Allow --config-settings-package to apply configuration settings at the package level (#14573)

## Summary Closes https://github.com/astral-sh/uv/issues/14564. Closes https://github.com/astral-sh/uv/issues/10940.
2025-10-17 05:47:45 +00:00 · 2025-07-17 21:27:54 -04:00 · 2025-07-17 21:27:54 -04:00 · e724ddc63f
commit e724ddc63f
parent a6a5e65e0c
30 changed files with 927 additions and 58 deletions
--- a/crates/uv-bench/benches/uv.rs
+++ b/crates/uv-bench/benches/uv.rs
@ -86,8 +86,8 @@ mod resolver {
    use uv_cache::Cache;
    use uv_client::RegistryClient;
    use uv_configuration::{
-        BuildOptions, Concurrency, ConfigSettings, Constraints, IndexStrategy, PreviewMode,
-        SourceStrategy,
+        BuildOptions, Concurrency, ConfigSettings, Constraints, IndexStrategy,
+        PackageConfigSettings, PreviewMode, SourceStrategy,
    };
    use uv_dispatch::{BuildDispatch, SharedState};
    use uv_distribution::DistributionDatabase;
@ -144,6 +144,7 @@ mod resolver {
        let build_options = BuildOptions::default();
        let concurrency = Concurrency::default();
        let config_settings = ConfigSettings::default();
+        let config_settings_package = PackageConfigSettings::default();
        let exclude_newer = Some(
            jiff::civil::date(2024, 9, 1)
                .to_zoned(jiff::tz::TimeZone::UTC)
@ -184,6 +185,7 @@ mod resolver {
            state,
            IndexStrategy::default(),
            &config_settings,
+            &config_settings_package,
            build_isolation,
            LinkMode::default(),
            &build_options,
--- a/crates/uv-cli/src/lib.rs
+++ b/crates/uv-cli/src/lib.rs
@ -10,8 +10,9 @@ use clap::{Args, Parser, Subcommand};

 use uv_cache::CacheArgs;
 use uv_configuration::{
-    ConfigSettingEntry, ExportFormat, IndexStrategy, KeyringProviderType, PackageNameSpecifier,
-    ProjectBuildBackend, TargetTriple, TrustedHost, TrustedPublishing, VersionControlSystem,
+    ConfigSettingEntry, ConfigSettingPackageEntry, ExportFormat, IndexStrategy,
+    KeyringProviderType, PackageNameSpecifier, ProjectBuildBackend, TargetTriple, TrustedHost,
+    TrustedPublishing, VersionControlSystem,
 };
 use uv_distribution_types::{Index, IndexUrl, Origin, PipExtraIndex, PipFindLinks, PipIndex};
 use uv_normalize::{ExtraName, GroupName, PackageName, PipGroupName};
@ -4693,6 +4694,14 @@ pub struct ToolUpgradeArgs {
    )]
    pub config_setting: Option<Vec<ConfigSettingEntry>>,

+    /// Settings to pass to the PEP 517 build backend for a specific package, specified as `PACKAGE:KEY=VALUE` pairs.
+    #[arg(
+        long,
+        alias = "config-settings-package",
+        help_heading = "Build options"
+    )]
+    pub config_setting_package: Option<Vec<ConfigSettingPackageEntry>>,
+
    /// Disable isolation when building source distributions.
    ///
    /// Assumes that build dependencies specified by PEP 518 are already installed.
@ -5484,6 +5493,14 @@ pub struct InstallerArgs {
    )]
    pub config_setting: Option<Vec<ConfigSettingEntry>>,

+    /// Settings to pass to the PEP 517 build backend for a specific package, specified as `PACKAGE:KEY=VALUE` pairs.
+    #[arg(
+        long,
+        alias = "config-settings-package",
+        help_heading = "Build options"
+    )]
+    pub config_settings_package: Option<Vec<ConfigSettingPackageEntry>>,
+
    /// Disable isolation when building source distributions.
    ///
    /// Assumes that build dependencies specified by PEP 518 are already installed.
@ -5671,6 +5688,14 @@ pub struct ResolverArgs {
    )]
    pub config_setting: Option<Vec<ConfigSettingEntry>>,

+    /// Settings to pass to the PEP 517 build backend for a specific package, specified as `PACKAGE:KEY=VALUE` pairs.
+    #[arg(
+        long,
+        alias = "config-settings-package",
+        help_heading = "Build options"
+    )]
+    pub config_settings_package: Option<Vec<ConfigSettingPackageEntry>>,
+
    /// Disable isolation when building source distributions.
    ///
    /// Assumes that build dependencies specified by PEP 518 are already installed.
@ -5860,6 +5885,14 @@ pub struct ResolverInstallerArgs {
    )]
    pub config_setting: Option<Vec<ConfigSettingEntry>>,

+    /// Settings to pass to the PEP 517 build backend for a specific package, specified as `PACKAGE:KEY=VALUE` pairs.
+    #[arg(
+        long,
+        alias = "config-settings-package",
+        help_heading = "Build options"
+    )]
+    pub config_settings_package: Option<Vec<ConfigSettingPackageEntry>>,
+
    /// Disable isolation when building source distributions.
    ///
    /// Assumes that build dependencies specified by PEP 518 are already installed.
--- a/crates/uv-cli/src/options.rs
+++ b/crates/uv-cli/src/options.rs
@ -1,7 +1,7 @@
 use anstream::eprintln;

 use uv_cache::Refresh;
-use uv_configuration::ConfigSettings;
+use uv_configuration::{ConfigSettings, PackageConfigSettings};
 use uv_resolver::PrereleaseMode;
 use uv_settings::{Combine, PipOptions, ResolverInstallerOptions, ResolverOptions};
 use uv_warnings::owo_colors::OwoColorize;
@ -62,6 +62,7 @@ impl From<ResolverArgs> for PipOptions {
            pre,
            fork_strategy,
            config_setting,
+            config_settings_package,
            no_build_isolation,
            no_build_isolation_package,
            build_isolation,
@ -84,6 +85,11 @@ impl From<ResolverArgs> for PipOptions {
            },
            config_settings: config_setting
                .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
+            config_settings_package: config_settings_package.map(|config_settings| {
+                config_settings
+                    .into_iter()
+                    .collect::<PackageConfigSettings>()
+            }),
            no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
            no_build_isolation_package: Some(no_build_isolation_package),
            exclude_newer,
@ -104,6 +110,7 @@ impl From<InstallerArgs> for PipOptions {
            index_strategy,
            keyring_provider,
            config_setting,
+            config_settings_package,
            no_build_isolation,
            build_isolation,
            exclude_newer,
@ -120,6 +127,11 @@ impl From<InstallerArgs> for PipOptions {
            keyring_provider,
            config_settings: config_setting
                .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
+            config_settings_package: config_settings_package.map(|config_settings| {
+                config_settings
+                    .into_iter()
+                    .collect::<PackageConfigSettings>()
+            }),
            no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
            exclude_newer,
            link_mode,
@ -147,6 +159,7 @@ impl From<ResolverInstallerArgs> for PipOptions {
            pre,
            fork_strategy,
            config_setting,
+            config_settings_package,
            no_build_isolation,
            no_build_isolation_package,
            build_isolation,
@ -173,6 +186,11 @@ impl From<ResolverInstallerArgs> for PipOptions {
            fork_strategy,
            config_settings: config_setting
                .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
+            config_settings_package: config_settings_package.map(|config_settings| {
+                config_settings
+                    .into_iter()
+                    .collect::<PackageConfigSettings>()
+            }),
            no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
            no_build_isolation_package: Some(no_build_isolation_package),
            exclude_newer,
@ -260,6 +278,7 @@ pub fn resolver_options(
        pre,
        fork_strategy,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        build_isolation,
@ -321,6 +340,11 @@ pub fn resolver_options(
        dependency_metadata: None,
        config_settings: config_setting
            .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
+        config_settings_package: config_settings_package.map(|config_settings| {
+            config_settings
+                .into_iter()
+                .collect::<PackageConfigSettings>()
+        }),
        no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
        no_build_isolation_package: Some(no_build_isolation_package),
        exclude_newer,
@ -353,6 +377,7 @@ pub fn resolver_installer_options(
        pre,
        fork_strategy,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        build_isolation,
@ -428,6 +453,11 @@ pub fn resolver_installer_options(
        dependency_metadata: None,
        config_settings: config_setting
            .map(|config_settings| config_settings.into_iter().collect::<ConfigSettings>()),
+        config_settings_package: config_settings_package.map(|config_settings| {
+            config_settings
+                .into_iter()
+                .collect::<PackageConfigSettings>()
+        }),
        no_build_isolation: flag(no_build_isolation, build_isolation, "build-isolation"),
        no_build_isolation_package: if no_build_isolation_package.is_empty() {
            None
--- a/crates/uv-configuration/src/config_settings.rs
+++ b/crates/uv-configuration/src/config_settings.rs
@ -3,6 +3,7 @@ use std::{
    str::FromStr,
 };
 use uv_cache_key::CacheKeyHasher;
+use uv_normalize::PackageName;

