properties for state management, messaging, and stream control that are common to CompiledStateGraph, ReactAgent, and DeepAgent streams.

This interface provides the foundation that all stream types build upon:

• State management (values, isLoading, error)
• Message handling (messages)
• Interrupt handling (interrupt)
• Stream lifecycle (submit, stop)
• Branching and history (branch, history)

Client-side implementation returned by headlessTool.implement(...).

Represents a headless tool interrupt payload emitted by LangChain's schema-only tool({ ... }) overload.

Servers may serialize the nested tool call as toolCall (JS) or tool_call (Python). Use parseHeadlessToolInterruptPayload to normalize either shape before reading fields.

An interrupt thrown inside a thread.

Stream interface for ReactAgent instances created with createAgent.

Extends UseGraphStream with tool calling capabilities. Tool calls are automatically typed based on the agent's tools configuration.

Use this interface when streaming from an agent created with createAgent. For subagent streaming capabilities, use UseDeepAgentStream with createDeepAgent.

This interface is subject to change.

Options for configuring an agent stream.

Use this options interface when calling useStream with a ReactAgent created via createAgent.

This interface is subject to change.

Stream interface for DeepAgent instances created with createDeepAgent.

Extends UseAgentStream with subagent streaming capabilities. Subagent streams are automatically typed based on the agent's subagent configuration, enabling type-safe access to subagent state and messages.

Use this interface when streaming from an agent created with createDeepAgent that orchestrates multiple specialized subagents.

This interface is subject to change.

Options for configuring a deep agent stream.

Use this options interface when calling useStream with a DeepAgent created via createDeepAgent. Includes all agent options plus subagent-specific configuration.

AI message type that can be parameterized with custom tool call types.

Template for the bag type.

Streaming custom data from inside the nodes.

Stream event with detailed debug information.

Default tool call type when no specific tool definitions are provided.

Stream event with error information.

Stream event with events occurring during execution.

Stream event with a feedback key to signed URL map. Set feedbackKeys in the RunsStreamPayload to receive this event.

Infer the Bag type from an agent, defaulting to the provided Bag.

Currently returns the provided Bag for all types. Can be extended in the future to extract Bag from agent types.

Infer the node names from a compiled graph.

Extracts the ~NodeType phantom property from CompiledGraph instances, providing a union of all node names defined in the graph.

Infer the per-node return types from a compiled graph.

Extracts the ~NodeReturnType phantom property from CompiledGraph instances, which is a mapped type of { [nodeName]: ReturnType } for each node.

Infer subagent state map from a DeepAgent.

For DeepAgent, creates a map of subagent names to their state types. For non-DeepAgent, returns DefaultSubagentStates.

Infer tool call types from an agent.

For agents, extracts typed tool calls from the agent's tools. For non-agents, returns DefaultToolCall.

Union of all message types.

Stream event with message chunks coming from LLM invocations inside nodes.

Metadata stream event with information about the run and thread

Resolves the appropriate stream interface based on the agent/graph type.

This type automatically selects the correct stream interface based on the type of agent or graph passed to useStream:

1. DeepAgent (~deepAgentTypes) → UseDeepAgentStream

   • Includes: values, messages, toolCalls, subagents, getSubagentsByType, getSubagentsByMessage

2. ReactAgent (~agentTypes) → UseAgentStream

   • Includes: values, messages, toolCalls, getToolCalls
   • Excludes: subagents, getSubagentsByType

3. CompiledGraph / Default → BaseStream

   • Includes: values, messages, submit, stop
   • Does NOT include: toolCalls, subagents (not applicable to raw graphs)

Resolves the appropriate options interface based on the agent/graph type.

This type automatically selects the correct options interface based on the type of agent or graph:

1. DeepAgent → UseDeepAgentStreamOptions

   • Includes: filterSubagentMessages option

2. ReactAgent → UseAgentStreamOptions

3. CompiledGraph / Default → UseGraphStreamOptions

import type { SubgraphCheckpointsStreamEvent } from "./types.stream.subgraph.js";

• Stream modes
• • "values": Stream only the state values.
• • "messages": Stream complete messages.
• • "messages-tuple": Stream (message chunk, metadata) tuples.
• • "updates": Stream updates to the state.
• • "events": Stream events occurring during execution.
• • "debug": Stream detailed debug information.
• • "custom": Stream custom events.

Infer a tool call type from a single tool. Works with tools created via tool() from @langchain/core/tools.

For DynamicStructuredTool, this extracts the input type from the _call method, which is the most reliable source as it's the pre-computed input type.

Infer a union of tool call types from an array of tools. Works with tools created via tool() from @langchain/core/tools.

The lifecycle state of a tool call.

• pending: Tool call received, awaiting result
• completed: Tool execution finished successfully
• error: Tool execution failed (result.status === "error")

Represents a tool call paired with its result. Useful for rendering tool invocations and their outputs together.

Stream event with updates to the state after each step. The streamed outputs include the name of the node that produced the update as well as the update.

Stream event with values after completion of each step.