diff --git a/mateclaw-ui/package.json b/mateclaw-ui/package.json
index 497643f4..49fae294 100644
--- a/mateclaw-ui/package.json
+++ b/mateclaw-ui/package.json
@@ -6,10 +6,10 @@
   "description": "MateClaw - Personal AI Assistant Web Console",
   "scripts": {
     "dev": "vite",
-    "build": "bash ../scripts/check-snowflake-precision.sh && node --max-old-space-size=6144 ./node_modules/vue-tsc/bin/vue-tsc.js --noEmit && node --max-old-space-size=6144 ./node_modules/vite/bin/vite.js build",
+    "build": "bash scripts/check-snowflake-precision.sh && node --max-old-space-size=6144 ./node_modules/vue-tsc/bin/vue-tsc.js --noEmit && node --max-old-space-size=6144 ./node_modules/vite/bin/vite.js build",
     "preview": "vite preview",
-    "lint": "eslint src --fix && bash ../scripts/check-snowflake-precision.sh",
-    "lint:precision": "bash ../scripts/check-snowflake-precision.sh",
+    "lint": "eslint src --fix && bash scripts/check-snowflake-precision.sh",
+    "lint:precision": "bash scripts/check-snowflake-precision.sh",
     "test": "vitest run",
     "test:watch": "vitest"
   },
diff --git a/mateclaw-ui/scripts/check-snowflake-precision.sh b/mateclaw-ui/scripts/check-snowflake-precision.sh
new file mode 100755
index 00000000..c2032ad4
--- /dev/null
+++ b/mateclaw-ui/scripts/check-snowflake-precision.sh
@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Snowflake ID precision checker for mateclaw-ui.
+#
+# Scans the Vue / TypeScript sources for patterns that round-trip a
+# backend-issued Snowflake ID through JS Number, silently truncating the
+# last digits whenever the value exceeds Number.MAX_SAFE_INTEGER (2^53-1).
+#
+# Backend-issued Snowflake IDs must remain strings throughout the UI because
+# JavaScript Number cannot exactly represent every 64-bit integer.
+#
+# Run locally from mateclaw-ui:
+#   bash scripts/check-snowflake-precision.sh
+#
+# Run in CI: invoked automatically from this package's `lint` and `build`
+# scripts. Keeping the checker inside mateclaw-ui also makes those commands
+# self-contained in the public repository, where private root scripts are not
+# published.
+#
+# Allowlisting a real exception:
+#   Append a trailing comment `// snowflake-precision-ok: <one-liner reason>`
+#   on the SAME line as the match. Only do this when the value is provably
+#   a small bounded integer (e.g. a per-stream sequence counter, a port
+#   number, a retry budget) — never as a shortcut to silence a real bug.
+#
+# Exit codes:
+#   0 — all checks clean
+#   1 — one or more violations found
+
+UI_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+UI_SRC="${UI_ROOT}/src"
+
+red()    { printf '\033[31m%s\033[0m\n' "$*"; }
+green()  { printf '\033[32m%s\033[0m\n' "$*"; }
+yellow() { printf '\033[33m%s\033[0m\n' "$*"; }
+
+if [[ ! -d "$UI_SRC" ]]; then
+  red "Missing UI src directory: $UI_SRC"
+  exit 1
+fi
+
+if ! command -v rg >/dev/null 2>&1; then
+  red "ripgrep (rg) is required. Install with: brew install ripgrep"
+  exit 1
+fi
+
+exit_code=0
+
+# Run one grep check. Hits carrying the allowlist annotation are skipped.
+#
+# Args:
+#   $1 — human-readable label printed when violations are found
+#   $2 — rg flags ("-n" for fixed-string-ish, "-nP" for PCRE)
+#   $3 — pattern
+run_check() {
+  local label="$1" flags="$2" pattern="$3"
+  local hits
+  # `|| true` so a "no match" exit-1 from rg doesn't trip `set -e`.
+  hits=$(rg $flags "$pattern" "$UI_SRC" 2>/dev/null | grep -vF 'snowflake-precision-ok' || true)
+  if [[ -n "$hits" ]]; then
+    red "✘ $label"
+    echo "$hits"
+    echo
+    exit_code=1
+  fi
+}
+
+# (1) v-model.number on a field whose name ends in Id — Vue's .number
+#     modifier runs looseToNumber on the bound value before write-back.
+run_check 'v-model.number bound to an *Id field' \
+  '-n' 'v-model\.number=".*[Ii]d"?'
+
+# (2) Number() / parseInt() / +id explicit coercion of an *Id-named value.
+run_check 'Number()/parseInt() on an *Id value' \
+  '-nP' '(Number|parseInt)\(\s*\w*[Ii]d\b'
+
+# (2b) Number()/parseInt() wrapping a member-access or call expression that
+#      ends in an id — e.g. Number(localStorage.getItem('mc-workspace-id')),
+#      Number(route.params.agentId), Number(store.currentKB.id). Check (2) only
+#      catches a bare *Id identifier; these compound forms slip past it but
+#      truncate just the same. The `\.[Ii]d\b` alternative covers a plain `.id`
+#      property access (e.g. `.currentKB.id)`) that the camelCase `[a-z]Id`
+#      and quoted `[Ii]d['"]` alternatives miss.
+run_check 'Number()/parseInt() on an *Id member-access / lookup' \
+  '-nP' '(Number|parseInt)\([^)]*(?:[a-z]Id\b|[Ii]d['"'"'"]|\.[Ii]d\b)'
+
+# (3) <input type="number"> v-modeled to an *Id field. Vue's vModelText
+#     runtime auto-applies looseToNumber whenever el.type === 'number',
+#     even WITHOUT the `.number` modifier, so the input type itself is
+#     the bug source.
+run_check 'input[type="number"] bound to an *Id field' \
+  '-nP' 'type="number"[^>]*v-model[^"]*[Ii]d"'
+
+# (4) `typeof xxxId === 'number'` presence checks. These silently drop the
+#     value when the backend hands us the string form (ToStringSerializer
+#     output), masking the real problem as "field unset".
+run_check "typeof <id> === 'number' silently drops string IDs" \
+  '-nP' "typeof\s+\S*[Ii]d\b\s*===\s*'number'"
+
+if [[ $exit_code -eq 0 ]]; then
+  green '✓ Snowflake ID precision check: clean'
+else
+  echo
+  red 'Snowflake ID precision violations found.'
+  yellow 'Keep backend-issued Snowflake IDs as strings throughout the UI.'
+  yellow 'If a hit is a confirmed small-integer exception, append'
+  yellow '`// snowflake-precision-ok: <reason>` on the same line.'
+fi
+
+exit $exit_code