> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mellea.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# mellea.backends.model_options

> Common ModelOptions for Backend Generation.

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Common ModelOptions for Backend Generation.

## Classes

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#4ADE8033]/20 text-[#15803D]">CLASS</span> `ModelOption` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/backends/model_options.py#L8" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

A type that wraps around model options.

Uses sentinel values (wrapped by @@@) to provide backend and model-agnostic keys for common model options.

Create a dictionary containing model options like this:

```python theme={null}
from mellea.backends import ModelOption
model_options = {{
    ModelOption.TEMPERATURE : 0.0,
    ModelOption.SYSTEM_PROMPT : "You are a helpful assistant"
}}
```

**Attributes:**

* `TOOLS`: Sentinel key for a list or dict of [`MelleaTool`](tools#class-melleatool) instances to expose for tool calling.
* `TOOL_CHOICE`: Key for tool choice strategy (passed through to the backend).
* `MAX_NEW_TOKENS`: Sentinel key for the maximum number of new tokens to generate.
* `SYSTEM_PROMPT`: Sentinel key for the system prompt string.
* `TEMPERATURE`: Key for the sampling temperature (passed through to the backend).
* `CONTEXT_WINDOW`: Sentinel key for the context window size.
* `THINKING`: Sentinel key for enabling/configuring reasoning/thinking mode.
* `SEED`: Sentinel key for the random seed for reproducible generation.
* `STREAM`: Sentinel key for enabling streaming responses.

<div className="h-8" />

**Methods:**

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#### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#3064E3]/20 text-[#1D4ED8]">FUNC</span> `replace_keys` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/backends/model_options.py#L50" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python theme={null}
replace_keys(options: dict, from_to: dict[str, str]) -> dict[str, Any]
```

Return a new dict with selected keys in `options` renamed according to `from_to`.

Returns a new dict with the keys in `options` replaced with the corresponding value for that key in `from_to`.

* Any key with value == None is treated the same as the key missing.

* If the destination key already exists in `options`, the original value is kept in the output.

* Regardless of the presence of the destination key in `options`,
  the source key is always absent in the output.

Example:

```python theme={null}
>>> options = {{"k1": "v1", "k2": "v2", "M1": "m1"}}
>>> from_to = {{"k1": "M1", "k2": "M2"}}

>>> new_options = replace_keys(options, from_to)
>>> print(new_options)
... {{"M1": "m1", "M2": "v2"}}
```

* Notice that "M1" keeps the original value "m1", rather than "v1".
* Notice that both "k1" and "k2" are absent in the output.

**Args:**

* `options`: The source dictionary whose keys may be renamed.
* `from_to`: Mapping of old key names to new key names.

**Returns:**

* dict\[str, Any]: A new dictionary with the specified keys renamed.

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#### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#3064E3]/20 text-[#1D4ED8]">FUNC</span> `remove_special_keys` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/backends/model_options.py#L122" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python theme={null}
remove_special_keys(model_options: dict[str, Any]) -> dict[str, Any]
```

Return a copy of `model_options` with all sentinel-valued keys removed.

Sentinel keys are those whose names start with `@@@` (e.g. `ModelOption.TOOLS`).
These are Mellea-internal keys that must not be forwarded to backend APIs.

**Args:**

* `model_options`: A model options dictionary that may contain sentinel keys.

**Returns:**

* dict\[str, Any]: A new dictionary with all `@@@`-prefixed keys omitted.

<div className="w-full h-px bg-gray-200 dark:bg-gray-700 my-4" />

#### <span className="ml-2 inline-flex items-center rounded-full px-2 py-1 text-[0.7rem] font-bold tracking-wide bg-[#3064E3]/20 text-[#1D4ED8]">FUNC</span> `merge_model_options` <sup><a href="https://github.com/generative-computing/mellea/blob/v0.6.0/mellea/backends/model_options.py#L141" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python theme={null}
merge_model_options(persistent_opts: dict[str, Any], overwrite_opts: dict[str, Any] | None) -> dict[str, Any]
```

Merge two model-options dicts, with `overwrite_opts` taking precedence on conflicts.

Creates a new dict that contains all keys and values from persistent opts and overwrite opts.
If there are duplicate keys, overwrite opts key value pairs will be used.

**Args:**

* `persistent_opts`: Base model options (lower precedence).
* `overwrite_opts`: Per-call model options that override
  `persistent_opts` on key conflicts; `None` is treated as empty.

**Returns:**

* dict\[str, Any]: A new merged dictionary.

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