 #[derive(Debug, Clone)]
 pub struct ConfigSettingEntry {
@ -28,6 +29,32 @@ impl FromStr for ConfigSettingEntry {
    }
 }

+#[derive(Debug, Clone)]
+pub struct ConfigSettingPackageEntry {
+    /// The package name to apply the setting to.
+    package: PackageName,
+    /// The config setting entry.
+    setting: ConfigSettingEntry,
+}
+
+impl FromStr for ConfigSettingPackageEntry {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let Some((package_str, config_str)) = s.split_once(':') else {
+            return Err(format!(
+                "Invalid config setting: {s} (expected `PACKAGE:KEY=VALUE`)"
+            ));
+        };
+
+        let package = PackageName::from_str(package_str.trim())
+            .map_err(|e| format!("Invalid package name: {e}"))?;
+        let setting = ConfigSettingEntry::from_str(config_str)?;
+
+        Ok(Self { package, setting })
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema), schemars(untagged))]
 enum ConfigSettingValue {
@ -212,6 +239,111 @@ impl<'de> serde::Deserialize<'de> for ConfigSettings {
    }
 }

+/// Settings to pass to PEP 517 build backends on a per-package basis.
+#[derive(Debug, Default, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct PackageConfigSettings(BTreeMap<PackageName, ConfigSettings>);
+
+impl FromIterator<ConfigSettingPackageEntry> for PackageConfigSettings {
+    fn from_iter<T: IntoIterator<Item = ConfigSettingPackageEntry>>(iter: T) -> Self {
+        let mut package_configs: BTreeMap<PackageName, Vec<ConfigSettingEntry>> = BTreeMap::new();
+
+        for entry in iter {
+            package_configs
+                .entry(entry.package)
+                .or_default()
+                .push(entry.setting);
+        }
+
+        let configs = package_configs
+            .into_iter()
+            .map(|(package, entries)| (package, entries.into_iter().collect()))
+            .collect();
+
+        Self(configs)
+    }
+}
+
+impl PackageConfigSettings {
+    /// Returns the config settings for a specific package, if any.
+    pub fn get(&self, package: &PackageName) -> Option<&ConfigSettings> {
+        self.0.get(package)
+    }
+
+    /// Returns `true` if there are no package-specific settings.
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    /// Merge two sets of package config settings, with the values in `self` taking precedence.
+    #[must_use]
+    pub fn merge(mut self, other: PackageConfigSettings) -> PackageConfigSettings {
+        for (package, settings) in other.0 {
+            match self.0.entry(package) {
+                Entry::Vacant(vacant) => {
+                    vacant.insert(settings);
+                }
+                Entry::Occupied(mut occupied) => {
+                    let merged = occupied.get().clone().merge(settings);
+                    occupied.insert(merged);
+                }
+            }
+        }
+        self
+    }
+}
+
+impl uv_cache_key::CacheKey for PackageConfigSettings {
+    fn cache_key(&self, state: &mut CacheKeyHasher) {
+        for (package, settings) in &self.0 {
+            package.to_string().cache_key(state);
+            settings.cache_key(state);
+        }
+    }
+}
+
+impl serde::Serialize for PackageConfigSettings {
+    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        use serde::ser::SerializeMap;
+
+        let mut map = serializer.serialize_map(Some(self.0.len()))?;
+        for (key, value) in &self.0 {
+            map.serialize_entry(&key.to_string(), value)?;
+        }
+        map.end()
+    }
+}
+
+impl<'de> serde::Deserialize<'de> for PackageConfigSettings {
+    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        struct Visitor;
+
+        impl<'de> serde::de::Visitor<'de> for Visitor {
+            type Value = PackageConfigSettings;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a map from package name to config settings")
+            }
+
+            fn visit_map<A: serde::de::MapAccess<'de>>(
+                self,
+                mut map: A,
+            ) -> Result<Self::Value, A::Error> {
+                let mut config = BTreeMap::default();
+                while let Some((key, value)) = map.next_entry::<String, ConfigSettings>()? {
+                    let package = PackageName::from_str(&key).map_err(|e| {
+                        serde::de::Error::custom(format!("Invalid package name: {e}"))
+                    })?;
+                    config.insert(package, value);
+                }
+                Ok(PackageConfigSettings(config))
+            }
+        }
+
+        deserializer.deserialize_map(Visitor)
+    }
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@ -291,4 +423,56 @@ mod tests {
        );
        assert_eq!(settings.escape_for_python(), r#"{"key":"val\\1 {}value"}"#);
    }
+
+    #[test]
+    fn parse_config_setting_package_entry() {
+        // Test valid parsing
+        let entry = ConfigSettingPackageEntry::from_str("numpy:editable_mode=compat").unwrap();
+        assert_eq!(entry.package.as_ref(), "numpy");
+        assert_eq!(entry.setting.key, "editable_mode");
+        assert_eq!(entry.setting.value, "compat");
+
+        // Test with package name containing hyphens
+        let entry = ConfigSettingPackageEntry::from_str("my-package:some_key=value").unwrap();
+        assert_eq!(entry.package.as_ref(), "my-package");
+        assert_eq!(entry.setting.key, "some_key");
+        assert_eq!(entry.setting.value, "value");
+
+        // Test with spaces around values
+        let entry = ConfigSettingPackageEntry::from_str("  numpy : key = value  ").unwrap();
+        assert_eq!(entry.package.as_ref(), "numpy");
+        assert_eq!(entry.setting.key, "key");
+        assert_eq!(entry.setting.value, "value");
+    }
+
+    #[test]
+    fn collect_config_settings_package() {
+        let settings: PackageConfigSettings = vec![
+            ConfigSettingPackageEntry::from_str("numpy:editable_mode=compat").unwrap(),
+            ConfigSettingPackageEntry::from_str("numpy:another_key=value").unwrap(),
+            ConfigSettingPackageEntry::from_str("scipy:build_option=fast").unwrap(),
+        ]
+        .into_iter()
+        .collect();
+
+        let numpy_settings = settings
+            .get(&PackageName::from_str("numpy").unwrap())
+            .unwrap();
+        assert_eq!(
+            numpy_settings.0.get("editable_mode"),
+            Some(&ConfigSettingValue::String("compat".to_string()))
+        );
+        assert_eq!(
+            numpy_settings.0.get("another_key"),
+            Some(&ConfigSettingValue::String("value".to_string()))
+        );
+
+        let scipy_settings = settings
+            .get(&PackageName::from_str("scipy").unwrap())
+            .unwrap();
+        assert_eq!(
+            scipy_settings.0.get("build_option"),
+            Some(&ConfigSettingValue::String("fast".to_string()))
+        );
+    }
 }
--- a/crates/uv-dispatch/src/lib.rs
+++ b/crates/uv-dispatch/src/lib.rs
@ -17,8 +17,8 @@ use uv_build_frontend::{SourceBuild, SourceBuildContext};
 use uv_cache::Cache;
 use uv_client::RegistryClient;
 use uv_configuration::{
-    BuildKind, BuildOptions, ConfigSettings, Constraints, IndexStrategy, PreviewMode, Reinstall,
-    SourceStrategy,
+    BuildKind, BuildOptions, ConfigSettings, Constraints, IndexStrategy, PackageConfigSettings,
+    PreviewMode, Reinstall, SourceStrategy,
 };
 use uv_configuration::{BuildOutput, Concurrency};
 use uv_distribution::DistributionDatabase;
@ -91,6 +91,7 @@ pub struct BuildDispatch<'a> {
    link_mode: uv_install_wheel::LinkMode,
    build_options: &'a BuildOptions,
    config_settings: &'a ConfigSettings,
+    config_settings_package: &'a PackageConfigSettings,
    hasher: &'a HashStrategy,
    exclude_newer: Option<ExcludeNewer>,
    source_build_context: SourceBuildContext,
@ -113,6 +114,7 @@ impl<'a> BuildDispatch<'a> {
        shared_state: SharedState,
        index_strategy: IndexStrategy,
        config_settings: &'a ConfigSettings,
+        config_settings_package: &'a PackageConfigSettings,
        build_isolation: BuildIsolation<'a>,
        link_mode: uv_install_wheel::LinkMode,
        build_options: &'a BuildOptions,
@ -134,6 +136,7 @@ impl<'a> BuildDispatch<'a> {
            dependency_metadata,
            index_strategy,
            config_settings,
+            config_settings_package,
            build_isolation,
            link_mode,
            build_options,
@ -200,6 +203,10 @@ impl BuildContext for BuildDispatch<'_> {
        self.config_settings
    }

