From 92d45bdbb50bd79ba6694145fdb8b81055d70258 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 11:40:20 -0400
Subject: [PATCH 01/17] Add initial work

---
 crates/uv-client/src/registry_client.rs |  19 ++-
 crates/uv/src/commands/pip/latest.rs    | 176 ++++++++++++++----------
 crates/uv/tests/it/pip_list.rs          |  45 ++++++
 3 files changed, 159 insertions(+), 81 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index d4b93e96b0bd1..9da19142caedd 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -21,7 +21,7 @@ use uv_configuration::IndexStrategy;
 use uv_configuration::KeyringProviderType;
 use uv_distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use uv_distribution_types::{
-    BuiltDist, File, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
+    BuiltDist, File, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
     IndexStatusCodeDecision, IndexStatusCodeStrategy, IndexUrl, IndexUrls, Name,
 };
 use uv_git::{GIT_LFS, GitError, GitHttpSettings, GitResolver, Reporter};
@@ -166,6 +166,7 @@ impl<'a> RegistryClientBuilder<'a> {
     pub fn build(mut self) -> Result<RegistryClient, ClientBuildError> {
         self.cache_index_credentials();
         let index_urls = self.index_locations.index_urls();
+        let flat_index = self.index_locations.flat_indexes().cloned().collect();
 
         // Build a base client
         let builder = self
@@ -188,6 +189,7 @@ impl<'a> RegistryClientBuilder<'a> {
             connectivity,
             client,
             read_timeout,
+            flat_index,
             flat_indexes: Arc::default(),
             pyx_token_store: PyxTokenStore::from_settings().ok(),
         })
@@ -197,6 +199,7 @@ impl<'a> RegistryClientBuilder<'a> {
     pub fn wrap_existing(mut self, existing: &BaseClient) -> RegistryClient {
         self.cache_index_credentials();
         let index_urls = self.index_locations.index_urls();
+        let flat_index = self.index_locations.flat_indexes().cloned().collect();
 
         // Wrap in any relevant middleware and handle connectivity.
         let client = self
@@ -218,6 +221,7 @@ impl<'a> RegistryClientBuilder<'a> {
             connectivity,
             client,
             read_timeout,
+            flat_index,
             flat_indexes: Arc::default(),
             pyx_token_store: PyxTokenStore::from_settings().ok(),
         }
@@ -233,6 +237,8 @@ pub struct RegistryClient {
     index_strategy: IndexStrategy,
     /// The strategy to use when selecting a PyTorch backend, if any.
     torch_backend: Option<TorchStrategy>,
+    /// The configured flat indexes (e.g., `--find-links`).
+    flat_index: Vec<Index>,
     /// The underlying HTTP client.
     client: CachedClient,
     /// Used for the remote wheel METADATA cache.
@@ -331,16 +337,19 @@ impl RegistryClient {
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        // If `--no-index` is specified, avoid fetching regardless of whether the index is implicit,
-        // explicit, etc.
-        if self.index_urls.no_index() {
+        let has_flat_indexes = !self.flat_index.is_empty();
+
+        // If `--no-index` is specified and no flat indexes are available, avoid fetching
+        // regardless of whether the index is implicit, explicit, etc.
+        if self.index_urls.no_index() && !has_flat_indexes {
             return Err(ErrorKind::NoIndex(package_name.to_string()).into());
         }
 
         let indexes = if let Some(index) = index {
             Either::Left(std::iter::once(index))
         } else {
-            Either::Right(self.index_urls_for(package_name))
+            let find_links = self.flat_index.iter().map(IndexMetadataRef::from);
+            Either::Right(self.index_urls_for(package_name).chain(find_links))
         };
 
         let mut results = Vec::new();
diff --git a/crates/uv/src/commands/pip/latest.rs b/crates/uv/src/commands/pip/latest.rs
index 9227c456871fc..ed29a75ef75d1 100644
--- a/crates/uv/src/commands/pip/latest.rs
+++ b/crates/uv/src/commands/pip/latest.rs
@@ -1,10 +1,10 @@
 use tokio::sync::Semaphore;
 use tracing::debug;
 
-use uv_client::{MetadataFormat, RegistryClient, VersionFiles};
+use uv_client::{FlatIndexEntry, MetadataFormat, RegistryClient, VersionFiles};
 use uv_distribution_filename::DistFilename;
 use uv_distribution_types::{
-    IndexCapabilities, IndexLocations, IndexMetadataRef, IndexUrl, RequiresPython,
+    File, IndexCapabilities, IndexLocations, IndexMetadataRef, IndexUrl, RequiresPython,
 };
 use uv_normalize::PackageName;
 use uv_platform_tags::Tags;
@@ -45,6 +45,26 @@ impl LatestClient<'_> {
     ) -> Result<Option<DistFilename>, uv_client::Error> {
         debug!("Fetching latest version of: `{package}`");
 
+        let mut latest: Option<DistFilename> = None;
+
+        let mut update_latest = |candidate: DistFilename| {
+            match latest.as_ref() {
+                Some(current) => {
+                    // Prefer higher versions, and prefer wheels over sdists at parity.
+                    if candidate.version() > current.version()
+                        || (candidate.version() == current.version()
+                            && matches!(candidate, DistFilename::WheelFilename(_))
+                            && matches!(current, DistFilename::SourceDistFilename(_)))
+                    {
+                        latest = Some(candidate);
+                    }
+                }
+                None => {
+                    latest = Some(candidate);
+                }
+            }
+        };
+
         let archives = match self
             .client
             .simple_detail(
@@ -66,98 +86,102 @@ impl LatestClient<'_> {
             }
         };
 
-        let mut latest: Option<DistFilename> = None;
         for (index, archive) in archives {
-            let MetadataFormat::Simple(archive) = archive else {
-                continue;
-            };
             let exclude_newer = self.effective_exclude_newer(package, index);
 
