Split preview mode into separate feature flags (#14823)

I think this would give us better hygiene than a global flag. It makes
it easier for users to opt-in to overlapping features, such as Python
upgrades and Python bin installations and to disable warnings for
preview mode without opting in to a bunch of other features. In general,
I want to reduce the burden for putting something under preview.

The `--preview` and `--no-preview` flags are retained as global
overrides. A new `--preview-features` option is added which accepts
comma separated features or can be passed multiple times, e.g.,
`--preview-features add-bounds,pylock`. There's a `UV_PREVIEW_FEATURES`
environment variable for that option (I'm not sure if we should overload
`UV_PREVIEW`, but could be convinced).

Cargo.lock

@@ -5037,6 +5037,7 @@ name = "uv-configuration"
 version = "0.0.1"
 dependencies = [
  "anyhow",
+ "bitflags 2.9.1",
  "clap",
  "either",
  "fs-err 3.1.1",
@@ -5061,6 +5062,7 @@ dependencies = [
  "uv-pep508",
  "uv-platform-tags",
  "uv-static",
+ "uv-warnings",
 ]
 
 [[package]]

crates/uv-bench/benches/uv.rs

@@ -87,7 +87,7 @@ mod resolver {
     use uv_client::RegistryClient;
     use uv_configuration::{
         BuildOptions, Concurrency, ConfigSettings, Constraints, IndexStrategy,
-        PackageConfigSettings, PreviewMode, SourceStrategy,
+        PackageConfigSettings, Preview, SourceStrategy,
     };
     use uv_dispatch::{BuildDispatch, SharedState};
     use uv_distribution::DistributionDatabase;
@@ -194,7 +194,7 @@ mod resolver {
             sources,
             workspace_cache,
             concurrency,
-            PreviewMode::Enabled,
+            Preview::default(),
         );
 
         let markers = if universal {

crates/uv-build-frontend/src/lib.rs

@@ -28,7 +28,7 @@ use tokio::sync::{Mutex, Semaphore};
 use tracing::{Instrument, debug, info_span, instrument, warn};
 
 use uv_cache_key::cache_digest;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_configuration::{BuildKind, BuildOutput, ConfigSettings, SourceStrategy};
 use uv_distribution::BuildRequires;
 use uv_distribution_types::{IndexLocations, Requirement, Resolution};
@@ -286,7 +286,7 @@ impl SourceBuild {
         mut environment_variables: FxHashMap<OsString, OsString>,
         level: BuildOutput,
         concurrent_builds: usize,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         let temp_dir = build_context.cache().venv_dir()?;
 

crates/uv-cli/src/lib.rs

@@ -11,8 +11,8 @@ use clap::{Args, Parser, Subcommand};
 use uv_cache::CacheArgs;
 use uv_configuration::{
     ConfigSettingEntry, ConfigSettingPackageEntry, ExportFormat, IndexStrategy,
-    KeyringProviderType, PackageNameSpecifier, ProjectBuildBackend, TargetTriple, TrustedHost,
+    KeyringProviderType, PackageNameSpecifier, PreviewFeatures, ProjectBuildBackend, TargetTriple,
-    TrustedPublishing, VersionControlSystem,
+    TrustedHost, TrustedPublishing, VersionControlSystem,
 };
 use uv_distribution_types::{Index, IndexUrl, Origin, PipExtraIndex, PipFindLinks, PipIndex};
 use uv_normalize::{ExtraName, GroupName, PackageName, PipGroupName};
@@ -273,7 +273,7 @@ pub struct GlobalArgs {
     )]
     pub allow_insecure_host: Option<Vec<Maybe<TrustedHost>>>,
 
-    /// Whether to enable experimental, preview features.
+    /// Whether to enable all experimental preview features.
     ///
     /// Preview features may change without warning.
     #[arg(global = true, long, hide = true, env = EnvVars::UV_PREVIEW, value_parser = clap::builder::BoolishValueParser::new(), overrides_with("no_preview"))]
@@ -282,6 +282,25 @@ pub struct GlobalArgs {
     #[arg(global = true, long, overrides_with("preview"), hide = true)]
     pub no_preview: bool,
 
+    /// Enable experimental preview features.
+    ///
+    /// Preview features may change without warning.
+    ///
+    /// Use comma-separated values or pass multiple times to enable multiple features.
+    ///
+    /// The following features are available: `python-install-default`, `python-upgrade`,
+    /// `json-output`, `pylock`, `add-bounds`.
+    #[arg(
+        global = true,
+        long = "preview-features",
+        env = EnvVars::UV_PREVIEW_FEATURES,
+        value_delimiter = ',',
+        hide = true,
+        alias = "preview-feature",
+        value_enum,
+    )]
+    pub preview_features: Vec<PreviewFeatures>,
+
     /// Avoid discovering a `pyproject.toml` or `uv.toml` file.
     ///
     /// Normally, configuration files are discovered in the current directory,

crates/uv-configuration/Cargo.toml

@@ -27,7 +27,9 @@ uv-pep440 = { workspace = true }
 uv-pep508 = { workspace = true, features = ["schemars"] }
 uv-platform-tags = { workspace = true }
 uv-static = { workspace = true }
+uv-warnings = { workspace = true }
 
+bitflags = { workspace = true }
 clap = { workspace = true, features = ["derive"], optional = true }
 either = { workspace = true }
 fs-err = { workspace = true }

crates/uv-configuration/src/preview.rs

@@ -1,37 +1,243 @@
-use std::fmt::{Display, Formatter};
+use std::{
+    fmt::{Display, Formatter},
+    str::FromStr,
+};
+
+use thiserror::Error;
+use uv_warnings::warn_user_once;
+
+bitflags::bitflags! {
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+    pub struct PreviewFeatures: u32 {
+        const PYTHON_INSTALL_DEFAULT = 1 << 0;
+        const PYTHON_UPGRADE = 1 << 1;
+        const JSON_OUTPUT = 1 << 2;
+        const PYLOCK = 1 << 3;
+        const ADD_BOUNDS = 1 << 4;
+    }
+}
+
+impl PreviewFeatures {
+    /// Returns the string representation of a single preview feature flag.
+    ///
+    /// Panics if given a combination of flags.
+    fn flag_as_str(self) -> &'static str {
+        match self {
+            Self::PYTHON_INSTALL_DEFAULT => "python-install-default",
+            Self::PYTHON_UPGRADE => "python-upgrade",
+            Self::JSON_OUTPUT => "json-output",
+            Self::PYLOCK => "pylock",
+            Self::ADD_BOUNDS => "add-bounds",
+            _ => panic!("`flag_as_str` can only be used for exactly one feature flag"),
+        }
+    }
+}
+
+impl Display for PreviewFeatures {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        if self.is_empty() {
+            write!(f, "none")
+        } else {
+            let features: Vec<&str> = self.iter().map(PreviewFeatures::flag_as_str).collect();
+            write!(f, "{}", features.join(","))
+        }
+    }
+}
+
+#[derive(Debug, Error, Clone)]
+pub enum PreviewFeaturesParseError {
+    #[error("Empty string in preview features: {0}")]
+    Empty(String),
+}
+
+impl FromStr for PreviewFeatures {
+    type Err = PreviewFeaturesParseError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut flags = PreviewFeatures::empty();
+
+        for part in s.split(',') {
+            let part = part.trim();
+            if part.is_empty() {
+                return Err(PreviewFeaturesParseError::Empty(
+                    "Empty string in preview features".to_string(),
+                ));
+            }
+
+            let flag = match part {
+                "python-install-default" => Self::PYTHON_INSTALL_DEFAULT,
+                "python-upgrade" => Self::PYTHON_UPGRADE,
+                "json-output" => Self::JSON_OUTPUT,
+                "pylock" => Self::PYLOCK,
+                "add-bounds" => Self::ADD_BOUNDS,
+                _ => {
+                    warn_user_once!("Unknown preview feature: `{part}`");
+                    continue;
+                }
+            };
+
+            flags |= flag;
+        }
+
+        Ok(flags)
+    }
+}
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
-pub enum PreviewMode {
+pub struct Preview {
-    #[default]
+    flags: PreviewFeatures,
-    Disabled,
-    Enabled,
 }
 
-impl PreviewMode {
+impl Preview {
-    pub fn is_enabled(&self) -> bool {
+    pub fn new(flags: PreviewFeatures) -> Self {
-        matches!(self, Self::Enabled)
+        Self { flags }
     }
 