+    fn config_settings_package(&self) -> &PackageConfigSettings {
+        self.config_settings_package
+    }
+
    fn sources(&self) -> SourceStrategy {
        self.sources
    }
@ -295,6 +302,7 @@ impl BuildContext for BuildDispatch<'_> {
            self.hasher,
            self.index_locations,
            self.config_settings,
+            self.config_settings_package,
            self.cache(),
            venv,
            tags,
@ -418,6 +426,17 @@ impl BuildContext for BuildDispatch<'_> {
            build_stack.insert(dist.distribution_id());
        }

+        // Get package-specific config settings if available; otherwise, use global settings.
+        let config_settings = if let Some(name) = dist_name {
+            if let Some(package_settings) = self.config_settings_package.get(name) {
+                package_settings.clone().merge(self.config_settings.clone())
+            } else {
+                self.config_settings.clone()
+            }
+        } else {
+            self.config_settings.clone()
+        };
+
        let builder = SourceBuild::setup(
            source,
            subdirectory,
@ -431,7 +450,7 @@ impl BuildContext for BuildDispatch<'_> {
            self.index_locations,
            sources,
            self.workspace_cache(),
-            self.config_settings.clone(),
+            config_settings,
            self.build_isolation,
            &build_stack,
            build_kind,
--- a/crates/uv-distribution/src/index/built_wheel_index.rs
+++ b/crates/uv-distribution/src/index/built_wheel_index.rs
@ -1,10 +1,12 @@
+use std::borrow::Cow;
 use uv_cache::{Cache, CacheBucket, CacheShard, WheelCache};
 use uv_cache_info::CacheInfo;
 use uv_cache_key::cache_digest;
-use uv_configuration::ConfigSettings;
+use uv_configuration::{ConfigSettings, PackageConfigSettings};
 use uv_distribution_types::{
    DirectUrlSourceDist, DirectorySourceDist, GitSourceDist, Hashed, PathSourceDist,
 };
+use uv_normalize::PackageName;
 use uv_platform_tags::Tags;
 use uv_types::HashStrategy;

@ -18,7 +20,8 @@ pub struct BuiltWheelIndex<'a> {
    cache: &'a Cache,
    tags: &'a Tags,
    hasher: &'a HashStrategy,
-    build_configuration: &'a ConfigSettings,
+    config_settings: &'a ConfigSettings,
+    config_settings_package: &'a PackageConfigSettings,
 }

 impl<'a> BuiltWheelIndex<'a> {
@ -27,13 +30,15 @@ impl<'a> BuiltWheelIndex<'a> {
        cache: &'a Cache,
        tags: &'a Tags,
        hasher: &'a HashStrategy,
-        build_configuration: &'a ConfigSettings,
+        config_settings: &'a ConfigSettings,
+        config_settings_package: &'a PackageConfigSettings,
    ) -> Self {
        Self {
            cache,
            tags,
            hasher,
-            build_configuration,
+            config_settings,
+            config_settings_package,
        }
    }

@ -63,10 +68,11 @@ impl<'a> BuiltWheelIndex<'a> {
        let cache_shard = cache_shard.shard(revision.id());

        // If there are build settings, we need to scope to a cache shard.
-        let cache_shard = if self.build_configuration.is_empty() {
+        let config_settings = self.config_settings_for(&source_dist.name);
+        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(self.build_configuration))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        Ok(self.find(&cache_shard))
@ -100,10 +106,11 @@ impl<'a> BuiltWheelIndex<'a> {
        let cache_shard = cache_shard.shard(revision.id());

        // If there are build settings, we need to scope to a cache shard.
-        let cache_shard = if self.build_configuration.is_empty() {
+        let config_settings = self.config_settings_for(&source_dist.name);
+        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(self.build_configuration))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        Ok(self
@ -148,10 +155,11 @@ impl<'a> BuiltWheelIndex<'a> {
        let cache_shard = cache_shard.shard(revision.id());

        // If there are build settings, we need to scope to a cache shard.
-        let cache_shard = if self.build_configuration.is_empty() {
+        let config_settings = self.config_settings_for(&source_dist.name);
+        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(self.build_configuration))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        Ok(self
@ -174,10 +182,11 @@ impl<'a> BuiltWheelIndex<'a> {
        );

        // If there are build settings, we need to scope to a cache shard.
-        let cache_shard = if self.build_configuration.is_empty() {
+        let config_settings = self.config_settings_for(&source_dist.name);
+        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(self.build_configuration))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        self.find(&cache_shard)
@ -239,4 +248,13 @@ impl<'a> BuiltWheelIndex<'a> {

        candidate
    }
+
+    /// Determine the [`ConfigSettings`] for the given package name.
+    fn config_settings_for(&self, name: &PackageName) -> Cow<'_, ConfigSettings> {
+        if let Some(package_settings) = self.config_settings_package.get(name) {
+            Cow::Owned(package_settings.clone().merge(self.config_settings.clone()))
+        } else {
+            Cow::Borrowed(self.config_settings)
+        }
+    }
 }
--- a/crates/uv-distribution/src/source/mod.rs
+++ b/crates/uv-distribution/src/source/mod.rs
@ -29,7 +29,7 @@ use uv_cache_key::cache_digest;
 use uv_client::{
    CacheControl, CachedClientError, Connectivity, DataWithCachePolicy, RegistryClient,
 };
-use uv_configuration::{BuildKind, BuildOutput, SourceStrategy};
+use uv_configuration::{BuildKind, BuildOutput, ConfigSettings, SourceStrategy};
 use uv_distribution_filename::{SourceDistExtension, WheelFilename};
 use uv_distribution_types::{
    BuildableSource, DirectorySourceUrl, GitSourceUrl, HashPolicy, Hashed, PathSourceUrl,
@ -373,6 +373,23 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        Ok(metadata)
    }

+    /// Determine the [`ConfigSettings`] for the given package name.
+    fn config_settings_for(&self, name: Option<&PackageName>) -> Cow<'_, ConfigSettings> {
+        if let Some(name) = name {
+            if let Some(package_settings) = self.build_context.config_settings_package().get(name) {
+                Cow::Owned(
+                    package_settings
+                        .clone()
+                        .merge(self.build_context.config_settings().clone()),
+                )
+            } else {
+                Cow::Borrowed(self.build_context.config_settings())
+            }
+        } else {
+            Cow::Borrowed(self.build_context.config_settings())
+        }
+    }
+
    /// Build a source distribution from a remote URL.
    async fn url<'data>(
        &self,
@ -407,11 +424,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        let source_dist_entry = cache_shard.entry(SOURCE);

