# What changed in json-schema-to-typescript

> 25 changes in json-schema-to-typescript 16 from its official release notes, upgrade guides and advisories: 6 breaking. Each one cited. Sources checked 2026-10-18. HTML: https://unstale.sh/npm/json-schema-to-typescript/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## json-schema-to-typescript 16

### Breaking changes

- Relative references are resolved against each schema file's directory rather than process.cwd(); an explicit --cwd still takes precedence. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Draft-3 and Swagger 2 property-level required: true now causes the property to be emitted as required. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- A named enum in a position with no name degrades to a union of literals instead of emitting a nameless enum declaration. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- The JSON null value is treated as type: "null" instead of as an untyped object. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- A root or untitled definition with an array type and properties now emits the union including non-object members, rather than making those members unreachable. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- unreachableDefinitions now declares definitions even when declareExternallyReferenced is off. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)

### Performance

- compile() no longer scans every definition once per parsed node, making schemas with thousands of definitions compile much faster without changing generated output. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Formatting large, mostly quote-free outputs is several times faster; a caller's style.filepath still takes precedence. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)

### Behavior and default changes

- Short unions that fit on one line are no longer wrapped. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- The description of an inline items schema is included in the array declaration's JSDoc as an Items paragraph. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)

### Tooling

- Generated type names can no longer start with a digit or collapse to an empty name. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)

### Fixes and other changes

- Members containing only unsupported keywords no longer add a stray {[k: string]: unknown} to the intersection. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- With inferStringEnumKeysFromValues enabled, const is emitted as a literal type again rather than a single-member enum. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- This option no longer produces invalid enum members for non-string, empty, or digit-leading values. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Nested array bounds are capped by their cumulative product against maxItems, falling back to an unbounded array rather than hanging or emitting enormous tuple unions. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- OpenAPI 3.0 schemas with nullable: true, including those next to a $ref, now emit T | null. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Nested properties and patternProperties are now intersected with compound types instead of being dropped. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Multiple patternProperties, including with additionalProperties: false, are folded into one index signature typed as the union of their value types. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Index signatures from patternProperties or additionalProperties are widened to cover sibling named properties so the interface typechecks. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Recursive schemas reaching the generator without a name receive a generated type name instead of overflowing the stack. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Draft-07 named-anchor references matching a sibling $id are resolved instead of crashing. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- References to definitions with dotted names now use the full name rather than truncating at the first dot. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- A root-level reference to a definition that is itself only a reference no longer crashes. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Root-level references to definitions that refer back to themselves compile instead of crashing; the referenced definition remains emitted alongside the root type. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)
- Piping a schema on stdin no longer prints a DEP0187 deprecation warning on Node 24. (16.0.0) — [release notes](https://github.com/bcherny/json-schema-to-typescript/blob/d86f2856eef238b95ebf74b41c913bb1db2dabd9/CHANGELOG.md#1600)