stone
Stone is an interface description language (IDL) for APIs.
Decision gist · record as of 2026-08-14
Yes, if you are building or maintaining an API that needs to be consumed by clients in multiple programming languages. Stone is production-grade, actively maintained, has no known vulnerabilities, and solves a real problem at scale. Install friction is minimal. If you only need SDKs in one or two languages or are not responsible for maintaining API consistency across multiple implementations, it may be overkill.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.11 or later.
- Low friction installation as a pure Python wheel with only two runtime dependencies.
- The project is actively maintained with a recent release and has been in production use since 2016.
License · maintenance · safety
MIT (permissive) — MIT license permits commercial and private use with minimal restrictions; you may use, modify, and distribute Stone freely as long as you include the license notice.
last release 2026-08-03 (11 days) · last repo commit 2026-08-03 · 414 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 2,273,028 downloads/mo, #3,176 on PyPI
Alternatives
Verify before relying
pip install stone
stone -h
Or with manual dependency setup:
pip install packaging Jinja2
python -m stone.cli -h- Whether the builtin backends (Javascript, Python, Obj-C, Swift, Typescript) are sufficient for your target languages or if you need to write a custom backend.
- Performance characteristics when processing large or complex API specifications.
- Maturity and stability of the JSON serialization scheme and msgpack support mentioned in the documentation.
What it is and what it does
Stone is an interface description language (IDL) and code-generation framework developed and actively used by Dropbox for their v2 API. You write your API specification once in Stone's language, then use backends (code generators) to automatically produce client libraries and server stubs in your choice of target languages. The package includes builtin backends for Javascript, Python, Obj-C, Swift, and Typescript, and provides a Python interface for writing custom backends to generate code for any target.
The core problem Stone solves is decoupling API specifications from SDK implementations—instead of maintaining separate SDKs in multiple languages that drift out of sync, you maintain a single spec and regenerate all client libraries from it. It also provides a single source of truth for API documentation and enforces consistency across your API design. Stone makes no assumptions about the protocol layer or RPC framework, focusing purely on data type and endpoint specification.
Use it for
- Generate client libraries in multiple languages from a single API specification for a multi-platform service.
- Maintain consistency and documentation across multiple language-specific SDKs by regenerating them from a canonical spec.
- Define custom code generators for proprietary or domain-specific languages by implementing a Stone backend.
- Evolve an API specification over time while automatically updating all generated client code to match the new schema.
- Decouple API design from SDK implementation so product teams can define APIs without needing expertise in every target language.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you are building or maintaining an API that needs to be consumed by clients in multiple programming languages.
Stone is production-grade, actively maintained, has no known vulnerabilities, and solves a real problem at scale. Install friction is minimal. If you only need SDKs in one or two languages or are not responsible for maintaining API consistency across multiple implementations, it may be overkill.
Install
stone on PyPI
Before you install
Low friction installation as a pure Python wheel with only two runtime dependencies. The project is actively maintained with a recent release and has been in production use since 2016.
Requires Python 3.11 or later.
License in practice
MIT license permits commercial and private use with minimal restrictions; you may use, modify, and distribute Stone freely as long as you include the license notice.
Quickstart
pip install stone
stone -h
Or with manual dependency setup:
pip install packaging Jinja2
python -m stone.cli -hVerify before relying
- Whether the builtin backends (Javascript, Python, Obj-C, Swift, Typescript) are sufficient for your target languages or if you need to write a custom backend.
- Performance characteristics when processing large or complex API specifications.
- Maturity and stability of the JSON serialization scheme and msgpack support mentioned in the documentation.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.11 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 2 packagespackagingJinja2 |
| Maintenance | Actively maintained 11 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 2,273,028 / month, #3,176 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 :: DevelopersOperating System :: OS IndependentProgramming Language :: Python :: 3Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Topic :: Software Development :: Code GeneratorsTopic :: Software Development :: Libraries :: Python Modules |
Evidence: stone-3.5.4-py3-none-any.whl
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