Remove the flat index types (#7759)

## Summary

I think these really don't pull their weight.

crates/uv-cli/src/lib.rs

@@ -14,7 +14,7 @@ use uv_configuration::{
     ConfigSettingEntry, ExportFormat, IndexStrategy, KeyringProviderType, PackageNameSpecifier,
     TargetTriple, TrustedHost, TrustedPublishing, VersionControlSystem,
 };
-use uv_distribution_types::{FlatIndexLocation, Index, IndexUrl};
+use uv_distribution_types::{Index, IndexUrl};
 use uv_normalize::{ExtraName, PackageName};
 use uv_pep508::Requirement;
 use uv_pypi_types::VerbatimParsedUrl;
@@ -786,18 +786,6 @@ fn parse_index_url(input: &str) -> Result<Maybe<IndexUrl>, String> {
     }
 }
 
-/// Parse a string into an [`FlatIndexLocation`], mapping the empty string to `None`.
-fn parse_flat_index(input: &str) -> Result<Maybe<FlatIndexLocation>, String> {
-    if input.is_empty() {
-        Ok(Maybe::None)
-    } else {
-        match FlatIndexLocation::from_str(input) {
-            Ok(url) => Ok(Maybe::Some(url)),
-            Err(err) => Err(err.to_string()),
-        }
-    }
-}
-
 /// Parse a string into an [`Index`], mapping the empty string to `None`.
 fn parse_index_source(input: &str) -> Result<Maybe<Index>, String> {
     if input.is_empty() {
@@ -3897,10 +3885,10 @@ pub struct IndexArgs {
         long,
         short,
         env = EnvVars::UV_FIND_LINKS,
-        value_parser = parse_flat_index,
+        value_parser = parse_index_url,
         help_heading = "Index options"
     )]
-    pub find_links: Option<Vec<Maybe<FlatIndexLocation>>>,
+    pub find_links: Option<Vec<Maybe<IndexUrl>>>,
 
     /// Ignore the registry index (e.g., PyPI), instead relying on direct URL dependencies and those
     /// provided via `--find-links`.

crates/uv-client/src/flat_index.rs

@@ -5,13 +5,14 @@ use reqwest::Response;
 use tracing::{debug, info_span, warn, Instrument};
 use url::Url;
 
-use crate::cached_client::{CacheControl, CachedClientError};
-use crate::html::SimpleHtml;
-use crate::{Connectivity, Error, ErrorKind, OwnedArchive, RegistryClient};
 use uv_cache::{Cache, CacheBucket};
 use uv_cache_key::cache_digest;
 use uv_distribution_filename::DistFilename;
-use uv_distribution_types::{File, FileLocation, FlatIndexLocation, IndexUrl, UrlString};
+use uv_distribution_types::{File, FileLocation, IndexUrl, UrlString};
+
+use crate::cached_client::{CacheControl, CachedClientError};
+use crate::html::SimpleHtml;
+use crate::{Connectivity, Error, ErrorKind, OwnedArchive, RegistryClient};
 
 #[derive(Debug, thiserror::Error)]
 pub enum FlatIndexError {
@@ -94,19 +95,19 @@ impl<'a> FlatIndexClient<'a> {
     #[allow(clippy::result_large_err)]
     pub async fn fetch(
         &self,
-        indexes: impl Iterator<Item = &FlatIndexLocation>,
+        indexes: impl Iterator<Item = &IndexUrl>,
     ) -> Result<FlatIndexEntries, FlatIndexError> {
         let mut fetches = futures::stream::iter(indexes)
             .map(|index| async move {
                 let entries = match index {
-                    FlatIndexLocation::Path(url) => {
+                    IndexUrl::Path(url) => {
                         let path = url
                             .to_file_path()
                             .map_err(|()| FlatIndexError::NonFileUrl(url.to_url()))?;
                         Self::read_from_directory(&path, index)
                             .map_err(|err| FlatIndexError::FindLinksDirectory(path.clone(), err))?
                     }
-                    FlatIndexLocation::Url(url) => self
+                    IndexUrl::Pypi(url) | IndexUrl::Url(url) => self
                         .read_from_url(url, index)
                         .await
                         .map_err(|err| FlatIndexError::FindLinksUrl(url.to_url(), err))?,
@@ -136,7 +137,7 @@ impl<'a> FlatIndexClient<'a> {
     async fn read_from_url(
         &self,
         url: &Url,
-        flat_index: &FlatIndexLocation,
+        flat_index: &IndexUrl,
     ) -> Result<FlatIndexEntries, Error> {
         let cache_entry = self.cache.entry(
             CacheBucket::FlatIndex,
@@ -210,7 +211,7 @@ impl<'a> FlatIndexClient<'a> {
                         Some((
                             DistFilename::try_from_normalized_filename(&file.filename)?,
                             file,
-                            IndexUrl::from(flat_index.clone()),
+                            flat_index.clone(),
                         ))
                     })
                     .collect();
@@ -226,7 +227,7 @@ impl<'a> FlatIndexClient<'a> {
     /// Read a flat remote index from a `--find-links` directory.
     fn read_from_directory(
         path: &Path,
-        flat_index: &FlatIndexLocation,
+        flat_index: &IndexUrl,
     ) -> Result<FlatIndexEntries, FindLinksDirectoryError> {
         let mut dists = Vec::new();
         for entry in fs_err::read_dir(path)? {
@@ -279,7 +280,7 @@ impl<'a> FlatIndexClient<'a> {
                 );
                 continue;
             };
-            dists.push((filename, file, IndexUrl::from(flat_index.clone())));
+            dists.push((filename, file, flat_index.clone()));
         }
         Ok(FlatIndexEntries::from_entries(dists))
     }

