Config Skills for LlamaFarm

Specialized patterns and best practices for the LlamaFarm configuration module (config/ ).

Module Overview

The config module provides YAML/TOML/JSON configuration loading with JSONSchema validation:

File Purpose

datamodel.py

Generated Pydantic v2 models from JSONSchema

schema.yaml

Source JSONSchema with $ref references

compile_schema.py

Dereferences $ref to create schema.deref.yaml

generate_types.py

Generates Python types via datamodel-codegen

validators.py

Custom validators beyond JSONSchema capabilities

helpers/loader.py

Config loading, saving, and format detection

helpers/generator.py

Template-based config generation

Links to Shared Skills

This module follows Python conventions from the shared skills:

Topic Link Key Relevance

Patterns python-skills/patterns.md Pydantic v2, dataclasses

Typing python-skills/typing.md Type hints, constrained types

Testing python-skills/testing.md Pytest fixtures, temp files

Errors python-skills/error-handling.md Custom exceptions

Security python-skills/security.md Path traversal prevention

Framework-Specific Checklists

Checklist Description

pydantic.md Pydantic v2 configuration patterns, nested models, constraints

jsonschema.md JSONSchema generation, dereferencing, validation

Tech Stack

• Python: 3.11+

• Pydantic: v2 with ConfigDict , Field , constrained types

• JSONSchema: Draft-07 with $ref dereferencing via jsonref

• YAML: ruamel.yaml for comment-preserving read/write

• Code Generation: datamodel-codegen for schema-to-Pydantic

Key Patterns

Generated Pydantic Models

The datamodel.py file is auto-generated from JSONSchema:

Generated by datamodel-codegen from schema.deref.yaml

from pydantic import BaseModel, ConfigDict, Field, conint, constr

class Database(BaseModel): model_config = ConfigDict(extra="forbid") name: constr(pattern=r"^[a-z][a-z0-9_]*$", min_length=1, max_length=50) type: Type config: dict[str, Any] | None = Field(None, description="Database-specific configuration")

Custom Validators for Cross-Field Constraints

JSONSchema draft-07 cannot express all constraints. Custom validators extend validation:

def validate_llamafarm_config(config_dict: dict[str, Any]) -> None: """Validate constraints beyond JSONSchema (uniqueness, references).""" # Check for duplicate prompt names prompt_names = [p.get("name") for p in config_dict.get("prompts", [])] duplicates = [name for name in prompt_names if prompt_names.count(name) > 1] if duplicates: raise ValueError(f"Duplicate prompt set names: {', '.join(set(duplicates))}")

Comment-Preserving YAML with ruamel.yaml

Configuration files preserve user comments when modified:

from ruamel.yaml import YAML from ruamel.yaml.comments import CommentedMap

def _get_ruamel_yaml() -> YAML: yaml_instance = YAML() yaml_instance.preserve_quotes = True yaml_instance.indent(mapping=2, sequence=4, offset=2) return yaml_instance

Directory Structure

config/ ├── pyproject.toml # UV-managed dependencies ├── schema.yaml # Source JSONSchema with $ref ├── schema.deref.yaml # Dereferenced schema (generated) ├── datamodel.py # Pydantic models (generated) ├── compile_schema.py # Schema compilation script ├── generate_types.py # Type generation script ├── validators.py # Custom validation beyond JSONSchema ├── validate_config.py # CLI validation wrapper ├── init.py # Public API exports ├── helpers/ │ ├── loader.py # Config loading/saving │ └── generator.py # Template-based generation ├── templates/ │ └── default.yaml # Default config template └── tests/ ├── conftest.py # Shared fixtures └── test_*.py # Test modules

Workflow: Schema Changes

When modifying the configuration schema:

• Edit schema.yaml (or referenced schemas like ../rag/schema.yaml )

• Run nx run generate-types to compile and generate types

• Update validators.py if new cross-field constraints are needed

• Test with uv run pytest config/tests/

Common Commands

Generate types from schema

nx run generate-types

Validate a config file

uv run python config/validate_config.py path/to/llamafarm.yaml --verbose

Run tests

uv run pytest config/tests/ -v

Lint and format

ruff check config/ --fix ruff format config/