# Call a UDF from Cypher

> Invoke registered UDFs within Cypher queries using LibraryName.FunctionName() syntax

- Skill: `falkordb/call-a-udf-from-cypher` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add falkordb/call-a-udf-from-cypher`
- Raw SKILL.md: https://api.skillmd.com/api/skills/falkordb/call-a-udf-from-cypher/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: falkordb (https://skillmd.com/u/falkordb)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/falkordb/call-a-udf-from-cypher

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# Call a UDF from Cypher

Invoke registered UDFs within Cypher queries as if they were built-in functions.

## Usage

Reference UDFs using the library namespace followed by the function name (e.g., `LibraryName.FunctionName()`).

## Example

```python
from falkordb import FalkorDB

db = FalkorDB(host='localhost', port=6379)
g = db.select_graph("social")
result = g.query("RETURN StringUtils.UpperCaseOdd('abcdef')").result_set
print(result)
```

## Notes

- UDFs are called using `LibraryName.FunctionName()` syntax
- They can be used anywhere built-in functions can be used
- UDFs can be part of `RETURN`, `WHERE`, `SET`, or other Cypher clauses
- Arguments are passed just like built-in functions
- Return values follow JavaScript type conversion rules