> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.instabase.com/flow/step-config-reference/apply-classifier/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.instabase.com/_mcp/server.

# Apply classifier

> Classify records using rule-based, code-driven split classification.

Enterprise Single-tenant

The *Apply classifier* step runs rule-based split classification using a custom Python classifier. Use it when you want code-driven, deterministic class assignments, for example rule-based routing, keyword or layout heuristics, or cases where external context is needed before classification. The step links to a classifier module (a classifier file) in your flow.

> **Note**
>
> For classification that uses a large language model with a schema you define, use the [Agent classifier](/flow/step-config-reference/apply-agent-classifier) step.

## Split PDF, TIF, and TIFF files

The **Split PDF and TIF source files** option, if enabled, splits and groups pages in PDF, TIF, and TIFF files into separate records according to their class. Split documents are assigned file names that indicate the original document, the assigned class, and the range of pages included.

For example, if pages 1–5 of a 10-page PDF file named `input.pdf` are classified as `class_name_1` and pages 6–10 are `class_name_2`, then:

* `labeled_outputs/class_name_1/input.class_name_1-1-5.pdf` contains pages 1–5 of `input.pdf`

* `labeled_outputs/class_name_2/input.class_name_2-6-10.pdf` contains pages 6–10 of `input.pdf`

> Classify records using rule-based, code-driven split classification.