> ## Documentation Index
> Fetch the complete documentation index at: https://ctrlrun-docs-python-3-13-3-14.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# InvalidArgument

> An argument cannot be accepted as given.

`ctrlrun.InvalidArgument` — class, defined at `src/ctrlrun/errors.py:8`

```python theme={null}
from ctrlrun import InvalidArgument
```

```python theme={null}
class InvalidArgument(CTRLRunError)
```

An argument cannot be accepted as given.

An Action field or argument that cannot be canonicalized (SPEC-v0.1 §2.3), and — the
same kind of wiring bug — a StateStore transition no record can make, such as committing
an effect nobody reserved.

## Next

* [Python API index](/docs/reference/api/index).
* [Get started](/docs/get-started/quickstart) · [Why](/docs/why).