# Hidden IO

> Performing input/output inside a supposedly pure function, hiding side effects from callers.

Record: `lex:hidden-io`
Kind: anti-pattern
Layer: [Computation Core](https://banes-lab.com/records/layer/computation-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lex-hidden-io

## category

- [Correctness / Determinism / Verification](https://banes-lab.com/records/lex-category/correctness-determinism-verification.md)

## referenced-by

- [Pure Functions](https://banes-lab.com/records/arch/pure-functions.md)