-            for datum in archive.iter().rev() {
-                // Find the first compatible distribution.
-                let files = rkyv::deserialize::<VersionFiles, rkyv::rancor::Error>(&datum.files)
-                    .expect("archived version files always deserializes");
-
-                // Determine whether there's a compatible wheel and/or source distribution.
-                let mut best = None;
-
-                for (filename, file) in files.all() {
-                    // Skip distributions uploaded after the cutoff.
-                    if let Some(exclude_newer) = &exclude_newer {
-                        match file.upload_time_utc_ms.as_ref() {
-                            Some(&upload_time) if upload_time >= exclude_newer.as_millisecond() => {
-                                continue;
-                            }
-                            None => {
-                                warn_user_once!(
-                                    "{} is missing an upload date, but user provided: {}",
-                                    file.filename,
-                                    exclude_newer
-                                );
-                            }
-                            _ => {}
+            let consider_candidate = |filename: &DistFilename, file: &File| {
+                if let Some(exclude_newer) = &exclude_newer {
+                    match file.upload_time_utc_ms.as_ref() {
+                        Some(&upload_time) if upload_time >= exclude_newer.as_millisecond() => {
+                            return false;
                         }
-                    }
-
-                    // Skip pre-release distributions.
-                    if !filename.version().is_stable() {
-                        if !matches!(self.prerelease, PrereleaseMode::Allow) {
-                            continue;
+                        None => {
+                            warn_user_once!(
+                                "{} is missing an upload date, but user provided: {}",
+                                file.filename,
+                                exclude_newer
+                            );
                         }
+                        _ => {}
                     }
+                }
 
-                    // Skip distributions that are yanked.
-                    if file.yanked.is_some_and(|yanked| yanked.is_yanked()) {
-                        continue;
-                    }
+                if !filename.version().is_stable()
+                    && !matches!(self.prerelease, PrereleaseMode::Allow)
+                {
+                    return false;
+                }
 
-                    // Skip distributions that are incompatible with the Python requirement.
-                    if let Some(requires_python) = self.requires_python {
-                        if file
-                            .requires_python
-                            .as_ref()
-                            .is_some_and(|file_requires_python| {
-                                !requires_python.is_contained_by(file_requires_python)
-                            })
-                        {
-                            continue;
-                        }
-                    }
+                if file
+                    .yanked
+                    .as_ref()
+                    .is_some_and(|yanked| yanked.is_yanked())
+                {
+                    return false;
+                }
 
-                    // Skip distributions that are incompatible with the current platform.
-                    if let DistFilename::WheelFilename(filename) = &filename {
-                        if self
-                            .tags
-                            .is_some_and(|tags| !filename.compatibility(tags).is_compatible())
-                        {
-                            continue;
-                        }
-                    }
+                if let Some(requires_python) = self.requires_python
+                    && file
+                        .requires_python
+                        .as_ref()
+                        .is_some_and(|file_requires_python| {
+                            !requires_python.is_contained_by(file_requires_python)
+                        })
+                {
+                    return false;
+                }
 
-                    match filename {
-                        DistFilename::WheelFilename(_) => {
-                            best = Some(filename);
-                            break;
-                        }
-                        DistFilename::SourceDistFilename(_) => {
-                            if best.is_none() {
-                                best = Some(filename);
+                if let DistFilename::WheelFilename(filename) = filename
+                    && self
+                        .tags
+                        .is_some_and(|tags| !filename.compatibility(tags).is_compatible())
+                {
+                    return false;
+                }
+
+                true
+            };
+
+            match archive {
+                MetadataFormat::Simple(archive) => {
+                    for datum in archive.iter().rev() {
+                        let files =
+                            rkyv::deserialize::<VersionFiles, rkyv::rancor::Error>(&datum.files)
+                                .expect("archived version files always deserializes");
+
+                        let mut best: Option<DistFilename> = None;
+                        for (filename, file) in files.all() {
+                            if !consider_candidate(&filename, &file) {
+                                continue;
+                            }
+
+                            match filename {
+                                DistFilename::WheelFilename(_) => {
+                                    best = Some(filename);
+                                    break;
+                                }
+                                DistFilename::SourceDistFilename(_) if best.is_none() => {
+                                    best = Some(filename);
+                                }
+                                DistFilename::SourceDistFilename(_) => {}
                             }
                         }
-                    }
-                }
 
-                match (latest.as_ref(), best) {
-                    (Some(current), Some(best)) if best.version() > current.version() => {
-                        latest = Some(best);
+                        if let Some(best) = best {
+                            update_latest(best);
+                        }
                     }
-                    (None, Some(best)) => {
-                        latest = Some(best);
+                }
+                MetadataFormat::Flat(entries) => {
+                    for FlatIndexEntry { filename, file, .. } in entries {
+                        if consider_candidate(&filename, &file) {
+                            update_latest(filename);
+                        }
                     }
-                    _ => {}
                 }
             }
         }
+
         Ok(latest)
     }
 }
diff --git a/crates/uv/tests/it/pip_list.rs b/crates/uv/tests/it/pip_list.rs
index 826adc084622e..7201d94995943 100644
--- a/crates/uv/tests/it/pip_list.rs
+++ b/crates/uv/tests/it/pip_list.rs
@@ -177,6 +177,51 @@ fn list_outdated_json() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn list_outdated_find_links() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let links_dir = context.workspace_root.join("scripts/links");
+
+    uv_snapshot!(context.filters(), context.pip_install()
+        .arg("validation==1.0.0")
+        .arg("--find-links")
+        .arg(&links_dir)
+        .arg("--no-index"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + validation==1.0.0
+    "###
+    );
+
+    uv_snapshot!(context.filters(), context.pip_list()
+        .arg("--outdated")
+        .arg("--find-links")
+        .arg(&links_dir)
+        .arg("--no-index"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    Package    Version Latest Type
+    ---------- ------- ------ -----
+    validation 1.0.0   3.0.0  wheel
+
+    ----- stderr -----
+    warning: validation-2.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
+    warning: validation-3.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
+    warning: validation-1.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
+    "###
+    );
+
+    Ok(())
+}
+
 #[test]
 fn list_outdated_freeze() {
     let context = uv_test::test_context!("3.12");

From e7484fe98f1a2f16bc3c11446c5d4843251d19cd Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 11:54:31 -0400
Subject: [PATCH 02/17] Remove result from test signature

---
 crates/uv/tests/it/pip_list.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/crates/uv/tests/it/pip_list.rs b/crates/uv/tests/it/pip_list.rs
index 7201d94995943..a25265ce6a178 100644
--- a/crates/uv/tests/it/pip_list.rs
+++ b/crates/uv/tests/it/pip_list.rs
@@ -178,7 +178,7 @@ fn list_outdated_json() -> Result<()> {
 }
 
