Class●Since v1.1

ContextOverflowError

Error class representing a context window overflow in a language model operation.

This error is thrown when the combined input to a language model (such as prompt tokens, historical messages, and/or instructions) exceeds the maximum context window or token limit that the model can process in a single request. Most models have defined upper limits for the number of tokens or characters allowed in a context, and exceeding this limit will prevent the operation from proceeding.

The ContextOverflowError extends the LangChainError base class with the marker "context-overflow".

class ContextOverflowError

Bases

LangChainError<this>

Use this error to programmatically identify cases where a user request, prompt, or input sequence is too long to be handled by the target model.
Model providers and framework integrations should throw this error if they detect a request cannot be processed due to its size.

Example

try {
  await model.invoke(veryLongInput);
} catch (err) {
  if (ContextOverflowError.isInstance(err)) {
    // Handle overflow, e.g., prompt user to shorten input or truncate text
    console.warn("Model context overflow:", err.message);
  } else {
    throw err;
  }
}

Constructors

constructor

Properties

property

cause: Error

The underlying error that caused this ContextOverflowError, if any.

This property is optionally set when wrapping a lower-level error using ContextOverflowError.fromError. It allows error handlers to access or inspect the original error that led to the context overflow.

property

message: string

property

name: "ContextOverflowError"

property

stack: string

property

isInstance: IsInstanceFn

property

stackTraceLimit: number

Methods

method

captureStackTrace

method

fromError→ ContextOverflowError

Creates a new ContextOverflowError instance from an existing error.

This static utility copies the message from the provided error and attaches the original error as the ContextOverflowError.cause property, enabling error handlers to inspect or propagate the original failure.

method

prepareStackTrace