@drzl/generator-json-schema

JSON Schema and OpenAPI schemas from your Drizzle analysis (insert / update / select).

No runtime dependency. The output is data.

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Use

Add to drzl.config.ts:

generators: [{ kind: 'json-schema', path: 'src/validators/json-schema' }];

Output

• Insert<Table>Schema, Update<Table>Schema, Select<Table>Schema, each a plain object declared as const
• Optional index barrel

OpenAPI

generators: [{ kind: 'json-schema', target: 'openapi-3.1', components: true, document: true }];

components: true writes components.ts, ready to spread into a document's components.schemas. document: true writes openapi.ts (and openapi.json with document: { format: 'both' }): the whole document, with a collection and an item path per table, the verbs on each, the request and response body per verb, and the status codes, including the one a schema causes when it refuses a request.

The path parameter is the table's real primary key, every column of it, at its real type, so a uuid key is /sessions/{token} and a composite key is /org_members/{orgId}/{userId}. A table with no primary key keeps its collection paths and loses the by-id ones rather than gaining a fictional id. servers is absent unless you supply one, which the specification reads as a single server at /. See the OpenAPI document docs for the whole set.

Dialect

generators: [{ kind: 'json-schema', target: 'openapi-3.0' }];

draft-2020-12 (default), openapi-3.1, or openapi-3.0. The last is a different dialect rather than an older version: nullable is nullable: true rather than a type array, an exclusive bound is a boolean beside the bound rather than its own keyword, a pinned value is a one-value enum rather than const, and base64 bytes are format: 'byte' rather than contentEncoding. Since an unknown keyword is ignored rather than rejected in JSON Schema, emitting the wrong one produces a document that validates and then accepts what the constraint exists to reject; inside an OpenAPI 3.0 document it is worse than that, because 3.0's Schema Object is closed and one unknown keyword makes the whole document invalid.

See the full generator docs for what the format cannot express and how each column type survives JSON.stringify.

Custom names

affix renames the exported schemas and type aliases, and tableCase: 'pascal' upper-camels the Drizzle export name (users -> Users) instead of interpolating it verbatim. Omit it and the names above are unchanged.

generators: [
  {
    kind: 'json-schema',
    path: 'src/validators/json-schema',
    affix: {
      tableCase: 'pascal',
      schema: { suffix: 'Schema' },
      type: {
        prefix: { insert: 'Create', update: 'Edit', select: '' },
        suffix: { insert: 'Input', update: 'Input', select: '' },
      },
    },
  },
];

Emits InsertUsersSchema / UpdateUsersSchema / SelectUsersSchema plus CreateUsersInput, EditUsersInput and a bare Users. Every prefix and suffix takes a string or a per-mode object keyed by insert, update, select. The legacy schemaSuffix still works and is the default for affix.schema.suffix.