diff --git a/lib/API.txt b/lib/API.txt
index d24317e..7aa63f9 100644
--- a/lib/API.txt
+++ b/lib/API.txt
@@ -42,6 +42,7 @@ _setup_nvidia_gpu
 _setup_rocm
 _tools_cleanup_temp_dirs
 _tools_register_temp_cleanup
+_uv_required_version
 cache_installed_version
 check_for_codeberg_release
 check_for_gh_branch
diff --git a/lib/runtime.func b/lib/runtime.func
index 649ceb0..92b73ac 100644
--- a/lib/runtime.func
+++ b/lib/runtime.func
@@ -2473,7 +2473,27 @@ setup_rust() {
 #   - Optionally installs a specific Python version via uv
 # ------------------------------------------------------------------------------
 
+# uv refuses to run when a project pins a required-version it does not match,
+# in either direction. Only the exact form is read; a range falls through to
+# whatever the caller would have installed anyway.
+_uv_required_version() {
+  local dir="${1:?dir}" f v
+  for f in "$dir/pyproject.toml" "$dir/uv.toml"; do
+    [[ -f "$f" ]] || continue
+    v="$(grep -m1 -E '^[[:space:]]*required-version[[:space:]]*=' "$f" 2>/dev/null |
+      sed -E 's/.*=[[:space:]]*"[[:space:]]*==[[:space:]]*([0-9][0-9A-Za-z.+-]*)"[[:space:]]*$/\1/')"
+    if [[ "$v" =~ ^[0-9] ]]; then
+      echo "$v"
+      return 0
+    fi
+  done
+  return 1
+}
+
+# UV_PROJECT_DIR - optional project directory; its uv pin wins over the latest
+# release. Set as a prefix, like PYTHON_VERSION and UV_VERSION.
 setup_uv() {
+  local PROJECT_DIR="${UV_PROJECT_DIR:-}"
   local UV_BIN="/usr/local/bin/uv"
   local UVX_BIN="/usr/local/bin/uvx"
   local TMP_DIR=$(mktemp -d)
@@ -2510,8 +2530,11 @@ setup_uv() {
 
   ensure_dependencies jq
 
-  # Fetch target version (pinned via UV_VERSION or latest release)
+  # Fetch target version (UV_VERSION, then the project's own pin, then latest)
   local TARGET_VERSION="${UV_VERSION:-}"
+  if [[ -z "$TARGET_VERSION" && -n "$PROJECT_DIR" ]]; then
+    TARGET_VERSION="$(_uv_required_version "$PROJECT_DIR")" || TARGET_VERSION=""
+  fi
   if [[ -z "$TARGET_VERSION" ]]; then
     TARGET_VERSION=$(get_latest_github_release "astral-sh/uv") || {
       msg_error "Could not fetch latest uv version from GitHub API"