Last updated: 2026-06-09. Governing law: Israel.
Open-Source Licenses and Attributions
The EyalSec / es2 Service and the es-python interpreter incorporate open-source software. This page summarizes the headline components and points to the full attributions. It does not replace the license texts, which govern.
es-python and CPython
es-python is a modified version of CPython 3.13. CPython is licensed under the Python Software Foundation (PSF) License Agreement, a permissive, GPL-compatible license. Our modifications add security instrumentation (taint tracking, fuzzing, and event reporting); the underlying interpreter remains CPython under the PSF License. The PSF License and copyright notices are retained as required.
Headline third-party components (summary)
| Component | Role | License (summary) |
|-----------|------|-------------------|
| CPython 3.13 | Base interpreter (modified into es-python) | PSF License Agreement |
| OpenSSL | TLS and cryptography (AES/RSA/TLS) used by Python's ssl/hashlib and by the platform | Apache License 2.0 (OpenSSL 3.x) |
| Cython | Building the compiled native extension(s) bundled with es-python | Apache License 2.0 |
| pip / setuptools / wheel | Python packaging tooling bootstrapped with es-python | MIT / MIT / MIT-style |
| Bootstrap | Front-end styling of the web dashboard | MIT License |
| Go modules (e.g., chi router, gorilla/sessions, pgx, AWS SDK for Go, goldmark, and others) | The es2 server, routing, sessions, database access, AWS integration, and Markdown rendering | Predominantly MIT / BSD / Apache-2.0 (see full attributions) |
The exact set and versions of bundled and linked components (including all Go module
dependencies and transitive dependencies) and their precise license texts are listed in
the bundled THIRD-PARTY-LICENSES.md and NOTICE files distributed with the
software. Those files are the authoritative attribution record; this page is a summary.
Trademark non-endorsement
- "Python" and the Python logos are trademarks of the Python Software Foundation
(PSF). EyalSec's use of "Python" (including in the name "es-python") is nominative,
to identify the underlying interpreter; it does not imply sponsorship, affiliation, or
endorsement by the PSF. (Use of the name "es-python" should be cleared with the PSF; see
/legal/export.) - "OpenSSL" is a trademark of the OpenSSL Software Foundation / OpenSSL project. Use here is descriptive and does not imply endorsement by the OpenSSL project.
- Other product and company names are the trademarks of their respective owners; their mention does not imply endorsement.
Source availability
For components whose licenses require offering source (and for the PSF-licensed CPython base), corresponding source or a written offer is available on request at eyal@eyalsec.com, and CPython source is publicly available from the PSF.