 #[test]
-fn list_outdated_find_links() -> Result<()> {
+fn list_outdated_find_links() {
     let context = TestContext::new("3.12");
 
     let links_dir = context.workspace_root.join("scripts/links");
@@ -218,8 +218,6 @@ fn list_outdated_find_links() -> Result<()> {
     warning: validation-1.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
     "###
     );
-
-    Ok(())
 }
 
 #[test]

From f4a4400a9403584cf2db1907aedb7bb4a7b97940 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 12:20:09 -0400
Subject: [PATCH 03/17] Update snapshot

---
 crates/uv/tests/it/pip_install.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/uv/tests/it/pip_install.rs b/crates/uv/tests/it/pip_install.rs
index 56f48718059d6..759884ce7acef 100644
--- a/crates/uv/tests/it/pip_install.rs
+++ b/crates/uv/tests/it/pip_install.rs
@@ -6942,7 +6942,7 @@ fn already_installed_dependent_editable() {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because first-local was not found in the provided package locations and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
+      ╰─▶ Because first-local was not found in the package registry and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
           And because only second-local==0.1.0 is available and you require second-local, we can conclude that your requirements are unsatisfiable.
     "
     );
@@ -7062,7 +7062,7 @@ fn already_installed_local_path_dependent() {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because first-local was not found in the provided package locations and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
+      ╰─▶ Because first-local was not found in the package registry and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
           And because only second-local==0.1.0 is available and you require second-local, we can conclude that your requirements are unsatisfiable.
     "
     );

From a4b8d5e3e18f6cac6ff874dc526b1d17de82e993 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 12:30:16 -0400
Subject: [PATCH 04/17] Tweak ordering

---
 crates/uv/tests/it/sync.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/uv/tests/it/sync.rs b/crates/uv/tests/it/sync.rs
index 958d8a0749735..d2b18f73d15f0 100644
--- a/crates/uv/tests/it/sync.rs
+++ b/crates/uv/tests/it/sync.rs
@@ -11820,8 +11820,8 @@ fn sync_build_tag() -> Result<()> {
         source = { registry = "[TEMP_DIR]/links" }
         wheels = [
             { path = "[TEMP_DIR]/links/build_tag-1.0.0-1-py2.py3-none-any.whl" },
-            { path = "[TEMP_DIR]/links/build_tag-1.0.0-3-py2.py3-none-any.whl" },
             { path = "[TEMP_DIR]/links/build_tag-1.0.0-5-py2.py3-none-any.whl" },
+            { path = "[TEMP_DIR]/links/build_tag-1.0.0-3-py2.py3-none-any.whl" },
         ]
 
         [[package]]

From 26befb9401b8e080309f3caf3912c2391e79ddb2 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 12:34:41 -0400
Subject: [PATCH 05/17] Sort flat index entries

---
 crates/uv/tests/it/pip_list.rs | 2 +-
 crates/uv/tests/it/sync.rs     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/crates/uv/tests/it/pip_list.rs b/crates/uv/tests/it/pip_list.rs
index a25265ce6a178..9ddbdcbd83887 100644
--- a/crates/uv/tests/it/pip_list.rs
+++ b/crates/uv/tests/it/pip_list.rs
@@ -213,9 +213,9 @@ fn list_outdated_find_links() {
     validation 1.0.0   3.0.0  wheel
 
     ----- stderr -----
+    warning: validation-1.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
     warning: validation-2.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
     warning: validation-3.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
-    warning: validation-1.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
     "###
     );
 }
diff --git a/crates/uv/tests/it/sync.rs b/crates/uv/tests/it/sync.rs
index d2b18f73d15f0..958d8a0749735 100644
--- a/crates/uv/tests/it/sync.rs
+++ b/crates/uv/tests/it/sync.rs
@@ -11820,8 +11820,8 @@ fn sync_build_tag() -> Result<()> {
         source = { registry = "[TEMP_DIR]/links" }
         wheels = [
             { path = "[TEMP_DIR]/links/build_tag-1.0.0-1-py2.py3-none-any.whl" },
-            { path = "[TEMP_DIR]/links/build_tag-1.0.0-5-py2.py3-none-any.whl" },
             { path = "[TEMP_DIR]/links/build_tag-1.0.0-3-py2.py3-none-any.whl" },
+            { path = "[TEMP_DIR]/links/build_tag-1.0.0-5-py2.py3-none-any.whl" },
         ]
 
         [[package]]

From 22a559cb949986b4f670528e553cb5ece07e5c02 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Thu, 2 Oct 2025 22:29:55 -0400
Subject: [PATCH 06/17] Keep existing message / semantics

---
 crates/uv-client/src/registry_client.rs | 4 ++++
 crates/uv/tests/it/pip_install.rs       | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index 9da19142caedd..ed43156ff0c2f 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -442,6 +442,10 @@ impl RegistryClient {
         }
 
         if results.is_empty() {
+            if self.index_urls.no_index() {
+                return Err(ErrorKind::NoIndex(package_name.to_string()).into());
+            }
+
             return match self.connectivity {
                 Connectivity::Online => {
                     Err(ErrorKind::RemotePackageNotFound(package_name.clone()).into())
diff --git a/crates/uv/tests/it/pip_install.rs b/crates/uv/tests/it/pip_install.rs
index 759884ce7acef..56f48718059d6 100644
--- a/crates/uv/tests/it/pip_install.rs
+++ b/crates/uv/tests/it/pip_install.rs
@@ -6942,7 +6942,7 @@ fn already_installed_dependent_editable() {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because first-local was not found in the package registry and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
+      ╰─▶ Because first-local was not found in the provided package locations and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
           And because only second-local==0.1.0 is available and you require second-local, we can conclude that your requirements are unsatisfiable.
     "
     );
@@ -7062,7 +7062,7 @@ fn already_installed_local_path_dependent() {
 
     ----- stderr -----
       × No solution found when resolving dependencies:
-      ╰─▶ Because first-local was not found in the package registry and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
+      ╰─▶ Because first-local was not found in the provided package locations and second-local==0.1.0 depends on first-local, we can conclude that second-local==0.1.0 cannot be used.
           And because only second-local==0.1.0 is available and you require second-local, we can conclude that your requirements are unsatisfiable.
     "
     );

From 7ba1843e93cf1ab7853c2edb6f3156f094a089bd Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Fri, 3 Oct 2025 11:13:20 -0400
Subject: [PATCH 07/17] Combine flat indexes into `IndexUrls`

