FYI: Multi-read optimization integrated into upstream python-snap7

.github/workflows/doc.yml

@@ -26,9 +26,7 @@ jobs:
         with:
           enable-cache: true
       - name: Install dependencies
-        run: |
-          uv venv
-          uv pip install ".[doc,cli]"
+        run: uv sync --extra doc --extra cli
       - name: Build documentation
         run: uv run sphinx-build -N -bhtml doc/ doc/_build -W
       - name: Upload Pages artifact
@@ -46,4 +44,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v5

.github/workflows/publish-pypi.yml

@@ -17,10 +17,12 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: "3.12"
-      - name: Install build
-        run: pip install build
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+        with:
+          enable-cache: true
       - name: Build distribution
-        run: python -m build
+        run: uv build
       - name: Upload artifact
         uses: actions/upload-artifact@v7
         with:

.github/workflows/publish-test-pypi.yml

@@ -16,10 +16,12 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: "3.12"
-      - name: Install build
-        run: pip install build
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+        with:
+          enable-cache: true
       - name: Build distribution
-        run: python -m build
+        run: uv build
       - name: Upload artifact
         uses: actions/upload-artifact@v7
         with:

.github/workflows/source-build.yml

@@ -23,13 +23,9 @@ jobs:
         uses: astral-sh/setup-uv@v7
         with:
           enable-cache: true
-      - name: Install build tools
-        run: |
-          uv venv
-          uv pip install build
       - name: Create source tarball
         run: |
-           uv run python -m build . --sdist
+           uv build --sdist
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v7

.github/workflows/test.yml

@@ -28,14 +28,6 @@ jobs:
         with:
           enable-cache: true
       - name: Install dependencies
-        run: |
-          uv venv --python python${{ matrix.python-version }}
-          uv pip install ".[test]"
+        run: uv sync --extra test --extra s7commplus --python python${{ matrix.python-version }}
       - name: Run pytest
-        run: uv run pytest --cov=snap7 --cov-report=xml --cov-report=term
-      - name: Upload coverage report
-        if: matrix.python-version == '3.13' && matrix.runs-on == 'ubuntu-24.04'
-        uses: actions/upload-artifact@v7
-        with:
-          name: coverage-report
-          path: coverage.xml
+        run: uv run pytest --cov=snap7 --cov-report=term

.gitignore

@@ -62,3 +62,4 @@ venv*/
 snap7.dll
 
 .claude/
+.hypothesis/

CHANGES.md

@@ -5,21 +5,43 @@ CHANGES
 -----
 
 Major release: python-snap7 is now a pure Python S7 communication library.
+This version completely breaks with the previous approach of wrapping the C snap7
+shared library. The entire S7 protocol stack is now implemented in pure Python,
+greatly improving portability and making it easier to install and extend.
 
 * **Breaking**: The C snap7 library is no longer required or used
 * Complete rewrite of the S7 protocol stack in pure Python
 * Native Python implementation of TPKT (RFC 1006) and COTP (ISO 8073) layers
 * Native S7 protocol PDU encoding/decoding
 * Pure Python server implementation for testing and simulation
-* No platform-specific binary dependencies
+* No platform-specific binary dependencies — works on any platform that runs Python
 * Improved error handling and connection management
 * Full type annotations with mypy strict mode
 * CLI interface for running an S7 server emulator (`pip install "python-snap7[cli]"`)
 
-If you experience issues with 3.0, pin to the last pre-3.0 release:
+If you experience issues with 3.0, please report them on the
+[issue tracker](https://github.com/gijzelaerr/python-snap7/issues) with a clear
+description and the version you are using. As a workaround, pin to the last
+pre-3.0 release:
 
     $ pip install "python-snap7<3"
 
+### Thanks
+
+Special thanks to the following people for testing, reporting issues, and providing
+feedback during the 3.0 development:
+
+* [@lupaulus](https://github.com/lupaulus) — extensive testing and bug reports
+* [@spreeker](https://github.com/spreeker) — testing and feedback
+* [@nikteliy](https://github.com/nikteliy) — review and feedback on the rewrite
+* [@amorelettronico](https://github.com/amorelettronico) — testing
+* [@razour08](https://github.com/razour08) — testing
+* [@core-engineering](https://github.com/core-engineering) — bug reports (#553)
+* [@AndreasScharf](https://github.com/AndreasScharf) — bug reports (#572)
+* [@Robatronic](https://github.com/Robatronic) — bug reports (#574)
+* [@hirotasoshu](https://github.com/hirotasoshu) — feedback (#545)
+* [@PoitrasJ](https://github.com/PoitrasJ) — bug reports (#479)
+
 1.2
 ---
 

CLAUDE.md

@@ -8,6 +8,7 @@ Python-snap7 is a pure Python S7 communication library for interfacing with Siem
 