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&&config_settings))
        };

        // If the cache contains a compatible wheel, return it.
@ -580,11 +597,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        }

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // Otherwise, we either need to build the metadata.
@ -779,11 +796,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        let source_entry = cache_shard.entry(SOURCE);

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // If the cache contains a compatible wheel, return it.
@ -941,11 +958,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        }

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // Otherwise, we need to build a wheel.
@ -1083,11 +1100,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        let cache_shard = cache_shard.shard(revision.id());

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // If the cache contains a compatible wheel, return it.
@ -1271,11 +1288,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        }

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // Otherwise, we need to build a wheel.
@ -1476,11 +1493,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        let _lock = cache_shard.lock().await.map_err(Error::CacheWrite)?;

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // If the cache contains a compatible wheel, return it.
@ -1779,11 +1796,11 @@ impl<'a, T: BuildContext> SourceDistributionBuilder<'a, T> {
        }

        // If there are build settings, we need to scope to a cache shard.
-        let config_settings = self.build_context.config_settings();
+        let config_settings = self.config_settings_for(source.name());
        let cache_shard = if config_settings.is_empty() {
            cache_shard
        } else {
-            cache_shard.shard(cache_digest(config_settings))
+            cache_shard.shard(cache_digest(&config_settings))
        };

        // Otherwise, we need to build a wheel.
--- a/crates/uv-installer/src/plan.rs
+++ b/crates/uv-installer/src/plan.rs
@ -4,7 +4,7 @@ use tracing::{debug, warn};

 use uv_cache::{Cache, CacheBucket, WheelCache};
 use uv_cache_info::Timestamp;
-use uv_configuration::{BuildOptions, ConfigSettings, Reinstall};
+use uv_configuration::{BuildOptions, ConfigSettings, PackageConfigSettings, Reinstall};
 use uv_distribution::{
    BuiltWheelIndex, HttpArchivePointer, LocalArchivePointer, RegistryWheelIndex,
 };
@ -52,6 +52,7 @@ impl<'a> Planner<'a> {
        hasher: &HashStrategy,
        index_locations: &IndexLocations,
        config_settings: &ConfigSettings,
+        config_settings_package: &PackageConfigSettings,
        cache: &Cache,
        venv: &PythonEnvironment,
        tags: &Tags,
@ -59,7 +60,13 @@ impl<'a> Planner<'a> {
        // Index all the already-downloaded wheels in the cache.
        let mut registry_index =
            RegistryWheelIndex::new(cache, tags, index_locations, hasher, config_settings);
-        let built_index = BuiltWheelIndex::new(cache, tags, hasher, config_settings);
+        let built_index = BuiltWheelIndex::new(
+            cache,
+            tags,
+            hasher,
+            config_settings,
+            config_settings_package,
+        );

        let mut cached = vec![];
        let mut remote = vec![];
--- a/crates/uv-settings/src/combine.rs
+++ b/crates/uv-settings/src/combine.rs
@ -4,8 +4,8 @@ use std::path::PathBuf;
 use url::Url;

 use uv_configuration::{
-    ConfigSettings, ExportFormat, IndexStrategy, KeyringProviderType, RequiredVersion,
-    TargetTriple, TrustedPublishing,
+    ConfigSettings, ExportFormat, IndexStrategy, KeyringProviderType, PackageConfigSettings,
+    RequiredVersion, TargetTriple, TrustedPublishing,
 };
 use uv_distribution_types::{Index, IndexUrl, PipExtraIndex, PipFindLinks, PipIndex};
 use uv_install_wheel::LinkMode;
@ -131,6 +131,17 @@ impl Combine for Option<ConfigSettings> {
    }
 }

+impl Combine for Option<PackageConfigSettings> {
+    /// Combine two maps by merging the map in `self` with the map in `other`, if they're both
+    /// `Some`.
+    fn combine(self, other: Option<PackageConfigSettings>) -> Option<PackageConfigSettings> {
+        match (self, other) {
+            (Some(a), Some(b)) => Some(a.merge(b)),
+            (a, b) => a.or(b),
+        }
+    }
+}
+
 impl Combine for serde::de::IgnoredAny {
    fn combine(self, _other: Self) -> Self {
        self
--- a/crates/uv-settings/src/settings.rs
+++ b/crates/uv-settings/src/settings.rs
@ -4,8 +4,8 @@ use serde::{Deserialize, Serialize};

 use uv_cache_info::CacheKey;
 use uv_configuration::{
-    ConfigSettings, IndexStrategy, KeyringProviderType, PackageNameSpecifier, RequiredVersion,
-    TargetTriple, TrustedHost, TrustedPublishing,
+    ConfigSettings, IndexStrategy, KeyringProviderType, PackageConfigSettings,
+    PackageNameSpecifier, RequiredVersion, TargetTriple, TrustedHost, TrustedPublishing,
 };
 use uv_distribution_types::{
    Index, IndexUrl, IndexUrlError, PipExtraIndex, PipFindLinks, PipIndex, StaticMetadata,
@ -361,6 +361,7 @@ pub struct ResolverOptions {
    pub fork_strategy: Option<ForkStrategy>,
    pub dependency_metadata: Option<Vec<StaticMetadata>>,
    pub config_settings: Option<ConfigSettings>,
+    pub config_settings_package: Option<PackageConfigSettings>,
    pub exclude_newer: Option<ExcludeNewer>,
    pub link_mode: Option<LinkMode>,
    pub upgrade: Option<bool>,
@ -587,6 +588,18 @@ pub struct ResolverInstallerOptions {
        "#
    )]
    pub config_settings: Option<ConfigSettings>,
+    /// Settings to pass to the [PEP 517](https://peps.python.org/pep-0517/) build backend for specific packages,
+    /// specified as `KEY=VALUE` pairs.
+    ///
+    /// Accepts a map from package names to string key-value pairs.
+    #[option(
+        default = "{}",
+        value_type = "dict",
+        example = r#"
+            config-settings-package = { numpy = { editable_mode = "compat" } }
+        "#
+    )]
+    pub config_settings_package: Option<PackageConfigSettings>,
    /// Disable isolation when building source distributions.
    ///
    /// Assumes that build dependencies specified by [PEP 518](https://peps.python.org/pep-0518/)
@ -1333,6 +1346,16 @@ pub struct PipOptions {
        "#
    )]
    pub config_settings: Option<ConfigSettings>,
+    /// Settings to pass to the [PEP 517](https://peps.python.org/pep-0517/) build backend for specific packages,
+    /// specified as `KEY=VALUE` pairs.
+    #[option(
+        default = "{}",
+        value_type = "dict",
+        example = r#"
+            config-settings-package = { numpy = { editable_mode = "compat" } }
+        "#
+    )]
+    pub config_settings_package: Option<PackageConfigSettings>,
    /// The minimum Python version that should be supported by the resolved requirements (e.g.,
    /// `3.8` or `3.8.17`).
    ///
@ -1651,6 +1674,7 @@ impl From<ResolverInstallerOptions> for ResolverOptions {
            fork_strategy: value.fork_strategy,
            dependency_metadata: value.dependency_metadata,
            config_settings: value.config_settings,
+            config_settings_package: value.config_settings_package,
            exclude_newer: value.exclude_newer,
            link_mode: value.link_mode,
            upgrade: value.upgrade,
@ -1714,6 +1738,7 @@ pub struct ToolOptions {
    pub fork_strategy: Option<ForkStrategy>,
    pub dependency_metadata: Option<Vec<StaticMetadata>>,
    pub config_settings: Option<ConfigSettings>,
+    pub config_settings_package: Option<PackageConfigSettings>,
    pub no_build_isolation: Option<bool>,
    pub no_build_isolation_package: Option<Vec<PackageName>>,
    pub exclude_newer: Option<ExcludeNewer>,
@ -1741,6 +1766,7 @@ impl From<ResolverInstallerOptions> for ToolOptions {
            fork_strategy: value.fork_strategy,
            dependency_metadata: value.dependency_metadata,
            config_settings: value.config_settings,
+            config_settings_package: value.config_settings_package,
            no_build_isolation: value.no_build_isolation,
            no_build_isolation_package: value.no_build_isolation_package,
            exclude_newer: value.exclude_newer,
@ -1770,6 +1796,7 @@ impl From<ToolOptions> for ResolverInstallerOptions {
            fork_strategy: value.fork_strategy,
            dependency_metadata: value.dependency_metadata,
            config_settings: value.config_settings,
+            config_settings_package: value.config_settings_package,
            no_build_isolation: value.no_build_isolation,
            no_build_isolation_package: value.no_build_isolation_package,
            exclude_newer: value.exclude_newer,
@ -1822,6 +1849,7 @@ pub struct OptionsWire {
    fork_strategy: Option<ForkStrategy>,
    dependency_metadata: Option<Vec<StaticMetadata>>,
    config_settings: Option<ConfigSettings>,
+    config_settings_package: Option<PackageConfigSettings>,
    no_build_isolation: Option<bool>,
    no_build_isolation_package: Option<Vec<PackageName>>,
    exclude_newer: Option<ExcludeNewer>,
@ -1911,6 +1939,7 @@ impl From<OptionsWire> for Options {
            fork_strategy,
            dependency_metadata,
            config_settings,
+            config_settings_package,
            no_build_isolation,
            no_build_isolation_package,
            exclude_newer,
@ -1977,6 +2006,7 @@ impl From<OptionsWire> for Options {
                fork_strategy,
                dependency_metadata,
                config_settings,
+                config_settings_package,
                no_build_isolation,
                no_build_isolation_package,
                exclude_newer,
--- a/crates/uv-types/src/traits.rs
+++ b/crates/uv-types/src/traits.rs
@ -7,7 +7,9 @@ use anyhow::Result;
 use rustc_hash::FxHashSet;