-    pub fn is_disabled(&self) -> bool {
+    pub fn all() -> Self {
-        matches!(self, Self::Disabled)
+        Self::new(PreviewFeatures::all())
     }
-}
 
-impl From<bool> for PreviewMode {
+    pub fn from_args(
-    fn from(version: bool) -> Self {
+        preview: bool,
-        if version {
+        no_preview: bool,
-            PreviewMode::Enabled
+        preview_features: &[PreviewFeatures],
-        } else {
+    ) -> Self {
-            PreviewMode::Disabled
+        if no_preview {
+            return Self::default();
         }
+
+        if preview {
+            return Self::all();
+        }
+
+        let mut flags = PreviewFeatures::empty();
+
+        for features in preview_features {
+            flags |= *features;
+        }
+
+        Self { flags }
+    }
+
+    pub fn is_enabled(&self, flag: PreviewFeatures) -> bool {
+        self.flags.contains(flag)
     }
 }
 
-impl Display for PreviewMode {
+impl Display for Preview {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        match self {
+        if self.flags.is_empty() {
-            Self::Disabled => write!(f, "disabled"),
+            write!(f, "disabled")
-            Self::Enabled => write!(f, "enabled"),
+        } else if self.flags == PreviewFeatures::all() {
+            write!(f, "enabled")
+        } else {
+            write!(f, "{}", self.flags)
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_preview_features_from_str() {
+        // Test single feature
+        let features = PreviewFeatures::from_str("python-install-default").unwrap();
+        assert_eq!(features, PreviewFeatures::PYTHON_INSTALL_DEFAULT);
+
+        // Test multiple features
+        let features = PreviewFeatures::from_str("python-upgrade,json-output").unwrap();
+        assert!(features.contains(PreviewFeatures::PYTHON_UPGRADE));
+        assert!(features.contains(PreviewFeatures::JSON_OUTPUT));
+        assert!(!features.contains(PreviewFeatures::PYLOCK));
+
+        // Test with whitespace
+        let features = PreviewFeatures::from_str("pylock , add-bounds").unwrap();
+        assert!(features.contains(PreviewFeatures::PYLOCK));
+        assert!(features.contains(PreviewFeatures::ADD_BOUNDS));
+
+        // Test empty string error
+        assert!(PreviewFeatures::from_str("").is_err());
+        assert!(PreviewFeatures::from_str("pylock,").is_err());
+        assert!(PreviewFeatures::from_str(",pylock").is_err());
+
+        // Test unknown feature (should be ignored with warning)
+        let features = PreviewFeatures::from_str("unknown-feature,pylock").unwrap();
+        assert!(features.contains(PreviewFeatures::PYLOCK));
+        assert_eq!(features.bits().count_ones(), 1);
+    }
+
+    #[test]
+    fn test_preview_features_display() {
+        // Test empty
+        let features = PreviewFeatures::empty();
+        assert_eq!(features.to_string(), "none");
+
+        // Test single feature
+        let features = PreviewFeatures::PYTHON_INSTALL_DEFAULT;
+        assert_eq!(features.to_string(), "python-install-default");
+
+        // Test multiple features
+        let features = PreviewFeatures::PYTHON_UPGRADE | PreviewFeatures::JSON_OUTPUT;
+        assert_eq!(features.to_string(), "python-upgrade,json-output");
+    }
+
+    #[test]
+    fn test_preview_display() {
+        // Test disabled
+        let preview = Preview::default();
+        assert_eq!(preview.to_string(), "disabled");
+
+        // Test enabled (all features)
+        let preview = Preview::all();
+        assert_eq!(preview.to_string(), "enabled");
+
+        // Test specific features
+        let preview = Preview::new(PreviewFeatures::PYTHON_UPGRADE | PreviewFeatures::PYLOCK);
+        assert_eq!(preview.to_string(), "python-upgrade,pylock");
+    }
+
+    #[test]
+    fn test_preview_from_args() {
+        // Test no_preview
+        let preview = Preview::from_args(true, true, &[]);
+        assert_eq!(preview.to_string(), "disabled");
+
+        // Test preview (all features)
+        let preview = Preview::from_args(true, false, &[]);
+        assert_eq!(preview.to_string(), "enabled");
+
+        // Test specific features
+        let features = vec![
+            PreviewFeatures::PYTHON_UPGRADE,
+            PreviewFeatures::JSON_OUTPUT,
+        ];
+        let preview = Preview::from_args(false, false, &features);
+        assert!(preview.is_enabled(PreviewFeatures::PYTHON_UPGRADE));
+        assert!(preview.is_enabled(PreviewFeatures::JSON_OUTPUT));
+        assert!(!preview.is_enabled(PreviewFeatures::PYLOCK));
+    }
+
+    #[test]
+    fn test_as_str_single_flags() {
+        assert_eq!(
+            PreviewFeatures::PYTHON_INSTALL_DEFAULT.flag_as_str(),
+            "python-install-default"
+        );
+        assert_eq!(
+            PreviewFeatures::PYTHON_UPGRADE.flag_as_str(),
+            "python-upgrade"
+        );
+        assert_eq!(PreviewFeatures::JSON_OUTPUT.flag_as_str(), "json-output");
+        assert_eq!(PreviewFeatures::PYLOCK.flag_as_str(), "pylock");
+        assert_eq!(PreviewFeatures::ADD_BOUNDS.flag_as_str(), "add-bounds");
+    }
+
+    #[test]
+    #[should_panic(expected = "`flag_as_str` can only be used for exactly one feature flag")]
+    fn test_as_str_multiple_flags_panics() {
+        let features = PreviewFeatures::PYTHON_UPGRADE | PreviewFeatures::JSON_OUTPUT;
+        let _ = features.flag_as_str();
+    }
+}

crates/uv-dev/src/compile.rs

@@ -4,7 +4,7 @@ use clap::Parser;
 use tracing::info;
 
 use uv_cache::{Cache, CacheArgs};
-use uv_configuration::{Concurrency, PreviewMode};
+use uv_configuration::{Concurrency, Preview};
 use uv_python::{EnvironmentPreference, PythonEnvironment, PythonRequest};
 
 #[derive(Parser)]
@@ -26,7 +26,7 @@ pub(crate) async fn compile(args: CompileArgs) -> anyhow::Result<()> {
             &PythonRequest::default(),
             EnvironmentPreference::OnlyVirtual,
             &cache,
-            PreviewMode::Disabled,
+            Preview::default(),
         )?
         .into_interpreter();
         interpreter.sys_executable().to_path_buf()

crates/uv-dispatch/src/lib.rs

@@ -18,7 +18,7 @@ use uv_cache::Cache;
 use uv_client::RegistryClient;
 use uv_configuration::{
     BuildKind, BuildOptions, ConfigSettings, Constraints, IndexStrategy, PackageConfigSettings,
-    PreviewMode, Reinstall, SourceStrategy,
+    Preview, Reinstall, SourceStrategy,
 };
 use uv_configuration::{BuildOutput, Concurrency};
 use uv_distribution::DistributionDatabase;
@@ -99,7 +99,7 @@ pub struct BuildDispatch<'a> {
     sources: SourceStrategy,
     workspace_cache: WorkspaceCache,
     concurrency: Concurrency,
-    preview: PreviewMode,
+    preview: Preview,
 }
 
 impl<'a> BuildDispatch<'a> {
@@ -123,7 +123,7 @@ impl<'a> BuildDispatch<'a> {
         sources: SourceStrategy,
         workspace_cache: WorkspaceCache,
         concurrency: Concurrency,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Self {
         Self {
             client,

crates/uv-python/src/discovery.rs

@@ -8,7 +8,7 @@ use std::{env, io, iter};
 use std::{path::Path, path::PathBuf, str::FromStr};
 use thiserror::Error;
 use tracing::{debug, instrument, trace};
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use which::{which, which_all};
 
