polylith-dependency-visualization

name	polylith-dependency-visualization
description	Visualize **brick × brick** dependencies with `poly deps` — find circular dependencies, inspect a brick's public interface, and detect interface-bypass violations. Use for "what depends on what", "circular deps", "interface violation". For brick × project usage, use `polylith-workspace-inspection`.

Dependency Visualization Skill

Quick command

uv run poly deps

Command prefix: If you do not know the package manager, list lock files with ls uv.lock poetry.lock pdm.lock 2>/dev/null (a pyproject.toml is always present, so it tells you nothing on its own). Use uv run poly (uv), poetry poly (poetry), pdm run poly (pdm), hatch run poly (hatch), or poly (activated venv). Examples below use uv run.

poly deps vs poly info:

• poly deps → brick × brick (dependencies between bricks; interface compliance).
• poly info → brick × project (which projects use which brick). Load polylith-workspace-inspection. ⚠ poly deps does not fail on warnings (circular deps, interface violations are informational). For pass/fail, use poly check (load polylith-check).

Command reference

Option	Default	Description
--brick	—	Restrict output to the named brick.
--interface	false	Show the brick's public interface and flag bricks that bypass it.
--save	false	Persist the report to a file under the workspace's output dir.
--directory	cwd	Restrict analysis to projects whose path matches this directory.

Examples

# Full matrix
uv run poly deps

# One brick + interface compliance check
uv run poly deps --brick message --interface

# Save report
uv run poly deps --save

Output format

                         d   g
                         a   r           m
                         t   e           e   s
                         a   e   k       s   c
                         b   t   a       s   h
                         a   i   f   l   a   e
                         s   n   k   o   g   m
  brick                  e   g   a   g   e   a
 ─────────────────────────────────────────────
  greeting               -   -   -   -   -   -
  kafka                  -   -   -   ✔   -   -
  message                ✔   -   ✔   -   -   ✔
  greet_api              -   ✔   -   ✔   -   -

✔ = row brick imports column brick.

Warning messages

ℹ brick_a is used by brick_b and also uses brick_a.        # circular
ℹ Found in brick_a: helloworld is not part of the public interface of brick_b.   # interface violation

Fixing an interface violation

When --interface reports a violation:

1. Identify the offending import in the violating brick (e.g. from <ns>.brick_b.internal import helloworld).
2. Add helloworld to <ns>/brick_b/__init__.py:

   from <ns>.brick_b.internal import helloworld
   

3. Update the importer to from <ns>.brick_b import helloworld.
4. Re-run poly deps --interface to confirm.

Notes for the agent

• Circular deps usually mean two bricks share a concept that should be extracted into a third brick — flag this for the user; don't silently break the cycle by hiding imports.