 use uv_cache::Cache;
-use uv_configuration::{BuildKind, BuildOptions, BuildOutput, ConfigSettings, SourceStrategy};
+use uv_configuration::{
+    BuildKind, BuildOptions, BuildOutput, ConfigSettings, PackageConfigSettings, SourceStrategy,
+};
 use uv_distribution_filename::DistFilename;
 use uv_distribution_types::{
    CachedDist, DependencyMetadata, DistributionId, IndexCapabilities, IndexLocations,
@ -87,6 +89,9 @@ pub trait BuildContext {
    /// The [`ConfigSettings`] used to build distributions.
    fn config_settings(&self) -> &ConfigSettings;

+    /// The [`ConfigSettings`] used to build a specific package.
+    fn config_settings_package(&self) -> &PackageConfigSettings;
+
    /// Whether to incorporate `tool.uv.sources` when resolving requirements.
    fn sources(&self) -> SourceStrategy;

--- a/crates/uv/src/commands/build_frontend.rs
+++ b/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,
-    PreviewMode, SourceStrategy,
+    PackageConfigSettings, PreviewMode, SourceStrategy,
 };
 use uv_dispatch::{BuildDispatch, SharedState};
 use uv_distribution_filename::{
@ -197,6 +197,7 @@ async fn build_impl(
        fork_strategy: _,
        dependency_metadata,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        exclude_newer,
@ -357,6 +358,7 @@ async fn build_impl(
            dependency_metadata,
            *link_mode,
            config_setting,
+            config_settings_package,
            preview,
        );
        async {
@ -434,6 +436,7 @@ async fn build_package(
    dependency_metadata: &DependencyMetadata,
    link_mode: LinkMode,
    config_setting: &ConfigSettings,
+    config_settings_package: &PackageConfigSettings,
    preview: PreviewMode,
 ) -> Result<Vec<BuildMessage>, Error> {
    let output_dir = if let Some(output_dir) = output_dir {
@ -568,6 +571,7 @@ async fn build_package(
        state.clone(),
        index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        link_mode,
        build_options,
--- a/crates/uv/src/commands/pip/compile.rs
+++ b/crates/uv/src/commands/pip/compile.rs
@ -14,7 +14,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
    BuildOptions, Concurrency, ConfigSettings, Constraints, ExportFormat, ExtrasSpecification,
-    IndexStrategy, NoBinary, NoBuild, PreviewMode, Reinstall, SourceStrategy, Upgrade,
+    IndexStrategy, NoBinary, NoBuild, PackageConfigSettings, PreviewMode, Reinstall,
+    SourceStrategy, Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@ -90,6 +91,7 @@ pub(crate) async fn pip_compile(
    keyring_provider: KeyringProviderType,
    network_settings: &NetworkSettings,
    config_settings: ConfigSettings,
+    config_settings_package: PackageConfigSettings,
    no_build_isolation: bool,
    no_build_isolation_package: Vec<PackageName>,
    build_options: BuildOptions,
@ -477,6 +479,7 @@ pub(crate) async fn pip_compile(
        state,
        index_strategy,
        &config_settings,
+        &config_settings_package,
        build_isolation,
        link_mode,
        &build_options,
--- a/crates/uv/src/commands/pip/install.rs
+++ b/crates/uv/src/commands/pip/install.rs
@ -11,7 +11,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
    BuildOptions, Concurrency, ConfigSettings, Constraints, DryRun, ExtrasSpecification,
-    HashCheckingMode, IndexStrategy, PreviewMode, Reinstall, SourceStrategy, Upgrade,
+    HashCheckingMode, IndexStrategy, PackageConfigSettings, PreviewMode, Reinstall, SourceStrategy,
+    Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@ -75,6 +76,7 @@ pub(crate) async fn pip_install(
    hash_checking: Option<HashCheckingMode>,
    installer_metadata: bool,
    config_settings: &ConfigSettings,
+    config_settings_package: &PackageConfigSettings,
    no_build_isolation: bool,
    no_build_isolation_package: Vec<PackageName>,
    build_options: BuildOptions,
@ -422,6 +424,7 @@ pub(crate) async fn pip_install(
        state.clone(),
        index_strategy,
        config_settings,
+        config_settings_package,
        build_isolation,
        link_mode,
        &build_options,
@ -513,6 +516,7 @@ pub(crate) async fn pip_install(
        compile,
        &index_locations,
        config_settings,
+        config_settings_package,
        &hasher,
        &tags,
        &client,
--- a/crates/uv/src/commands/pip/operations.rs
+++ b/crates/uv/src/commands/pip/operations.rs
@ -13,7 +13,7 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, RegistryClient};
 use uv_configuration::{
    BuildOptions, Concurrency, ConfigSettings, Constraints, DependencyGroups, DryRun,
-    ExtrasSpecification, Overrides, Reinstall, Upgrade,
+    ExtrasSpecification, Overrides, PackageConfigSettings, Reinstall, Upgrade,
 };
 use uv_dispatch::BuildDispatch;
 use uv_distribution::{DistributionDatabase, SourcedDependencyGroups};
@ -445,6 +445,7 @@ pub(crate) async fn install(
    compile: bool,
    index_urls: &IndexLocations,
    config_settings: &ConfigSettings,
+    config_settings_package: &PackageConfigSettings,
    hasher: &HashStrategy,
    tags: &Tags,
    client: &RegistryClient,
@ -470,6 +471,7 @@ pub(crate) async fn install(
            hasher,
            index_urls,
            config_settings,
+            config_settings_package,
            cache,
            venv,
            tags,
--- a/crates/uv/src/commands/pip/sync.rs
+++ b/crates/uv/src/commands/pip/sync.rs
@ -9,7 +9,8 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
    BuildOptions, Concurrency, ConfigSettings, Constraints, DryRun, ExtrasSpecification,
-    HashCheckingMode, IndexStrategy, PreviewMode, Reinstall, SourceStrategy, Upgrade,
+    HashCheckingMode, IndexStrategy, PackageConfigSettings, PreviewMode, Reinstall, SourceStrategy,
+    Upgrade,
 };
 use uv_configuration::{KeyringProviderType, TargetTriple};
 use uv_dispatch::{BuildDispatch, SharedState};
@ -60,6 +61,7 @@ pub(crate) async fn pip_sync(
    allow_empty_requirements: bool,
