Class: Legion::Extensions::Llm::ErrorMiddleware

Inherits:
Faraday::Middleware
  • Object
show all
Defined in:
lib/legion/extensions/llm/error.rb

Overview

Faraday middleware that maps provider-specific API errors to Legion::Extensions::Llm errors.

Defined Under Namespace

Classes: ResponseWithBody

Constant Summary collapse

STREAM_ERROR_BODY_KEY = 
:legion_llm_stream_error_body
CONTEXT_LENGTH_PATTERNS = 
[
  /context length/i,
  /context window/i,
  /maximum context/i,
  /request too large/i,
  /too many tokens/i,
  /token count exceeds/i,
  /input[_\s-]?token/i,
  /input or output tokens? must be reduced/i,
  /reduce the length of messages/i
].freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ ErrorMiddleware

Returns a new instance of ErrorMiddleware.



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# File 'lib/legion/extensions/llm/error.rb', line 59

def initialize(app, options = {})
  super(app)
  @provider = options[:provider]
end

Class Method Details

.parse_error(provider:, response:) ⇒ Object

rubocop:disable Metrics/PerceivedComplexity



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# File 'lib/legion/extensions/llm/error.rb', line 83

def parse_error(provider:, response:) # rubocop:disable Metrics/PerceivedComplexity
  response = response_with_stream_error_body(response)
  message = provider&.parse_error(response)

  case response.status
  when 200..399
    message
  when 400
    if context_length_exceeded?(message)
      raise ContextLengthExceededError.new(response, message || 'Context length exceeded')
    end

    raise BadRequestError.new(response, message || 'Invalid request - please check your input')
  when 401
    raise UnauthorizedError.new(response, message || 'Invalid API key - check your credentials')
  when 402
    raise PaymentRequiredError.new(response, message || 'Payment required - please top up your account')
  when 403
    raise ForbiddenError.new(response,
                             message || 'Forbidden - you do not have permission to access this resource')
  when 429
    if context_length_exceeded?(message)
      raise ContextLengthExceededError.new(response, message || 'Context length exceeded')
    end

    raise RateLimitError.new(response, message || 'Rate limit exceeded - please wait a moment')
  when 500
    raise ServerError.new(response, message || 'API server error - please try again')
  when 502..504
    raise ServiceUnavailableError.new(response, message || 'API server unavailable - please try again later')
  when 529
    raise OverloadedError.new(response, message || 'Service overloaded - please try again later')
  else
    raise Error.new(response, message || 'An unknown error occurred')
  end
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/legion/extensions/llm/error.rb', line 64

def call(env)
  @app.call(env).on_complete do |response|
    self.class.parse_error(provider: @provider, response: response)
  end
end