# Seriatim Transcript JSON

This document is the external input contract consumed by the production
Seriatim input adapter. Selectable input-adapter keys are cataloged in
[Configuration](../config.md#implemented-production-modules).

## Adapter

- Source format: `application/vnd.seriatim+json`

## Accepted Shape

The input must be one JSON object with top-level `metadata` and `segments`
fields. This covers the maintained minimal fixture and Seriatim intermediate
output that provides the same required segment fields.

The maintained example is
[examples/seriatim-minimal-transcript.json](../../examples/seriatim-minimal-transcript.json).

Required top-level fields:

- `metadata`: an object. Its entries are accepted as source metadata.
- `segments`: a non-empty array of segment objects.

Required segment fields:

- `id`: a positive integer JSON number or canonical decimal string without
  leading zeros or surrounding whitespace;
- `start`: a finite, non-negative JSON number or numeric string;
- `end`: a finite, non-negative JSON number or numeric string that is not less
  than `start`;
- `speaker`: a non-empty string;
- `text`: a non-empty string.

Other top-level and segment fields, such as `categories`, are ignored.

Multiple top-level JSON values are rejected.

## Validation

The adapter rejects empty input, malformed JSON, multiple top-level JSON values,
non-object segment values, duplicate segment IDs, and any violation of the
shape or field constraints above.

Segment text is preserved as provided, but it must not be empty after trimming.

## Derived Identity

Notarius identifies the parsed source in this order:

1. `metadata.id`, when it is a non-empty string after trimming;
2. `metadata.source_id`, when it is a non-empty string after trimming;
3. `seriatim:<first-16-hex-chars-of-raw-sha256>`.

The exact raw input SHA-256 remains the basis of the fallback source ID. The
source digest recorded in output provenance is instead the SHA-256 of the
canonical generic source document, excluding the digest field itself. It covers
the derived source identity, document kind and format, ordered units and their
self-references, and accepted metadata. Segment IDs become the unit IDs used by
artifact source references; each produced unit carries a self-reference whose
source ID is the derived document ID and whose start and end IDs both equal the
segment ID.

## Compatibility Limit

This contract covers only Seriatim transcript JSON with the top-level
`metadata` object and `segments` array described here. Broader Seriatim output
schemas are compatible only when they provide these required fields with the
accepted types.