 ## Key Architecture
 
+### snap7/ — Legacy S7 protocol (S7-300/400, PUT/GET on S7-1200/1500)
 - **snap7/client.py**: Main Client class for connecting to S7 PLCs
 - **snap7/server.py**: Server implementation for PLC simulation
 - **snap7/logo.py**: Logo PLC communication
@@ -19,6 +20,20 @@ Python-snap7 is a pure Python S7 communication library for interfacing with Siem
 - **snap7/type.py**: Type definitions and enums (Area, Block, WordLen, etc.)
 - **snap7/error.py**: Error handling and exceptions
 
+### s7/ — Unified client with S7CommPlus + legacy fallback
+- **s7/client.py**: Unified Client — tries S7CommPlus, falls back to snap7.Client
+- **s7/async_client.py**: Unified AsyncClient — same pattern, async
+- **s7/server.py**: Unified Server wrapping both legacy and S7CommPlus
+- **s7/_protocol.py**: Protocol enum (AUTO/LEGACY/S7COMMPLUS)
+- **s7/_s7commplus_client.py**: Pure S7CommPlus sync client (internal)
+- **s7/_s7commplus_async_client.py**: Pure S7CommPlus async client (internal)
+- **s7/_s7commplus_server.py**: S7CommPlus server emulator (internal)
+- **s7/connection.py**: S7CommPlus low-level connection
+- **s7/protocol.py**: S7CommPlus protocol constants/enums
+- **s7/codec.py**: S7CommPlus encoding/decoding
+- **s7/vlq.py**: Variable-Length Quantity encoding
+- **s7/legitimation.py**: Authentication helpers
+
 ## Implementation Details
 
 ### Protocol Stack
@@ -41,24 +56,31 @@ The library implements the complete S7 protocol stack:
 - Block operations (list, info, upload, download)
 - Date/time operations
 
-### Usage
+### Usage (unified s7 package — recommended for S7-1200/1500)
+
+```python
+from s7 import Client
+
+client = Client()
+client.connect("192.168.1.10", 0, 1)  # auto-detects S7CommPlus vs legacy
+data = client.db_read(1, 0, 4)
+client.disconnect()
+```
+
+### Usage (legacy snap7 package — S7-300/400)
 
 ```python
 import snap7
 
-# Create and connect client
 client = snap7.Client()
 client.connect("192.168.1.10", 0, 1)
 
-# Read/write operations
 data = client.db_read(1, 0, 4)
 client.db_write(1, 0, bytearray([1, 2, 3, 4]))
 
-# Memory area access
 marker_data = client.mb_read(0, 4)
 client.mb_write(0, 4, bytearray([1, 2, 3, 4]))
 
-# Disconnect
 client.disconnect()
 ```
 
@@ -98,15 +120,15 @@ pytest tests/test_client.py
 ### Code Quality
 ```bash
 # Type checking
-mypy snap7 tests example
+mypy snap7 s7 tests example
 
 # Linting and formatting check
-ruff check snap7 tests example
-ruff format --diff snap7 tests example
+ruff check snap7 s7 tests example
+ruff format --diff snap7 s7 tests example
 
 # Auto-format code
-ruff format snap7 tests example
-ruff check --fix snap7 tests example
+ruff format snap7 s7 tests example
+ruff check --fix snap7 s7 tests example
 ```
 
 ### Development with tox

Makefile

@@ -29,8 +29,8 @@ doc: .venv/bin/sphinx-build
 
 .PHONY: check
 check: .venv/bin/pytest
-	 uv run ruff check snap7 tests example
-	 uv run ruff format --diff snap7 tests example
+	 uv run ruff check snap7 s7 tests example
+	 uv run ruff format --diff snap7 s7 tests example
 
 .PHONY: ruff
 ruff: .venv/bin/tox

README.rst

@@ -1,25 +1,32 @@
-About
-=====
+.. image:: https://img.shields.io/pypi/v/python-snap7.svg
+   :target: https://pypi.org/project/python-snap7/
 
-Python-snap7 is a pure Python S7 communication library for interfacing with Siemens S7 PLCs.
+.. image:: https://img.shields.io/pypi/pyversions/python-snap7.svg
+   :target: https://pypi.org/project/python-snap7/
 
-Python-snap7 is tested with Python 3.10+, on Windows, Linux and OS X.
+.. image:: https://img.shields.io/github/license/gijzelaerr/python-snap7.svg
+   :target: https://github.com/gijzelaerr/python-snap7/blob/master/LICENSE
 
-The full documentation is available on `Read The Docs <https://python-snap7.readthedocs.io/en/latest/>`_.
+.. image:: https://github.com/gijzelaerr/python-snap7/actions/workflows/test.yml/badge.svg
+   :target: https://github.com/gijzelaerr/python-snap7/actions/workflows/test.yml
 
+.. image:: https://readthedocs.org/projects/python-snap7/badge/
+   :target: https://python-snap7.readthedocs.io/en/latest/
 
-Version 3.0 - Breaking Changes
-===============================
 
-Version 3.0 is a major release that rewrites python-snap7 as a pure Python
-implementation. The C snap7 library is no longer required.
+python-snap7
+============
 
-This release may contain breaking changes. If you experience issues, you can
-pin to the last pre-3.0 release::
+Python-snap7 is a pure Python S7 communication library for interfacing with
+Siemens S7 PLCs. It supports Python 3.10+ and runs on Windows, Linux, and macOS
+without any native dependencies.
 
