Support uv for environment setup and dependency install

AGENTS.md

@@ -59,3 +59,21 @@ Run checks appropriate to the change; use `docs/tests.md` to select focused unit
 | Full frontend suite | `npm test` |
 
 Use the **project venv** for backend tests (`.venv/bin/python` on Unix). System Python may lack runtime dependencies and produce misleading failures.
+
+## Environment: uv
+
+`uv` is a supported alternative to `pip` for the project venv; everything works
+the same whether the venv was created with `python -m venv` or `uv venv`.
+
+- The backend install paths are uv-aware: `install.sh` uses `uv venv --seed` +
+  `uv pip install` when `uv` is on PATH (falling back to `python -m venv` +
+  `pip`), and the in-app updater runs `uv pip install --python <sys.executable>`
+  when available (`backend/services/git_update.py:dependency_install_command`),
+  otherwise the venv's own `pip`.
+- `--seed` is required when creating a venv at all: `install.sh`, the in-app
+  updater, and shell workflows that still call `python -m pip` all assume pip
+  exists in the venv. Recreating with a plain (pip-less) `uv venv` breaks them.
+- There is no `pyproject.toml`, so manage dependencies with
+  `uv pip install -r requirements.txt` — do not use `uv sync`.
+- Startup scripts (`mac_linux_start.sh`, `mac_linux_silent_start.sh`) only
+  execute `.venv/bin/python`, so they are uv-agnostic.

CONTRIBUTING.md

@@ -31,6 +31,11 @@ Then install the Python dependencies **into the venv**:
 .venv/bin/python -m pip install -r requirements.txt
 ```
 
+> **Prefer uv?** `uv venv --seed` (or `--seed --python 3.12`) and
+> `uv pip install -r requirements.txt` are drop-in equivalents; the setup,
+> `install.sh`, and the in-app updater all detect uv and use it automatically.
+> `--seed` matters: the updater and `install.sh` assume pip exists in the venv.
+
 > **Always use the venv Python.** System Python lacks `huggingface_hub` and
 > the other runtime dependencies, so tests fail with misleading import
 > errors deep inside unrelated modules. Every Python command below shows the

README.md

@@ -52,7 +52,7 @@ Special thanks to ggml-org for [llama.cpp](https://github.com/ggml-org/llama.cpp
 
 ## Requirements
 
-- Python 3.9+, `pip`, and virtual environment support (`python -m venv`)
+- Python 3.9+, `pip`, and virtual environment support (or [uv](https://astral.sh/uv), which the installers and the in-app updater detect and use automatically)
 - Internet access for release downloads, optional app updates, and optional Chat web search
 - A supported OS/architecture for the prebuilt `llama.cpp` binaries you want
 
@@ -90,6 +90,8 @@ Install dependencies:
 - macOS/Linux: `./install.sh`
 - Windows: `windows_install.bat`
 
+If [uv](https://astral.sh/uv) is on PATH, setup uses it automatically — the venv is created with `uv venv --seed` and requirements are installed with `uv pip install`. The in-app updater prefers uv the same way. The plain `pip` flow remains fully supported.
+
 If macOS/Linux reports `permission denied`, restore the executable bit:
 
 ```bash

backend/services/git_update.py

@@ -2,6 +2,7 @@
 
 import os
 import re
+import shutil
 import subprocess
 import sys
 from typing import Any
@@ -231,14 +232,34 @@ def find_latest_release_tag(base_dir, upstream_ref):
     return {"tag": "", "error": ""}
 
 
+def dependency_install_command(requirements_path):
+    """Pick uv when available, else the venv's own pip.
+
+    ``uv pip install --python <sys.executable>`` installs into the interpreter
+    that is running the app (the project venv), while falling back to pip keeps
+    plain ``python -m venv`` setups working unchanged.
+    """
+    if shutil.which("uv"):
+        return [
+            "uv",
+            "pip",
+            "install",
+            "--python",
+            sys.executable,
+            "-r",
+            str(requirements_path),
+        ]
+    return [sys.executable, "-m", "pip", "install", "-r", str(requirements_path)]
+
+
 def install_python_dependencies(ctx: AppContext) -> dict[str, Any]:
     requirements_path = ctx.paths.root / "requirements.txt"
     if not requirements_path.exists():
         return {"installed": False, "message": "requirements.txt was not found."}
 
