Configuring YAML File

This section describes the config.yml file schema used to configure the NeMo Guardrails library. The config.yml file is the primary configuration file for defining LLM models, guardrails behavior, prompts, knowledge base settings, and tracing options.

Overview

The following is a complete schema for a config.yml file:

1 # LLM model configuration
2 models:
3   - type: main
4     engine: openai
5     model: gpt-4o
6 
7 # Instructions for the LLM (similar to system prompts)
8 instructions:
9   - type: general
10     content: |
11       You are a helpful AI assistant.
12 
13 # Guardrails configuration
14 rails:
15   input:
16     flows:
17       - self check input
18   output:
19     flows:
20       - self check output
21   ... # Other rail configurations
22 
23 # Prompt customization
24 prompts:
25   - task: self_check_input
26     content: |
27       Your task is to check if the user message complies with policy.
28 
29 # Knowledge base settings
30 knowledge_base:
31   embedding_search_provider:
32     name: default
33 
34 # Tracing and monitoring
35 tracing:
36   enabled: true
37   adapters:
38     - name: FileSystem
39       filepath: "./logs/traces.jsonl"

Configuration YAML Schema Reference

For a complete, consolidated reference of all configuration options, see the YAML Schema Reference.

Configuration Sections

The following sections provide detailed documentation for each configuration section of the overall config.yml file:

Models

Configure LLM engines, embedding models, and task-specific models in config.yml.

Reference

Guardrails

Configure input, output, dialog, retrieval, and execution rails in config.yml to control LLM behavior.

Reference

Prompts

Customize prompts for self-check, fact-checking, and intent generation tasks.

Reference

Tracing

Configure FileSystem and OpenTelemetry tracing adapters to monitor guardrails.

Reference

Streaming

Configure streaming for LLM token generation and output rail processing in config.yml.

Reference

File Organization

Configuration files should be organized in a config folder with the following structure:

.
├── config
│   ├── config.yml        # Main configuration file
│   ├── prompts.yml       # Custom prompts (optional)
│   ├── rails/            # Colang flow definitions (optional)
│   │   ├── input.co
│   │   ├── output.co
│   │   └── ...
│   ├── kb/               # Knowledge base documents (optional)
│   │   ├── doc1.md
│   │   └── ...
│   ├── actions.py        # Custom actions (optional)
│   └── config.py         # Custom initialization (optional)