-    $ pip install "python-snap7<3"
+The name "python-snap7" is historical — the library originally started as a
+Python wrapper around the `Snap7 <http://snap7.sourceforge.net/>`_ C library.
+As of version 3.0, the C library is no longer used, but the name is kept for
+backwards compatibility.
 
-The latest stable pre-3.0 release is version 2.1.0.
+The full documentation is available on `Read The Docs <https://python-snap7.readthedocs.io/en/latest/>`_.
 
 
 Installation
@@ -29,4 +36,71 @@ Install using pip::
 
    $ pip install python-snap7
 
-No native libraries or platform-specific dependencies are required - python-snap7 is a pure Python package that works on all platforms.
+No native libraries or platform-specific dependencies are required — python-snap7
+is a pure Python package that works on all platforms.
+
+
+Version 3.0 — Pure Python Rewrite
+==================================
+
+Version 3.0 was a ground-up rewrite of python-snap7. The library no longer wraps
+the C snap7 shared library — instead, the entire S7 protocol stack (TPKT, COTP,
+and S7) is implemented in pure Python.
+
+* **Portability**: No more platform-specific shared libraries (``.dll``, ``.so``, ``.dylib``).
+  Works on any platform that runs Python — including ARM, Alpine Linux, and other
+  environments where the C library was difficult or impossible to install.
+* **Easier installation**: Just ``pip install python-snap7``. No native dependencies,
+  no compiler toolchains, no manual library setup.
+* **Easier to extend**: New features and protocol support can be added directly in Python.
+
+**If you experience issues with 3.0:**
+
+1. Please report them on the `issue tracker <https://github.com/gijzelaerr/python-snap7/issues>`_.
+2. As a workaround, you can pin to the last pre-3.0 release::
+
+       $ pip install "python-snap7<3"
+
+   Documentation for pre-3.0 versions is available at
+   `Read The Docs <https://python-snap7.readthedocs.io/en/2.1.1/>`_.
+
+
+Version 3.1 — S7CommPlus Protocol Support (unreleased)
+=======================================================
+
+Version 3.1 adds support for the S7CommPlus protocol (up to V3), which is required
+for communicating with newer Siemens S7-1200 and S7-1500 PLCs that have PUT/GET
+disabled. This is fully backwards compatible with 3.0.
+
+The biggest change is the new ``s7`` module, which is now the recommended entry point
+for connecting to any supported S7 PLC::
+
+   from s7 import Client
+
+   client = Client()
+   client.connect("192.168.1.10", 0, 1)  # auto-detects S7CommPlus vs legacy S7
+   data = client.db_read(1, 0, 4)
+   client.disconnect()
+
+The ``s7.Client`` automatically tries S7CommPlus first, and falls back to legacy S7
+if the PLC does not support it. The existing ``snap7.Client`` continues to work
+unchanged for legacy S7 connections.
+
+**Help us test!** Version 3.1 needs more real-world testing before release. If you
+have access to any of the following PLCs, we would greatly appreciate testing and
+feedback:
+
+* S7-1200 (any firmware version)
+* S7-1500 (any firmware version)
+* S7-1500 with TLS enabled
+* S7-300
+* S7-400
+* S7-1200/1500 with PUT/GET disabled (S7CommPlus-only)
+* LOGO! 0BA8 and newer
+
+Please report your results — whether it works or not — on the
+`issue tracker <https://github.com/gijzelaerr/python-snap7/issues>`_.
+
+To install the development version::
+
+   $ pip install git+https://github.com/gijzelaerr/python-snap7.git@master

doc/API/async_client.rst

@@ -0,0 +1,49 @@
+AsyncClient
+===========
+
+.. warning::
+
+   The ``AsyncClient`` is **experimental**. The API may change in future
+   releases. If you encounter problems, please `open an issue
+   <https://github.com/gijzelaerr/python-snap7/issues>`_.
+
+The :class:`~snap7.async_client.AsyncClient` provides a native ``asyncio``
+interface for communicating with Siemens S7 PLCs.  It has feature parity with
+the synchronous :class:`~snap7.client.Client` and is safe for concurrent use
+via ``asyncio.gather()``.
+
+Quick start
+-----------
+
+.. code-block:: python
+
+   import asyncio
+   import snap7
+
+   async def main():
+       async with snap7.AsyncClient() as client:
+           await client.connect("192.168.1.10", 0, 1)
+           data = await client.db_read(1, 0, 4)
+           print(data)
+
+   asyncio.run(main())
+
+Concurrent reads
+----------------
+
+An internal ``asyncio.Lock`` serialises each send/receive cycle so that
+multiple coroutines can safely share a single connection:
+
+.. code-block:: python
+
+   results = await asyncio.gather(
+       client.db_read(1, 0, 4),
+       client.db_read(1, 10, 4),
+   )
+
+API reference
+-------------
+
+.. automodule:: snap7.async_client
+   :members:
+   :exclude-members: AsyncISOTCPConnection