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

# Post-Extraction Filtering

> Filter extraction results to keep only the data that matches your conditions

# Post-Extraction Filtering

**Post-extraction filtering** lets you define conditions that extraction results must match. Only items that pass the filter are kept — everything else is discarded. This runs after extraction, so you're filtering structured data, not raw HTML.

## When to use filters

* Keep only products above a price threshold
* Exclude items in certain categories
* Match URLs against a pattern
* Filter for items that have a specific field present
* Combine conditions with AND/OR logic

## Filter structure

A filter configuration has two parts:

1. **Mode** — `all` (AND) or `any` (OR)
2. **Conditions** — a list of field/operator/value checks

```json theme={null}
{
  "mode": "all",
  "conditions": [
    {"field": "price", "operator": "gt", "value": "50"},
    {"field": "category", "operator": "contains", "value": "electronics"}
  ]
}
```

With `mode: "all"`, an item must match **every** condition. With `mode: "any"`, an item matches if **at least one** condition is true.

## Operator reference

| Operator       | Description                       | Requires `value` |
| -------------- | --------------------------------- | :--------------: |
| `contains`     | Field contains substring          |        Yes       |
| `not_contains` | Field does not contain substring  |        Yes       |
| `equals`       | Exact match                       |        Yes       |
| `not_equals`   | Not an exact match                |        Yes       |
| `regex_match`  | Regex pattern match               |        Yes       |
| `exists`       | Field exists and is non-empty     |        No        |
| `not_exists`   | Field is missing or empty         |        No        |
| `gt`           | Greater than (numeric comparison) |        Yes       |
| `lt`           | Less than (numeric comparison)    |        Yes       |

All string operators support an optional `case_sensitive` flag (default: `false`).

## Where filters apply

### Strategy generation

Pass a `filter_config` when generating a strategy to filter results at extraction time:

```python theme={null}
result = client.generate_strategy(
    url="https://shop.com/products",
    description="Extract product listings",
    name="Premium Products",
    filter_config={
        "mode": "all",
        "conditions": [
            {"field": "price", "operator": "gt", "value": "100"},
            {"field": "in_stock", "operator": "equals", "value": "true"}
        ]
    }
)
```

### Strategy updates

Update an existing strategy's filter:

```bash theme={null}
curl -X PATCH https://api.meter.sh/api/strategies/{strategy_id} \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "filter_config": {
      "mode": "any",
      "conditions": [
        {"field": "category", "operator": "equals", "value": "electronics"},
        {"field": "category", "operator": "equals", "value": "computers"}
      ]
    }
  }'
```

### Workflow edges

Filters on workflow edges control which results pass between nodes. See [Workflows](/concepts/workflows#filters) for details.

```python theme={null}
from meter_sdk.workflow import Workflow, Filter

workflow = Workflow("Filtered Pipeline")
index = workflow.start("index", index_strategy_id, urls=["https://news.com"])

# Only pass articles in the technology section
tech = index.then(
    "tech",
    article_strategy_id,
    url_field="link",
    filter=Filter.contains("category", "technology")
)
```

### Watch creation

Pass `filter_config` when creating a watch (combined strategy + schedule):

```bash theme={null}
curl -X POST https://api.meter.sh/api/watch \
  -H "Authorization: Bearer sk_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://jobs.com/listings",
    "description": "Extract job listings",
    "name": "Remote Jobs",
    "interval_seconds": 3600,
    "filter_config": {
      "mode": "all",
      "conditions": [
        {"field": "location", "operator": "contains", "value": "remote"}
      ]
    }
  }'
```

## Examples

### Price threshold filtering

Keep only items above a minimum price:

```json theme={null}
{
  "mode": "all",
  "conditions": [
    {"field": "price", "operator": "gt", "value": "50"}
  ]
}
```

### Category filtering with OR logic

Keep items in any of several categories:

```json theme={null}
{
  "mode": "any",
  "conditions": [
    {"field": "category", "operator": "equals", "value": "electronics"},
    {"field": "category", "operator": "equals", "value": "computers"},
    {"field": "category", "operator": "equals", "value": "phones"}
  ]
}
```

### Regex URL pattern matching

Keep items whose URL matches a pattern:

```json theme={null}
{
  "mode": "all",
  "conditions": [
    {"field": "url", "operator": "regex_match", "value": "/products/\\d+$"}
  ]
}
```

### Combined AND conditions

Keep only in-stock premium products:

```json theme={null}
{
  "mode": "all",
  "conditions": [
    {"field": "price", "operator": "gt", "value": "100"},
    {"field": "in_stock", "operator": "equals", "value": "true"},
    {"field": "image_url", "operator": "exists"}
  ]
}
```

## Next steps

<CardGroup cols={2}>
  <Card title="Strategies" icon="brain" href="/concepts/strategies">
    Apply filters during strategy generation
  </Card>

  <Card title="Workflows" icon="diagram-project" href="/concepts/workflows">
    Use filters on workflow edges between nodes
  </Card>

  <Card title="Output Schemas" icon="table" href="/concepts/output-schemas">
    Define extraction result structure
  </Card>

  <Card title="Strategy API" icon="brackets-curly" href="/api-reference/rest/strategies">
    Update strategy filters via REST API
  </Card>
</CardGroup>

## Need help?

Email me at [mckinnon@meter.sh](mailto:mckinnon@meter.sh)