nested Option Chain not working on indices

tried another example from the documentation:

It looks like it only works on stocks / ETF's. When trying to pull indices like 'SPX' or 'XSP' this throws an error.

My code:

from tastytrade.instruments import NestedOptionChain

n_chain = NestedOptionChain.get_chain(session, 'SPX')
print(n_chain.expirations[0].strikes[0])

## Does not work on SPX

The error message:

---------------------------------------------------------------------------
ValidationError                           Traceback (most recent call last)
Cell In[43], line 3
      1 from tastytrade.instruments import NestedOptionChain
----> 3 n_chain = NestedOptionChain.get_chain(session, 'SPX')
      4 print(n_chain.expirations[0].strikes[0])
      6 ## Does not work on SPX

File [~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/tastytrade/instruments.py:547](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/tastytrade/instruments.py:547), in NestedOptionChain.get_chain(cls, session, symbol)
    [543](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/tastytrade/instruments.py:543) validate_response(response)
    [545](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/tastytrade/instruments.py:545) data = response.json()['data']['items'][0]
--> [547](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/tastytrade/instruments.py:547) return cls(**data)

File [~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:341](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:341), in BaseModel.__init__(__pydantic_self__, **data)
    [339](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:339) values, fields_set, validation_error = validate_model(__pydantic_self__.__class__, data)
    [340](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:340) if validation_error:
--> [341](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:341)     raise validation_error
    [342](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:342) try:
    [343](https://file+.vscode-resource.vscode-cdn.net/Users/crg/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/~/VSCode_Python/VENVS/python_3_12/tasty_api/.venv/lib/python3.12/site-packages/pydantic/main.py:343)     object_setattr(__pydantic_self__, '__dict__', values)

ValidationError: 2 validation errors for NestedOptionChain
deliverables -> 0 -> symbol
  field required (type=value_error.missing)
deliverables -> 0 -> instrument-type
  field required (type=value_error.missing)

Pulling 'SPY', this works like a charm.

Did not find any documentation for Indices.

tastyware / tastytrade

nested Option Chain not working on indices #126