---
title: "Standard library | Grafana Agent documentation"
description: "The standard library is a list of functions used in expressions when assigning values to attributes"
---

# Standard library

The standard library is a list of functions which can be used in expressions when assigning values to attributes.

All standard library functions are [pure functions](https://en.wikipedia.org/wiki/Pure_function): they will always return the same output if given the same input.

- [coalesce](/docs/agent/v0.43/flow/reference/stdlib/coalesce/)
- [concat](/docs/agent/v0.43/flow/reference/stdlib/concat/)
- [constants](/docs/agent/v0.43/flow/reference/stdlib/constants/)
- [env](/docs/agent/v0.43/flow/reference/stdlib/env/)
- [format](/docs/agent/v0.43/flow/reference/stdlib/format/)
- [join](/docs/agent/v0.43/flow/reference/stdlib/join/)
- [json\_decode](/docs/agent/v0.43/flow/reference/stdlib/json_decode/)
- [json\_path](/docs/agent/v0.43/flow/reference/stdlib/json_path/)
- [nonsensitive](/docs/agent/v0.43/flow/reference/stdlib/nonsensitive/)
- [replace](/docs/agent/v0.43/flow/reference/stdlib/replace/)
- [split](/docs/agent/v0.43/flow/reference/stdlib/split/)
- [to\_lower](/docs/agent/v0.43/flow/reference/stdlib/to_lower/)
- [to\_upper](/docs/agent/v0.43/flow/reference/stdlib/to_upper/)
- [trim](/docs/agent/v0.43/flow/reference/stdlib/trim/)
- [trim\_prefix](/docs/agent/v0.43/flow/reference/stdlib/trim_prefix/)
- [trim\_space](/docs/agent/v0.43/flow/reference/stdlib/trim_space/)
- [trim\_suffix](/docs/agent/v0.43/flow/reference/stdlib/trim_suffix/)