Data Designer Declarative Columns Plugin

A Data Designer utility that allows loading multiple column configurations from YAML.

Features

• Multi-column YAML: Load entire column configurations from a YAML file or inline string
• All column types supported: sampler, llm-text, llm-code, llm-structured, llm-judge, expression, validation
• MCP Tool Configs: Define tool_configs in YAML for MCP tool use workflows
• Reusable configurations: Share column definitions across projects via YAML files
• Full parity with Python API: YAML configs are equivalent to programmatic add_column() calls

Installation

Install from PyPI:

pip install data-designer-declarative-columns

Or with uv:

uv add data-designer-declarative-columns

For development (editable install):

git clone https://github.com/webmaxru/data-designer-declarative-columns.git
cd data-designer-declarative-columns
pip install -e .

Usage

From YAML File

from data_designer_declarative_columns import DeclarativeColumnsConfig

import data_designer.config as dd
from data_designer.interface import DataDesigner

data_designer = DataDesigner()
config_builder = dd.DataDesignerConfigBuilder()

# Load columns from YAML file
config = DeclarativeColumnsConfig(file="examples/product_reviews.yaml")
config.add_columns_to_builder(config_builder)

# Run preview
preview_results = data_designer.preview(config_builder=config_builder, num_records=3)
preview_results.display_sample_record()

From Inline YAML

from data_designer_declarative_columns import DeclarativeColumnsConfig

import data_designer.config as dd
from data_designer.interface import DataDesigner

data_designer = DataDesigner()
config_builder = dd.DataDesignerConfigBuilder()

# Define columns inline (excerpt from product_reviews.yaml)
config = DeclarativeColumnsConfig(yaml_content="""
columns:
  - name: product_category
    column_type: sampler
    sampler_type: category
    params:
      values: [Electronics, Clothing, Books, Home & Garden]
      weights: [3, 2, 2, 1]

  - name: price
    column_type: sampler
    sampler_type: uniform
    params:
      low: 9.99
      high: 499.99

  - name: customer
    column_type: sampler
    sampler_type: person_from_faker
    params:
      locale: en_US
      age_range: [18, 65]

  - name: review
    column_type: llm-text
    model_alias: nvidia-text
    prompt: |
      Write a realistic customer review for a product in the {{ product_category }} category.
      The product costs ${{ price | round(2) }}.

  - name: customer_name
    column_type: expression
    expr: "{{ customer.first_name }} {{ customer.last_name }}"
""")

config.add_columns_to_builder(config_builder)
preview_results = data_designer.preview(config_builder=config_builder, num_records=3)
preview_results.display_sample_record()

With MCP Tool Configs

For MCP tool use workflows, define tool_configs in the YAML and use get_tool_configs():

from data_designer_declarative_columns import DeclarativeColumnsConfig

import data_designer.config as dd
from data_designer.interface import DataDesigner

# Load configuration with tool_configs
config = DeclarativeColumnsConfig(file="examples/basic_mcp.yaml")

# Create builder WITH tool configs from YAML
config_builder = dd.DataDesignerConfigBuilder(tool_configs=config.get_tool_configs())
config.add_columns_to_builder(config_builder)

# Define MCP provider (server code must still be Python)
mcp_provider = dd.LocalStdioMCPProvider(
    name="basic-tools",
    command=sys.executable,
    args=["your_mcp_server.py", "serve"],
)

# Create DataDesigner with MCP provider
data_designer = DataDesigner(mcp_providers=[mcp_provider])
preview_results = data_designer.preview(config_builder, num_records=2)

YAML with tool_configs:

tool_configs:
  - tool_alias: basic-tools
    providers: [basic-tools]
    allow_tools: [get_fact, add_numbers]
    max_tool_call_turns: 5
    timeout_sec: 30.0

columns:
  - name: topic
    column_type: sampler
    sampler_type: category
    params:
      values: [python, earth, water]

  - name: fact_response
    column_type: llm-text
    model_alias: nvidia-text
    prompt: "Use the get_fact tool to look up '{{ topic }}'"
    tool_alias: basic-tools
    with_trace: true

YAML Configuration Format

product_reviews.yaml (excerpt):

columns:
  - name: product_category
    column_type: sampler
    sampler_type: category
    params:
      values: [Electronics, Clothing, Books, Home & Garden]
      weights: [3, 2, 2, 1]

  - name: customer
    column_type: sampler
    sampler_type: person_from_faker
    params:
      locale: en_US
      age_range: [18, 65]

  - name: review
    column_type: llm-text
    model_alias: nvidia-text
    prompt: |
      Write a realistic customer review for a {{ product_subcategory }} 
      in the {{ product_category }} category.

  - name: review_analysis
    column_type: llm-structured
    model_alias: nvidia-text
    prompt: |
      Analyze this product review and extract structured information:
      Review: "{{ review }}"
    output_format:
      type: object
      properties:
        sentiment:
          type: string
          enum: [positive, neutral, negative]
        would_recommend:
          type: boolean
      required: [sentiment, would_recommend]

Inspecting Loaded Columns

config = DeclarativeColumnsConfig(file="examples/product_reviews.yaml")

# Get list of column names
print(config.get_column_names())
# ['request_id', 'product_category', 'product_subcategory', 'price', ...]

# Get number of columns
print(len(config))
# 14

# Access raw column definitions
for col in config.columns:
    print(f"{col['name']}: {col['column_type']}")

Supported Column Types

Examples

See the examples/ folder for complete YAML configurations:

• product_reviews.yaml - Comprehensive example with all column types:

  • Samplers: UUID, Category, Subcategory, Uniform, Gaussian, DateTime, Person (Faker)
  • LLM Text: Product review generation
  • LLM Code: SQL query generation
  • LLM Structured: Review sentiment analysis
  • LLM Judge: Review quality scoring
  • Expressions: Derived values (word count, price tier, customer name)

• text_to_python.yaml - Python code generation with validation

• text_to_sql.yaml - SQL query generation

• multi_turn_chat.yaml - Multi-turn conversations

• product_info_qa.yaml - Product Q&A

• basic_mcp.yaml - MCP tool use

• pdf_qa.yaml - Document Q&A with MCP

License

Apache-2.0