Add python client generator fixes

Author: Tommel71

clients/python-compat/README.md

@@ -0,0 +1,109 @@
+# Python Client Compatibility Layer
+
+This directory contains the backward compatibility layer for the OpenAPI v7 generated Python client.
+
+## Purpose
+
+The v7 OpenAPI generator produces clients with breaking changes from v5:
+- `@validate_call` rejects unknown kwargs like `async_req`
+- Union types (oneOf/anyOf) require `.actual_instance` access
+- ModelSimple wrappers removed (no more `.value` on Height, TxInputs, etc.)
+- Pydantic v2 models don't support dict-style access
+
+This compatibility layer patches the generated client to maintain backward compatibility with existing user code.
+
+## Files
+
+- `patch_compat.py` - Post-processing script that patches the generated client
+- `test_compat.py` - Comprehensive tests for backward compatibility
+- `README.md` - This file
+
+## Usage
+
+The patch script is called automatically by the Makefile after code generation:
+
+```bash
+cd clients/python
+make generate-openapi-client
+```
+
+To run just the compatibility tests:
+
+```bash
+python clients/python-compat/test_compat.py
+# Or specify a client directory:
+python clients/python-compat/test_compat.py clients/python
+```
+
+## What Gets Patched
+
+### 1. Compat Types (`compat.py`)
+
+- **CompatInt**: Integer subclass with `.value` property and arithmetic that preserves type
+- **CompatList**: List subclass with `.value` property
+- **DictModel**: Dict wrapper with attribute access for oneOf/anyOf models
+- **Height**: Alias for CompatInt
+
+### 2. Model Files
+
+- Height fields (`height`, `before_block`, `after_block`) wrapped in CompatInt
+- List fields (`inputs`, `outputs`, `actors`, `address`) wrapped in CompatList
+- OneOf models get transparent `__getattr__` delegation to `actual_instance`
+
+### 3. API Files
+
+- `@validate_call` replaced with `@validate_call_compat` that:
+  - Accepts `async_req`, `_preload_content`, `_return_http_data_only` kwargs
+  - Converts datetime to ISO 8601 strings for date parameters
+  - Submits to thread pool when `async_req=True`
+
+### 4. ApiClient
+
+- `pool_threads` parameter creates ThreadPoolExecutor for async support
+- List responses wrapped in CompatList
+- Headers properly converted to dict
+
+## Features
+
+### Arithmetic Preservation (Fix 3)
+```python
+h = CompatInt(100)
+result = h + 1  # Returns CompatInt(101), not plain int
+result.value    # Still works: 101
+```
+
+### Dict Protocol (Fix 2)
+```python
+d = DictModel({'a': 1, 'b': 2})
+'a' in d        # True
+len(d)          # 2
+list(d.keys())  # ['a', 'b']
+```
+
+### Serialization (Fix 4)
+```python
+import pickle, copy
+h = CompatInt(100)
+pickle.loads(pickle.dumps(h))  # CompatInt(100)
+copy.deepcopy(h)               # CompatInt(100)
+```
+
+### Caching (Fix 5)
+```python
+d = DictModel({'nested': {'x': 1}})
+d.nested is d.nested  # True (cached)
+```
+
+### Thread Pool (Fix 1)
+```python
+# Default pool_threads=1 now creates a thread pool
+with ApiClient(config, pool_threads=1) as client:
+    api = AddressesApi(client)
+    result = api.get_address("btc", "addr", async_req=True)
+    data = result.get()  # Blocks until complete
+```
+
+## Known Limitations
+
+- Nested lists in models are not wrapped in CompatList (only top-level)
+- Thread pool warning when `async_req=True` but `pool_threads=0`