 use uv_cache::Cache;
@@ -335,7 +335,7 @@ fn python_executables_from_installed<'a>(
     implementation: Option<&'a ImplementationName>,
     platform: PlatformRequest,
     preference: PythonPreference,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Box<dyn Iterator<Item = Result<(PythonSource, PathBuf), Error>> + 'a> {
     let from_managed_installations = iter::once_with(move || {
         ManagedPythonInstallations::from_settings(None)
@@ -485,7 +485,7 @@ fn python_executables<'a>(
     platform: PlatformRequest,
     environments: EnvironmentPreference,
     preference: PythonPreference,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Box<dyn Iterator<Item = Result<(PythonSource, PathBuf), Error>> + 'a> {
     // Always read from `UV_INTERNAL__PARENT_INTERPRETER` — it could be a system interpreter
     let from_parent_interpreter = iter::once_with(|| {
@@ -705,7 +705,7 @@ fn python_interpreters<'a>(
     environments: EnvironmentPreference,
     preference: PythonPreference,
     cache: &'a Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> impl Iterator<Item = Result<(PythonSource, Interpreter), Error>> + 'a {
     python_interpreters_from_executables(
         // Perform filtering on the discovered executables based on their source. This avoids
@@ -1053,7 +1053,7 @@ pub fn find_python_installations<'a>(
     environments: EnvironmentPreference,
     preference: PythonPreference,
     cache: &'a Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Box<dyn Iterator<Item = Result<FindPythonResult, Error>> + 'a> {
     let sources = DiscoveryPreferences {
         python_preference: preference,
@@ -1254,7 +1254,7 @@ pub(crate) fn find_python_installation(
     environments: EnvironmentPreference,
     preference: PythonPreference,
     cache: &Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<FindPythonResult, Error> {
     let installations =
         find_python_installations(request, environments, preference, cache, preview);
@@ -1353,7 +1353,7 @@ pub(crate) fn find_best_python_installation(
     environments: EnvironmentPreference,
     preference: PythonPreference,
     cache: &Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<FindPythonResult, Error> {
     debug!("Starting Python discovery for {}", request);
 

crates/uv-python/src/environment.rs

@@ -7,7 +7,7 @@ use owo_colors::OwoColorize;
 use tracing::debug;
 
 use uv_cache::Cache;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_fs::{LockedFile, Simplified};
 use uv_pep440::Version;
 
@@ -153,7 +153,7 @@ impl PythonEnvironment {
         request: &PythonRequest,
         preference: EnvironmentPreference,
         cache: &Cache,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         let installation = match find_python_installation(
             request,

crates/uv-python/src/installation.rs

@@ -8,7 +8,7 @@ use tracing::{debug, info};
 
 use uv_cache::Cache;
 use uv_client::BaseClientBuilder;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_pep440::{Prerelease, Version};
 
 use crate::discovery::{
@@ -58,7 +58,7 @@ impl PythonInstallation {
         environments: EnvironmentPreference,
         preference: PythonPreference,
         cache: &Cache,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         let installation =
             find_python_installation(request, environments, preference, cache, preview)??;
@@ -72,7 +72,7 @@ impl PythonInstallation {
         environments: EnvironmentPreference,
         preference: PythonPreference,
         cache: &Cache,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         Ok(find_best_python_installation(
             request,
@@ -97,7 +97,7 @@ impl PythonInstallation {
         python_install_mirror: Option<&str>,
         pypy_install_mirror: Option<&str>,
         python_downloads_json_url: Option<&str>,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         let request = request.unwrap_or(&PythonRequest::Default);
 
@@ -220,7 +220,7 @@ impl PythonInstallation {
         reporter: Option<&dyn Reporter>,
         python_install_mirror: Option<&str>,
         pypy_install_mirror: Option<&str>,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, Error> {
         let installations = ManagedPythonInstallations::from_settings(None)?.init()?;
         let installations_dir = installations.root();

crates/uv-python/src/lib.rs

@@ -135,7 +135,7 @@ mod tests {
     use indoc::{formatdoc, indoc};
     use temp_env::with_vars;
     use test_log::test;
-    use uv_configuration::PreviewMode;
+    use uv_configuration::Preview;
     use uv_static::EnvVars;
 
     use uv_cache::Cache;
@@ -468,7 +468,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         });
         assert!(
@@ -483,7 +483,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         });
         assert!(
@@ -508,7 +508,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         });
         assert!(
@@ -530,7 +530,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert!(
@@ -592,7 +592,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert!(
@@ -624,7 +624,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         });
         assert!(
@@ -661,7 +661,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::default(),
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert!(
@@ -693,7 +693,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -715,7 +715,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -741,7 +741,7 @@ mod tests {
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -767,7 +767,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -790,7 +790,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -824,7 +824,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -858,7 +858,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -880,7 +880,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -902,7 +902,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -936,7 +936,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -973,7 +973,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert!(
@@ -1004,7 +1004,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert!(
@@ -1039,7 +1039,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert_eq!(
@@ -1065,7 +1065,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert_eq!(
@@ -1092,7 +1092,7 @@ mod tests {
                     EnvironmentPreference::OnlyVirtual,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1117,7 +1117,7 @@ mod tests {
                     EnvironmentPreference::OnlyVirtual,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )?;
@@ -1139,7 +1139,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1162,7 +1162,7 @@ mod tests {
                     EnvironmentPreference::OnlyVirtual,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1195,7 +1195,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1216,7 +1216,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1243,7 +1243,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -1261,7 +1261,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -1290,7 +1290,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert_eq!(
@@ -1328,7 +1328,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1356,7 +1356,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1381,7 +1381,7 @@ mod tests {
                     EnvironmentPreference::ExplicitSystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1406,7 +1406,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1431,7 +1431,7 @@ mod tests {
                     EnvironmentPreference::OnlyVirtual,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1469,7 +1469,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1497,7 +1497,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert_eq!(
@@ -1514,7 +1514,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })??;
         assert_eq!(
@@ -1531,7 +1531,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })?;
         assert!(
@@ -1553,7 +1553,7 @@ mod tests {
                 EnvironmentPreference::OnlyVirtual,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1570,7 +1570,7 @@ mod tests {
                     EnvironmentPreference::OnlySystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )?;
@@ -1592,7 +1592,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1607,7 +1607,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1621,7 +1621,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1650,7 +1650,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1666,7 +1666,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1696,7 +1696,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1712,7 +1712,7 @@ mod tests {
                 EnvironmentPreference::ExplicitSystem,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1728,7 +1728,7 @@ mod tests {
                 EnvironmentPreference::OnlyVirtual,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1744,7 +1744,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1768,7 +1768,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1783,7 +1783,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1807,7 +1807,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1827,7 +1827,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             },
         )??;
@@ -1856,7 +1856,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1878,7 +1878,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1908,7 +1908,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -1924,7 +1924,7 @@ mod tests {
                 EnvironmentPreference::ExplicitSystem,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1951,7 +1951,7 @@ mod tests {
                     EnvironmentPreference::ExplicitSystem,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -1976,7 +1976,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -1993,7 +1993,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2008,7 +2008,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2034,7 +2034,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2049,7 +2049,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2075,7 +2075,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2102,7 +2102,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2129,7 +2129,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2156,7 +2156,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2183,7 +2183,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2211,7 +2211,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })?;
         assert!(
@@ -2233,7 +2233,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2248,7 +2248,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2274,7 +2274,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2289,7 +2289,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
         assert_eq!(
@@ -2327,7 +2327,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2345,7 +2345,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2387,7 +2387,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2405,7 +2405,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2442,7 +2442,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2465,7 +2465,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2488,7 +2488,7 @@ mod tests {
                     EnvironmentPreference::Any,
                     PythonPreference::OnlySystem,
                     &context.cache,
-                    PreviewMode::Disabled,
+                    Preview::default(),
                 )
             })
             .unwrap()
@@ -2527,7 +2527,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 
@@ -2580,7 +2580,7 @@ mod tests {
                 EnvironmentPreference::Any,
                 PythonPreference::OnlySystem,
                 &context.cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             )
         })??;
 

crates/uv-python/src/managed.rs

@@ -12,7 +12,7 @@ use itertools::Itertools;
 use same_file::is_same_file;
 use thiserror::Error;
 use tracing::{debug, warn};
-use uv_configuration::PreviewMode;
+use uv_configuration::{Preview, PreviewFeatures};
 #[cfg(windows)]
 use windows_sys::Win32::Storage::FileSystem::FILE_ATTRIBUTE_REPARSE_POINT;
 
