diff --git a/.gitignore b/.gitignore
index a3dd3fd..80d07ce 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,6 +23,7 @@ crash_handler*
 *.log
 
 # Local environment and secrets
+.venv/
 .env
 .env.*
 !.env.example
diff --git a/AGENTS.md b/AGENTS.md
index 5856181..86177bf 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -25,21 +25,31 @@ systems project, not a content dump. The expected working style is:
 
 Only Godot 4.7 matters for this project.
 
-Use the project quality gate from PowerShell:
+Use the project quality gate for the current platform:
+
+```bash
+# macOS / Linux
+./tools/quality.sh
+```
 
 ```powershell
+# Windows
 powershell -ExecutionPolicy Bypass -File .\tools\quality.ps1
 ```
 
 For changed-file quick checks:
 
+```bash
+./tools/quality.sh --changed
+```
+
 ```powershell
 powershell -ExecutionPolicy Bypass -File .\tools\quality.ps1 -Changed
 ```
 
 The quality scripts isolate Godot's user profile under `logs/quality/godot_profile`
-so headless Godot 4.7 can run without crashing on blocked Windows app-data paths.
-Do not remove that behavior.
+so headless Godot 4.7 can run without crashing when platform user-data paths
+are unavailable. Do not remove that behavior.
 
 Useful extra checks:
 
diff --git a/docs/local_quality_gate.md b/docs/local_quality_gate.md
index 5788476..e9af141 100644
--- a/docs/local_quality_gate.md
+++ b/docs/local_quality_gate.md
@@ -5,12 +5,20 @@ parser errors, and LLM-generated garbage before committing.
 
 ## Requirements
 
-- **Python 3** with `gdtoolkit` (gdscript-toolkit):
+- **Python 3** with the pinned `gdtoolkit` (gdscript-toolkit). The recommended
+  setup uses `uv` and a project-local environment:
+
   ```bash
-  pip install gdtoolkit
+  uv venv .venv
+  uv pip install --python .venv/bin/python -r requirements-dev.txt
   ```
+
+  On Windows, use `.venv/Scripts/python.exe` for the `--python` value.
 - **Godot 4** binary on `PATH`, or set the `GODOT_BIN` environment variable
 
+The quality and format scripts discover `.venv` automatically; activating it
+is optional.
+
 ## Usage
 
 ### Full project check
@@ -102,7 +110,7 @@ to the terminal.
 To add this to CI, install the dependencies and run:
 
 ```bash
-pip install gdtoolkit
+python -m pip install -r requirements-dev.txt
 ./tools/quality.sh
 ```
 
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..a11100f
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1 @@
+gdtoolkit==4.5.0
diff --git a/tools/fix_format.sh b/tools/fix_format.sh
index 885eb8b..1fe40b0 100644
--- a/tools/fix_format.sh
+++ b/tools/fix_format.sh
@@ -8,14 +8,16 @@ cd "$ROOT"
 
 # detect gdformat
 FMT=""
-if command -v gdformat &>/dev/null; then
+if [[ -x "$ROOT/.venv/bin/gdformat" ]]; then
+  FMT="$ROOT/.venv/bin/gdformat"
+elif command -v gdformat &>/dev/null; then
   FMT="gdformat"
 elif python -m gdtoolkit.formatter --help &>/dev/null 2>&1; then
   FMT="python -m gdtoolkit.formatter"
 fi
 
 if [[ -z "$FMT" ]]; then
-  echo "ERROR: gdformat not found. Install: pip install gdtoolkit"
+  echo "ERROR: gdformat not found. Install requirements-dev.txt; see docs/local_quality_gate.md."
   exit 1
 fi
 
diff --git a/tools/quality.ps1 b/tools/quality.ps1
index d0e9b92..7589b5a 100644
--- a/tools/quality.ps1
+++ b/tools/quality.ps1
@@ -59,6 +59,7 @@ function Find-Godot {
 }
 
 function Test-GdFormat {
+  if (Test-Path "$ROOT/.venv/Scripts/gdformat.exe") { return $true }
   if (Get-Command gdformat -ErrorAction SilentlyContinue) { return $true }
   try {
     $null = & python -m gdtoolkit.formatter --help 2>&1
@@ -72,6 +73,7 @@ function Test-GdFormat {
 }
 
 function Test-GdLint {
+  if (Test-Path "$ROOT/.venv/Scripts/gdlint.exe") { return $true }
   if (Get-Command gdlint -ErrorAction SilentlyContinue) { return $true }
   try {
     $null = & python -m gdtoolkit.linter --help 2>&1
@@ -86,7 +88,10 @@ function Test-GdLint {
 
