diff --git a/mobile/.easignore b/mobile/.easignore
new file mode 100644
index 0000000..567c90c
--- /dev/null
+++ b/mobile/.easignore
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+# EAS Build archive exclusions — see mobile/.gitignore for the reasoning
+# behind most of these; this file matters because EAS's archiving isn't
+# strictly limited to git-tracked files, so untracked local artifacts
+# (an accidental `expo prebuild`/`expo run:android` output, IDE state,
+# etc.) can otherwise get swept into the upload.
+
+# Local native prebuild output — regenerated fresh by EAS's Continuous
+# Native Generation from app.json on every build. Keeping this out of the
+# archive isn't just about upload size: if either folder is present, EAS
+# treats the project as "bare workflow" and builds it as-is instead of
+# regenerating from app.json, silently ignoring app.json changes.
+/android
+/ios
+
+.idea
+.expo
+.vscode
+
+# Never needed — EAS installs dependencies itself on the build worker.
+node_modules
+
+# Not part of this app.
+.git