@@ -519,7 +519,7 @@ impl ManagedPythonInstallation {
 
     /// Ensure the environment contains the symlink directory (or junction on Windows)
     /// pointing to the patch directory for this minor version.
-    pub fn ensure_minor_version_link(&self, preview: PreviewMode) -> Result<(), Error> {
+    pub fn ensure_minor_version_link(&self, preview: Preview) -> Result<(), Error> {
         if let Some(minor_version_link) = PythonMinorVersionLink::from_installation(self, preview) {
             minor_version_link.create_directory()?;
         }
@@ -531,7 +531,7 @@ impl ManagedPythonInstallation {
     ///
     /// Unlike [`ensure_minor_version_link`], will not create a new symlink directory
     /// if one doesn't already exist,
-    pub fn update_minor_version_link(&self, preview: PreviewMode) -> Result<(), Error> {
+    pub fn update_minor_version_link(&self, preview: Preview) -> Result<(), Error> {
         if let Some(minor_version_link) = PythonMinorVersionLink::from_installation(self, preview) {
             if !minor_version_link.exists() {
                 return Ok(());
@@ -702,7 +702,7 @@ impl PythonMinorVersionLink {
     pub fn from_executable(
         executable: &Path,
         key: &PythonInstallationKey,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Option<Self> {
         let implementation = key.implementation();
         if !matches!(
@@ -755,7 +755,7 @@ impl PythonMinorVersionLink {
         // If preview mode is disabled, still return a `MinorVersionSymlink` for
         // existing symlinks, allowing continued operations without the `--preview`
         // flag after initial symlink directory installation.
-        if preview.is_disabled() && !minor_version_link.exists() {
+        if !preview.is_enabled(PreviewFeatures::PYTHON_UPGRADE) && !minor_version_link.exists() {
             return None;
         }
         Some(minor_version_link)
@@ -763,7 +763,7 @@ impl PythonMinorVersionLink {
 
     pub fn from_installation(
         installation: &ManagedPythonInstallation,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Option<Self> {
         PythonMinorVersionLink::from_executable(
             installation.executable(false).as_path(),

crates/uv-static/src/env_vars.rs

@@ -225,6 +225,9 @@ impl EnvVars {
     /// Equivalent to the `--preview` argument. Enables preview mode.
     pub const UV_PREVIEW: &'static str = "UV_PREVIEW";
 
+    /// Equivalent to the `--preview-features` argument. Enables specific preview features.
+    pub const UV_PREVIEW_FEATURES: &'static str = "UV_PREVIEW_FEATURES";
+
     /// Equivalent to the `--token` argument for self update. A GitHub token for authentication.
     pub const UV_GITHUB_TOKEN: &'static str = "UV_GITHUB_TOKEN";
 

crates/uv-tool/src/lib.rs

@@ -1,7 +1,7 @@
 use core::fmt;
 use fs_err as fs;
 
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_dirs::user_executable_directory;
 use uv_pep440::Version;
 use uv_pep508::{InvalidNameError, PackageName};
@@ -258,7 +258,7 @@ impl InstalledTools {
         &self,
         name: &PackageName,
         interpreter: Interpreter,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<PythonEnvironment, Error> {
         let environment_path = self.tool_dir(name);
 

crates/uv-virtualenv/src/lib.rs

@@ -3,7 +3,7 @@ use std::path::Path;
 
 use thiserror::Error;
 
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_python::{Interpreter, PythonEnvironment};
 
 pub use virtualenv::{OnExisting, remove_virtualenv};
@@ -56,7 +56,7 @@ pub fn create_venv(
     relocatable: bool,
     seed: bool,
     upgradeable: bool,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<PythonEnvironment, Error> {
     // Create the virtualenv at the given location.
     let virtualenv = virtualenv::create(

crates/uv-virtualenv/src/virtualenv.rs

@@ -12,7 +12,7 @@ use itertools::Itertools;
 use owo_colors::OwoColorize;
 use tracing::{debug, trace};
 
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_fs::{CWD, Simplified, cachedir};
 use uv_pypi_types::Scheme;
 use uv_python::managed::{PythonMinorVersionLink, create_link_to_executable};
@@ -59,7 +59,7 @@ pub(crate) fn create(
     relocatable: bool,
     seed: bool,
     upgradeable: bool,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<VirtualEnvironment, Error> {
     // Determine the base Python executable; that is, the Python executable that should be
     // considered the "base" for the virtual environment.

crates/uv/src/commands/build_frontend.rs

@@ -16,7 +16,7 @@ use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     BuildKind, BuildOptions, BuildOutput, Concurrency, ConfigSettings, Constraints,
     DependencyGroupsWithDefaults, HashCheckingMode, IndexStrategy, KeyringProviderType,
-    PackageConfigSettings, PreviewMode, SourceStrategy,
+    PackageConfigSettings, Preview, SourceStrategy,
 };
 use uv_dispatch::{BuildDispatch, SharedState};
 use uv_distribution_filename::{
@@ -117,7 +117,7 @@ pub(crate) async fn build_frontend(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let build_result = build_impl(
         project_dir,
@@ -185,7 +185,7 @@ async fn build_impl(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<BuildResult> {
     // Extract the resolver settings.
     let ResolverSettings {
@@ -437,7 +437,7 @@ async fn build_package(
     link_mode: LinkMode,
     config_setting: &ConfigSettings,
     config_settings_package: &PackageConfigSettings,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<Vec<BuildMessage>, Error> {
     let output_dir = if let Some(output_dir) = output_dir {
         Cow::Owned(std::path::absolute(output_dir)?)

crates/uv/src/commands/pip/check.rs

@@ -5,7 +5,7 @@ use anyhow::Result;
 use owo_colors::OwoColorize;
 
 use uv_cache::Cache;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_distribution_types::{Diagnostic, InstalledDist};
 use uv_installer::{SitePackages, SitePackagesDiagnostic};
 use uv_python::{EnvironmentPreference, PythonEnvironment, PythonRequest};
@@ -20,7 +20,7 @@ pub(crate) fn pip_check(
     system: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let start = Instant::now();
 

crates/uv/src/commands/pip/compile.rs

@@ -14,8 +14,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     BuildOptions, Concurrency, ConfigSettings, Constraints, ExportFormat, ExtrasSpecification,
-    IndexStrategy, NoBinary, NoBuild, PackageConfigSettings, PreviewMode, Reinstall,
+    IndexStrategy, NoBinary, NoBuild, PackageConfigSettings, Preview, Reinstall, SourceStrategy,
-    SourceStrategy, Upgrade,
+    Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@@ -110,7 +110,7 @@ pub(crate) async fn pip_compile(
     quiet: bool,
     cache: Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // If the user provides a `pyproject.toml` or other TOML file as the output file, raise an
     // error.

crates/uv/src/commands/pip/freeze.rs

@@ -6,7 +6,7 @@ use itertools::Itertools;
 use owo_colors::OwoColorize;
 
 use uv_cache::Cache;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_distribution_types::{Diagnostic, InstalledDist, Name};
 use uv_installer::SitePackages;
 use uv_python::{EnvironmentPreference, PythonEnvironment, PythonRequest};
@@ -24,7 +24,7 @@ pub(crate) fn pip_freeze(
     paths: Option<Vec<PathBuf>>,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Detect the current Python interpreter.
     let environment = PythonEnvironment::find(

crates/uv/src/commands/pip/install.rs

@@ -10,8 +10,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     BuildOptions, Concurrency, ConfigSettings, Constraints, DryRun, ExtrasSpecification,
-    HashCheckingMode, IndexStrategy, PackageConfigSettings, PreviewMode, Reinstall, SourceStrategy,
+    HashCheckingMode, IndexStrategy, PackageConfigSettings, Preview, PreviewFeatures, Reinstall,
-    Upgrade,
+    SourceStrategy, Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@@ -95,7 +95,7 @@ pub(crate) async fn pip_install(
     cache: Cache,
     dry_run: DryRun,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> anyhow::Result<ExitStatus> {
     let start = std::time::Instant::now();
 
