diff --git a/easel/src/app-server.mjs b/easel/src/app-server.mjs
index 687d472f10..2e5b90a259 100644
--- a/easel/src/app-server.mjs
+++ b/easel/src/app-server.mjs
@@ -53,11 +53,19 @@ export class AppServer extends EventEmitter {
     });
 
     createInterface({ input: this.child.stdout }).on("line", (line) => {
-      if (!line.trim()) return;
+      const trimmed = line.trim();
+      if (!trimmed) return;
       try {
-        this.#receive(JSON.parse(line));
+        this.#receive(JSON.parse(trimmed));
       } catch (error) {
-        this.emit("protocolError", new Error(`invalid engine message: ${error.message}`));
+        // See claude-server.mjs: a line that was meant to be JSON is a protocol
+        // fault; anything else is the CLI addressing a person and belongs in the
+        // log rather than in someone's transcript as an error.
+        if (trimmed.startsWith("{") || trimmed.startsWith("[")) {
+          this.emit("protocolError", new Error(`invalid engine message: ${error.message}`));
+        } else {
+          this.emit("log", trimmed);
+        }
       }
     });
 
diff --git a/easel/src/claude-server.mjs b/easel/src/claude-server.mjs
index 9dc66b3337..c30db50849 100644
--- a/easel/src/claude-server.mjs
+++ b/easel/src/claude-server.mjs
@@ -304,11 +304,26 @@ export class ClaudeServer extends EventEmitter {
     });
 
     createInterface({ input: child.stdout }).on("line", (line) => {
-      if (!line.trim()) return;
+      const trimmed = line.trim();
+      if (!trimmed) return;
       try {
-        this.#receive(JSON.parse(line));
+        this.#receive(JSON.parse(trimmed));
       } catch (error) {
-        this.emit("protocolError", new Error(`invalid engine message: ${error.message}`));
+        // A vendor CLI writes to stdout for two audiences: this protocol, and
+        // the person running it. Connector notices and model-catalog warnings
+        // arrive on the same pipe as the messages, and parsing them as protocol
+        // put "invalid engine message: Unexpected token" in the transcript for
+        // something that was never addressed to us.
+        //
+        // A line that opens with a brace or a bracket was meant to be JSON, and
+        // failing to parse that is a real protocol fault worth surfacing.
+        // Anything else is the CLI talking, and belongs in the log beside the
+        // stderr it would have used if it had chosen the other pipe.
+        if (trimmed.startsWith("{") || trimmed.startsWith("[")) {
+          this.emit("protocolError", new Error(`invalid engine message: ${error.message}`));
+        } else {
+          this.emit("log", trimmed);
+        }
       }
     });
     createInterface({ input: child.stderr }).on("line", (line) => {
diff --git a/slab/bin/slab-web b/slab/bin/slab-web
index f3a150a928..fcc4dd5a73 100755
--- a/slab/bin/slab-web
+++ b/slab/bin/slab-web
@@ -32,6 +32,29 @@ case "$url" in
   *)             url="https://aesthetic.computer/$url" ;;  # bare token → AC piece/$code
 esac
 
+# A preview window is small, and two of AC's defaults are tuned for a full
+# screen rather than a tile.
+#
+# The system paints its corner label at (6, 6) so a visitor can get back. In a
+# window a few hundred pixels wide that label is a sizeable fraction of the
+# frame and there is nowhere to go back to, so `nolabel` reclaims it.
+#
+# Density is an upscale factor, not a resolution: a higher number draws each AC
+# pixel across more screen pixels, so the canvas holds fewer, larger ones. The
+# name reads backwards and I had it backwards — measured at 420x300, density=0.5
+# was illegible, 1 was readable, 2 was comfortable. 2 it is: chunkier pixels,
+# which is what a piece being watched out of the corner of an eye wants.
+#
+# Only for aesthetic.computer: a file:// study or an arbitrary URL has no idea
+# what these mean.
+case "$url" in
+  https://aesthetic.computer/*|https://prompt.ac/*)
+    sep="?"
+    case "$url" in *\?*) sep="&" ;; esac
+    url="${url}${sep}nolabel&density=${SLAB_WEB_DENSITY:-2}"
+    ;;
+esac
+
 if [ "$CHROME" = "1" ]; then
   # Real Chrome, --app (frameless) mode, main profile (authed). Invoke the
   # binary directly so a running Chrome forwards the new app window into your