crates/uv-distribution-types/src/index.rs

@@ -94,6 +94,16 @@ impl Index {
         }
     }
 
+    /// Initialize an [`Index`] from a pip-style `--find-links`.
+    pub fn from_find_links(url: IndexUrl) -> Self {
+        Self {
+            url,
+            name: None,
+            explicit: false,
+            default: false,
+        }
+    }
+
     /// Return the [`IndexUrl`] of the index.
     pub fn url(&self) -> &IndexUrl {
         &self.url

crates/uv-distribution-types/src/index_url.rs

@@ -99,15 +99,6 @@ impl Verbatim for IndexUrl {
     }
 }
 
-impl From<FlatIndexLocation> for IndexUrl {
-    fn from(location: FlatIndexLocation) -> Self {
-        match location {
-            FlatIndexLocation::Path(url) => Self::Path(url),
-            FlatIndexLocation::Url(url) => Self::Url(url),
-        }
-    }
-}
-
 /// An error that can occur when parsing an [`IndexUrl`].
 #[derive(Error, Debug)]
 pub enum IndexUrlError {
@@ -185,117 +176,6 @@ impl Deref for IndexUrl {
     }
 }
 
-/// A directory with distributions or a URL to an HTML file with a flat listing of distributions.
-///
-/// Also known as `--find-links`.
-#[derive(Debug, Clone, Hash, Eq, PartialEq)]
-pub enum FlatIndexLocation {
-    Path(VerbatimUrl),
-    Url(VerbatimUrl),
-}
-
-#[cfg(feature = "schemars")]
-impl schemars::JsonSchema for FlatIndexLocation {
-    fn schema_name() -> String {
-        "FlatIndexLocation".to_string()
-    }
-
-    fn json_schema(_gen: &mut schemars::gen::SchemaGenerator) -> schemars::schema::Schema {
-        schemars::schema::SchemaObject {
-            instance_type: Some(schemars::schema::InstanceType::String.into()),
-            metadata: Some(Box::new(schemars::schema::Metadata {
-                description: Some("The path to a directory of distributions, or a URL to an HTML file with a flat listing of distributions.".to_string()),
-              ..schemars::schema::Metadata::default()
-            })),
-            ..schemars::schema::SchemaObject::default()
-        }
-        .into()
-    }
-}
-
-impl FlatIndexLocation {
-    /// Return the raw URL for the `--find-links` index.
-    pub fn url(&self) -> &Url {
-        match self {
-            Self::Url(url) => url.raw(),
-            Self::Path(url) => url.raw(),
-        }
-    }
-
-    /// Return the redacted URL for the `--find-links` index, omitting any sensitive credentials.
-    pub fn redacted(&self) -> Cow<'_, Url> {
-        let url = self.url();
-        if url.username().is_empty() && url.password().is_none() {
-            Cow::Borrowed(url)
-        } else {
-            let mut url = url.clone();
-            let _ = url.set_username("");
-            let _ = url.set_password(None);
-            Cow::Owned(url)
-        }
-    }
-}
-
-impl Display for FlatIndexLocation {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::Url(url) => Display::fmt(url, f),
-            Self::Path(url) => Display::fmt(url, f),
-        }
-    }
-}
-
-impl Verbatim for FlatIndexLocation {
-    fn verbatim(&self) -> Cow<'_, str> {
-        match self {
-            Self::Url(url) => url.verbatim(),
-            Self::Path(url) => url.verbatim(),
-        }
-    }
-}
-
-impl FromStr for FlatIndexLocation {
-    type Err = IndexUrlError;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let url = if Path::new(s).exists() {
-            VerbatimUrl::from_absolute_path(std::path::absolute(s)?)?
-        } else {
-            VerbatimUrl::parse_url(s)?
-        };
-        Ok(Self::from(url.with_given(s)))
-    }
-}
-
-impl serde::ser::Serialize for FlatIndexLocation {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::ser::Serializer,
-    {
-        self.to_string().serialize(serializer)
-    }
-}
-
-impl<'de> serde::de::Deserialize<'de> for FlatIndexLocation {
-    fn deserialize<D>(deserializer: D) -> Result<FlatIndexLocation, D::Error>
-    where
-        D: serde::de::Deserializer<'de>,
-    {
-        let s = String::deserialize(deserializer)?;
-        FlatIndexLocation::from_str(&s).map_err(serde::de::Error::custom)
-    }
-}
-
-impl From<VerbatimUrl> for FlatIndexLocation {
-    fn from(url: VerbatimUrl) -> Self {
-        if url.scheme() == "file" {
-            Self::Path(url)
-        } else {
-            Self::Url(url)
-        }
-    }
-}
-
 /// The index locations to use for fetching packages. By default, uses the PyPI index.
 ///
 /// This type merges the legacy `--index-url`, `--extra-index-url`, and `--find-links` options,
@@ -304,13 +184,13 @@ impl From<VerbatimUrl> for FlatIndexLocation {
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 pub struct IndexLocations {
     indexes: Vec<Index>,
-    flat_index: Vec<FlatIndexLocation>,
+    flat_index: Vec<Index>,
     no_index: bool,
 }
 
