This is with my patch:
```python
>>> 
>>> 
>>> val = {"key": "Definitely \u0000 an \u200f annoying string \n"}
>>> api.add_json(val)
'QmXXPk1tvHa4CmtEcwd2XTruPqymXvGBH36hVB56hBke54'
>>> api.get_json('QmXXPk1tvHa4CmtEcwd2XTruPqymXvGBH36hVB56hBke54')
{'key': 'Definitely \x00 an \u200f annoying string \n'}
>>> 
>>> 
>>> 
```
https://ipfs.io/ipfs/QmXXPk1tvHa4CmtEcwd2XTruPqymXvGBH36hVB56hBke54