diff --git a/.gitignore b/.gitignore
index e0503a9..0a9e680 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,6 +42,7 @@ logo-options/
 .zed/keymap.json
 .zed/tasks.json
 .zed/sim
+.zed/run.sh
 buildServer.json
 
 # Generated by XcodeGen from project.yml
diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index 07a9d9f..919be54 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -56,6 +56,8 @@ Find your device UDID with `xcrun devicectl list devices`.
 ```bash
 just sim               # Build + install + launch on simulator (production API)
 just sim-local         # Build + install + launch on simulator (local/dev API)
+just sim-fresh         # Same as `just sim`, but uninstalls first (wipes app sandbox)
+just sim-local-fresh   # Same as `just sim-local`, but uninstalls first
 just device DEVICE_ID  # Build + install to a plugged-in iOS device
 just test              # Run tests (iPhone 17 Pro Max simulator)
 just generate          # Regenerate Xcode project from project.yml
@@ -64,4 +66,6 @@ just lint-fix          # Fix lint violations
 just release           # Bump build, archive, upload to App Store Connect
 ```
 
+The `*-fresh` variants `xcrun simctl uninstall` your app's bundle id before installing, which clears URLCache, UserDefaults, on-disk caches (FeedCache, LabelDefinitionsCache), and Documents/Caches. Pass `SIM_UDID=<udid>` to target a specific simulator (otherwise uses the booted one).
+
 > **Note:** The Xcode project is generated from `project.yml` — run `just generate` after adding or removing Swift files, or after pulling changes that touch `project.yml`.
diff --git a/docs/development.md b/docs/development.md
index 1f9246a..5883761 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -61,6 +61,8 @@ This bumps the build number, archives, and uploads to App Store Connect. Builds
 | `just generate` | Regenerate Xcode project from `project.yml` |
 | `just sim` | Build + run on booted simulator (production API) |
 | `just sim-local` | Build + run on booted simulator (local API) |
+| `just sim-fresh` | Same as `just sim`, but uninstalls first to wipe app sandbox (URLCache, UserDefaults, on-disk caches) |
+| `just sim-local-fresh` | Same as `just sim-local`, but uninstalls first |
 | `just device <udid>` | Build + install to plugged-in iPhone |
 | `just test` | Run tests |
 | `just format-fix` | Auto-fix formatting |
diff --git a/justfile b/justfile
index 23e998e..88ff40d 100644
--- a/justfile
+++ b/justfile
@@ -57,6 +57,27 @@ sim:
     xcrun simctl spawn "$SIM" log config --subsystem {{bundle_id}} --mode level:debug
     echo "Installed and launched on simulator (grain.social)"
 
+# Build + install + launch on simulator (production API, fresh — uninstalls app first
+# to wipe URLCache, UserDefaults, FeedCache, LabelDefinitionsCache, Documents/Caches, etc.)
+sim-fresh:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    SIM=${SIM_UDID:-booted}
+    xcrun simctl boot "$SIM" 2>/dev/null || true
+    xcrun simctl bootstatus "$SIM" -b >/dev/null
+    xcrun simctl uninstall "$SIM" {{bundle_id}} 2>/dev/null || true
+    SIM_UDID="$SIM" just sim
+
+# Build + install + launch on simulator (local/dev API, fresh — uninstalls app first)
+sim-local-fresh:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    SIM=${SIM_UDID:-booted}
+    xcrun simctl boot "$SIM" 2>/dev/null || true
+    xcrun simctl bootstatus "$SIM" -b >/dev/null
+    xcrun simctl uninstall "$SIM" {{bundle_id}} 2>/dev/null || true
+    SIM_UDID="$SIM" just sim-local
+
 # Run tests
 test:
     set -o pipefail && xcodebuild test -scheme Grain -destination 'platform=iOS Simulator,name=iPhone 17 Pro Max' PRODUCT_BUNDLE_IDENTIFIER={{bundle_id}} 2>&1 | xcbeautify