 impl IndexLocations {
     /// Determine the index URLs to use for fetching packages.
-    pub fn new(indexes: Vec<Index>, flat_index: Vec<FlatIndexLocation>, no_index: bool) -> Self {
+    pub fn new(indexes: Vec<Index>, flat_index: Vec<Index>, no_index: bool) -> Self {
         Self {
             indexes,
             flat_index,
@@ -325,12 +205,7 @@ impl IndexLocations {
     ///
     /// If the current index location has an `index` set, it will be preserved.
     #[must_use]
-    pub fn combine(
+    pub fn combine(self, indexes: Vec<Index>, flat_index: Vec<Index>, no_index: bool) -> Self {
-        self,
-        indexes: Vec<Index>,
-        flat_index: Vec<FlatIndexLocation>,
-        no_index: bool,
-    ) -> Self {
         Self {
             indexes: self.indexes.into_iter().chain(indexes).collect(),
             flat_index: self.flat_index.into_iter().chain(flat_index).collect(),
@@ -407,7 +282,7 @@ impl<'a> IndexLocations {
     }
 
     /// Return an iterator over the [`FlatIndexLocation`] entries.
-    pub fn flat_indexes(&'a self) -> impl Iterator<Item = &'a FlatIndexLocation> + 'a {
+    pub fn flat_indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
         self.flat_index.iter()
     }
 
@@ -426,13 +301,12 @@ impl<'a> IndexLocations {
 
     /// Return an iterator over all allowed [`Index`] entries.
     ///
-    /// This includes both explicit and implicit indexes, as well as the default index (but _not_
+    /// This includes explicit indexes, implicit indexes flat indexes, and the default index.
-    /// the flat indexes).
     ///
-    /// If `no_index` was enabled, then this always returns an empty
+    /// If `no_index` was enabled, then this always returns an empty iterator.
-    /// iterator.
     pub fn allowed_indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
-        self.explicit_indexes()
+        self.flat_indexes()
+            .chain(self.explicit_indexes())
             .chain(self.implicit_indexes())
             .chain(self.default_index())
     }

crates/uv-distribution/src/index/registry_wheel_index.rs

@@ -14,13 +14,13 @@ use crate::source::{HttpRevisionPointer, LocalRevisionPointer, HTTP_REVISION, LO
 
 /// An entry in the [`RegistryWheelIndex`].
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
-pub struct IndexEntry {
+pub struct IndexEntry<'index> {
     /// The cached distribution.
     pub dist: CachedRegistryDist,
-    /// The index from which the wheel was downloaded.
-    pub index: Index,
     /// Whether the wheel was built from source (true), or downloaded from the registry directly (false).
     pub built: bool,
+    /// The index from which the wheel was downloaded.
+    pub index: &'index Index,
 }
 
 /// A local index of distributions that originate from a registry, like `PyPI`.
@@ -30,7 +30,7 @@ pub struct RegistryWheelIndex<'a> {
     tags: &'a Tags,
     index_locations: &'a IndexLocations,
     hasher: &'a HashStrategy,
-    index: FxHashMap<&'a PackageName, Vec<IndexEntry>>,
+    index: FxHashMap<&'a PackageName, Vec<IndexEntry<'a>>>,
 }
 
 impl<'a> RegistryWheelIndex<'a> {
@@ -73,21 +73,16 @@ impl<'a> RegistryWheelIndex<'a> {
     }
 
     /// Add a package to the index by reading from the cache.
-    fn index(
+    fn index<'index>(
         package: &PackageName,
         cache: &Cache,
         tags: &Tags,
-        index_locations: &IndexLocations,
+        index_locations: &'index IndexLocations,
         hasher: &HashStrategy,
-    ) -> Vec<IndexEntry> {
+    ) -> Vec<IndexEntry<'index>> {
         let mut entries = vec![];
 
