# Domain Models -- Technical Specification

**Version**: v1.0.0 | **Status**: Reserved | **Last Updated**: May 2026

## Overview

Reserved submodule for domain model definitions within the FPF (Fetch-Parse-Format) framework. Intended to provide structured data models representing fetched content, parsed entities, and formatted output objects used throughout the FPF pipeline.

## Architecture

This submodule currently reserves an import namespace with `__all__ = []`. When populated, it is expected to provide immutable dataclass-based models that flow through the fetch, parse, and format stages.

## Planned Components

| Component | Purpose |
|-----------|---------|
| FetchResult | Container for raw fetched data with source metadata |
| ParsedEntity | Structured representation of extracted content |
| FormatSpec | Configuration for output formatting rules |
| PipelineContext | Shared state flowing through FPF pipeline stages |

## Dependencies

- **Internal**: Expected to be imported by `fpf.constraints` for validation and `fpf.reasoning` for inference
- **External**: None planned (Python stdlib)

## Constraints

- No implementation exists yet; all access will raise `ImportError` or `NotImplementedError`.
- Zero-mock: when implemented, models must represent real data; no synthetic stand-ins in production flows.
- All models should be serializable to JSON for pipeline checkpointing.

## Error Handling

- Unimplemented features raise `NotImplementedError`.
- All errors logged before propagation.

## Navigation

- **Self**: `SPEC.md`
- **Parent**: [../README.md](../README.md)
- **Readme**: [README.md](README.md)
- **Agents**: [AGENTS.md](AGENTS.md)
- **Repository Root**: [README.md](../../../../README.md)
