diff --git a/docs/self-evolution.md b/docs/self-evolution.md
index 2f07d1e..c510a34 100644
--- a/docs/self-evolution.md
+++ b/docs/self-evolution.md
@@ -9,7 +9,7 @@ Historical verification snapshot: `51be33361422e55e1f2f00c33a0e0f8c56132a91`
 (the post-#54 `main` revision, captured before this #55 documentation-only
 update). Snapshot date: 2026-09-04.
 
-Current repository test count at this snapshot: **196 unittest cases**.
+Current repository test count at this snapshot: **198 unittest cases**.
 
 ## Verified surface
 
diff --git a/install.ps1 b/install.ps1
index 394b440..9798794 100644
--- a/install.ps1
+++ b/install.ps1
@@ -85,6 +85,13 @@ if (-not $pythonVersion) {
 
 Write-Output "[INFO] Installing OpenKyrozen $releaseTag from its immutable GitHub release with Python $pythonVersion..."
 & $uvCommand.Source tool install --python $pythonVersion --force --with fastapi --with uvicorn $releaseWheelUrl
+if ($LASTEXITCODE -ne 0) {
+    Write-Output "[INFO] uv cache was incomplete; retrying without the existing cache..."
+    & $uvCommand.Source --no-cache tool install --python $pythonVersion --force --with fastapi --with uvicorn $releaseWheelUrl
+}
+if ($LASTEXITCODE -ne 0) {
+    Fail "OpenKyrozen installation failed from release $releaseTag."
+}
 try { & $uvCommand.Source tool update-shell *> $null } catch { }
 
 $userPath = [Environment]::GetEnvironmentVariable("Path", "User")
diff --git a/install.sh b/install.sh
index 207e55b..2d7a550 100755
--- a/install.sh
+++ b/install.sh
@@ -70,8 +70,14 @@ else
 fi
 
 info "Installing OpenKyrozen $release_tag from its immutable GitHub release with Python $python_version..."
-"$uv_bin" tool install --python "$python_version" --force \
-  --with fastapi --with uvicorn "$release_wheel_url"
+install_openkyrozen() {
+    "$uv_bin" "$@" tool install --python "$python_version" --force \
+      --with fastapi --with uvicorn "$release_wheel_url"
+}
+if ! install_openkyrozen; then
+    info 'uv cache was incomplete; retrying without the existing cache...'
+    install_openkyrozen --no-cache
+fi
 "$uv_bin" tool update-shell >/dev/null 2>&1 || true
 
 profile=''
diff --git a/main.py b/main.py
index 166b614..3eb9498 100644
--- a/main.py
+++ b/main.py
@@ -1287,14 +1287,26 @@ def _self_update() -> str:
         f"{sys.version_info.major}.{sys.version_info.minor}"
         if sys.version_info[:2] in {(3, 12), (3, 13)} else "3.12"
     )
+    command = [
+        "uv", "tool", "install", "--python", requested_python, "--force",
+        "--with", "fastapi", "--with", "uvicorn", RELEASE_WHEEL_URL,
+    ]
     try:
         result = subprocess.run(
-            ["uv", "tool", "install", "--python", requested_python, "--force",
-             "--with", "fastapi", "--with", "uvicorn", RELEASE_WHEEL_URL],
+            command,
             capture_output=True,
             text=True,
             timeout=60,
         )
+        if result.returncode != 0:
+            retry = subprocess.run(
+                ["uv", "--no-cache", *command[1:]],
+                capture_output=True,
+                text=True,
+                timeout=60,
+            )
+            if retry.returncode == 0:
+                result = retry
         out = result.stdout.strip() or ""
         err = result.stderr.strip() or ""
         if result.returncode != 0:
diff --git a/tests/test_distribution.py b/tests/test_distribution.py
index 2f2c880..b71502f 100644
--- a/tests/test_distribution.py
+++ b/tests/test_distribution.py
@@ -92,6 +92,7 @@ def test_posix_installer_has_valid_syntax_and_idempotent_user_path_logic(self):
         self.assertIn("release_version='2.0.2'", text)
         self.assertIn("releases/download", text)
         self.assertIn("--with fastapi --with uvicorn", text)
+        self.assertIn("--no-cache", text)
         self.assertNotIn("pypi.org", text)
         self.assertIn("installed_version=", text)
 