-        let flat_index_urls: Vec<Index> = index_locations
+        for index in index_locations.allowed_indexes() {
-            .flat_indexes()
-            .map(|flat_index| Index::from_extra_index_url(IndexUrl::from(flat_index.clone())))
-            .collect();
-
-        for index in index_locations.indexes().chain(flat_index_urls.iter()) {
             // Index all the wheels that were downloaded directly from the registry.
             let wheel_dir = cache.shard(
                 CacheBucket::Wheels,
@@ -117,7 +112,7 @@ impl<'a> RegistryWheelIndex<'a> {
                                     ) {
                                         entries.push(IndexEntry {
                                             dist: wheel.into_registry_dist(),
-                                            index: index.clone(),
+                                            index,
                                             built: false,
                                         });
                                     }
@@ -144,7 +139,7 @@ impl<'a> RegistryWheelIndex<'a> {
                                     ) {
                                         entries.push(IndexEntry {
                                             dist: wheel.into_registry_dist(),
-                                            index: index.clone(),
+                                            index,
                                             built: false,
                                         });
                                     }
@@ -200,7 +195,7 @@ impl<'a> RegistryWheelIndex<'a> {
                                 ) {
                                     entries.push(IndexEntry {
                                         dist: wheel.into_registry_dist(),
-                                        index: index.clone(),
+                                        index,
                                         built: true,
                                     });
                                 }

crates/uv-requirements/src/specification.rs

@@ -32,12 +32,11 @@ use std::path::{Path, PathBuf};
 use anyhow::{Context, Result};
 use rustc_hash::FxHashSet;
 use tracing::instrument;
-
 use uv_cache_key::CanonicalUrl;
 use uv_client::BaseClientBuilder;
 use uv_configuration::{NoBinary, NoBuild};
 use uv_distribution_types::{
-    FlatIndexLocation, IndexUrl, NameRequirementSpecification, UnresolvedRequirement,
+    IndexUrl, NameRequirementSpecification, UnresolvedRequirement,
     UnresolvedRequirementSpecification,
 };
 use uv_fs::{Simplified, CWD};
@@ -71,7 +70,7 @@ pub struct RequirementsSpecification {
     /// Whether to disallow index usage.
     pub no_index: bool,
     /// The `--find-links` locations to use for fetching packages.
-    pub find_links: Vec<FlatIndexLocation>,
+    pub find_links: Vec<IndexUrl>,
     /// The `--no-binary` flags to enforce when selecting distributions.
     pub no_binary: NoBinary,
     /// The `--no-build` flags to enforce when selecting distributions.
@@ -142,7 +141,7 @@ impl RequirementsSpecification {
                     find_links: requirements_txt
                         .find_links
                         .into_iter()
-                        .map(FlatIndexLocation::from)
+                        .map(IndexUrl::from)
                         .collect(),
                     no_binary: requirements_txt.no_binary,
                     no_build: requirements_txt.only_binary,

crates/uv-resolver/src/lock/mod.rs

@@ -20,10 +20,9 @@ use uv_distribution::DistributionDatabase;
 use uv_distribution_filename::{DistExtension, ExtensionError, SourceDistExtension, WheelFilename};
 use uv_distribution_types::{
     BuiltDist, DependencyMetadata, DirectUrlBuiltDist, DirectUrlSourceDist, DirectorySourceDist,
-    Dist, DistributionMetadata, FileLocation, FlatIndexLocation, GitSourceDist, IndexLocations,
+    Dist, DistributionMetadata, FileLocation, GitSourceDist, IndexLocations, IndexUrl, Name,
-    IndexUrl, Name, PathBuiltDist, PathSourceDist, RegistryBuiltDist, RegistryBuiltWheel,
+    PathBuiltDist, PathSourceDist, RegistryBuiltDist, RegistryBuiltWheel, RegistrySourceDist,
-    RegistrySourceDist, RemoteSource, Resolution, ResolvedDist, StaticMetadata, ToUrlError,
+    RemoteSource, Resolution, ResolvedDist, StaticMetadata, ToUrlError, UrlString,
-    UrlString,
 };
 use uv_fs::{relative_to, PortablePath, PortablePathBuf};
 use uv_git::{GitReference, GitSha, RepositoryReference, ResolvedRepositoryReference};
@@ -1065,16 +1064,6 @@ impl Lock {
                     }
                     IndexUrl::Path(_) => None,
                 })
-                .chain(
-                    locations
-                        .flat_indexes()
-                        .filter_map(|index_url| match index_url {
-                            FlatIndexLocation::Url(_) => {
-                                Some(UrlString::from(index_url.redacted()))
-                            }
-                            FlatIndexLocation::Path(_) => None,
-                        }),
-                )
                 .collect::<BTreeSet<_>>()
         });
 