@@ -133,9 +133,10 @@ pub(crate) async fn pip_install(
     .await?;
 
     if pylock.is_some() {
-        if preview.is_disabled() {
+        if !preview.is_enabled(PreviewFeatures::PYLOCK) {
             warn_user!(
-                "The `--pylock` setting is experimental and may change without warning. Pass `--preview` to disable this warning."
+                "The `--pylock` setting is experimental and may change without warning. Pass `--preview-features {}` to disable this warning.",
+                PreviewFeatures::PYLOCK
             );
         }
     }

crates/uv/src/commands/pip/list.rs

@@ -15,7 +15,7 @@ use uv_cache::{Cache, Refresh};
 use uv_cache_info::Timestamp;
 use uv_cli::ListFormat;
 use uv_client::{BaseClientBuilder, RegistryClientBuilder};
-use uv_configuration::{Concurrency, IndexStrategy, KeyringProviderType, PreviewMode};
+use uv_configuration::{Concurrency, IndexStrategy, KeyringProviderType, Preview};
 use uv_distribution_filename::DistFilename;
 use uv_distribution_types::{
     Diagnostic, IndexCapabilities, IndexLocations, InstalledDist, Name, RequiresPython,
@@ -54,7 +54,7 @@ pub(crate) async fn pip_list(
     system: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Disallow `--outdated` with `--format freeze`.
     if outdated && matches!(format, ListFormat::Freeze) {

crates/uv/src/commands/pip/show.rs

@@ -7,7 +7,7 @@ use owo_colors::OwoColorize;
 use rustc_hash::FxHashMap;
 
 use uv_cache::Cache;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_distribution_types::{Diagnostic, Name};
 use uv_fs::Simplified;
 use uv_install_wheel::read_record_file;
@@ -28,7 +28,7 @@ pub(crate) fn pip_show(
     files: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     if packages.is_empty() {
         #[allow(clippy::print_stderr)]

crates/uv/src/commands/pip/sync.rs

@@ -9,8 +9,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     BuildOptions, Concurrency, ConfigSettings, Constraints, DryRun, ExtrasSpecification,
-    HashCheckingMode, IndexStrategy, PackageConfigSettings, PreviewMode, Reinstall, SourceStrategy,
+    HashCheckingMode, IndexStrategy, PackageConfigSettings, Preview, PreviewFeatures, Reinstall,
-    Upgrade,
+    SourceStrategy, Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@@ -83,7 +83,7 @@ pub(crate) async fn pip_sync(
     cache: Cache,
     dry_run: DryRun,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let client_builder = BaseClientBuilder::new()
         .retries_from_env()?
@@ -126,9 +126,10 @@ pub(crate) async fn pip_sync(
     .await?;
 
     if pylock.is_some() {
-        if preview.is_disabled() {
+        if !preview.is_enabled(PreviewFeatures::PYLOCK) {
             warn_user!(
-                "The `--pylock` setting is experimental and may change without warning. Pass `--preview` to disable this warning."
+                "The `--pylock` setting is experimental and may change without warning. Pass `--preview-features {}` to disable this warning.",
+                PreviewFeatures::PYLOCK
             );
         }
     }

crates/uv/src/commands/pip/tree.rs

@@ -13,7 +13,7 @@ use tokio::sync::Semaphore;
 use uv_cache::{Cache, Refresh};
 use uv_cache_info::Timestamp;
 use uv_client::{BaseClientBuilder, RegistryClientBuilder};
-use uv_configuration::{Concurrency, IndexStrategy, KeyringProviderType, PreviewMode};
+use uv_configuration::{Concurrency, IndexStrategy, KeyringProviderType, Preview};
 use uv_distribution_types::{Diagnostic, IndexCapabilities, IndexLocations, Name, RequiresPython};
 use uv_installer::SitePackages;
 use uv_normalize::PackageName;
@@ -52,7 +52,7 @@ pub(crate) async fn pip_tree(
     system: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Detect the current Python interpreter.
     let environment = PythonEnvironment::find(

crates/uv/src/commands/pip/uninstall.rs

@@ -7,7 +7,7 @@ use tracing::{debug, warn};
 
 use uv_cache::Cache;
 use uv_client::BaseClientBuilder;
-use uv_configuration::{DryRun, KeyringProviderType, PreviewMode};
+use uv_configuration::{DryRun, KeyringProviderType, Preview};
 use uv_distribution_types::Requirement;
 use uv_distribution_types::{InstalledMetadata, Name, UnresolvedRequirement};
 use uv_fs::Simplified;
@@ -37,7 +37,7 @@ pub(crate) async fn pip_uninstall(
     network_settings: &NetworkSettings,
     dry_run: DryRun,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let start = std::time::Instant::now();
 

crates/uv/src/commands/project/add.rs

@@ -18,8 +18,8 @@ use uv_cache_key::RepositoryUrl;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     Concurrency, Constraints, DependencyGroups, DependencyGroupsWithDefaults, DevMode, DryRun,
-    EditableMode, ExtrasSpecification, ExtrasSpecificationWithDefaults, InstallOptions,
+    EditableMode, ExtrasSpecification, ExtrasSpecificationWithDefaults, InstallOptions, Preview,
-    PreviewMode, SourceStrategy,
+    PreviewFeatures, SourceStrategy,
 };
 use uv_dispatch::BuildDispatch;
 use uv_distribution::DistributionDatabase;
@@ -95,10 +95,13 @@ pub(crate) async fn add(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
-    if bounds.is_some() && preview.is_disabled() {
+    if bounds.is_some() && !preview.is_enabled(PreviewFeatures::ADD_BOUNDS) {
-        warn_user_once!("The bounds option is in preview and may change in any future release.");
+        warn_user_once!(
+            "The `bounds` option is in preview and may change in any future release. Pass `--preview-features {}` to disable this warning.",
+            PreviewFeatures::ADD_BOUNDS
+        );
     }
 
     for source in &requirements {
@@ -944,7 +947,7 @@ async fn lock_and_sync(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<(), ProjectError> {
     let mut lock = project::lock::LockOperation::new(
         if locked {

crates/uv/src/commands/project/environment.rs

@@ -12,7 +12,7 @@ use crate::settings::{NetworkSettings, ResolverInstallerSettings};
 
 use uv_cache::{Cache, CacheBucket};
 use uv_cache_key::{cache_digest, hash_digest};
-use uv_configuration::{Concurrency, Constraints, PreviewMode};
+use uv_configuration::{Concurrency, Constraints, Preview};
 use uv_distribution_types::{Name, Resolution};
 use uv_fs::PythonExt;
 use uv_python::{Interpreter, PythonEnvironment, canonicalize_executable};
@@ -119,7 +119,7 @@ impl CachedEnvironment {
         concurrency: Concurrency,
         cache: &Cache,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, ProjectError> {
         let interpreter = Self::base_interpreter(interpreter, cache)?;
 

crates/uv/src/commands/project/export.rs

@@ -9,7 +9,7 @@ use owo_colors::OwoColorize;
 use uv_cache::Cache;
 use uv_configuration::{
     Concurrency, DependencyGroups, EditableMode, ExportFormat, ExtrasSpecification, InstallOptions,
-    PreviewMode,
+    Preview,
 };
 use uv_normalize::{DefaultExtras, DefaultGroups, PackageName};
 use uv_python::{PythonDownloads, PythonPreference, PythonRequest};
@@ -79,7 +79,7 @@ pub(crate) async fn export(
     quiet: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Identify the target.
     let workspace_cache = WorkspaceCache::default();

crates/uv/src/commands/project/init.rs

@@ -12,7 +12,7 @@ use uv_cache::Cache;
 use uv_cli::AuthorFrom;
 use uv_client::BaseClientBuilder;
 use uv_configuration::{
-    DependencyGroupsWithDefaults, PreviewMode, ProjectBuildBackend, VersionControlError,
+    DependencyGroupsWithDefaults, Preview, ProjectBuildBackend, VersionControlError,
     VersionControlSystem,
 };
 use uv_fs::{CWD, Simplified};
@@ -62,7 +62,7 @@ pub(crate) async fn init(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     match init_kind {
         InitKind::Script => {
@@ -201,7 +201,7 @@ async fn init_script(
     pin_python: bool,
     package: bool,
     no_config: bool,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<()> {
     if no_workspace {
         warn_user_once!("`--no-workspace` is a no-op for Python scripts, which are standalone");
@@ -296,7 +296,7 @@ async fn init_project(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<()> {
     // Discover the current workspace, if it exists.
     let workspace_cache = WorkspaceCache::default();

crates/uv/src/commands/project/lock.rs

@@ -12,8 +12,8 @@ use tracing::debug;
 use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
-    Concurrency, Constraints, DependencyGroupsWithDefaults, DryRun, ExtrasSpecification,
+    Concurrency, Constraints, DependencyGroupsWithDefaults, DryRun, ExtrasSpecification, Preview,
-    PreviewMode, Reinstall, Upgrade,
+    Reinstall, Upgrade,
 };
 use uv_dispatch::BuildDispatch;
 use uv_distribution::DistributionDatabase;
@@ -93,7 +93,7 @@ pub(crate) async fn lock(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> anyhow::Result<ExitStatus> {
     // If necessary, initialize the PEP 723 script.
     let script = match script {
@@ -271,7 +271,7 @@ pub(super) struct LockOperation<'env> {
     cache: &'env Cache,
     workspace_cache: &'env WorkspaceCache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 }
 
 impl<'env> LockOperation<'env> {
@@ -286,7 +286,7 @@ impl<'env> LockOperation<'env> {
         cache: &'env Cache,
         workspace_cache: &'env WorkspaceCache,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Self {
         Self {
             mode,
@@ -418,7 +418,7 @@ async fn do_lock(
     cache: &Cache,
     workspace_cache: &WorkspaceCache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<LockResult, ProjectError> {
     let start = std::time::Instant::now();
 

