# Lineage Snapshot Schema

`lineage.snapshot.json` is the canonical machine-readable artifact for a business domain.

## Top-Level Fields

| Field | Meaning |
| --- | --- |
| `schema_version` | Format version. |
| `domain_id` | Stable domain identifier. |
| `generated_at` | ISO timestamp. |
| `modules` | Domain or sub-domain lanes. |
| `data_nodes` | Tables, files, APIs, caches, memory objects, business objects. |
| `process_steps` | Business/technical processing steps. |
| `edges` | Relationships between data nodes and process steps. |
| `field_mappings` | Important field-level lineage. |
| `evidence` | Code, SQL, report, sample, or DB evidence. |
| `validation_checks` | Verification state and drift notes. |
| `layout_overrides` | Visualization-only metadata. |

## Validation Status

- `verified`
- `code_verified`
- `db_verified`
- `partial`
- `stale`
- `blocked`