@@ -117,6 +118,7 @@ def test_powershell_installer_is_static_safe_and_parses_when_available(self):
         self.assertIn("v2.0.2", text)
         self.assertIn("releases/download", text)
         self.assertIn("--with fastapi --with uvicorn", text)
+        self.assertIn("--no-cache", text)
         self.assertNotIn("pypi.org", text)
         powershell = shutil.which("pwsh") or shutil.which("powershell")
         if powershell is None:
@@ -129,6 +131,56 @@ def test_powershell_installer_is_static_safe_and_parses_when_available(self):
         )
         self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
 
+    def test_posix_installer_retries_with_uncached_uv_install(self):
+        with tempfile.TemporaryDirectory() as home, tempfile.TemporaryDirectory() as bin_dir:
+            home_path = Path(home)
+            bin_path = Path(bin_dir)
+            log_path = home_path / "uv.log"
+            uv_path = bin_path / "uv"
+            uv_path.write_text(
+                r"""#!/bin/sh
+printf '%s\n' "$*" >> "$UV_TEST_LOG"
+if [ "$1" = "python" ] && [ "$2" = "find" ]; then
+    exit 0
+fi
+if [ "$1" = "tool" ] && [ "$2" = "install" ]; then
+    exit 1
+fi
+if [ "$1" = "--no-cache" ] && [ "$2" = "tool" ] && [ "$3" = "install" ]; then
+    mkdir -p "$HOME/.local/bin"
+    printf '%s\n' '#!/bin/sh' 'if [ "$1" = "--version" ]; then printf "%s\n" "OpenKyrozen 2.0.2"; fi' > "$HOME/.local/bin/kyrozen"
+    chmod +x "$HOME/.local/bin/kyrozen"
+    exit 0
+fi
+exit 0
+""",
+                encoding="utf-8",
+            )
+            curl_path = bin_path / "curl"
+            curl_path.write_text("#!/bin/sh\nexit 0\n", encoding="utf-8")
+            os.chmod(uv_path, 0o755)
+            os.chmod(curl_path, 0o755)
+            env = os.environ.copy()
+            env.update({
+                "HOME": str(home_path),
+                "PATH": f"{bin_path}:{env.get('PATH', '')}",
+                "SHELL": "/bin/sh",
+                "UV_TEST_LOG": str(log_path),
+            })
+            result = subprocess.run(
+                ["sh", str(ROOT / "install.sh")],
+                cwd=ROOT, env=env, capture_output=True, text=True, timeout=30,
+            )
+            self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+            install_calls = [
+                line for line in log_path.read_text(encoding="utf-8").splitlines()
+                if "tool install" in line
+            ]
+            self.assertEqual(len(install_calls), 2)
+            self.assertTrue(install_calls[0].startswith("tool install "))
+            self.assertTrue(install_calls[1].startswith("--no-cache tool install "))
+            self.assertIn("Installation complete.", result.stdout)
+
     def test_cli_and_web_help_version_flags_work_without_provider_setup(self):
         with tempfile.TemporaryDirectory() as home:
             env = os.environ.copy()
@@ -195,6 +247,25 @@ def test_update_uses_the_package_manager_instead_of_git_pull(self):
         self.assertIn("uvicorn", command)
         self.assertTrue(command[-1].endswith("/v2.0.2/openkyrozen-2.0.2-py3-none-any.whl"))
 
+    def test_update_retries_without_uv_cache_after_install_failure(self):
+        import main
+
+        failed = subprocess.CompletedProcess(
+            ["uv", "tool", "install"], 1, stdout="", stderr="missing archive",
+        )
+        completed = subprocess.CompletedProcess(
+            ["uv", "--no-cache", "tool", "install"], 0, stdout="upgraded", stderr="",
+        )
+        with patch("main.shutil.which", return_value="/usr/local/bin/uv"), \
+             patch("main.subprocess.run", side_effect=[failed, completed]) as run:
+            result = main._self_update()
+        self.assertIn("upgraded", result)
+        self.assertEqual(run.call_count, 2)
+        self.assertEqual(
+            run.call_args_list[1].args[0][:3],
+            ["uv", "--no-cache", "tool"],
+        )
+
     def test_docker_starts_server_in_explicit_project_mode(self):
         dockerfile = (ROOT / "Dockerfile").read_text(encoding="utf-8")
         self.assertIn('"server.py", "--project", "/app"', dockerfile)