@@ -1091,20 +1080,6 @@ impl Lock {
                         Some(path)
                     }
                 })
-                .chain(
-                    locations
-                        .flat_indexes()
-                        .filter_map(|index_url| match index_url {
-                            FlatIndexLocation::Url(_) => None,
-                            FlatIndexLocation::Path(index_url) => {
-                                let path = index_url.to_file_path().ok()?;
-                                let path = relative_to(&path, workspace.install_path())
-                                    .or_else(|_| std::path::absolute(path))
-                                    .ok()?;
-                                Some(path)
-                            }
-                        }),
-                )
                 .collect::<BTreeSet<_>>()
         });
 

crates/uv-settings/src/settings.rs

@@ -7,7 +7,7 @@ use uv_configuration::{
     ConfigSettings, IndexStrategy, KeyringProviderType, PackageNameSpecifier, TargetTriple,
     TrustedHost, TrustedPublishing,
 };
-use uv_distribution_types::{FlatIndexLocation, Index, IndexUrl, StaticMetadata};
+use uv_distribution_types::{Index, IndexUrl, StaticMetadata};
 use uv_install_wheel::linker::LinkMode;
 use uv_macros::{CombineOptions, OptionsMetadata};
 use uv_normalize::{ExtraName, PackageName};
@@ -234,7 +234,7 @@ pub struct InstallerOptions {
     pub index_url: Option<IndexUrl>,
     pub extra_index_url: Option<Vec<IndexUrl>>,
     pub no_index: Option<bool>,
-    pub find_links: Option<Vec<FlatIndexLocation>>,
+    pub find_links: Option<Vec<IndexUrl>>,
     pub index_strategy: Option<IndexStrategy>,
     pub keyring_provider: Option<KeyringProviderType>,
     pub allow_insecure_host: Option<Vec<TrustedHost>>,
@@ -259,7 +259,7 @@ pub struct ResolverOptions {
     pub index_url: Option<IndexUrl>,
     pub extra_index_url: Option<Vec<IndexUrl>>,
     pub no_index: Option<bool>,
-    pub find_links: Option<Vec<FlatIndexLocation>>,
+    pub find_links: Option<Vec<IndexUrl>>,
     pub index_strategy: Option<IndexStrategy>,
     pub keyring_provider: Option<KeyringProviderType>,
     pub allow_insecure_host: Option<Vec<TrustedHost>>,
@@ -386,7 +386,7 @@ pub struct ResolverInstallerOptions {
             find-links = ["https://download.pytorch.org/whl/torch_stable.html"]
         "#
     )]
-    pub find_links: Option<Vec<FlatIndexLocation>>,
+    pub find_links: Option<Vec<IndexUrl>>,
     /// The strategy to use when resolving against multiple index URLs.
     ///
     /// By default, uv will stop at the first index on which a given package is available, and
@@ -798,7 +798,7 @@ pub struct PipOptions {
             find-links = ["https://download.pytorch.org/whl/torch_stable.html"]
         "#
     )]
-    pub find_links: Option<Vec<FlatIndexLocation>>,
+    pub find_links: Option<Vec<IndexUrl>>,
     /// The strategy to use when resolving against multiple index URLs.
     ///
     /// By default, uv will stop at the first index on which a given package is available, and
@@ -1414,7 +1414,7 @@ pub struct ToolOptions {
     pub index_url: Option<IndexUrl>,
     pub extra_index_url: Option<Vec<IndexUrl>>,
     pub no_index: Option<bool>,
-    pub find_links: Option<Vec<FlatIndexLocation>>,
+    pub find_links: Option<Vec<IndexUrl>>,
     pub index_strategy: Option<IndexStrategy>,
     pub keyring_provider: Option<KeyringProviderType>,
     pub allow_insecure_host: Option<Vec<TrustedHost>>,
@@ -1520,7 +1520,7 @@ pub struct OptionsWire {
     index_url: Option<IndexUrl>,
     extra_index_url: Option<Vec<IndexUrl>>,
     no_index: Option<bool>,
-    find_links: Option<Vec<FlatIndexLocation>>,
+    find_links: Option<Vec<IndexUrl>>,
     index_strategy: Option<IndexStrategy>,
     keyring_provider: Option<KeyringProviderType>,
     allow_insecure_host: Option<Vec<TrustedHost>>,

crates/uv/src/commands/build_frontend.rs

@@ -5,12 +5,13 @@ use std::io::Write as _;
 use std::path::{Path, PathBuf};
 
 use anyhow::Result;
+
 use owo_colors::OwoColorize;
 use uv_distribution_filename::SourceDistExtension;
-use uv_distribution_types::{DependencyMetadata, IndexLocations};
+use uv_distribution_types::{DependencyMetadata, Index, IndexLocations};
 use uv_install_wheel::linker::LinkMode;
 