---
 crates/uv-client/src/registry_client.rs       | 13 +---
 crates/uv-distribution-types/src/index_url.rs | 59 ++++++++++++-------
 crates/uv/src/commands/project/add.rs         |  2 +-
 crates/uv/tests/it/show_settings.rs           | 30 +++++-----
 4 files changed, 57 insertions(+), 47 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index ed43156ff0c2f..f4c7043d21caa 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -21,7 +21,7 @@ use uv_configuration::IndexStrategy;
 use uv_configuration::KeyringProviderType;
 use uv_distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use uv_distribution_types::{
-    BuiltDist, File, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
+    BuiltDist, File, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
     IndexStatusCodeDecision, IndexStatusCodeStrategy, IndexUrl, IndexUrls, Name,
 };
 use uv_git::{GIT_LFS, GitError, GitHttpSettings, GitResolver, Reporter};
@@ -166,7 +166,6 @@ impl<'a> RegistryClientBuilder<'a> {
     pub fn build(mut self) -> Result<RegistryClient, ClientBuildError> {
         self.cache_index_credentials();
         let index_urls = self.index_locations.index_urls();
-        let flat_index = self.index_locations.flat_indexes().cloned().collect();
 
         // Build a base client
         let builder = self
@@ -189,7 +188,6 @@ impl<'a> RegistryClientBuilder<'a> {
             connectivity,
             client,
             read_timeout,
-            flat_index,
             flat_indexes: Arc::default(),
             pyx_token_store: PyxTokenStore::from_settings().ok(),
         })
@@ -199,7 +197,6 @@ impl<'a> RegistryClientBuilder<'a> {
     pub fn wrap_existing(mut self, existing: &BaseClient) -> RegistryClient {
         self.cache_index_credentials();
         let index_urls = self.index_locations.index_urls();
-        let flat_index = self.index_locations.flat_indexes().cloned().collect();
 
         // Wrap in any relevant middleware and handle connectivity.
         let client = self
@@ -221,7 +218,6 @@ impl<'a> RegistryClientBuilder<'a> {
             connectivity,
             client,
             read_timeout,
-            flat_index,
             flat_indexes: Arc::default(),
             pyx_token_store: PyxTokenStore::from_settings().ok(),
         }
@@ -237,8 +233,6 @@ pub struct RegistryClient {
     index_strategy: IndexStrategy,
     /// The strategy to use when selecting a PyTorch backend, if any.
     torch_backend: Option<TorchStrategy>,
-    /// The configured flat indexes (e.g., `--find-links`).
-    flat_index: Vec<Index>,
     /// The underlying HTTP client.
     client: CachedClient,
     /// Used for the remote wheel METADATA cache.
@@ -337,7 +331,7 @@ impl RegistryClient {
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        let has_flat_indexes = !self.flat_index.is_empty();
+        let has_flat_indexes = self.index_urls.flat_indexes().next().is_some();
 
         // If `--no-index` is specified and no flat indexes are available, avoid fetching
         // regardless of whether the index is implicit, explicit, etc.
@@ -348,8 +342,7 @@ impl RegistryClient {
         let indexes = if let Some(index) = index {
             Either::Left(std::iter::once(index))
         } else {
-            let find_links = self.flat_index.iter().map(IndexMetadataRef::from);
-            Either::Right(self.index_urls_for(package_name).chain(find_links))
+            Either::Right(self.index_urls_for(package_name))
         };
 
         let mut results = Vec::new();
diff --git a/crates/uv-distribution-types/src/index_url.rs b/crates/uv-distribution-types/src/index_url.rs
index e09b42bc7eed8..c5fefb25240d9 100644
--- a/crates/uv-distribution-types/src/index_url.rs
+++ b/crates/uv-distribution-types/src/index_url.rs
@@ -256,16 +256,16 @@ impl Deref for IndexUrl {
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 pub struct IndexLocations {
     indexes: Vec<Index>,
-    flat_index: Vec<Index>,
+    flat_indexes: 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<Index>, no_index: bool) -> Self {
+    pub fn new(indexes: Vec<Index>, flat_indexes: Vec<Index>, no_index: bool) -> Self {
         Self {
             indexes,
-            flat_index,
+            flat_indexes,
             no_index,
         }
     }
@@ -277,10 +277,10 @@ impl IndexLocations {
     ///
     /// If the current index location has an `index` set, it will be preserved.
     #[must_use]
-    pub fn combine(self, indexes: Vec<Index>, flat_index: Vec<Index>, no_index: bool) -> Self {
+    pub fn combine(self, indexes: Vec<Index>, flat_indexes: Vec<Index>, no_index: bool) -> Self {
         Self {
             indexes: self.indexes.into_iter().chain(indexes).collect(),
-            flat_index: self.flat_index.into_iter().chain(flat_index).collect(),
+            flat_indexes: self.flat_indexes.into_iter().chain(flat_indexes).collect(),
             no_index: self.no_index || no_index,
         }
     }
@@ -383,7 +383,7 @@ impl<'a> IndexLocations {
 
     /// Return an iterator over the [`FlatIndexLocation`] entries.
     pub fn flat_indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
-        self.flat_index.iter()
+        self.flat_indexes.iter()
     }
 
     /// Return the `--no-index` flag.
@@ -395,6 +395,7 @@ impl<'a> IndexLocations {
     pub fn index_urls(&'a self) -> IndexUrls {
         IndexUrls {
             indexes: self.indexes.clone(),
+            flat_indexes: self.flat_indexes.clone(),
             no_index: self.no_index,
         }
     }
@@ -407,7 +408,7 @@ impl<'a> IndexLocations {
     /// that the last-defined index is the first item in the vector.
     pub fn allowed_indexes(&'a self) -> Vec<&'a Index> {
         if self.no_index {
-            self.flat_index.iter().rev().collect()
+            self.flat_indexes.iter().rev().collect()
         } else {
             let mut indexes = vec![];
 