crates/uv/src/commands/project/mod.rs

@@ -12,8 +12,8 @@ use uv_cache::{Cache, CacheBucket};
 use uv_cache_key::cache_digest;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
-    Concurrency, Constraints, DependencyGroupsWithDefaults, DryRun, ExtrasSpecification,
+    Concurrency, Constraints, DependencyGroupsWithDefaults, DryRun, ExtrasSpecification, Preview,
-    PreviewMode, Reinstall, SourceStrategy, Upgrade,
+    PreviewFeatures, Reinstall, SourceStrategy, Upgrade,
 };
 use uv_dispatch::{BuildDispatch, SharedState};
 use uv_distribution::{DistributionDatabase, LoweredRequirement};
@@ -647,7 +647,7 @@ impl ScriptInterpreter {
         active: Option<bool>,
         cache: &Cache,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, ProjectError> {
         // For now, we assume that scripts are never evaluated in the context of a workspace.
         let workspace = None;
@@ -887,7 +887,7 @@ impl ProjectInterpreter {
         active: Option<bool>,
         cache: &Cache,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, ProjectError> {
         // Resolve the Python request and requirement for the workspace.
         let WorkspacePython {
@@ -1269,7 +1269,7 @@ impl ProjectEnvironment {
         cache: &Cache,
         dry_run: DryRun,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, ProjectError> {
         // Lock the project environment to avoid synchronization issues.
         let _lock = ProjectInterpreter::lock(workspace)
@@ -1279,7 +1279,7 @@ impl ProjectEnvironment {
             })
             .ok();
 
-        let upgradeable = preview.is_enabled()
+        let upgradeable = preview.is_enabled(PreviewFeatures::PYTHON_UPGRADE)
             && python
                 .as_ref()
                 .is_none_or(|request| !request.includes_patch());
@@ -1501,7 +1501,7 @@ impl ScriptEnvironment {
         cache: &Cache,
         dry_run: DryRun,
         printer: Printer,
-        preview: PreviewMode,
+        preview: Preview,
     ) -> Result<Self, ProjectError> {
         // Lock the script environment to avoid synchronization issues.
         let _lock = ScriptInterpreter::lock(script)
@@ -1658,7 +1658,7 @@ pub(crate) async fn resolve_names(
     cache: &Cache,
     workspace_cache: &WorkspaceCache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<Vec<Requirement>, uv_requirements::Error> {
     // Partition the requirements into named and unnamed requirements.
     let (mut requirements, unnamed): (Vec<_>, Vec<_>) =
@@ -1829,7 +1829,7 @@ pub(crate) async fn resolve_environment(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ResolverOutput, ProjectError> {
     warn_on_requirements_txt_setting(&spec.requirements, settings);
 
@@ -2017,7 +2017,7 @@ pub(crate) async fn sync_environment(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<PythonEnvironment, ProjectError> {
     let InstallerSettingsRef {
         index_locations,
@@ -2175,7 +2175,7 @@ pub(crate) async fn update_environment(
     workspace_cache: WorkspaceCache,
     dry_run: DryRun,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<EnvironmentUpdate, ProjectError> {
     warn_on_requirements_txt_setting(&spec, &settings.resolver);
 
@@ -2416,7 +2416,7 @@ pub(crate) async fn init_script_python_requirement(
     client_builder: &BaseClientBuilder<'_>,
     cache: &Cache,
     reporter: &PythonDownloadReporter,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> anyhow::Result<RequiresPython> {
     let python_request = if let Some(request) = python {
         // (1) Explicit request from user

crates/uv/src/commands/project/remove.rs

@@ -10,7 +10,7 @@ use tracing::{debug, warn};
 use uv_cache::Cache;
 use uv_configuration::{
     Concurrency, DependencyGroups, DryRun, EditableMode, ExtrasSpecification, InstallOptions,
-    PreviewMode,
+    Preview,
 };
 use uv_fs::Simplified;
 use uv_normalize::{DEV_DEPENDENCIES, DefaultExtras, DefaultGroups};
@@ -60,7 +60,7 @@ pub(crate) async fn remove(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let target = if let Some(script) = script {
         // If we found a PEP 723 script and the user provided a project-only setting, warn.

crates/uv/src/commands/project/run.rs

@@ -19,7 +19,7 @@ use uv_cli::ExternalCommand;
 use uv_client::BaseClientBuilder;
 use uv_configuration::{
     Concurrency, Constraints, DependencyGroups, DryRun, EditableMode, ExtrasSpecification,
-    InstallOptions, PreviewMode,
+    InstallOptions, Preview,
 };
 use uv_distribution_types::Requirement;
 use uv_fs::which::is_executable;
@@ -94,7 +94,7 @@ pub(crate) async fn run(
     printer: Printer,
     env_file: Vec<PathBuf>,
     no_env_file: bool,
-    preview: PreviewMode,
+    preview: Preview,
     max_recursion_depth: u32,
 ) -> anyhow::Result<ExitStatus> {
     // Check if max recursion depth was exceeded. This most commonly happens

crates/uv/src/commands/project/sync.rs

@@ -14,7 +14,7 @@ use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     Concurrency, Constraints, DependencyGroups, DependencyGroupsWithDefaults, DryRun, EditableMode,
     ExtrasSpecification, ExtrasSpecificationWithDefaults, HashCheckingMode, InstallOptions,
-    PreviewMode, TargetTriple,
+    Preview, PreviewFeatures, TargetTriple,
 };
 use uv_dispatch::BuildDispatch;
 use uv_distribution_types::{
@@ -77,12 +77,14 @@ pub(crate) async fn sync(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
     output_format: SyncFormat,
 ) -> Result<ExitStatus> {
-    if preview.is_enabled() && matches!(output_format, SyncFormat::Json) {
+    if preview.is_enabled(PreviewFeatures::JSON_OUTPUT) && matches!(output_format, SyncFormat::Json)
+    {
         warn_user!(
-            "The `--output-format json` option is experimental and the schema may change without warning. Pass `--preview` to disable this warning."
+            "The `--output-format json` option is experimental and the schema may change without warning. Pass `--preview-features {}` to disable this warning.",
+            PreviewFeatures::JSON_OUTPUT
         );
     }
 
@@ -564,7 +566,7 @@ pub(super) async fn do_sync(
     workspace_cache: WorkspaceCache,
     dry_run: DryRun,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<(), ProjectError> {
     // Extract the project settings.
     let InstallerSettingsRef {

crates/uv/src/commands/project/tree.rs

@@ -7,7 +7,7 @@ use tokio::sync::Semaphore;
 use uv_cache::{Cache, Refresh};
 use uv_cache_info::Timestamp;
 use uv_client::RegistryClientBuilder;
-use uv_configuration::{Concurrency, DependencyGroups, PreviewMode, TargetTriple};
+use uv_configuration::{Concurrency, DependencyGroups, Preview, TargetTriple};
 use uv_distribution_types::IndexCapabilities;
 use uv_normalize::DefaultGroups;
 use uv_pep508::PackageName;
@@ -57,7 +57,7 @@ pub(crate) async fn tree(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Find the project requirements.
     let workspace_cache = WorkspaceCache::default();

crates/uv/src/commands/project/version.rs

@@ -11,7 +11,7 @@ use uv_cli::version::VersionInfo;
 use uv_cli::{VersionBump, VersionFormat};
 use uv_configuration::{
     Concurrency, DependencyGroups, DependencyGroupsWithDefaults, DryRun, EditableMode,
-    ExtrasSpecification, InstallOptions, PreviewMode,
+    ExtrasSpecification, InstallOptions, Preview,
 };
 use uv_fs::Simplified;
 use uv_normalize::DefaultExtras;
@@ -76,7 +76,7 @@ pub(crate) async fn project_version(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Read the metadata
     let project = find_target(project_dir, package.as_ref(), explicit_project).await?;
@@ -414,7 +414,7 @@ async fn print_frozen_version(
     short: bool,
     output_format: VersionFormat,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // Discover the interpreter (this is the same interpreter --no-sync uses).
     let interpreter = ProjectInterpreter::discover(
@@ -509,7 +509,7 @@ async fn lock_and_sync(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     // If frozen, don't touch the lock or sync at all
     if frozen {

crates/uv/src/commands/python/find.rs

@@ -3,7 +3,7 @@ use std::fmt::Write;
 use std::path::Path;
 
 use uv_cache::Cache;
-use uv_configuration::{DependencyGroupsWithDefaults, PreviewMode};
+use uv_configuration::{DependencyGroupsWithDefaults, Preview};
 use uv_fs::Simplified;
 use uv_python::{
     EnvironmentPreference, PythonDownloads, PythonInstallation, PythonPreference, PythonRequest,
@@ -32,7 +32,7 @@ pub(crate) async fn find(
     python_preference: PythonPreference,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let environment_preference = if system {
         EnvironmentPreference::OnlySystem
@@ -123,7 +123,7 @@ pub(crate) async fn find_script(
     no_config: bool,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let interpreter = match ScriptInterpreter::discover(
         script,

crates/uv/src/commands/python/install.rs

@@ -14,7 +14,7 @@ use owo_colors::OwoColorize;
 use rustc_hash::{FxHashMap, FxHashSet};
 use tracing::{debug, trace};
 
