sigtools
Utilities for working with inspect.Signature objects.
Decision gist · record as of 2026-08-14
Yes, but with caution. The package is stable and permissively licensed, with low install friction and no known vulnerabilities. However, it is abandoned—no maintenance since October 2022. Install it if you need signature introspection and manipulation for existing code or stable use cases, but do not rely on it for active development or expect security updates. Consider forking or finding an actively maintained alternative if you need ongoing support.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.6 or later.
- Low install friction with a single lightweight dependency (attrs).
- However, the package is abandoned—last release was in October 2022.
License · maintenance · safety
MIT (permissive) — MIT license is permissive and imposes no significant restrictions on use, modification, or redistribution in most contexts.
last release 2022-10-13 (1401 days)
0 known vulnerabilities (OSV.dev, 2026-08-14) · 836,195 downloads/mo, #4,933 on PyPI
Alternatives
Verify before relying
pip install sigtools
import sigtools
# Resolve a function's signature, accounting for decorators
sig = sigtools.signature(some_function)- Whether the package's decorator and signature-manipulation features work correctly with Python versions beyond 3.9 despite abandonment.
- Whether existing code depending on sigtools continues to function in current production environments without maintenance patches.
What it is and what it does
Sigtools is a library for working with Python function signatures at runtime. It provides tools to resolve the true signature of a function even when decorators have wrapped or modified it, and utilities to define keyword-only parameters, annotations, and positional-only parameters in a way that can be introspected. The library also includes decorators for specifying how *args and **kwargs are handled, and function combination routines that preserve signature metadata.
The package is most useful for library authors and framework developers who need to preserve or manipulate callable signatures through layers of decoration, or who want to provide introspectable APIs with explicit parameter handling. It depends only on attrs and installs with low friction.
Use it for
- Decorators that need to preserve the original function's signature so introspection tools see the correct parameters.
- Building frameworks where *args/**kwargs handling must be explicitly documented and introspectable by tools.
- Libraries that wrap functions and need to expose the wrapped function's true signature to callers.
- Code requiring keyword-only or positional-only parameter syntax with explicit introspection support.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, but with caution.
The package is stable and permissively licensed, with low install friction and no known vulnerabilities. However, it is abandoned—no maintenance since October 2022. Install it if you need signature introspection and manipulation for existing code or stable use cases, but do not rely on it for active development or expect security updates. Consider forking or finding an actively maintained alternative if you need ongoing support.
Install
sigtools on PyPI
Before you install
Low install friction with a single lightweight dependency (attrs). However, the package is abandoned—last release was in October 2022. No active maintenance or security updates should be expected.
Requires Python 3.6 or later.
License in practice
MIT license is permissive and imposes no significant restrictions on use, modification, or redistribution in most contexts.
Quickstart
pip install sigtools
import sigtools
# Resolve a function's signature, accounting for decorators
sig = sigtools.signature(some_function)Verify before relying
- Whether the package's decorator and signature-manipulation features work correctly with Python versions beyond 3.9 despite abandonment.
- Whether existing code depending on sigtools continues to function in current production environments without maintenance patches.
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.6 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packageattrs |
| Maintenance | Abandoned 1,401 days since the last release |
| First released | |
| Downloads | 836,195 / month, #4,933 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 :: MIT LicenseOperating System :: OS IndependentProgramming Language :: Python :: 3Programming Language :: Python :: 3.4Programming Language :: Python :: 3.5Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Topic :: Software Development :: Libraries :: Python Modules |
Evidence: sigtools-4.0.1-py2.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 › “function signature inspection”
- sigtoolsSigtools provides utilities to inspect and manipulate Python function…
- funcsigsProvides Python function signature introspection (PEP 362) for Python…
- signifyValidates and inspects Windows Authenticode digital signatures…
Give your agent the search over MCP, or paste the wish link into any chat.
More Python Modules packages
Converts domain names between Unicode and ASCII-compatible encoding (Punycode) according to IDNA 2008 and Unicode Technical Standard 46, with security validation and broader script coverage than the standard library.
Install it if you work with internationalized domain names, need to validate domains, or use HTTP clients that depend on it transitively.
Setuptools is a Python build backend and package management tool that handles building, distributing, and installing Python packages, including support for C/C++ extension modules.
PyYAML parses and emits YAML 1.1 data format, enabling serialization and deserialization of configuration files and Python objects to and from human-readable YAML text.
Pydantic validates Python data structures against type hints, coercing and checking input at runtime to ensure it matches a declared schema.
Provides reusable metadata objects for use with PEP-593 `typing.Annotated` to express common constraints like bounds, collection sizes, and predicates on types.
Install it if you use or build libraries that need to express type constraints in a standardized, inspectable way—or if you want to annotate your own types with…
Provides runtime tools to inspect and introspect Python type annotations, enabling programmatic examination of type hints at execution time.
See also decopatch · funcsigs · wrapt · decorator · undecorated · makefun · griffe · typing-inspect · inspect2