    installer_metadata: bool,
    config_settings: &ConfigSettings,
+    config_settings_package: &PackageConfigSettings,
    no_build_isolation: bool,
    no_build_isolation_package: Vec<PackageName>,
    build_options: BuildOptions,
@ -355,6 +357,7 @@ pub(crate) async fn pip_sync(
        state.clone(),
        index_strategy,
        config_settings,
+        config_settings_package,
        build_isolation,
        link_mode,
        &build_options,
@ -448,6 +451,7 @@ pub(crate) async fn pip_sync(
        compile,
        &index_locations,
        config_settings,
+        config_settings_package,
        &hasher,
        &tags,
        &client,
--- a/crates/uv/src/commands/project/add.rs
+++ b/crates/uv/src/commands/project/add.rs
@ -436,6 +436,7 @@ pub(crate) async fn add(
                state.clone().into_inner(),
                settings.resolver.index_strategy,
                &settings.resolver.config_setting,
+                &settings.resolver.config_settings_package,
                build_isolation,
                settings.resolver.link_mode,
                &settings.resolver.build_options,
--- a/crates/uv/src/commands/project/lock.rs
+++ b/crates/uv/src/commands/project/lock.rs
@ -432,6 +432,7 @@ async fn do_lock(
        fork_strategy,
        dependency_metadata,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        exclude_newer,
@ -674,6 +675,7 @@ async fn do_lock(
        state.fork().into_inner(),
        *index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        *link_mode,
        build_options,
--- a/crates/uv/src/commands/project/mod.rs
+++ b/crates/uv/src/commands/project/mod.rs
@ -1674,6 +1674,7 @@ pub(crate) async fn resolve_names(
            ResolverSettings {
                build_options,
                config_setting,
+                config_settings_package,
                dependency_metadata,
                exclude_newer,
                fork_strategy: _,
@ -1742,6 +1743,7 @@ pub(crate) async fn resolve_names(
        state.clone(),
        *index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        *link_mode,
        build_options,
@ -1832,6 +1834,7 @@ pub(crate) async fn resolve_environment(
        fork_strategy,
        dependency_metadata,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        exclude_newer,
@ -1948,6 +1951,7 @@ pub(crate) async fn resolve_environment(
        state.clone().into_inner(),
        *index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        *link_mode,
        build_options,
@ -2013,6 +2017,7 @@ pub(crate) async fn sync_environment(
        keyring_provider,
        dependency_metadata,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        exclude_newer,
@ -2084,6 +2089,7 @@ pub(crate) async fn sync_environment(
        state.clone().into_inner(),
        index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        link_mode,
        build_options,
@ -2106,6 +2112,7 @@ pub(crate) async fn sync_environment(
        compile_bytecode,
        index_locations,
        config_setting,
+        config_settings_package,
        &hasher,
        tags,
        &client,
@ -2169,6 +2176,7 @@ pub(crate) async fn update_environment(
            ResolverSettings {
                build_options,
                config_setting,
+                config_settings_package,
                dependency_metadata,
                exclude_newer,
                fork_strategy,
@ -2305,6 +2313,7 @@ pub(crate) async fn update_environment(
        state.clone(),
        *index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        *link_mode,
        build_options,
@ -2362,6 +2371,7 @@ pub(crate) async fn update_environment(
        *compile_bytecode,
        index_locations,
        config_setting,
+        config_settings_package,
        &hasher,
        tags,
        &client,
--- a/crates/uv/src/commands/project/sync.rs
+++ b/crates/uv/src/commands/project/sync.rs
@ -573,6 +573,7 @@ pub(super) async fn do_sync(
        keyring_provider,
        dependency_metadata,
        config_setting,
+        config_settings_package,
        no_build_isolation,
        no_build_isolation_package,
        exclude_newer,
@ -709,6 +710,7 @@ pub(super) async fn do_sync(
        state.clone().into_inner(),
        index_strategy,
        config_setting,
+        config_settings_package,
        build_isolation,
        link_mode,
        build_options,
@ -733,6 +735,7 @@ pub(super) async fn do_sync(
        compile_bytecode,
        index_locations,
        config_setting,
+        config_settings_package,
        &hasher,
        &tags,
        &client,
--- a/crates/uv/src/commands/project/tree.rs
+++ b/crates/uv/src/commands/project/tree.rs
@ -200,6 +200,7 @@ pub(crate) async fn tree(
                fork_strategy: _,
                dependency_metadata: _,
                config_setting: _,
+                config_settings_package: _,
                no_build_isolation: _,
                no_build_isolation_package: _,
                exclude_newer: _,
--- a/crates/uv/src/commands/venv.rs
+++ b/crates/uv/src/commands/venv.rs
@ -12,7 +12,7 @@ use uv_cache::Cache;
 use uv_client::{BaseClientBuilder, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
    BuildOptions, Concurrency, ConfigSettings, Constraints, DependencyGroups, IndexStrategy,
-    KeyringProviderType, NoBinary, NoBuild, PreviewMode, SourceStrategy,
+    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, PreviewMode, SourceStrategy,
 };
 use uv_dispatch::{BuildDispatch, SharedState};
 use uv_distribution_types::Requirement;
@ -269,6 +269,7 @@ pub(crate) async fn venv(
        let build_constraints = Constraints::default();
        let build_hasher = HashStrategy::default();
        let config_settings = ConfigSettings::default();
+        let config_settings_package = PackageConfigSettings::default();
        let sources = SourceStrategy::Disabled;

