---
title: "Filter (Expression)"
description: "Local-first visual environment for building and running AI workflows. Build agents visually, deploy anywhere, privacy by design."
canonical: https://docs.nodetool.ai/nodes/nodetool/control/filterexpression
markdown: https://docs.nodetool.ai/nodes/nodetool/control/filterexpression.md
product: NodeTool
source: https://github.com/nodetool-ai/nodetool/blob/main/docs/nodes/nodetool/control/filterexpression.md
---

# Filter (Expression)

**Type:** `nodetool.control.FilterCode`

**Namespace:** `nodetool.control`

## Description

Pass items through when a safe expression returns truthy (comparisons, boolean logic, arithmetic, property access on `item`).
    filter, predicate, expression, condition, stream, where

    Use cases:
    - Keep items matching arbitrary criteria (e.g. item.score > 0.5)
    - Drop empty or malformed records
    - Custom field-based filtering

## Properties

| Property | Type | Description | Default |
|----------|------|-------------|---------|
| input_item | `any` | Streaming input — each item is tested against the predicate. | null |
| predicate | `str` | Safe expression evaluated per item (comparisons, boolean logic, arithmetic, property access). The current value is bound to `item`. Examples: `item > 0`, `item.score > 0.5`, `typeof item === 'string'`. | `true` |

## Outputs

| Output | Type | Description |
|--------|------|-------------|
| output | `any` |  |

## Related Nodes

Browse other nodes in the [nodetool.control](./) namespace.