-use uv_auth::{store_credentials, store_credentials_from_url};
+use uv_auth::store_credentials;
 use uv_cache::{Cache, CacheBucket};
 use uv_client::{BaseClientBuilder, Connectivity, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
@@ -405,9 +406,6 @@ async fn build_package(
             store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        store_credentials_from_url(index.url());
-    }
 
     // Read build constraints.
     let build_constraints = operations::read_constraints(build_constraints, client_builder).await?;
@@ -459,7 +457,9 @@ async fn build_package(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, None, &hasher, build_options)
     };
 

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

@@ -278,7 +278,7 @@ pub(crate) async fn pip_compile(
             .map(Index::from_extra_index_url)
             .chain(index_url.map(Index::from_index_url))
             .collect(),
-        find_links,
+        find_links.into_iter().map(Index::from_find_links).collect(),
         no_index,
     );
 
@@ -288,9 +288,6 @@ pub(crate) async fn pip_compile(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::try_from(client_builder)?
@@ -312,7 +309,9 @@ pub(crate) async fn pip_compile(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, &cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, tags.as_deref(), &hasher, &build_options)
     };
 
@@ -470,7 +469,7 @@ pub(crate) async fn pip_compile(
     // If necessary, include the `--find-links` locations.
     if include_find_links {
         for flat_index in index_locations.flat_indexes() {
-            writeln!(writer, "--find-links {}", flat_index.verbatim())?;
+            writeln!(writer, "--find-links {}", flat_index.url().verbatim())?;
             wrote_preamble = true;
         }
     }

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

@@ -280,7 +280,7 @@ pub(crate) async fn pip_install(
             .map(Index::from_extra_index_url)
             .chain(index_url.map(Index::from_index_url))
             .collect(),
-        find_links,
+        find_links.into_iter().map(Index::from_find_links).collect(),
         no_index,
     );
 
@@ -290,9 +290,6 @@ pub(crate) async fn pip_install(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::try_from(client_builder)?
@@ -309,7 +306,9 @@ pub(crate) async fn pip_install(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, &cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(&tags), &hasher, &build_options)
     };
 

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

@@ -216,7 +216,7 @@ pub(crate) async fn pip_sync(
             .map(Index::from_extra_index_url)
             .chain(index_url.map(Index::from_index_url))
             .collect(),
-        find_links,
+        find_links.into_iter().map(Index::from_find_links).collect(),
         no_index,
     );
 
@@ -226,9 +226,6 @@ pub(crate) async fn pip_sync(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::try_from(client_builder)?
@@ -245,7 +242,9 @@ pub(crate) async fn pip_sync(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, &cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(&tags), &hasher, &build_options)
     };
 

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

@@ -251,9 +251,6 @@ pub(crate) async fn add(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in settings.index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::try_from(client_builder)?
@@ -282,7 +279,7 @@ pub(crate) async fn add(
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
         let entries = client
-            .fetch(settings.index_locations.flat_indexes())
+            .fetch(settings.index_locations.flat_indexes().map(Index::url))
             .await?;
         FlatIndex::from_entries(entries, Some(&tags), &hasher, &settings.build_options)
     };

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

@@ -17,7 +17,7 @@ use uv_configuration::{
 use uv_dispatch::BuildDispatch;
 use uv_distribution::DistributionDatabase;
 use uv_distribution_types::{
-    DependencyMetadata, IndexLocations, NameRequirementSpecification,
+    DependencyMetadata, Index, IndexLocations, NameRequirementSpecification,
     UnresolvedRequirementSpecification,
 };
 use uv_git::ResolvedRepositoryReference;
@@ -369,9 +369,6 @@ async fn do_lock(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::new(cache.clone())
@@ -414,7 +411,9 @@ async fn do_lock(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, None, &hasher, build_options)
     };
 

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

@@ -651,9 +651,6 @@ pub(crate) async fn resolve_names(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::new(cache.clone())
@@ -803,9 +800,6 @@ pub(crate) async fn resolve_environment<'a>(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::new(cache.clone())
@@ -866,7 +860,9 @@ pub(crate) async fn resolve_environment<'a>(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(tags), &hasher, build_options)
     };
 
@@ -966,9 +962,6 @@ pub(crate) async fn sync_environment(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::new(cache.clone())
@@ -1001,7 +994,9 @@ pub(crate) async fn sync_environment(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(tags), &hasher, build_options)
     };
 
@@ -1159,9 +1154,6 @@ pub(crate) async fn update_environment(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     // Initialize the registry client.
     let client = RegistryClientBuilder::new(cache.clone())
@@ -1208,7 +1200,9 @@ pub(crate) async fn update_environment(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(tags), &hasher, build_options)
     };
 
