Backends

How to enable specific functionality.

---

Pants has some basic, non-language-specific functionality built in to its core. For example, you can count the lines of code under some directory in your repo:

Bash

$ ./pants count-loc 'src/**'
───────────────────────────────────────────────────────────────────────────────
Language                 Files     Lines   Blanks  Comments     Code Complexity
───────────────────────────────────────────────────────────────────────────────
Python                      13       155       50        22       83          5
BASH                         2       261       29        22      210         10
JSON                         2        25        0         0       25          0
...

However most Pants functionality, including all language-specific functionality, is provided via backends.

A backend is a Python package that implements some required functionality, and uses hooks to register itself with Pants. You enable a backend by listing it under the backend_packages config key in pants.toml.

For example, to enable Python support:

pants.toml

[GLOBAL]
backend_packages = ["pants.backend.python"]