LiteLLM Chat Model icon

LiteLLM Chat Model

For advanced usage with an AI chain

Overview

This node acts as an interface to a language model API, designed for advanced usage within AI chains or agents. It allows users to generate text completions or structured JSON responses by specifying a model and various generation options. Typical use cases include generating conversational replies, completing text prompts, or producing structured data outputs in workflows that integrate AI capabilities.

Practical examples:

  • Generating chatbot responses dynamically based on user input.
  • Creating content summaries or expansions.
  • Producing JSON-formatted data from natural language prompts for further automated processing.

Properties

Name Meaning
This node must be connected to an AI chain. Insert one A notice indicating that this node requires connection to an AI chain or agent node to function properly.
If using JSON response format, you must include word "json" in the prompt in your chain or agent. Also, make sure to select latest models released post November 2023. A notice shown when the response format is set to JSON, reminding users to include the word "json" in their prompt and to use recent models for proper JSON output.
Model The language model used to generate completions. Options are dynamically loaded from the API endpoint /v1/models. Default is "gemini/2.0-flash".
Options Additional parameters to customize the completion behavior:
  Frequency Penalty Penalizes new tokens based on their existing frequency in the generated text to reduce repetition. Range: -2 to 2.
  Maximum Number of Tokens Maximum number of tokens to generate in the completion. Supports up to 32,768 tokens depending on the model. Default is -1 (no limit).
  Response Format Output format of the response. Options: Text (regular text) or JSON (ensures the model generates valid JSON). Default is text.
  Presence Penalty Penalizes new tokens based on whether they appear in the text so far, encouraging the model to talk about new topics. Range: -2 to 2.
  Sampling Temperature Controls randomness of completions. Lower values produce more deterministic results. Range: 0 to 1. Default is 0.7.
  Timeout Maximum time allowed for the request in milliseconds. Default is 60000 (60 seconds).
  Max Retries Maximum number of retry attempts if the request fails. Default is 2.
  Top P Controls diversity via nucleus sampling. Values between 0 and 1, where lower values consider fewer likely options. Default is 1.

Output

The node outputs data under the key ai_languageModel with the following structure:

  • json: Contains the text or JSON response generated by the language model, depending on the selected response format.
  • If the response format is JSON, the output guarantees valid JSON content suitable for downstream processing.
  • No binary data output is produced by this node.

Dependencies

  • Requires an API key credential for authentication with the LiteLLM service.
  • Connects to the LiteLLM API base URL specified in credentials.
  • Uses the OpenAI-compatible client library internally to communicate with the model endpoint.
  • Requires connection to an AI chain or agent node in n8n to provide prompts and context.

Troubleshooting

  • Common issues:

    • Failure to connect due to missing or invalid API credentials.
    • Timeout errors if the model takes too long to respond; can be adjusted via the Timeout property.
    • Rate limiting errors from the API; the node retries automatically but may fail after max retries.
    • Invalid JSON output if the prompt does not include the word "json" when using JSON response format.
  • Error messages:

    • Rate limit errors will throw a descriptive message advising to check API usage limits.
    • Node API errors wrap underlying HTTP or API errors with additional context.
  • Resolutions:

    • Ensure valid API key and base URL are configured.
    • Include the word "json" in prompts when expecting JSON output.
    • Adjust timeout and retry settings according to network conditions.
    • Use latest models released after November 2023 for JSON mode.

Links and References

  • OpenAI Models Overview
  • Documentation on model parameters and usage can be found in the official LiteLLM or OpenAI API docs.

Discussion