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

# PostProcessor

`PostProcessor` operators apply labels on anomalies returned by `AnomalyDetector` operators. Labels can be filters, priorities or any metadata that can help when investigating an anomaly. Filtered anomalies are not notified, and by default they are hidden in the anomalies list and charts.

`PostProcessor` can use side inputs and be chained.

There are many types of post-processors detectors. The `type` is given in the node parameters.

```json theme={null}
 {
  "name": "root",               # name of the operator
  "type": "PostProcessor",      # type of operator
  "params": {
    "type": "COLD_START",       # type of post-processor
    # other parameters ...
    "component.ignore": "true",
    ...
  },
  "inputs" : [
    {
      "sourcePlanNode": "anomalyDetector"
    },
    ... # other optional inputs
  ],
  "outputs" : [...]
}
```

## Inputs

Anomalies inputs are passed with the `sourcePlanNode` name only:

```json theme={null}
"inputs" : [
    {
      "sourcePlanNode": "anomalyDetector"
    }
 ]
```

The post-processor automatically finds the detection result and the data that was used.
To chain post-processor operators, apply the next post-processor to the previous post-processor. See [example here](https://github.com/startreedata/thirdeye/blob/master/thirdeye-plugins/thirdeye-bootstrap-open-core/src/main/resources/alert-templates/startree-threshold.json).

Other side-inputs should be passed with the usual standard:

```json theme={null}
"inputs" : [
    {
      "targetProperty": "current",
      "sourcePlanNode": "controlSideInputData",
      "sourceProperty": "controlSideData"
    }
 ]
```

Refer to the sub-sections for side inputs.

## Shared parameters

Post-processors share a set of parameters. Type specific parameters are described in the sub-sections.

| name               | description                                                                                                   | default value |
| ------------------ | ------------------------------------------------------------------------------------------------------------- | ------------- |
| `type`             | The type of post-processor.                                                                                   |               |
| `component.ignore` | If true, anomalies that match the rule will be filtered. The default behaviour depends on the post-processor. |               |