# What changed in jsii-diff

> 21 changes in jsii-diff 1 from its official release notes, upgrade guides and advisories: 2 breaking, 1 security, 2 new APIs and options. Each one cited. Sources checked 2026-10-25. HTML: https://unstale.sh/npm/jsii-diff/

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

## jsii-diff 1

### Breaking changes

- Python modules now require Python 3.10 or later. (1.133.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11330-2026-06-01)
- Python 3.9 is no longer supported; Python 3.10 is now the minimum required version. (1.130.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11300-2026-05-14)

### Security

- The npm: argument type is no longer vulnerable to shell injection. (1.131.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11310-2026-05-19)

### New APIs and options

- Java stack traces can now be sent to the host. (1.136.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11360-2026-06-18)
- Class covariant overrides are now supported in the kernel, tools, and documentation. (1.117.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11170-2025-10-22)

### Performance

- Resolution is cached for runtime type checking, reducing repeated type-hint resolution. (1.138.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11380-2026-07-02)
- Kernel performance improves by about 10% by deferring error-context and cache serialization values. (1.136.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11360-2026-06-18)
- typeguard is centralized and lazy-loaded to improve Python import times. (1.134.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11340-2026-06-03)
- Eager submodule imports are replaced with lazy loading. (1.133.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11330-2026-06-01)

### Behavior and default changes

- Host-language stack traces are now propagated through the jsii protocol. (1.136.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11360-2026-06-18)

### Tooling

- Adds support for jsii-rosetta 6.0. (1.135.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11350-2026-06-11)

### Fixes and other changes

- Fixes an IndentationError that occurred after cdktf strips submodule imports. (1.139.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11390-2026-07-17)
- Fixes a KeyError when an interface from an un-imported submodule is encountered under lazy loading. (1.137.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11370-2026-06-22)
- The typeguard check now runs on every call instead of once per process. (1.136.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11360-2026-06-18)
- Sibling module dependencies are eagerly loaded even when they are used only for type annotations. (1.136.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11360-2026-06-18)
- Fixes annotation dependencies leaking onto consumers' runtime classpath. (1.134.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11340-2026-06-03)
- Fixes javax.annotation-api leaking onto consumers' runtime classpath. (1.134.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11340-2026-06-03)
- Fixes org.jetbrains:annotations leaking onto consumers' runtime classpath. (1.133.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11330-2026-06-01)
- Only declared arguments are forwarded to language overrides. (1.132.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11320-2026-05-22)
- Circular arguments no longer let unsafe JSON.stringify hide the original error. (1.132.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11320-2026-05-22)
- Resolved promises are cleaned up from the kernel's promises map. (1.128.0) — [release notes](https://github.com/aws/jsii/blob/1788377905091624d3696fb17fbfcb7507d795e5/CHANGELOG.md#11280-2026-04-09)