@@ -416,7 +417,7 @@ impl<'a> IndexLocations {
             for index in {
                 self.indexes
                     .iter()
-                    .chain(self.flat_index.iter())
+                    .chain(self.flat_indexes.iter())
                     .filter(move |index| index.name.as_ref().is_none_or(|name| seen.insert(name)))
             } {
                 if index.default {
@@ -446,11 +447,11 @@ impl<'a> IndexLocations {
     /// that the last-defined index is the first item in the vector.
     pub fn known_indexes(&'a self) -> impl Iterator<Item = &'a Index> {
         if self.no_index {
-            Either::Left(self.flat_index.iter().rev())
+            Either::Left(self.flat_indexes.iter().rev())
         } else {
             Either::Right(
                 std::iter::once(&*DEFAULT_INDEX)
-                    .chain(self.flat_index.iter().rev())
+                    .chain(self.flat_indexes.iter().rev())
                     .chain(self.indexes.iter().rev()),
             )
         }
@@ -512,17 +513,24 @@ impl From<&IndexLocations> for uv_auth::Indexes {
 #[derive(Default, Debug, Clone, PartialEq, Eq)]
 pub struct IndexUrls {
     indexes: Vec<Index>,
+    flat_indexes: Vec<Index>,
     no_index: bool,
 }
 
 impl<'a> IndexUrls {
-    pub fn from_indexes(indexes: Vec<Index>) -> Self {
+    pub fn from_indexes(indexes: Vec<Index>, flat_indexes: Vec<Index>) -> Self {
         Self {
             indexes,
+            flat_indexes,
             no_index: false,
         }
     }
 
+    /// Return an iterator over the configured flat-index locations.
+    pub fn flat_indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
+        self.flat_indexes.iter()
+    }
+
     /// Return the default [`Index`] entry.
     ///
     /// If `--no-index` is set, return `None`.
@@ -563,14 +571,23 @@ impl<'a> IndexUrls {
     /// Prioritizes the `[tool.uv.index]` definitions over the `--extra-index-url` definitions
     /// over the `--index-url` definition.
     ///
-    /// If `no_index` was enabled, then this always returns an empty
-    /// iterator.
+    /// If `no_index` was enabled, then this always returns only the flat indexes.
     pub fn indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
         let mut seen = FxHashSet::default();
-        self.implicit_indexes()
-            .chain(self.default_index())
-            .filter(|index| !index.explicit)
-            .filter(move |index| seen.insert(index.raw_url())) // Filter out redundant raw URLs
+
+        let simple_indexes = if self.no_index {
+            Either::Left(std::iter::empty::<&'a Index>())
+        } else {
+            Either::Right(
+                self.implicit_indexes()
+                    .chain(self.default_index())
+                    .filter(|index| !index.explicit),
+            )
+        };
+
+        simple_indexes
+            .chain(self.flat_indexes.iter())
+            .filter(move |index| seen.insert(index.raw_url()))
     }
 
     /// Return an iterator over all user-defined [`Index`] entries in order.
@@ -798,7 +815,7 @@ mod tests {
             },
         ];
 
-        let index_urls = IndexUrls::from_indexes(indexes);
+        let index_urls = IndexUrls::from_indexes(indexes, Vec::new());
 
         let url1 = IndexUrl::from_str("https://index1.example.com/simple").unwrap();
         assert_eq!(
@@ -836,7 +853,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone());
+        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let pytorch_url = IndexUrl::from_str("https://download.pytorch.org/whl/cu118").unwrap();
@@ -883,7 +900,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone());
+        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let pytorch_url = IndexUrl::from_str("https://download.pytorch.org/whl/cu118").unwrap();
@@ -926,7 +943,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone());
+        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let nvidia_url = IndexUrl::from_str("https://pypi.nvidia.com").unwrap();
diff --git a/crates/uv/src/commands/project/add.rs b/crates/uv/src/commands/project/add.rs
index 1ebcb879d84d3..0a04d8e12e814 100644
--- a/crates/uv/src/commands/project/add.rs
+++ b/crates/uv/src/commands/project/add.rs
@@ -686,7 +686,7 @@ pub(crate) async fn add(
 
     // Add any indexes that were provided on the command-line, in priority order.
     if !raw {
-        let urls = IndexUrls::from_indexes(indexes);
+        let urls = IndexUrls::from_indexes(indexes, Vec::new());
         let mut indexes = urls.defined_indexes().collect::<Vec<_>>();
         indexes.reverse();
         for index in indexes {
diff --git a/crates/uv/tests/it/show_settings.rs b/crates/uv/tests/it/show_settings.rs
index 01a592ba1ce22..08cf0e1fc52bf 100644
--- a/crates/uv/tests/it/show_settings.rs
+++ b/crates/uv/tests/it/show_settings.rs
@@ -106,7 +106,7 @@ fn pip_compile_baseline() {
         settings: PipSettings {
             index_locations: IndexLocations {
                 indexes: [],
-                flat_index: [],
+                flat_indexes: [],
                 no_index: false,
             },
             python: None,
@@ -291,7 +291,7 @@ fn pip_install_baseline() {
         settings: PipSettings {
             index_locations: IndexLocations {
                 indexes: [],
-                flat_index: [],
+                flat_indexes: [],
                 no_index: false,
             },
             python: None,
@@ -488,7 +488,7 @@ fn lock_baseline() {
             fork_strategy: RequiresPython,
             index_locations: IndexLocations {
                 indexes: [],
-                flat_index: [],
+                flat_indexes: [],
                 no_index: false,
             },
             index_strategy: FirstIndex,
@@ -617,7 +617,7 @@ fn version_baseline() {
                 fork_strategy: RequiresPython,
                 index_locations: IndexLocations {
                     indexes: [],
-                    flat_index: [],
+                    flat_indexes: [],
                     no_index: false,
                 },
                 index_strategy: FirstIndex,
@@ -784,7 +784,7 @@ fn tool_install_baseline() {
                 fork_strategy: RequiresPython,
                 index_locations: IndexLocations {
                     indexes: [],
-                    flat_index: [],
+                    flat_indexes: [],
                     no_index: false,
                 },
                 index_strategy: FirstIndex,
@@ -902,7 +902,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -1058,7 +1058,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -1251,7 +1251,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     "#
@@ -1357,9 +1357,9 @@ fn resolve_find_links() -> anyhow::Result<()> {
          settings: PipSettings {
              index_locations: IndexLocations {
                  indexes: [],
-    -            flat_index: [],
+    -            flat_indexes: [],
     -            no_index: false,
-    +            flat_index: [
+    +            flat_indexes: [
     +                Index {
     +                    name: None,
     +                    url: Url(
@@ -1554,7 +1554,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     "#
@@ -1973,7 +1973,7 @@ fn resolve_both() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -2105,7 +2105,7 @@ fn resolve_both_special_fields() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -2318,7 +2318,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     @@ -120,7 +156,7 @@
@@ -2656,7 +2656,7 @@ fn index_priority() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_index: [],
+                 flat_indexes: [],
                  no_index: false,
              },
     "#