        // Do not allow builds
@ -286,6 +287,7 @@ pub(crate) async fn venv(
            state.clone(),
            index_strategy,
            &config_settings,
+            &config_settings_package,
            BuildIsolation::Isolated,
            link_mode,
            &build_options,
--- a/crates/uv/src/lib.rs
+++ b/crates/uv/src/lib.rs
@ -524,6 +524,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                args.settings.keyring_provider,
                &globals.network_settings,
                args.settings.config_setting,
+                args.settings.config_settings_package,
                args.settings.no_build_isolation,
                args.settings.no_build_isolation_package,
                args.settings.build_options,
@ -594,6 +595,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                args.settings.allow_empty_requirements,
                globals.installer_metadata,
                &args.settings.config_setting,
+                &args.settings.config_settings_package,
                args.settings.no_build_isolation,
                args.settings.no_build_isolation_package,
                args.settings.build_options,
@ -745,6 +747,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                args.settings.hash_checking,
                globals.installer_metadata,
                &args.settings.config_setting,
+                &args.settings.config_settings_package,
                args.settings.no_build_isolation,
                args.settings.no_build_isolation_package,
                args.settings.build_options,
--- a/crates/uv/src/settings.rs
+++ b/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, PreviewMode, ProjectBuildBackend, Reinstall,
-    RequiredVersion, SourceStrategy, TargetTriple, TrustedHost, TrustedPublishing, Upgrade,
-    VersionControlSystem,
+    KeyringProviderType, NoBinary, NoBuild, PackageConfigSettings, PreviewMode,
+    ProjectBuildBackend, Reinstall, RequiredVersion, SourceStrategy, TargetTriple, TrustedHost,
+    TrustedPublishing, Upgrade, VersionControlSystem,
 };
 use uv_distribution_types::{DependencyMetadata, Index, IndexLocations, IndexUrl, Requirement};
 use uv_install_wheel::LinkMode;
@ -712,6 +712,7 @@ impl ToolUpgradeSettings {
            pre,
            fork_strategy,
            config_setting,
+            config_setting_package: config_settings_package,
            no_build_isolation,
            no_build_isolation_package,
            build_isolation,
@ -746,6 +747,7 @@ impl ToolUpgradeSettings {
            pre,
            fork_strategy,
            config_setting,
+            config_settings_package,
            no_build_isolation,
            no_build_isolation_package,
            build_isolation,
@ -2694,6 +2696,7 @@ pub(crate) struct InstallerSettingsRef<'a> {
    pub(crate) keyring_provider: KeyringProviderType,
    pub(crate) dependency_metadata: &'a DependencyMetadata,
    pub(crate) config_setting: &'a ConfigSettings,
+    pub(crate) config_settings_package: &'a PackageConfigSettings,
    pub(crate) no_build_isolation: bool,
    pub(crate) no_build_isolation_package: &'a [PackageName],
    pub(crate) exclude_newer: Option<ExcludeNewer>,
@ -2712,6 +2715,7 @@ pub(crate) struct InstallerSettingsRef<'a> {
 pub(crate) struct ResolverSettings {
    pub(crate) build_options: BuildOptions,
    pub(crate) config_setting: ConfigSettings,
+    pub(crate) config_settings_package: PackageConfigSettings,
    pub(crate) dependency_metadata: DependencyMetadata,
    pub(crate) exclude_newer: Option<ExcludeNewer>,
    pub(crate) fork_strategy: ForkStrategy,
@ -2770,6 +2774,7 @@ impl From<ResolverOptions> for ResolverSettings {
            index_strategy: value.index_strategy.unwrap_or_default(),
            keyring_provider: value.keyring_provider.unwrap_or_default(),
            config_setting: value.config_settings.unwrap_or_default(),
+            config_settings_package: value.config_settings_package.unwrap_or_default(),
            no_build_isolation: value.no_build_isolation.unwrap_or_default(),
            no_build_isolation_package: value.no_build_isolation_package.unwrap_or_default(),
            exclude_newer: value.exclude_newer,
@ -2849,6 +2854,7 @@ impl From<ResolverInstallerOptions> for ResolverInstallerSettings {
                    NoBuild::from_args(value.no_build, value.no_build_package.unwrap_or_default()),
                ),
                config_setting: value.config_settings.unwrap_or_default(),
+                config_settings_package: value.config_settings_package.unwrap_or_default(),
                dependency_metadata: DependencyMetadata::from_entries(
                    value.dependency_metadata.into_iter().flatten(),
                ),
@ -2918,6 +2924,7 @@ pub(crate) struct PipSettings {
    pub(crate) custom_compile_command: Option<String>,
    pub(crate) generate_hashes: bool,
    pub(crate) config_setting: ConfigSettings,
+    pub(crate) config_settings_package: PackageConfigSettings,
    pub(crate) python_version: Option<PythonVersion>,
    pub(crate) python_platform: Option<TargetTriple>,
    pub(crate) universal: bool,
@ -2987,6 +2994,7 @@ impl PipSettings {
            custom_compile_command,
            generate_hashes,
            config_settings,
+            config_settings_package,
            python_version,
            python_platform,
            universal,
@ -3022,6 +3030,7 @@ impl PipSettings {
            fork_strategy: top_level_fork_strategy,
            dependency_metadata: top_level_dependency_metadata,
            config_settings: top_level_config_settings,
+            config_settings_package: top_level_config_settings_package,
            no_build_isolation: top_level_no_build_isolation,
            no_build_isolation_package: top_level_no_build_isolation_package,
            exclude_newer: top_level_exclude_newer,
@ -3054,6 +3063,8 @@ impl PipSettings {
        let fork_strategy = fork_strategy.combine(top_level_fork_strategy);
        let dependency_metadata = dependency_metadata.combine(top_level_dependency_metadata);
        let config_settings = config_settings.combine(top_level_config_settings);
+        let config_settings_package =
+            config_settings_package.combine(top_level_config_settings_package);
        let no_build_isolation = no_build_isolation.combine(top_level_no_build_isolation);
        let no_build_isolation_package =
            no_build_isolation_package.combine(top_level_no_build_isolation_package);
@ -3156,6 +3167,10 @@ impl PipSettings {
                .config_settings
                .combine(config_settings)
                .unwrap_or_default(),
+            config_settings_package: args
+                .config_settings_package
+                .combine(config_settings_package)
+                .unwrap_or_default(),
            torch_backend: args.torch_backend.combine(torch_backend),
            python_version: args.python_version.combine(python_version),
            python_platform: args.python_platform.combine(python_platform),
@ -3249,6 +3264,7 @@ impl<'a> From<&'a ResolverInstallerSettings> for InstallerSettingsRef<'a> {
            keyring_provider: settings.resolver.keyring_provider,
            dependency_metadata: &settings.resolver.dependency_metadata,
            config_setting: &settings.resolver.config_setting,
+            config_settings_package: &settings.resolver.config_settings_package,
            no_build_isolation: settings.resolver.no_build_isolation,
            no_build_isolation_package: &settings.resolver.no_build_isolation_package,
            exclude_newer: settings.resolver.exclude_newer,
--- a/crates/uv/tests/it/pip_install.rs
+++ b/crates/uv/tests/it/pip_install.rs
@ -4054,13 +4054,13 @@ fn config_settings_path() -> Result<()> {
    "###
    );

-    // When installed without `--editable_mode=compat`, the `finder.py` file should be present.
+    // When installed without `editable_mode=compat`, the `finder.py` file should be present.
    let finder = context
        .site_packages()
        .join("__editable___setuptools_editable_0_1_0_finder.py");
    assert!(finder.exists());

-    // Reinstalling with `--editable_mode=compat` should be a no-op; changes in build configuration
+    // Reinstalling with `editable_mode=compat` should be a no-op; changes in build configuration
    // don't invalidate the environment.
    uv_snapshot!(context.filters(), context.pip_install()
        .arg("-r")
@ -4089,7 +4089,7 @@ fn config_settings_path() -> Result<()> {
     - setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
    "###);

-    // Install the editable package with `--editable_mode=compat`. We should ignore the cached
+    // Install the editable package with `editable_mode=compat`. We should ignore the cached
    // build configuration and rebuild.
    uv_snapshot!(context.filters(), context.pip_install()
        .arg("-r")
@ -4109,7 +4109,7 @@ fn config_settings_path() -> Result<()> {
    "###
    );

