# CustomMetric

Custom metric for monitoring business-specific and domain-specific KPIs.

CustomMetric enables creation of user-defined metrics that calculate specific values from model data using SQL-like expressions. Custom metrics extend Fiddler's built-in monitoring capabilities to support business requirements, domain-specific quality measures, and complex performance indicators.

## Example

```python
# Business conversion rate metric
conversion_rate = CustomMetric(
    name="weekly_conversion_rate",
    model_id=model.id,
    definition="sum(if(prediction_score > 0.7 and converted == 1, 1, 0)) / sum(if(prediction_score > 0.7, 1, 0))",
    description="Conversion rate for high-confidence predictions"
).create()

# Data quality metric
missing_rate = CustomMetric(
    name="feature_missing_rate",
    model_id=model.id,
    definition="sum(if(is_null(income), 1, 0)) / count(income)",
    description="Percentage of records with missing income values"
).create()

# Fairness metric
fairness_metric = CustomMetric(
    name="demographic_parity",
    model_id=model.id,
    definition="abs((sum(if(gender == 'Male', predicted_churn, 0)) / sum(if(gender == 'Male', 1, 0))) - (sum(if(gender == 'Female', predicted_churn, 0)) / sum(if(gender == 'Female', 1, 0))))",
    description="Demographic parity difference between gender groups"
).create()

# Use in alert rule
alert_rule = AlertRule(
    name="conversion_rate_alert",
    model_id=model.id,
    metric_id=conversion_rate.id,
    priority=Priority.HIGH,
    compare_to=CompareTo.TIME_PERIOD,
    condition=AlertCondition.LESSER,
    bin_size=BinSize.DAY,
    critical_threshold=0.15,  # Alert if conversion drops below 15%
    compare_bin_delta=7
).create()
```

{% hint style="info" %}
Custom metrics are calculated during data ingestion and monitoring cycles. Complex expressions may impact performance, so optimize for efficiency. Test expressions thoroughly before using in production alert rules.
{% endhint %}

## create()

Create a new CustomMetric on the Fiddler platform.

Registers this CustomMetric with the Fiddler platform. The expression must have a name, model\_id, and definition specified before calling create().

## Returns

The same CustomMetric instance with updated server-side attributes (id, created\_at, etc.).

## Raises

* **ApiError** -- If there's an error communicating with the Fiddler API.
* **Conflict** -- If a CustomMetric with the same name already exists for this model.

**Return type:** *CustomMetric*

## delete()

Delete this CustomMetric from the Fiddler platform.

Permanently removes the CustomMetric. This action cannot be undone. Any alert rules or monitors using this CustomMetric must be deleted first.

## Raises

* **NotFound** -- If the CustomMetric no longer exists.
* **ApiError** -- If there's an error communicating with the Fiddler API.
* **Conflict** -- If the CustomMetric is still being used by alert rules or monitors. **Return type:** None

## *classmethod* from\_name(name, model\_id)

Retrieve a CustomMetric by name and model.

Fetches a CustomMetric from the Fiddler platform using its name and associated model ID.

## Parameters

| Parameter  | Type   | Required | Default | Description                               |
| ---------- | ------ | -------- | ------- | ----------------------------------------- |
| `name`     | `str`  | ✗        | `None`  | The name of the CustomMetric to retrieve. |
| `model_id` | \`UUID | str\`    | ✗       | `None`                                    |

## Returns

The CustomMetric instance for the provided parameters.

## Raises

* **NotFound** -- If no CustomMetric exists with the specified name and model.
* **ApiError** -- If there's an error communicating with the Fiddler API.

**Return type:** *CustomMetric*

## *classmethod* get(id\_)

Retrieve a CustomMetric by its unique identifier.

Fetches a CustomMetric from the Fiddler platform using its UUID.

## Parameters

| Parameter | Type   | Required | Default | Description |
| --------- | ------ | -------- | ------- | ----------- |
| `id_`     | \`UUID | str\`    | ✗       | `None`      |

## Returns

The CustomMetric instance with all its configuration and metadata.

## Raises

* **NotFound** -- If no CustomMetric exists with the specified ID.
* **ApiError** -- If there's an error communicating with the Fiddler API.

**Return type:** *CustomMetric*

## *classmethod* get\_organization\_id()

Get the organization UUID from the global connection.

## Returns

Unique identifier of the organization associated with the current connection.

**Return type:** UUID

## *classmethod* get\_organization\_name()

Get the organization name from the global connection.

## Returns

Name of the organization associated with the current connection.

**Return type:** str

## *classmethod* list(model\_id)

List all CustomMetric instances for a model.

Retrieves all CustomMetric instances associated with a specific model.

## Parameters

| Parameter  | Type   | Required | Default | Description |
| ---------- | ------ | -------- | ------- | ----------- |
| `model_id` | \`UUID | str\`    | ✗       | `None`      |

## Yields

CustomMetric instances for each CustomMetric in the model.

## Raises

**ApiError** -- If there's an error communicating with the Fiddler API. **Return type:** *Iterator*\[*CustomMetric*]

## **init**(name, model\_id, definition, description=None)

Construct a custom metric instance.

**Return type:** None