@@ -1387,7 +1381,11 @@ fn warn_on_requirements_txt_setting(
             }
         }
         for find_link in find_links {
-            if !settings.index_locations.flat_indexes().contains(find_link) {
+            if !settings
+                .index_locations
+                .flat_indexes()
+                .any(|index| index.url() == find_link)
+            {
                 warn_user_once!(
                     "Ignoring `--find-links` from requirements file: `{find_link}`. Instead, use the `--find-links` command-line argument, or set `find-links` in a `uv.toml` or `pyproject.toml` file.`"
                 );

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

@@ -1,17 +1,10 @@
-use crate::commands::pip::loggers::{DefaultInstallLogger, DefaultResolveLogger, InstallLogger};
-use crate::commands::pip::operations;
-use crate::commands::pip::operations::Modifications;
-use crate::commands::project::lock::do_safe_lock;
-use crate::commands::project::{ProjectError, SharedState};
-use crate::commands::{diagnostics, pip, project, ExitStatus};
-use crate::printer::Printer;
-use crate::settings::{InstallerSettingsRef, ResolverInstallerSettings};
-use anyhow::{Context, Result};
-use itertools::Itertools;
 use std::borrow::Cow;
 use std::path::Path;
 use std::str::FromStr;
-use uv_auth::{store_credentials, store_credentials_from_url};
+
+use anyhow::{Context, Result};
+use itertools::Itertools;
+use uv_auth::store_credentials;
 use uv_cache::Cache;
 use uv_client::{Connectivity, FlatIndexClient, RegistryClientBuilder};
 use uv_configuration::{
@@ -19,7 +12,7 @@ use uv_configuration::{
     HashCheckingMode, InstallOptions,
 };
 use uv_dispatch::BuildDispatch;
-use uv_distribution_types::{DirectorySourceDist, Dist, ResolvedDist, SourceDist};
+use uv_distribution_types::{DirectorySourceDist, Dist, Index, ResolvedDist, SourceDist};
 use uv_installer::SitePackages;
 use uv_normalize::{PackageName, DEV_DEPENDENCIES};
 use uv_pep508::{MarkerTree, Requirement, VersionOrUrl};
@@ -33,6 +26,15 @@ use uv_warnings::warn_user;
 use uv_workspace::pyproject::{Source, Sources, ToolUvSources};
 use uv_workspace::{DiscoveryOptions, InstallTarget, MemberDiscovery, VirtualProject, Workspace};
 
+use crate::commands::pip::loggers::{DefaultInstallLogger, DefaultResolveLogger, InstallLogger};
+use crate::commands::pip::operations;
+use crate::commands::pip::operations::Modifications;
+use crate::commands::project::lock::do_safe_lock;
+use crate::commands::project::{ProjectError, SharedState};
+use crate::commands::{diagnostics, pip, project, ExitStatus};
+use crate::printer::Printer;
+use crate::settings::{InstallerSettingsRef, ResolverInstallerSettings};
+
 /// Sync the project environment.
 #[allow(clippy::fn_params_excessive_bools)]
 pub(crate) async fn sync(
@@ -282,9 +284,6 @@ pub(super) async fn do_sync(
             store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        store_credentials_from_url(index.url());
-    }
 
     // Populate credentials from the workspace.
     store_credentials_from_workspace(target.workspace());
@@ -322,7 +321,9 @@ pub(super) async fn do_sync(
     // Resolve the flat indexes from `--find-links`.
     let flat_index = {
         let client = FlatIndexClient::new(&client, cache);
-        let entries = client.fetch(index_locations.flat_indexes()).await?;
+        let entries = client
+            .fetch(index_locations.flat_indexes().map(Index::url))
+            .await?;
         FlatIndex::from_entries(entries, Some(tags), &hasher, build_options)
     };
 

crates/uv/src/commands/venv.rs

@@ -16,7 +16,7 @@ use uv_configuration::{
     NoBinary, NoBuild, SourceStrategy, TrustedHost,
 };
 use uv_dispatch::BuildDispatch;
-use uv_distribution_types::{DependencyMetadata, IndexLocations};
+use uv_distribution_types::{DependencyMetadata, Index, IndexLocations};
 use uv_fs::Simplified;
 use uv_install_wheel::linker::LinkMode;
 use uv_pypi_types::Requirement;
@@ -233,9 +233,6 @@ async fn venv_impl(
             uv_auth::store_credentials(index.raw_url(), credentials);
         }
     }
-    for index in index_locations.flat_indexes() {
-        uv_auth::store_credentials_from_url(index.url());
-    }
 
     if managed {
         writeln!(
@@ -287,9 +284,6 @@ async fn venv_impl(
                 uv_auth::store_credentials(index.raw_url(), credentials);
             }
         }
-        for index in index_locations.flat_indexes() {
-            uv_auth::store_credentials_from_url(index.url());
-        }
 