-    // When installed without `--editable_mode=compat`, the `finder.py` file should _not_ be present.
+    // When installed without `editable_mode=compat`, the `finder.py` file should _not_ be present.
    let finder = context
        .site_packages()
        .join("__editable___setuptools_editable_0_1_0_finder.py");
@ -11739,3 +11739,114 @@ fn install_python_preference() {
    Audited 1 package in [TIME]
    ");
 }
+
+#[test]
+fn config_settings_package() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.write_str(&format!(
+        "-e {}",
+        context
+            .workspace_root
+            .join("scripts/packages/setuptools_editable")
+            .display()
+    ))?;
+
+    // Install the editable package.
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("-r")
+        .arg("requirements.txt"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 2 packages in [TIME]
+    Prepared 2 packages in [TIME]
+    Installed 2 packages in [TIME]
+     + iniconfig==2.0.0
+     + setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
+    "###
+    );
+
+    // When installed without `editable_mode=compat`, the `finder.py` file should be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___setuptools_editable_0_1_0_finder.py");
+    assert!(finder.exists());
+
+    // Uninstall the package.
+    uv_snapshot!(context.filters(), context.pip_uninstall()
+        .arg("setuptools-editable"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Uninstalled 1 package in [TIME]
+     - setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
+    "###);
+
+    // Install the editable package with `editable_mode=compat`, scoped to the package.
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("-r")
+        .arg("requirements.txt")
+        .arg("--config-settings-package")
+        .arg("setuptools-editable:editable_mode=compat"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 2 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
+    "
+    );
+
+    // When installed with `editable_mode=compat`, the `finder.py` file should _not_ be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___setuptools_editable_0_1_0_finder.py");
+    assert!(!finder.exists());
+
+    // Uninstall the package.
+    uv_snapshot!(context.filters(), context.pip_uninstall()
+        .arg("setuptools-editable"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Uninstalled 1 package in [TIME]
+     - setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
+    "###);
+
+    // Install the editable package with `editable_mode=compat`, by scoped to a different package.
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("-r")
+        .arg("requirements.txt")
+        .arg("--config-settings-package")
+        .arg("setuptools:editable_mode=compat")
+        , @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 2 packages in [TIME]
+    Installed 1 package in [TIME]
+     + setuptools-editable==0.1.0 (from file://[WORKSPACE]/scripts/packages/setuptools_editable)
+    "
+    );
+
+    // When installed without `editable_mode=compat`, the `finder.py` file should be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___setuptools_editable_0_1_0_finder.py");
+    assert!(finder.exists());
+
+    Ok(())
+}
--- a/crates/uv/tests/it/show_settings.rs
+++ b/crates/uv/tests/it/show_settings.rs
@ -203,6 +203,9 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -385,6 +388,9 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -568,6 +574,9 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -783,6 +792,9 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -933,6 +945,9 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -1127,6 +1142,9 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: Some(
                X8664UnknownLinuxGnu,
@ -1369,6 +1387,9 @@ fn resolve_index_url() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -1621,6 +1642,9 @@ fn resolve_index_url() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -1828,6 +1852,9 @@ fn resolve_find_links() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2000,6 +2027,9 @@ fn resolve_top_level() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2232,6 +2262,9 @@ fn resolve_top_level() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2447,6 +2480,9 @@ fn resolve_top_level() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2618,6 +2654,9 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2773,6 +2812,9 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -2928,6 +2970,9 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -3085,6 +3130,9 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -3208,6 +3256,7 @@ fn resolve_tool() -> anyhow::Result<()> {
            fork_strategy: None,
            dependency_metadata: None,
            config_settings: None,
+            config_settings_package: None,
            no_build_isolation: None,
            no_build_isolation_package: None,
            exclude_newer: None,
@ -3234,6 +3283,9 @@ fn resolve_tool() -> anyhow::Result<()> {
                config_setting: ConfigSettings(
                    {},
                ),
+                config_settings_package: PackageConfigSettings(
+                    {},
+                ),
                dependency_metadata: DependencyMetadata(
                    {},
                ),
@ -3426,6 +3478,9 @@ fn resolve_poetry_toml() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -3643,6 +3698,9 @@ fn resolve_both() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -3950,6 +4008,9 @@ fn resolve_config_file() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -4004,7 +4065,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
      |
    1 | [project]
      |  ^^^^^^^
-    unknown field `project`, expected one of `required-version`, `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `fork-strategy`, `dependency-metadata`, `config-settings`, `no-build-isolation`, `no-build-isolation-package`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `python-downloads-json-url`, `publish-url`, `trusted-publishing`, `check-url`, `add-bounds`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `build-constraint-dependencies`, `environments`, `required-environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dependency-groups`, `dev-dependencies`, `build-backend`
+    unknown field `project`, expected one of `required-version`, `native-tls`, `offline`, `no-cache`, `cache-dir`, `preview`, `python-preference`, `python-downloads`, `concurrent-downloads`, `concurrent-builds`, `concurrent-installs`, `index`, `index-url`, `extra-index-url`, `no-index`, `find-links`, `index-strategy`, `keyring-provider`, `allow-insecure-host`, `resolution`, `prerelease`, `fork-strategy`, `dependency-metadata`, `config-settings`, `config-settings-package`, `no-build-isolation`, `no-build-isolation-package`, `exclude-newer`, `link-mode`, `compile-bytecode`, `no-sources`, `upgrade`, `upgrade-package`, `reinstall`, `reinstall-package`, `no-build`, `no-build-package`, `no-binary`, `no-binary-package`, `python-install-mirror`, `pypy-install-mirror`, `python-downloads-json-url`, `publish-url`, `trusted-publishing`, `check-url`, `add-bounds`, `pip`, `cache-keys`, `override-dependencies`, `constraint-dependencies`, `build-constraint-dependencies`, `environments`, `required-environments`, `conflicts`, `workspace`, `sources`, `managed`, `package`, `default-groups`, `dependency-groups`, `dev-dependencies`, `build-backend`
    "
    );

@ -4199,6 +4260,9 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -4357,6 +4421,9 @@ fn resolve_skip_empty() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -4534,6 +4601,9 @@ fn allow_insecure_host() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -4772,6 +4842,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -4989,6 +5062,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -5212,6 +5288,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -5430,6 +5509,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -5655,6 +5737,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -5873,6 +5958,9 @@ fn index_priority() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6035,6 +6123,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6183,6 +6274,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6329,6 +6423,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6477,6 +6574,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6623,6 +6723,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
@ -6770,6 +6873,9 @@ fn verify_hashes() -> anyhow::Result<()> {
            config_setting: ConfigSettings(
                {},
            ),
+            config_settings_package: PackageConfigSettings(
+                {},
+            ),
            python_version: None,
            python_platform: None,
            universal: false,
--- a/crates/uv/tests/it/sync.rs
+++ b/crates/uv/tests/it/sync.rs
@ -11126,3 +11126,146 @@ fn sync_python_preference() -> Result<()> {

    Ok(())
 }
+
+#[test]
+fn sync_config_settings_package() -> Result<()> {
+    let context = TestContext::new("3.12").with_exclude_newer("2025-07-25T00:00:00Z");
+
+    // Create a child project that uses `setuptools`.
+    let dependency = context.temp_dir.child("dependency");
+    dependency.child("pyproject.toml").write_str(
+        r#"
+        [project]
+        name = "dependency"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = []
+        [build-system]
+        requires = ["setuptools>=42"]
+        build-backend = "setuptools.build_meta"
+        "#,
+    )?;
+    dependency
+        .child("dependency")
+        .child("__init__.py")
+        .touch()?;
+
+    // Install the `dependency` without `editable_mode=compat`.
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["dependency"]
+
+        [tool.uv.sources]
+        dependency = { path = "dependency", editable = true }
+        "#,
+    )?;
+
+    // Lock the project
+    context.lock().assert().success();
+
+    uv_snapshot!(context.filters(), context.sync(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 2 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + dependency==0.1.0 (from file://[TEMP_DIR]/dependency)
+    ");
+
+    // When installed without `editable_mode=compat`, the `finder.py` file should be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___dependency_0_1_0_finder.py");
+    assert!(finder.exists());
+
+    // Remove the virtual environment.
+    fs_err::remove_dir_all(&context.venv)?;
+
+    // Install the `dependency` with `editable_mode=compat` scoped to the package.
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["dependency"]
+
+        [tool.uv.sources]
+        dependency = { path = "dependency", editable = true }
+
+        [tool.uv.config-settings-package]
+        dependency = { editable_mode = "compat" }
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.sync(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Resolved 2 packages in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + dependency==0.1.0 (from file://[TEMP_DIR]/dependency)
+    ");
+
+    // When installed with `editable_mode=compat`, the `finder.py` file should _not_ be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___dependency_0_1_0_finder.py");
+    assert!(!finder.exists());
+
+    // Remove the virtual environment.
+    fs_err::remove_dir_all(&context.venv)?;
+
+    // Install the `dependency` with `editable_mode=compat` scoped to another package.
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["dependency"]
+
+        [tool.uv.sources]
+        dependency = { path = "dependency", editable = true }
+
+        [tool.uv.config-settings-package]
+        setuptools = { editable_mode = "compat" }
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.sync(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Using CPython 3.12.[X] interpreter at: [PYTHON-3.12]
+    Creating virtual environment at: .venv
+    Resolved 2 packages in [TIME]
+    Installed 1 package in [TIME]
+     + dependency==0.1.0 (from file://[TEMP_DIR]/dependency)
+    ");
+
+    // When installed without `editable_mode=compat`, the `finder.py` file should be present.
+    let finder = context
+        .site_packages()
+        .join("__editable___dependency_0_1_0_finder.py");
+    assert!(finder.exists());
+
+    Ok(())
+}