 function Invoke-GdFormat {
   $args = $args
-  if (Get-Command gdformat -ErrorAction SilentlyContinue) {
+  $localTool = "$ROOT/.venv/Scripts/gdformat.exe"
+  if (Test-Path $localTool) {
+    & $localTool @args 2>&1
+  } elseif (Get-Command gdformat -ErrorAction SilentlyContinue) {
     & gdformat @args 2>&1
   } else {
     & python -m gdtoolkit.formatter @args 2>&1
@@ -95,7 +100,10 @@ function Invoke-GdFormat {
 
 function Invoke-GdLint {
   $args = $args
-  if (Get-Command gdlint -ErrorAction SilentlyContinue) {
+  $localTool = "$ROOT/.venv/Scripts/gdlint.exe"
+  if (Test-Path $localTool) {
+    & $localTool @args 2>&1
+  } elseif (Get-Command gdlint -ErrorAction SilentlyContinue) {
     & gdlint @args 2>&1
   } else {
     & python -m gdtoolkit.linter @args 2>&1
@@ -161,7 +169,7 @@ $fmtResult = "PASS"
 Set-Content -Path "$LOG/gdformat.log" -Value "" -Encoding utf8
 if (-not $fmtAvail) {
   $fmtResult = "SKIPPED"
-  Add-Content -Path "$LOG/gdformat.log" -Value "gdformat not found -- install: pip install gdtoolkit" -Encoding utf8
+  Add-Content -Path "$LOG/gdformat.log" -Value "gdformat not found -- install requirements-dev.txt (see docs/local_quality_gate.md)" -Encoding utf8
 } else {
   if ($Changed) {
     $files = Get-ChangedGd
@@ -203,7 +211,7 @@ $lintResult = "PASS"
 Set-Content -Path "$LOG/gdlint.log" -Value "" -Encoding utf8
 if (-not $lintAvail) {
   $lintResult = "SKIPPED"
-  Add-Content -Path "$LOG/gdlint.log" -Value "gdlint not found -- install: pip install gdtoolkit" -Encoding utf8
+  Add-Content -Path "$LOG/gdlint.log" -Value "gdlint not found -- install requirements-dev.txt (see docs/local_quality_gate.md)" -Encoding utf8
 } else {
   if ($Changed) {
     $files = Get-ChangedGd
diff --git a/tools/quality.sh b/tools/quality.sh
index 72783fc..09b1154 100755
--- a/tools/quality.sh
+++ b/tools/quality.sh
@@ -54,12 +54,14 @@ find_godot() {
 }
 
 find_gdformat() {
+  if [[ -x "$ROOT/.venv/bin/gdformat" ]]; then echo "$ROOT/.venv/bin/gdformat"; return 0; fi
   if command -v gdformat &>/dev/null; then echo "gdformat"; return 0; fi
   if python -m gdtoolkit.formatter --help &>/dev/null 2>&1; then echo "python -m gdtoolkit.formatter"; return 0; fi
   return 1
 }
 
 find_gdlint() {
+  if [[ -x "$ROOT/.venv/bin/gdlint" ]]; then echo "$ROOT/.venv/bin/gdlint"; return 0; fi
   if command -v gdlint &>/dev/null; then echo "gdlint"; return 0; fi
   if python -m gdtoolkit.linter --help &>/dev/null 2>&1; then echo "python -m gdtoolkit.linter"; return 0; fi
   return 1
@@ -99,7 +101,7 @@ fmt_result="PASS"
 : > "$LOG/gdformat.log"
 if [[ -z "$fmt_tool" ]]; then
   fmt_result="SKIPPED"
-  echo "gdformat not found — install: pip install gdtoolkit" > "$LOG/gdformat.log"
+  echo "gdformat not found — install requirements-dev.txt (see docs/local_quality_gate.md)" > "$LOG/gdformat.log"
 else
   if $CHANGED; then
     files=$(changed_gd)
@@ -137,7 +139,7 @@ lint_result="PASS"
 : > "$LOG/gdlint.log"
 if [[ -z "$lint_tool" ]]; then
   lint_result="SKIPPED"
-  echo "gdlint not found — install: pip install gdtoolkit" > "$LOG/gdlint.log"
+  echo "gdlint not found — install requirements-dev.txt (see docs/local_quality_gate.md)" > "$LOG/gdlint.log"
 else
   if $CHANGED; then
     files=$(changed_gd)