diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5fbaec1..aa6f394 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,7 @@ first public release
 - **makefile `deps` target** — added `make deps` to automatically install `libpam0g-dev` and `build-essential`, and verify go is present
 - **readme overhaul** — rewrote for clarity: added "what problem does this solve", "how it works", known issues, simpler install instructions, and proper dependency listing
 - **view cleanup** — removed the non-functional automata background overlay from `View()` (the `Frame()` was never called, and the black-space placeholder caused `EEEE` garbage characters on some terminals). also removed a hardcoded 80-char width on the top bar so it adapts to the terminal
+- **session environment setup** — `spawnSession` now calls `SetBasicVariables`, `SetDisplay`, `SetSessionParams`, `SetSeatVars`, `SetSessionVars`, and `SetXDGCommonPaths` before spawning the desktop. fixes `setupX` failing immediately with `missing DISPLAY/XDG_VTNR/HOME env vars` because none were set
 
 ### What's Missing
 
diff --git a/src/main.go b/src/main.go
index 005b939..e1161bb 100644
--- a/src/main.go
+++ b/src/main.go
@@ -156,6 +156,16 @@ func spawnSession(res *login.Result) error {
 		return fmt.Errorf("pam session: %w", err)
 	}
 
+	session.SetBasicVariables(creds.Username, creds.HomeDir, creds.Shell, res.Config.InitialPath)
+	if res.Env.Kind == "x11" {
+		session.SetDisplay(res.Config.X11.Display)
+	}
+	session.RemoveXDG()
+	session.SetSessionParams(res.Env.Kind)
+	session.SetSeatVars(res.Config.TTY)
+	session.SetSessionVars(creds.UID)
+	session.SetXDGCommonPaths(creds.HomeDir)
+
 	sess, err := session.Spawn(&res.Env, creds.UID, creds.PrimaryGID, creds.AllGIDs, &res.Config)
 	if err != nil {
 		return fmt.Errorf("spawn: %w", err)