State Node

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Node Details

• Name: seqState
• Type: State
• Category: Sequential Agents
• Version: 2.0

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Parameters

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Custom State

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Option 1: Custom State (Table)

• Type: Data Grid
• Description: Allows users to define the state structure using a table interface.
• Columns:
  • Key: The name of the state variable
  • Operation: The type of operation to perform (Replace or Append)
  • Default Value: The initial value for the state variable

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Option 2: Custom State (Code)

• Type: Code Input
• Description: Allows users to define the state structure using a JSON object
• Default:
  Copy

  {
    aggregate: {
      value: (x, y) => x.concat(y), // append new message to existing messages
      default: () => []
    }
  }
  

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Functionality

1. The node initializes a state object based on the user’s input.
2. For each key in the state:
   • If the operation is “Replace”, it creates a function that replaces the existing value with a new one (or keeps the existing if the new is null).
   • If the operation is “Append”, it creates a function that appends the new value to the existing array.
3. The node can handle both UI-based input and code-based input, allowing for flexibility in defining the state structure.

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Output

• id: The node’s unique identifier
• node: The state object with defined keys and their corresponding update functions
• name: ‘state’
• label: ‘state’
• type: ‘state’
• output: START (a constant from @langchain/langgraph)

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Use Cases

• Maintaining conversation history in a chatbot
• Tracking progress through a multi-step process
• Aggregating information from multiple API calls or data sources
• Storing intermediate results in complex workflows

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Notes

• The node uses a sandbox environment (NodeVM) to safely execute user-provided code when using the code-based input option.
• It supports both built-in and external dependencies, which can be configured through environment variables.
• The state object is highly flexible and can be customized to fit various use cases in sequential agent flows.