From 1bbffb15279b37ef861d6df01fe98a12fd18fde7 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Fri, 3 Oct 2025 11:37:02 -0400
Subject: [PATCH 08/17] Split up functions

---
 crates/uv-client/src/registry_client.rs       |  6 ++----
 crates/uv-distribution-types/src/index_url.rs | 11 ++++++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index f4c7043d21caa..d8592162b87b5 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -331,11 +331,9 @@ impl RegistryClient {
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        let has_flat_indexes = self.index_urls.flat_indexes().next().is_some();
-
         // If `--no-index` is specified and no flat indexes are available, avoid fetching
         // regardless of whether the index is implicit, explicit, etc.
-        if self.index_urls.no_index() && !has_flat_indexes {
+        if self.index_urls.no_indexes() {
             return Err(ErrorKind::NoIndex(package_name.to_string()).into());
         }
 
@@ -435,7 +433,7 @@ impl RegistryClient {
         }
 
         if results.is_empty() {
-            if self.index_urls.no_index() {
+            if self.index_urls.simple_indexes_disabled() {
                 return Err(ErrorKind::NoIndex(package_name.to_string()).into());
             }
 
diff --git a/crates/uv-distribution-types/src/index_url.rs b/crates/uv-distribution-types/src/index_url.rs
index c5fefb25240d9..d7389912d626f 100644
--- a/crates/uv-distribution-types/src/index_url.rs
+++ b/crates/uv-distribution-types/src/index_url.rs
@@ -576,7 +576,7 @@ impl<'a> IndexUrls {
         let mut seen = FxHashSet::default();
 
         let simple_indexes = if self.no_index {
-            Either::Left(std::iter::empty::<&'a Index>())
+            Either::Left(std::iter::empty())
         } else {
             Either::Right(
                 self.implicit_indexes()
@@ -621,11 +621,16 @@ impl<'a> IndexUrls {
         Either::Right(non_default.into_iter().chain(default))
     }
 
-    /// Return the `--no-index` flag.
-    pub fn no_index(&self) -> bool {
+    /// Returns `true` if simple indexes (e.g., PyPI or `--extra-index-url`) are disabled via `--no-index`.
+    pub fn simple_indexes_disabled(&self) -> bool {
         self.no_index
     }
 
+    /// Returns `true` if there are no index sources at all (simple indexes disabled and no flat indexes).
+    pub fn no_indexes(&self) -> bool {
+        self.no_index && self.flat_indexes.is_empty()
+    }
+
     /// Return the [`IndexStatusCodeStrategy`] for an [`IndexUrl`].
     pub fn status_code_strategy_for(&self, url: &IndexUrl) -> IndexStatusCodeStrategy {
         for index in &self.indexes {

From 4da88957418c7b1ca73dce73d9aec3d3140ee96b Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Fri, 24 Oct 2025 22:06:14 -0400
Subject: [PATCH 09/17] Move the candidate filtering closure into a dedicated
 helper

---
 crates/uv/src/commands/pip/latest.rs | 126 +++++++++++++++------------
 1 file changed, 69 insertions(+), 57 deletions(-)

diff --git a/crates/uv/src/commands/pip/latest.rs b/crates/uv/src/commands/pip/latest.rs
index ed29a75ef75d1..884c293a4105b 100644
--- a/crates/uv/src/commands/pip/latest.rs
+++ b/crates/uv/src/commands/pip/latest.rs
@@ -1,7 +1,7 @@
 use tokio::sync::Semaphore;
 use tracing::debug;
 
-use uv_client::{FlatIndexEntry, MetadataFormat, RegistryClient, VersionFiles};
+use uv_client::{MetadataFormat, RegistryClient, VersionFiles};
 use uv_distribution_filename::DistFilename;
 use uv_distribution_types::{
     File, IndexCapabilities, IndexLocations, IndexMetadataRef, IndexUrl, RequiresPython,
@@ -36,6 +36,70 @@ impl LatestClient<'_> {
             .exclude_newer_package_for_index(package, self.index_locations.exclude_newer_for(index))
     }
 
+    fn consider_candidate(
+        &self,
+        filename: &DistFilename,
+        file: &File,
+        exclude_newer: Option<&jiff::Timestamp>,
+    ) -> bool {
+        // Respect any exclude-newer cutoffs that were provided.
+        if let Some(exclude_newer) = exclude_newer {
+            match file.upload_time_utc_ms.as_ref() {
+                Some(&upload_time) if upload_time >= exclude_newer.as_millisecond() => {
+                    return false;
+                }
+                None => {
+                    warn_user_once!(
+                        "{} is missing an upload date, but user provided: {}",
+                        file.filename,
+                        exclude_newer
+                    );
+                }
+                _ => {}
+            }
+        }
+
+        // Unless explicitly allowed, skip pre-release artifacts.
+        if !filename.version().is_stable() {
+            if !matches!(self.prerelease, PrereleaseMode::Allow) {
+                return false;
+            }
+        }
+
+        // Avoid yanked or otherwise withdrawn files.
+        if file
+            .yanked
+            .as_ref()
+            .is_some_and(|yanked| yanked.is_yanked())
+        {
+            return false;
+        }
+
+        // Enforce the interpreter's `Requires-Python` constraints.
+        if let Some(requires_python) = self.requires_python
+            && file
+                .requires_python
+                .as_ref()
+                .is_some_and(|file_requires_python| {
+                    !requires_python.is_contained_by(file_requires_python)
+                })
+        {
+            return false;
+        }
+
+        // Skip wheels that aren't compatible with the current platform.
+        if let DistFilename::WheelFilename(filename) = filename {
+            if self
+                .tags
+                .is_some_and(|tags| !filename.compatibility(tags).is_compatible())
+            {
+                return false;
+            }
+        }
+
+        true
+    }
+
     /// Find the latest version of a package from an index.
     pub(crate) async fn find_latest(
         &self,
@@ -89,59 +153,6 @@ impl LatestClient<'_> {
         for (index, archive) in archives {
             let exclude_newer = self.effective_exclude_newer(package, index);
 
-            let consider_candidate = |filename: &DistFilename, file: &File| {
-                if let Some(exclude_newer) = &exclude_newer {
-                    match file.upload_time_utc_ms.as_ref() {
-                        Some(&upload_time) if upload_time >= exclude_newer.as_millisecond() => {
-                            return false;
-                        }
-                        None => {
-                            warn_user_once!(
-                                "{} is missing an upload date, but user provided: {}",
-                                file.filename,
-                                exclude_newer
-                            );
-                        }
-                        _ => {}
-                    }
-                }
-
-                if !filename.version().is_stable()
-                    && !matches!(self.prerelease, PrereleaseMode::Allow)
-                {
-                    return false;
-                }
-
-                if file
-                    .yanked
-                    .as_ref()
-                    .is_some_and(|yanked| yanked.is_yanked())
-                {
-                    return false;
-                }
-
-                if let Some(requires_python) = self.requires_python
-                    && file
-                        .requires_python
-                        .as_ref()
-                        .is_some_and(|file_requires_python| {
-                            !requires_python.is_contained_by(file_requires_python)
-                        })
-                {
-                    return false;
-                }
-
-                if let DistFilename::WheelFilename(filename) = filename
-                    && self
-                        .tags
-                        .is_some_and(|tags| !filename.compatibility(tags).is_compatible())
-                {
-                    return false;
-                }
-
-                true
-            };
-
             match archive {
                 MetadataFormat::Simple(archive) => {
                     for datum in archive.iter().rev() {
@@ -151,7 +162,7 @@ impl LatestClient<'_> {
 
                         let mut best: Option<DistFilename> = None;
                         for (filename, file) in files.all() {
-                            if !consider_candidate(&filename, &file) {
+                            if !self.consider_candidate(&filename, &file, exclude_newer.as_ref()) {
                                 continue;
                             }
 
@@ -173,8 +184,9 @@ impl LatestClient<'_> {
                     }
                 }
                 MetadataFormat::Flat(entries) => {
-                    for FlatIndexEntry { filename, file, .. } in entries {
-                        if consider_candidate(&filename, &file) {
+                    for entry in entries {
+                        let (filename, file, _) = entry.into_parts();
+                        if self.consider_candidate(&filename, &file, exclude_newer.as_ref()) {
                             update_latest(filename);
                         }
                     }

From 00c13b8d780038178124831ade8b79ce87edbc39 Mon Sep 17 00:00:00 2001
From: Liam <liam@scalzulli.com>
Date: Fri, 24 Oct 2025 22:15:44 -0400
Subject: [PATCH 10/17] Drop exclude newer from snapshot tests

---
 crates/uv/tests/it/pip_list.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/crates/uv/tests/it/pip_list.rs b/crates/uv/tests/it/pip_list.rs
index 9ddbdcbd83887..978624eb97bf1 100644
--- a/crates/uv/tests/it/pip_list.rs
+++ b/crates/uv/tests/it/pip_list.rs
@@ -5,6 +5,7 @@ use assert_fs::fixture::FileWriteStr;
 use assert_fs::fixture::PathChild;
 use assert_fs::prelude::*;
 
+use uv_static::EnvVars;
 use uv_test::uv_snapshot;
 
 #[test]
@@ -179,11 +180,12 @@ fn list_outdated_json() -> Result<()> {
 
 #[test]
 fn list_outdated_find_links() {
-    let context = TestContext::new("3.12");
+    let context = uv_test::test_context!("3.12");
 
-    let links_dir = context.workspace_root.join("scripts/links");
+    let links_dir = context.workspace_root.join("test/links");
 
     uv_snapshot!(context.filters(), context.pip_install()
+        .env_remove(EnvVars::UV_EXCLUDE_NEWER)
         .arg("validation==1.0.0")
         .arg("--find-links")
         .arg(&links_dir)
@@ -201,6 +203,7 @@ fn list_outdated_find_links() {
     );
 
     uv_snapshot!(context.filters(), context.pip_list()
+        .env_remove(EnvVars::UV_EXCLUDE_NEWER)
         .arg("--outdated")
         .arg("--find-links")
         .arg(&links_dir)
@@ -213,9 +216,6 @@ fn list_outdated_find_links() {
     validation 1.0.0   3.0.0  wheel
 
     ----- stderr -----
-    warning: validation-1.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
-    warning: validation-2.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
-    warning: validation-3.0.0-py3-none-any.whl is missing an upload date, but user provided: global: 2024-03-25T00:00:00Z
     "###
     );
 }

From d2e771781efaf91f346074636fbda8e2c8e36969 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 22:45:35 -0400
Subject: [PATCH 11/17] Merge candidates from all flat indexes

---
 crates/uv-client/src/registry_client.rs       | 19 +++++++++++++++
 crates/uv-distribution-types/src/index_url.rs | 19 ++++-----------
 crates/uv/tests/it/pip_list.rs                | 24 +++++++++++++++++--
 3 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index d8592162b87b5..92c1aca5ed0f3 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -337,6 +337,7 @@ impl RegistryClient {
             return Err(ErrorKind::NoIndex(package_name.to_string()).into());
         }
 
+        let has_explicit_index = index.is_some();
         let indexes = if let Some(index) = index {
             Either::Left(std::iter::once(index))
         } else {
@@ -432,6 +433,24 @@ impl RegistryClient {
             }
         }
 