-use uv_configuration::PreviewMode;
+use uv_configuration::{Preview, PreviewFeatures};
 use uv_fs::Simplified;
 use uv_python::downloads::{
     self, ArchRequest, DownloadResult, ManagedPythonDownload, PythonDownloadRequest,
@@ -161,7 +161,7 @@ pub(crate) async fn install(
     default: bool,
     python_downloads: PythonDownloads,
     no_config: bool,
-    preview: PreviewMode,
+    preview: Preview,
     printer: Printer,
 ) -> Result<ExitStatus> {
     let start = std::time::Instant::now();
@@ -170,15 +170,17 @@ pub(crate) async fn install(
     // `--default` is used. It's not clear how this overlaps with a global Python pin, but I'd be
     // surprised if `uv python find` returned the "newest" Python version rather than the one I just
     // installed with the `--default` flag.
-    if default && !preview.is_enabled() {
+    if default && !preview.is_enabled(PreviewFeatures::PYTHON_INSTALL_DEFAULT) {
         warn_user!(
-            "The `--default` option is experimental and may change without warning. Pass `--preview` to disable this warning"
+            "The `--default` option is experimental and may change without warning. Pass `--preview-features {}` to disable this warning",
+            PreviewFeatures::PYTHON_INSTALL_DEFAULT
         );
     }
 
-    if upgrade && preview.is_disabled() {
+    if upgrade && !preview.is_enabled(PreviewFeatures::PYTHON_UPGRADE) {
         warn_user!(
-            "`uv python upgrade` is experimental and may change without warning. Pass `--preview` to disable this warning"
+            "`uv python upgrade` is experimental and may change without warning. Pass `--preview-features {}` to disable this warning",
+            PreviewFeatures::PYTHON_UPGRADE
         );
     }
 
@@ -737,12 +739,13 @@ fn create_bin_links(
     installations: &[&ManagedPythonInstallation],
     changelog: &mut Changelog,
     errors: &mut Vec<(InstallErrorKind, PythonInstallationKey, Error)>,
-    preview: PreviewMode,
+    preview: Preview,
 ) {
     // TODO(zanieb): We want more feedback on the `is_default_install` behavior before stabilizing
     // it. In particular, it may be confusing because it does not apply when versions are loaded
     // from a `.python-version` file.
-    let targets = if (default || (is_default_install && preview.is_enabled()))
+    let targets = if (default
+        || (is_default_install && preview.is_enabled(PreviewFeatures::PYTHON_INSTALL_DEFAULT)))
         && first_request.matches_installation(installation)
     {
         vec![

crates/uv/src/commands/python/list.rs

@@ -2,7 +2,7 @@ use serde::Serialize;
 use std::collections::BTreeSet;
 use std::fmt::Write;
 use uv_cli::PythonListFormat;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_pep440::Version;
 
 use anyhow::Result;
@@ -65,7 +65,7 @@ pub(crate) async fn list(
     python_downloads: PythonDownloads,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let request = request.as_deref().map(PythonRequest::parse);
     let base_download_request = if python_preference == PythonPreference::OnlySystem {

crates/uv/src/commands/python/pin.rs

@@ -8,7 +8,7 @@ use tracing::debug;
 
 use uv_cache::Cache;
 use uv_client::BaseClientBuilder;
-use uv_configuration::{DependencyGroupsWithDefaults, PreviewMode};
+use uv_configuration::{DependencyGroupsWithDefaults, Preview};
 use uv_fs::Simplified;
 use uv_python::{
     EnvironmentPreference, PYTHON_VERSION_FILENAME, PythonDownloads, PythonInstallation,
@@ -39,7 +39,7 @@ pub(crate) async fn pin(
     network_settings: NetworkSettings,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let workspace_cache = WorkspaceCache::default();
     let virtual_project = if no_project {
@@ -270,7 +270,7 @@ fn warn_if_existing_pin_incompatible_with_project(
     virtual_project: &VirtualProject,
     python_preference: PythonPreference,
     cache: &Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) {
     // Check if the pinned version is compatible with the project.
     if let Some(pin_version) = pep440_version_from_request(pin) {

crates/uv/src/commands/python/uninstall.rs

@@ -11,7 +11,7 @@ use owo_colors::OwoColorize;
 use rustc_hash::{FxHashMap, FxHashSet};
 use tracing::{debug, warn};
 
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_fs::Simplified;
 use uv_python::downloads::PythonDownloadRequest;
 use uv_python::managed::{
@@ -30,7 +30,7 @@ pub(crate) async fn uninstall(
     targets: Vec<String>,
     all: bool,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let installations = ManagedPythonInstallations::from_settings(install_dir)?.init()?;
 
@@ -66,7 +66,7 @@ async fn do_uninstall(
     targets: Vec<String>,
     all: bool,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let start = std::time::Instant::now();
 

crates/uv/src/commands/tool/common.rs

@@ -7,7 +7,7 @@ use std::{collections::BTreeSet, ffi::OsString};
 use tracing::{debug, warn};
 use uv_cache::Cache;
 use uv_client::BaseClientBuilder;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_distribution_types::Requirement;
 use uv_distribution_types::{InstalledDist, Name};
 use uv_fs::Simplified;
@@ -81,7 +81,7 @@ pub(crate) async fn refine_interpreter(
     python_preference: PythonPreference,
     python_downloads: PythonDownloads,
     cache: &Cache,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> anyhow::Result<Option<Interpreter>, ProjectError> {
     let pip::operations::Error::Resolve(uv_resolver::ResolveError::NoSolution(no_solution_err)) =
         err

crates/uv/src/commands/tool/dir.rs

@@ -2,12 +2,12 @@ use anstream::println;
 use anyhow::Context;
 use owo_colors::OwoColorize;
 
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_fs::Simplified;
 use uv_tool::{InstalledTools, tool_executable_dir};
 
 /// Show the tool directory.
-pub(crate) fn dir(bin: bool, _preview: PreviewMode) -> anyhow::Result<()> {
+pub(crate) fn dir(bin: bool, _preview: Preview) -> anyhow::Result<()> {
     if bin {
         let executable_directory = tool_executable_dir()?;
         println!("{}", executable_directory.simplified_display().cyan());

crates/uv/src/commands/tool/install.rs

@@ -8,7 +8,7 @@ use tracing::{debug, trace};
 use uv_cache::{Cache, Refresh};
 use uv_cache_info::Timestamp;
 use uv_client::BaseClientBuilder;
-use uv_configuration::{Concurrency, Constraints, DryRun, PreviewMode, Reinstall, Upgrade};
+use uv_configuration::{Concurrency, Constraints, DryRun, Preview, Reinstall, Upgrade};
 use uv_distribution_types::{
     NameRequirementSpecification, Requirement, RequirementSource,
     UnresolvedRequirementSpecification,
@@ -62,7 +62,7 @@ pub(crate) async fn install(
     concurrency: Concurrency,
     cache: Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let client_builder = BaseClientBuilder::new()
         .retries_from_env()?

crates/uv/src/commands/tool/run.rs

@@ -17,7 +17,7 @@ use uv_cache_info::Timestamp;
 use uv_cli::ExternalCommand;
 use uv_client::BaseClientBuilder;
 use uv_configuration::Constraints;
-use uv_configuration::{Concurrency, PreviewMode};
+use uv_configuration::{Concurrency, Preview};
 use uv_distribution_types::InstalledDist;
 use uv_distribution_types::{
     IndexUrl, Name, NameRequirementSpecification, Requirement, RequirementSource,
@@ -101,7 +101,7 @@ pub(crate) async fn run(
     printer: Printer,
     env_file: Vec<PathBuf>,
     no_env_file: bool,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> anyhow::Result<ExitStatus> {
     /// Whether or not a path looks like a Python script based on the file extension.
     fn has_python_script_ext(path: &Path) -> bool {
@@ -686,7 +686,7 @@ async fn get_or_create_environment(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<(ToolRequirement, PythonEnvironment), ProjectError> {
     let client_builder = BaseClientBuilder::new()
         .retries_from_env()?

