diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..5ac54fa
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,6 @@
+include LICENSE
+include README.md
+include pyproject.toml
+recursive-include src *.py
+global-exclude __pycache__
+global-exclude *.py[co]
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index e160108..fb58497 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,6 +35,11 @@ where = ["src"]
 
 [tool.setuptools]
 zip-safe = false
+include-package-data = true
+license-files = ["LICENSE"]
+
+[tool.setuptools.package-data]
+"*" = ["py.typed"]
 
 [project.urls]
 Homepage = "https://github.com/worsch/can-you-assist"
diff --git a/workplans/CYA-WP-0004-dev-install-and-release-packaging.md b/workplans/CYA-WP-0004-dev-install-and-release-packaging.md
index 0466ad4..41c7d72 100644
--- a/workplans/CYA-WP-0004-dev-install-and-release-packaging.md
+++ b/workplans/CYA-WP-0004-dev-install-and-release-packaging.md
@@ -122,19 +122,23 @@ completed: "2026-05-27"
 
 ```task
 id: CYA-WP-0004-T04
-status: todo
+status: done
 priority: high
 state_hub_task_id: "d49a3362-865f-4397-b127-372a2aa2c4a2"
+started: "2026-05-27 ralph iter 4"
+completed: "2026-05-27"
 ```
 
-- Adopt the modern `build` frontend (`python -m build`).
-- Ensure `pyproject.toml` + package data produces high-quality sdists and wheels.
-- Add or improve `MANIFEST.in` / `pyproject.toml` configuration so that necessary files (README, LICENSE, etc.) are included.
-- Verify that the resulting packages can be installed in a fresh environment and provide a working `cya` command.
+**Done.**
 
-**Acceptance criteria**:
-- `python -m build` produces a clean sdist and wheel.
-- The wheel installs correctly and `cya --version` works in an isolated environment.
+- Created `MANIFEST.in` for proper sdist inclusion.
+- Improved `pyproject.toml` (include-package-data, license-files under setuptools, package-data).
+- `python -m build` successfully produces clean sdist + wheel.
+- Verified in isolated venv: the wheel installs cleanly and `cya --version` works (shows proper dev version from setuptools_scm).
+
+**Acceptance criteria met**:
+- Clean, usable distribution packages can now be built.
+- They install and run correctly in fresh environments.
 
 ### T05 — Create a lightweight release process