# Document Transcription System Requirements (Version 4)

This document defines the baseline requirements for the document transcription system.

## Requirements Model

| ID | Category | Requirement | Verify Method |
| --- | --- | --- | --- |
| REQ-0 | System | Provide end-to-end multi-page document transcription with persistent, inspectable async job states. | demonstration |
| REQ-1 | Functional | Allow users to upload one or more images as ordered `Source` pages under a `Document`. | test |
| REQ-2 | Functional | Process page transcription asynchronously using an `asyncio` worker pool bounded by rate limits. | test |
| REQ-3 | Functional | Persist submission-time request provenance and accurately labeled page-level SDK evidence; V4.2 adds exact OpenRouter-boundary transport evidence for new attempts. | test |
| REQ-4 | Functional | Support job states `queued`, `processing`, `completed`, `partial_success`, and `failed`, plus page states `pending`, `transcribed`, and `failed`. | inspection |
| REQ-5 | Functional | Allow users to manage historical `Person` records and link each Person to a Document once with exactly one role. | test |
| REQ-6 | Functional | Support an extensible role taxonomy for document-person relationships. | inspection |
| REQ-7 | Policy Constraint | Enforce deterministic relationship-role writes with uniqueness on `(document_id, person_id)` and explicit conflict responses for duplicate Person links. | test |
| REQ-8 | Functional | Use set-based synchronization for document-person mutations so updates add and remove only the intended links. | test |
| REQ-9 | Functional | Maintain selected machine output and exact attempt provenance on `Source` while permitting independent human edits on `Source.revised_text`. | test |
| REQ-10 | Functional | Support a UUID-identified `DocumentType` taxonomy with unique user-facing labels and active/inactive lifecycle control. | test |
| REQ-11 | Data Constraint | Store `Document` type as a controlled reference to `DocumentType`. | test |
| REQ-12 | Interface | Render multi-page transcriptions sequentially by `page_number` with document, people, and document-type metadata. | demonstration |
| REQ-13 | Interface | Document create/edit UI must provide one staged Linked People table and select active registry entries by UUID and label. | demonstration |
| REQ-14 | API Constraint | Expose additive, role-aware retrieval and write behavior for document-person links and UUID-based selection for document types. | test |
| REQ-15 | Data Constraint | Calculate and store cryptographic file hashes (SHA-256) and file sizes for uploaded source images. | test |
| REQ-16 | Data Constraint | Preserve a portable relational model across supported backends using SQLModel, SQLAlchemy, SQLite, and PostgreSQL. | inspection |
| REQ-17 | Reliability | Ensure delete and update flows for documents, people, and relationship links remain deterministic and safe. | test |
| REQ-18 | Operations Constraint | Keep canonical development, testing, restore, and recovery workflows OS-independent; for AI-run unit tests, require a pre-test backup of `./data` and an always-shown post-success confirmation prompt before any restore action. | inspection |
| REQ-19 | Quality | Provide automated coverage for async transcription workflows, relationship-role enforcement, document-type selection, and regression behavior. | test |
| REQ-20 | Data Constraint | Permit hidden immutable semantic keys only on protected built-in Document Types and Person Roles while retaining UUID as relationship identity. | test |
| REQ-21 | Reliability | Persist Document fields and their complete Linked People set atomically. | test |
| REQ-22 | Interface | Provide safe browser-native Facsimile and Text-only print views from persisted Document Detail. | demonstration |
| REQ-23 | Security | Escape stored print text and serve Source images through record-validated application routes without disclosing local paths. | test |
| REQ-24 | Functional | Print current human-preferred Source text, semantic Author metadata, deterministic Source order, and oldest-to-newest Job metadata. | test |
| REQ-25 | Quality | Physically apply recognized raster orientation metadata to provider-input derivatives without changing original Source bytes. | test |
| REQ-26 | Quality | Persist deterministic, non-mutating output warnings without automatic paid retries. | test |
| REQ-27 | Functional | Create one-Source retranscription Jobs from a configured model allowlist and preserve later successes as candidates until explicit promotion. | test |

## Clarifying Constraints

1. `DocumentType.id` and `PersonRole.id` are their public and relationship identities; labels are unique ignoring case and surrounding whitespace.
2. Nullable `semantic_key` values identify protected application built-ins, remain internal, and never change.
3. Relationship-write policy and conflict handling must be consistent across UI, API, services, and persistence.
4. One Person may appear only once per Document and every link has exactly one role.
5. Relationship conflicts must fail deterministically without partial Document or link mutation.
6. Source page reordering and server-generated PDF files remain outside this revision.

## Element Satisfaction Mapping

- UI (NiceGUI): Satisfies REQ-0, REQ-1, REQ-5, REQ-9, REQ-12, REQ-13, REQ-22, REQ-24.
- API (FastAPI): Satisfies REQ-1, REQ-4, REQ-5, REQ-7, REQ-8, REQ-14, REQ-23.
- Worker (`asyncio`): Satisfies REQ-2, REQ-3, REQ-4.
- Persistence (SQLModel / SQLAlchemy): Satisfies REQ-3, REQ-7, REQ-9, REQ-10, REQ-11, REQ-15, REQ-16, REQ-17, REQ-20, REQ-21.
- Test Suite: Verifies all test-marked requirements and satisfies REQ-19.

## Related Local References

- [System Overview](index_v4.md)
- [System Architecture](architecture_v4.md)
- [Data Model](schema_v4.md)
- [Error Handling Policy](error_handling_v4.md)