     try:
         res = subprocess.run(
-            [sys.executable, "-m", "pip", "install", "-r", str(requirements_path)],
+            dependency_install_command(requirements_path),
             cwd=str(ctx.paths.root),
             capture_output=True,
             text=True,
@@ -248,14 +269,14 @@ def install_python_dependencies(ctx: AppContext) -> dict[str, Any]:
         )
     except subprocess.TimeoutExpired:
         print(
-            f"[git_update] pip install timed out after {DEPENDENCY_INSTALL_TIMEOUT_SECONDS}s",
+            f"[git_update] dependency install timed out after {DEPENDENCY_INSTALL_TIMEOUT_SECONDS}s",
             file=sys.stderr,
         )
         return {"installed": False, "error": "Dependency installation timed out."}
     output = (res.stdout or res.stderr or "").strip()
     if res.returncode != 0:
         print(
-            f"[git_update] pip install failed: {(res.stderr or res.stdout or '').strip()}",
+            f"[git_update] dependency install failed: {(res.stderr or res.stdout or '').strip()}",
             file=sys.stderr,
         )
         return {

install.sh

@@ -23,9 +23,21 @@ if ! "$PY_CMD" -c 'import sys; raise SystemExit(0 if sys.version_info >= (3, 9)
     exit 1
 fi
 
+if command -v uv >/dev/null 2>&1; then
+    UV_AVAILABLE=1
+else
+    UV_AVAILABLE=0
+fi
+
 if [ ! -d ".venv" ]; then
     echo "Creating local virtual environment..."
-    "$PY_CMD" -m venv .venv
+    if [ "$UV_AVAILABLE" -eq 1 ]; then
+        # --seed keeps pip available for the in-app updater and for shell
+        # workflows that still call "python -m pip".
+        uv venv --seed --python "$PY_CMD" .venv
+    else
+        "$PY_CMD" -m venv .venv
+    fi
 fi
 
 VENV_PYTHON="$SCRIPT_DIR/.venv/bin/python"
@@ -43,11 +55,16 @@ if [ "$(uname -s)" = "Linux" ] && ! "$VENV_PYTHON" -c 'import tkinter' >/dev/nul
     echo "Llama GUI will still install; add Tk and restart it to enable Browse/Change dialogs."
 fi
 
-echo "Upgrading pip..."
-"$VENV_PYTHON" -m pip install --upgrade pip
+if [ "$UV_AVAILABLE" -eq 1 ]; then
+    echo "Installing Python dependencies from requirements.txt with uv..."
+    uv pip install --python "$VENV_PYTHON" -r requirements.txt
+else
+    echo "Upgrading pip..."
+    "$VENV_PYTHON" -m pip install --upgrade pip
 
-echo "Installing Python dependencies from requirements.txt..."
-"$VENV_PYTHON" -m pip install -r requirements.txt
+    echo "Installing Python dependencies from requirements.txt..."
+    "$VENV_PYTHON" -m pip install -r requirements.txt
+fi
 
 mkdir -p llama/custom/bin llama/custom/grammars
 mkdir -p llama/custom-02/bin llama/custom-02/grammars

tests/backend/test_extracted_routes.py

@@ -5744,6 +5744,34 @@ def test_install_deps_subprocess_called(self):
         self.assertIn("pip", args)
         self.assertIn("install", args)
 
+    def test_install_deps_prefers_uv_when_available(self):
+        (self.ctx.paths.root / "requirements.txt").write_text("requests\n")
+        with (
+            mock.patch.object(srv.shutil, "which", return_value="/usr/local/bin/uv"),
+            mock.patch.object(srv.subprocess, "run") as mock_run,
+        ):
+            mock_run.return_value = self.proc_result(stdout="Successfully installed")
+            result = srv.install_python_dependencies(self.ctx)
+        self.assertTrue(result["installed"])
+        args = mock_run.call_args[0][0]
+        self.assertEqual(args[0], "uv")
+        self.assertIn("pip", args)
+        self.assertIn("--python", args)
+
+    def test_install_deps_falls_back_to_pip_without_uv(self):
+        (self.ctx.paths.root / "requirements.txt").write_text("requests\n")
+        with (
+            mock.patch.object(srv.shutil, "which", return_value=None),
+            mock.patch.object(srv.subprocess, "run") as mock_run,
+        ):
+            mock_run.return_value = self.proc_result(stdout="Successfully installed")
+            result = srv.install_python_dependencies(self.ctx)
+        self.assertTrue(result["installed"])
+        args = mock_run.call_args[0][0]
+        self.assertEqual(args[0], srv.sys.executable)
+        self.assertIn("-m", args)
+        self.assertIn("pip", args)
+
     def test_install_deps_subprocess_fails(self):
         (self.ctx.paths.root / "requirements.txt").write_text("bad_package\n")
         with mock.patch.object(srv.subprocess, "run") as mock_run: