Definition Resource Design Patterns

Definition Resource Design Patterns

Guide for designing Definition resources that serve as reusable plugin templates. Definitions are the "Law" that Instances must follow.

When to Use

Apply when:

• Creating new plugin types (PipelineDef, StoreDef, etc.)
• Designing the interface contract a plugin must implement
• Specifying input/​output schemas for validation
• Defining compatibility rules for upstream/​downstream connections
• Embedding guardrail contracts that enforce data quality

Core Concept: The Law

Definition resources contain the rules that Instance resources must follow:

Definition = The Law
├── interface_spec        # Abstract interface to implement
├── input_schema          # Expected input format
├── output_schema         # Expected output format
├── compatibility_rules   # What can connect upstream/​downstream
└── guardrail_contracts   # Validation rules (enforced by Engine)

Definition Types

Schema Structure

See references/​schema-structure.md for complete JSON schema.

Minimal Definition

definition_metadata = {
    "interface_spec": "optaic.interfaces.BasePipeline",
    "input_schema": {"datasets": {"type": "array"}},
    "output_schema": {"type": "DataFrame", "columns": ["date", "entity", "value"]},
}

Full Definition with Contracts

definition_metadata = {
    "interface_spec": "optaic.interfaces.SignalPipeline",
    "version": "1.0",

    "input_schema": {
        "datasets": {"type": "array", "items": {"$ref": "#/​DatasetInstance"}},
        "parameters": {"type": "object", "properties": {...}}
    },

    "output_schema": {
        "type": "DataFrame",
        "columns": ["date", "entity", "value"],
        "value_range": {"min": -1, "max": 1}
    },

    "compatibility_rules": {
        "upstream_types": ["DatasetInstance"],
        "downstream_types": ["SignalInstance", "BacktestInstance"]
    },

    "guardrail_contracts": [
        {"kind": "signal.bounds", "config": {"min": -1, "max": 1, "allow_nan": False}},
        {"kind": "pit.policy", "config": {"knowledge_date_required": True}},
    ]
}

Implementation Checklist

1. Define interface_spec pointing to abstract base class
2. Specify input_schema with JSON Schema format
3. Specify output_schema with expected structure
4. Define compatibility_rules for resource graph connections
5. Embed guardrail_contracts for validation
6. Create extension table in libs/​db/​models/
7. Add to ResourceType enum

Reference Files

• Schema Structure - Complete JSON schema spec
• Examples - Example Definition implementations