crates/uv/src/commands/tool/upgrade.rs

@@ -7,7 +7,7 @@ use tracing::debug;
 
 use uv_cache::Cache;
 use uv_client::BaseClientBuilder;
-use uv_configuration::{Concurrency, Constraints, DryRun, PreviewMode};
+use uv_configuration::{Concurrency, Constraints, DryRun, Preview};
 use uv_distribution_types::Requirement;
 use uv_fs::CWD;
 use uv_normalize::PackageName;
@@ -47,7 +47,7 @@ pub(crate) async fn upgrade(
     concurrency: Concurrency,
     cache: &Cache,
     printer: Printer,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let installed_tools = InstalledTools::from_settings()?.init()?;
     let _lock = installed_tools.lock().await?;
@@ -221,7 +221,7 @@ async fn upgrade_tool(
     filesystem: &ResolverInstallerOptions,
     installer_metadata: bool,
     concurrency: Concurrency,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<UpgradeOutcome> {
     // Ensure the tool is installed.
     let existing_tool_receipt = match installed_tools.get_tool_receipt(name) {

crates/uv/src/commands/venv.rs

@@ -11,7 +11,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
     BuildOptions, Concurrency, ConfigSettings, Constraints, DependencyGroups, IndexStrategy,
-    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, PreviewMode, SourceStrategy,
+    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, Preview, PreviewFeatures,
+    SourceStrategy,
 };
 use uv_dispatch::{BuildDispatch, SharedState};
 use uv_distribution_types::Requirement;
@@ -81,7 +82,7 @@ pub(crate) async fn venv(
     cache: &Cache,
     printer: Printer,
     relocatable: bool,
-    preview: PreviewMode,
+    preview: Preview,
 ) -> Result<ExitStatus> {
     let workspace_cache = WorkspaceCache::default();
     let project = if no_project {
@@ -198,7 +199,7 @@ pub(crate) async fn venv(
         path.user_display().cyan()
     )?;
 
-    let upgradeable = preview.is_enabled()
+    let upgradeable = preview.is_enabled(PreviewFeatures::PYTHON_UPGRADE)
         && python_request
             .as_ref()
             .is_none_or(|request| !request.includes_patch());

crates/uv/src/settings.rs

@@ -23,9 +23,9 @@ use uv_client::Connectivity;
 use uv_configuration::{
     BuildOptions, Concurrency, ConfigSettings, DependencyGroups, DryRun, EditableMode,
     ExportFormat, ExtrasSpecification, HashCheckingMode, IndexStrategy, InstallOptions,
-    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, PreviewMode,
+    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, Preview, ProjectBuildBackend,
-    ProjectBuildBackend, Reinstall, RequiredVersion, SourceStrategy, TargetTriple, TrustedHost,
+    Reinstall, RequiredVersion, SourceStrategy, TargetTriple, TrustedHost, TrustedPublishing,
-    TrustedPublishing, Upgrade, VersionControlSystem,
+    Upgrade, VersionControlSystem,
 };
 use uv_distribution_types::{DependencyMetadata, Index, IndexLocations, IndexUrl, Requirement};
 use uv_install_wheel::LinkMode;
@@ -63,7 +63,7 @@ pub(crate) struct GlobalSettings {
     pub(crate) network_settings: NetworkSettings,
     pub(crate) concurrency: Concurrency,
     pub(crate) show_settings: bool,
-    pub(crate) preview: PreviewMode,
+    pub(crate) preview: Preview,
     pub(crate) python_preference: PythonPreference,
     pub(crate) python_downloads: PythonDownloads,
     pub(crate) no_progress: bool,
@@ -117,10 +117,12 @@ impl GlobalSettings {
                     .unwrap_or_else(Concurrency::threads),
             },
             show_settings: args.show_settings,
-            preview: PreviewMode::from(
+            preview: Preview::from_args(
                 flag(args.preview, args.no_preview, "preview")
                     .combine(workspace.and_then(|workspace| workspace.globals.preview))
                     .unwrap_or(false),
+                args.no_preview,
+                &args.preview_features,
             ),
             python_preference,
             python_downloads: flag(

crates/uv/tests/it/common/mod.rs

@@ -21,7 +21,7 @@ use regex::Regex;
 
 use tokio::io::AsyncWriteExt;
 use uv_cache::Cache;
-use uv_configuration::PreviewMode;
+use uv_configuration::Preview;
 use uv_fs::Simplified;
 use uv_python::managed::ManagedPythonInstallations;
 use uv_python::{
@@ -1505,7 +1505,7 @@ pub fn python_installations_for_versions(
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::Managed,
                 &cache,
-                PreviewMode::Disabled,
+                Preview::default(),
             ) {
                 python.into_interpreter().sys_executable().to_owned()
             } else {

crates/uv/tests/it/edit.rs

@@ -13021,7 +13021,7 @@ fn add_bounds() -> Result<()> {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The bounds option is in preview and may change in any future release.
+    warning: The `bounds` option is in preview and may change in any future release. Pass `--preview-features add-bounds` to disable this warning.
     Resolved 2 packages in [TIME]
     Prepared 1 package in [TIME]
     Installed 1 package in [TIME]
@@ -13061,7 +13061,7 @@ fn add_bounds() -> Result<()> {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The bounds option is in preview and may change in any future release.
+    warning: The `bounds` option is in preview and may change in any future release. Pass `--preview-features add-bounds` to disable this warning.
     Resolved 4 packages in [TIME]
     Prepared 2 packages in [TIME]
     Installed 2 packages in [TIME]

crates/uv/tests/it/python_install.rs

@@ -630,14 +630,14 @@ fn python_install_preview() {
     "###);
 
     // Should be a no-op when already installed
-    uv_snapshot!(context.filters(), context.python_install().arg("--preview"), @r###"
+    uv_snapshot!(context.filters(), context.python_install().arg("--preview"), @r"
     success: true
     exit_code: 0
     ----- stdout -----
 
     ----- stderr -----
     Python is already installed. Use `uv python install <request>` to install another version.
-    "###);
+    ");
 
     // You can opt-in to a reinstall
     uv_snapshot!(context.filters(), context.python_install().arg("--preview").arg("--reinstall"), @r"
@@ -1260,7 +1260,7 @@ fn python_install_default() {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The `--default` option is experimental and may change without warning. Pass `--preview` to disable this warning
+    warning: The `--default` option is experimental and may change without warning. Pass `--preview-features python-install-default` to disable this warning
     Installed Python 3.13.5 in [TIME]
      + cpython-3.13.5-[PLATFORM] (python, python3)
     ");
@@ -1294,7 +1294,7 @@ fn python_install_default() {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The `--default` option is experimental and may change without warning. Pass `--preview` to disable this warning
+    warning: The `--default` option is experimental and may change without warning. Pass `--preview-features python-install-default` to disable this warning
     Installed Python 3.13.5 in [TIME]
      + cpython-3.13.5-[PLATFORM] (python, python3, python3.13)
     ");
@@ -1379,7 +1379,7 @@ fn python_install_default() {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The `--default` option is experimental and may change without warning. Pass `--preview` to disable this warning
+    warning: The `--default` option is experimental and may change without warning. Pass `--preview-features python-install-default` to disable this warning
     error: The `--default` flag cannot be used with multiple targets
     ");
 
@@ -1390,7 +1390,7 @@ fn python_install_default() {
     ----- stdout -----
 
     ----- stderr -----
-    warning: The `--default` option is experimental and may change without warning. Pass `--preview` to disable this warning
+    warning: The `--default` option is experimental and may change without warning. Pass `--preview-features python-install-default` to disable this warning
     Installed Python 3.12.11 in [TIME]
      + cpython-3.12.11-[PLATFORM] (python, python3, python3.12)
     ");

docs/reference/environment.md

@@ -306,6 +306,10 @@ Equivalent to the `--prerelease` command-line argument. For example, if set to
 
 Equivalent to the `--preview` argument. Enables preview mode.
 
+### `UV_PREVIEW_FEATURES`
+
+Equivalent to the `--preview-features` argument. Enables specific preview features.
+
 ### `UV_PROJECT`
 
 Equivalent to the `--project` command-line argument.