# Seriatim Transcript Input

This document defines the JSON transcript accepted by the production Seriatim
input adapter. It is a source input, not a durable lane artifact. Configure the
input adapter through [Configuration](../config.md#production-module-keys).

## Contract Identity

| Property | Value |
| --- | --- |
| Consumer | Seriatim input adapter |
| Media type | `application/vnd.seriatim+json` |
| Source document kind | `transcript` |
| Source-unit kind | `transcript_segment` |

## Accepted Shape

The input is one JSON object containing `metadata` and a non-empty `segments`
array. This minimal document is valid:

```json
{
  "metadata": {"id": "session-alpha"},
  "segments": [
    {
      "id": 1,
      "start": 0,
      "end": 4,
      "speaker": "Aria",
      "text": "Aria casts Cure Wounds."
    }
  ]
}
```

The maintained two-segment input is
[seriatim-minimal-transcript.json](../../examples/seriatim-minimal-transcript.json).

| Field | Required | Meaning and constraints |
| --- | --- | --- |
| `metadata` | Yes | JSON object. Its entries become source metadata; no particular metadata key is otherwise required. |
| `segments` | Yes | Non-empty array of segment objects, kept in input order. |
| `segments[].id` | Yes | Positive canonical decimal integer, supplied as a JSON number or string. IDs must be unique. |
| `segments[].start` | Yes | Finite, non-negative numeric value, supplied as a JSON number or string. |
| `segments[].end` | Yes | Finite, non-negative numeric value that is not earlier than `start`. |
| `segments[].speaker` | Yes | String that is non-empty after trimming. |
| `segments[].text` | Yes | String that is non-empty after trimming. Its original text is retained. |

Additional top-level and segment fields are ignored. A missing required field,
`null` in place of an object or array, malformed JSON, or more than one
top-level JSON value is rejected.

## Source Identity And References

The adapter chooses the source ID in this order:

1. a non-empty source ID supplied by the calling request;
2. non-empty string `metadata.id`;
3. non-empty string `metadata.source_id`;
4. `seriatim:` followed by the first 16 hexadecimal characters of the raw
   input’s SHA-256 digest.

Each accepted segment becomes one source unit whose unit ID is `segments[].id`.
Its self-reference uses the derived source ID and the same segment ID for both
range endpoints. Artifact contracts use those segment IDs when they cite
transcript evidence.

## Compatibility

This adapter accepts only the shape described here. A broader Seriatim export
is usable only when it supplies this object, metadata, and segment shape with
the stated types and constraints. Unknown additional fields do not add
Notarius behavior.