# 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`         | ✓        | `-`     | The name of the CustomMetric to retrieve.            |
| `model_id` | `UUID \| str` | ✓        | `-`     | `UUID` or string identifier of the associated Model. |

### 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` | ✓        | `-`     | The unique identifier (`UUID`) of the CustomMetric to retrieve. Can be provided as a `UUID` object or string representation. |

### 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` | ✓        | `-`     | `UUID` or string identifier of the Model. |

### 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


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.fiddler.ai/api/fiddler-python-client-sdk/entities/custom-metric.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.