         // Instantiate a client.
         let client = RegistryClientBuilder::try_from(client_builder)
@@ -308,7 +302,7 @@ async fn venv_impl(
             let tags = interpreter.tags().map_err(VenvError::Tags)?;
             let client = FlatIndexClient::new(&client, cache);
             let entries = client
-                .fetch(index_locations.flat_indexes())
+                .fetch(index_locations.flat_indexes().map(Index::url))
                 .await
                 .map_err(VenvError::FlatIndex)?;
             FlatIndex::from_entries(

crates/uv/src/settings.rs

@@ -1981,7 +1981,12 @@ impl From<ResolverOptions> for ResolverSettings {
                     )
                     .chain(value.index_url.into_iter().map(Index::from_index_url))
                     .collect(),
-                value.find_links.unwrap_or_default(),
+                value
+                    .find_links
+                    .into_iter()
+                    .flatten()
+                    .map(Index::from_find_links)
+                    .collect(),
                 value.no_index.unwrap_or_default(),
             ),
             resolution: value.resolution.unwrap_or_default(),
@@ -2119,7 +2124,12 @@ impl From<ResolverInstallerOptions> for ResolverInstallerSettings {
                     )
                     .chain(value.index_url.into_iter().map(Index::from_index_url))
                     .collect(),
-                value.find_links.unwrap_or_default(),
+                value
+                    .find_links
+                    .into_iter()
+                    .flatten()
+                    .map(Index::from_find_links)
+                    .collect(),
                 value.no_index.unwrap_or_default(),
             ),
             resolution: value.resolution.unwrap_or_default(),
@@ -2353,7 +2363,12 @@ impl PipSettings {
                     )
                     .chain(index_url.into_iter().map(Index::from_index_url))
                     .collect(),
-                args.find_links.combine(find_links).unwrap_or_default(),
+                args.find_links
+                    .combine(find_links)
+                    .into_iter()
+                    .flatten()
+                    .map(Index::from_find_links)
+                    .collect(),
                 args.no_index.combine(no_index).unwrap_or_default(),
             ),
             extras: ExtrasSpecification::from_args(

crates/uv/tests/it/show_settings.rs

@@ -1410,28 +1410,33 @@ fn resolve_find_links() -> anyhow::Result<()> {
             index_locations: IndexLocations {
                 indexes: [],
                 flat_index: [
-                    Url(
+                    Index {
-                        VerbatimUrl {
+                        name: None,
-                            url: Url {
+                        url: Url(
-                                scheme: "https",
+                            VerbatimUrl {
-                                cannot_be_a_base: false,
+                                url: Url {
-                                username: "",
+                                    scheme: "https",
-                                password: None,
+                                    cannot_be_a_base: false,
-                                host: Some(
+                                    username: "",
-                                    Domain(
+                                    password: None,
-                                        "download.pytorch.org",
+                                    host: Some(
+                                        Domain(
+                                            "download.pytorch.org",
+                                        ),
                                     ),
+                                    port: None,
+                                    path: "/whl/torch_stable.html",
+                                    query: None,
+                                    fragment: None,
+                                },
+                                given: Some(
+                                    "https://download.pytorch.org/whl/torch_stable.html",
                                 ),
-                                port: None,
-                                path: "/whl/torch_stable.html",
-                                query: None,
-                                fragment: None,
                             },
-                            given: Some(
+                        ),
-                                "https://download.pytorch.org/whl/torch_stable.html",
+                        explicit: false,
-                            ),
+                        default: false,
-                        },
+                    },
-                    ),
                 ],
                 no_index: true,
             },

crates/uv/tests/it/sync.rs

@@ -3126,7 +3126,6 @@ fn sync_explicit() -> Result<()> {
     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]
      + idna==2.7
     "###);

uv.schema.json

@@ -144,7 +144,7 @@
         "null"
       ],
       "items": {
-        "$ref": "#/definitions/FlatIndexLocation"
+        "$ref": "#/definitions/IndexUrl"
       }
     },
     "index": {
@@ -551,10 +551,6 @@
       "description": "The normalized name of an extra dependency.\n\nConverts the name to lowercase and collapses runs of `-`, `_`, and `.` down to a single `-`. For example, `---`, `.`, and `__` are all converted to a single `-`.\n\nSee: - <https://peps.python.org/pep-0685/#specification/> - <https://packaging.python.org/en/latest/specifications/name-normalization/>",
       "type": "string"
     },
-    "FlatIndexLocation": {
-      "description": "The path to a directory of distributions, or a URL to an HTML file with a flat listing of distributions.",
-      "type": "string"
-    },
     "Index": {
       "type": "object",
       "required": [
@@ -835,7 +831,7 @@
             "null"
           ],
           "items": {
-            "$ref": "#/definitions/FlatIndexLocation"
+            "$ref": "#/definitions/IndexUrl"
           }
         },
         "generate-hashes": {