jsii
Python client for jsii runtime
Decision gist · record as of 2026-08-14
Yes, if you are using jsii-compiled libraries in Python. The package is actively maintained, has no known vulnerabilities, installs with low friction, and carries a permissive Apache-2.0 license. Install only if you have a concrete need to consume jsii-compiled bindings; it is not useful as a standalone tool.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later.
- The package is a runtime client for jsii-compiled libraries; you need pre-compiled bindings to use it effectively.
- Low friction installation with six stable runtime dependencies (attrs, cattrs, publication, typeguard, python-dateutil, typing_extensions).
License · maintenance · safety
Apache-2.0 (permissive) — Apache-2.0 permissive license allows commercial and private use with minimal restrictions; you must include a copy of the license and notice file but face no copyleft obligations.
last release 2026-07-17 (28 days) · last repo commit 2026-08-12 · 2,866 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 9,003,259 downloads/mo, #1,569 on PyPI
Alternatives
Verify before relying
pip install jsii
import jsii
# jsii provides runtime support for consuming compiled bindings
# Typically used with pre-compiled jsii libraries- Whether all listed Python versions (3.10–3.14) are actively tested or if some are aspirational.
- Performance characteristics and memory overhead when bridging between Python and JavaScript runtimes.
- Availability and ecosystem of jsii-compiled libraries beyond the primary use case.
What it is and what it does
jsii is the Python runtime layer for the jsii polyglot framework, which allows a single TypeScript class library to be consumed natively from Python, Java, C#, and other languages. When you install jsii, you get the Python bindings and runtime machinery needed to call JavaScript classes as if they were native Python objects—the framework handles marshalling, type conversion, and cross-language method dispatch behind the scenes.
The primary use case is consuming jsii-compiled libraries from Python code. Rather than rewriting libraries in every target language, teams author once in TypeScript, compile to jsii format, and jsii's language-specific runtimes (including this Python client) make those classes available with natural syntax in each language. It depends on attrs, cattrs, typeguard, publication, python-dateutil, and typing_extensions to handle serialization, type checking, and object lifecycle across the language boundary.
Use it for
- Consume jsii-compiled TypeScript libraries from Python with native class and method syntax.
- Build polyglot infrastructure or application frameworks where a single TypeScript codebase serves multiple language ecosystems.
- Integrate Python applications with JavaScript libraries that have been published in jsii format.
- Maintain type safety and IDE support when calling cross-language bindings through typeguard validation.
- Use libraries authored in TypeScript without rewriting them for Python environments.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you are using jsii-compiled libraries in Python.
The package is actively maintained, has no known vulnerabilities, installs with low friction, and carries a permissive Apache-2.0 license. Install only if you have a concrete need to consume jsii-compiled bindings; it is not useful as a standalone tool.
Install
jsii on PyPI
Before you install
Low friction installation with six stable runtime dependencies (attrs, cattrs, publication, typeguard, python-dateutil, typing_extensions). Active maintenance with a release within the last month and no known vulnerabilities. Requires Python 3.10 or later.
Requires Python 3.10 or later. The package is a runtime client for jsii-compiled libraries; you need pre-compiled bindings to use it effectively.
License in practice
Apache-2.0 permissive license allows commercial and private use with minimal restrictions; you must include a copy of the license and notice file but face no copyleft obligations.
Quickstart
pip install jsii
import jsii
# jsii provides runtime support for consuming compiled bindings
# Typically used with pre-compiled jsii librariesVerify before relying
- Whether all listed Python versions (3.10–3.14) are actively tested or if some are aspirational.
- Performance characteristics and memory overhead when bridging between Python and JavaScript runtimes.
- Availability and ecosystem of jsii-compiled libraries beyond the primary use case.
Package facts
| License | Apache-2.0 permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 6 packagesattrscattrspublicationtypeguardpython-dateutiltyping_extensions |
| Maintenance | Actively maintained 28 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 9,003,259 / month, #1,569 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersLicense :: OSI Approved :: Apache Software LicenseProgramming Language :: JavaScriptProgramming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Topic :: Software Development :: LibrariesTopic :: UtilitiesTyping :: Typed |
Evidence: jsii-1.139.0-py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “polyglot library bindings”
- jsiijsii is a Python runtime client that enables Python code to interact…
- thriftThrift is the Python bindings for Apache Thrift, an RPC framework…
- spdlogProvides a Python wrapper around the C++ spdlog logging library,…
Give your agent the search over MCP, or paste the wish link into any chat.
More Libraries packages
urllib3 is an HTTP client library that provides thread-safe connection pooling, SSL/TLS verification, multipart file uploads, request retries, compression support, and proxy handling for Python applications.
Requests is a Python HTTP library that simplifies sending HTTP/1.1 requests with automatic handling of headers, authentication, cookies, and response parsing.
Pluggy provides a plugin system that lets you define hook specifications and register implementations to be called in sequence, enabling extensible Python applications without tight coupling.
Install it if you're building an extensible application or framework.
Provides parsing, arithmetic, and recurrence rule computation for dates and times, with timezone support and iCalendar RFC compliance.
Install it if you need to parse flexible date strings, compute relative dates, handle timezones, or work with recurrence rules—it's the de facto choice for these tasks.
Six provides utility functions to write Python code that runs on both Python 2.7 and Python 3.3+, smoothing over language differences between the two versions.
pytest is a testing framework that lets you write test functions using plain assert statements and automatically discovers and runs them, with detailed failure reporting.
See also dukpy · py4j · quickjs-rs · deno · rjsmin · pydantic-to-typescript2 · jpype1 · RachioPy · jsmin · pydantic-to-typescript