WSME

0.12.1 verified Fri May 01 auth: no python

WSME (Web Service Made Easy) simplifies writing REST APIs by using Python type annotations to define web service protocols, supporting JSON and XML. Version 0.12.1 is the latest stable release, with a maintenance cadence.

pip install wsme

Common errors

error No module named 'wsmeext' ↓

cause wsmeext subpackage removed in version 0.12; previously housed extensions like pecan.

fix

Use the replacement package eg 'pecan-wsme' or 'wsme' core only.

error ImportError: cannot import name 'WSPromise' from 'wsme' ↓

cause Older version of wsme (<0.11) didn't export WSPromise from the top level.

fix

Upgrade wsme to 0.11 or later: pip install wsme>=0.11

Warnings

breaking WSME 0.12 removed support for Python 2 and dropped the wsmeext.pecan module. Users must migrate to Python 3.8+ and use pecan-wsme instead. ↓

fix Upgrade to Python >=3.8 and replace 'from wsmeext.pecan import ...' with 'from pecan_wsme import ...' (install pecan-wsme).

deprecated Importing types from wsme.api is deprecated; use from wsme import types instead. ↓

fix Change imports to 'from wsme import types'.

gotcha Type annotations must be strings (types.text) not Python builtins (str). Using builtins may cause serialization errors. ↓

fix Always use wsme.types types, e.g., types.text, types.int, etc.

Imports

WSPromise
wrong
```
from wsme.api import WSPromise
```
correct
```
from wsme import WSPromise
```
WSPromise is now a top-level export; importing from wsme.api is deprecated and may break in future versions.
types
wrong
```
import wsme.types
```
correct
```
from wsme import types
```
Use from wsme import types for consistency with the package's intended use.

Quickstart

Define a simple web service with WSME using type annotations and WSPromise.

from wsme import WSPromise, types

class MyService:
    @WSPromise(returns=types.text)
    def greet(self, name: types.text) -> str:
        return f"Hello, {name}!"

if __name__ == '__main__':
    # In a real app, you would set up a WSGI server
    pass