+        if !has_explicit_index {
+            let flat_results = futures::stream::iter(self.index_urls.flat_indexes())
+                .map(async |index| {
+                    let _permit = download_concurrency.acquire().await;
+                    let entries = self.flat_single_index(package_name, index.url()).await?;
+                    Ok((index.url(), entries))
+                })
+                .buffered(8)
+                .filter_map(async |result: Result<_, Error>| match result {
+                    Ok((_, entries)) if entries.is_empty() => None,
+                    Ok((index, entries)) => Some(Ok((index, MetadataFormat::Flat(entries)))),
+                    Err(err) => Some(Err(err)),
+                })
+                .try_collect::<Vec<_>>()
+                .await?;
+            results.extend(flat_results);
+        }
+
         if results.is_empty() {
             if self.index_urls.simple_indexes_disabled() {
                 return Err(ErrorKind::NoIndex(package_name.to_string()).into());
diff --git a/crates/uv-distribution-types/src/index_url.rs b/crates/uv-distribution-types/src/index_url.rs
index d7389912d626f..f1c20b733aeea 100644
--- a/crates/uv-distribution-types/src/index_url.rs
+++ b/crates/uv-distribution-types/src/index_url.rs
@@ -571,22 +571,13 @@ impl<'a> IndexUrls {
     /// Prioritizes the `[tool.uv.index]` definitions over the `--extra-index-url` definitions
     /// over the `--index-url` definition.
     ///
-    /// If `no_index` was enabled, then this always returns only the flat indexes.
+    /// If `no_index` was enabled, then this always returns an empty
+    /// iterator.
     pub fn indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
         let mut seen = FxHashSet::default();
-
-        let simple_indexes = if self.no_index {
-            Either::Left(std::iter::empty())
-        } else {
-            Either::Right(
-                self.implicit_indexes()
-                    .chain(self.default_index())
-                    .filter(|index| !index.explicit),
-            )
-        };
-
-        simple_indexes
-            .chain(self.flat_indexes.iter())
+        self.implicit_indexes()
+            .chain(self.default_index())
+            .filter(|index| !index.explicit)
             .filter(move |index| seen.insert(index.raw_url()))
     }
 
diff --git a/crates/uv/tests/it/pip_list.rs b/crates/uv/tests/it/pip_list.rs
index 978624eb97bf1..a6f212f9d1251 100644
--- a/crates/uv/tests/it/pip_list.rs
+++ b/crates/uv/tests/it/pip_list.rs
@@ -179,10 +179,26 @@ fn list_outdated_json() -> Result<()> {
 }
 
 #[test]
-fn list_outdated_find_links() {
+fn list_outdated_find_links() -> Result<()> {
     let context = uv_test::test_context!("3.12");
 
     let links_dir = context.workspace_root.join("test/links");
+    let first_links_dir = context.temp_dir.child("first-links");
+    first_links_dir.create_dir_all()?;
+    fs_err::copy(
+        links_dir.join("validation-2.0.0-py3-none-any.whl"),
+        first_links_dir
+            .child("validation-2.0.0-py3-none-any.whl")
+            .path(),
+    )?;
+    let second_links_dir = context.temp_dir.child("second-links");
+    second_links_dir.create_dir_all()?;
+    fs_err::copy(
+        links_dir.join("validation-3.0.0-py3-none-any.whl"),
+        second_links_dir
+            .child("validation-3.0.0-py3-none-any.whl")
+            .path(),
+    )?;
 
     uv_snapshot!(context.filters(), context.pip_install()
         .env_remove(EnvVars::UV_EXCLUDE_NEWER)
@@ -206,7 +222,9 @@ fn list_outdated_find_links() {
         .env_remove(EnvVars::UV_EXCLUDE_NEWER)
         .arg("--outdated")
         .arg("--find-links")
-        .arg(&links_dir)
+        .arg(first_links_dir.path())
+        .arg("--find-links")
+        .arg(second_links_dir.path())
         .arg("--no-index"), @r###"
     success: true
     exit_code: 0
@@ -218,6 +236,8 @@ fn list_outdated_find_links() {
     ----- stderr -----
     "###
     );
+
+    Ok(())
 }
 
 #[test]

From 0c7e74c72507db40f7b5d30447f3fe0f706b4912 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 22:48:57 -0400
Subject: [PATCH 12/17] Honor no-index for simple registry lookups

---
 crates/uv-client/src/registry_client.rs       | 93 +++++++++++++++++--
 crates/uv-distribution-types/src/index_url.rs |  5 -
 2 files changed, 85 insertions(+), 13 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index 92c1aca5ed0f3..93980dfee4262 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -331,18 +331,15 @@ impl RegistryClient {
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        // If `--no-index` is specified and no flat indexes are available, avoid fetching
-        // regardless of whether the index is implicit, explicit, etc.
-        if self.index_urls.no_indexes() {
-            return Err(ErrorKind::NoIndex(package_name.to_string()).into());
-        }
-
         let has_explicit_index = index.is_some();
         let indexes = if let Some(index) = index {
             Either::Left(std::iter::once(index))
         } else {
             Either::Right(self.index_urls_for(package_name))
         };
+        let indexes = indexes.filter(|index| {
+            index.format == IndexFormat::Flat || !self.index_urls.simple_indexes_disabled()
+        });
 
         let mut results = Vec::new();
 
@@ -1714,18 +1711,24 @@ impl Connectivity {
 mod tests {
     use std::str::FromStr;
 
+    use tokio::sync::Semaphore;
     use url::Url;
     use uv_normalize::PackageName;
     use uv_pypi_types::PypiSimpleDetail;
     use uv_redacted::DisplaySafeUrl;
+    use uv_torch::{TorchBackend, TorchSource, TorchStrategy};
 
     use crate::{
-        BaseClientBuilder, SimpleDetailMetadata, SimpleDetailMetadatum, html::SimpleDetailHTML,
+        BaseClientBuilder, Connectivity, SimpleDetailMetadata, SimpleDetailMetadatum,
+        html::SimpleDetailHTML,
     };
 
     use crate::RegistryClientBuilder;
     use uv_cache::Cache;
-    use uv_distribution_types::{FileLocation, ToUrlError};
+    use uv_distribution_types::{
+        FileLocation, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
+        IndexUrl, ToUrlError,
+    };
     use uv_small_str::SmallString;
     use wiremock::matchers::{basic_auth, method, path_regex};
     use wiremock::{Mock, MockServer, ResponseTemplate};
@@ -1749,6 +1752,80 @@ mod tests {
         server
     }
 
+    #[tokio::test]
+    async fn no_index_disables_explicit_simple_index() -> Result<(), Error> {
+        let server = MockServer::start().await;
+        let explicit_index = IndexUrl::from_str(&format!("{}/simple", server.uri()))?;
+        let flat_index = Index::from_find_links(IndexUrl::from_str("https://example.com/flat")?);
+        let registry_client =
+            RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
+                .index_locations(IndexLocations::new(vec![], vec![flat_index], true))
+                .build()?;
+
+        let error = registry_client
+            .simple_detail(
+                &PackageName::from_str("validation")?,
+                Some(IndexMetadataRef {
+                    url: &explicit_index,
+                    format: IndexFormat::Simple,
+                }),
+                &IndexCapabilities::default(),
+                &Semaphore::new(1),
+            )
+            .await
+            .expect_err("explicit simple index should be disabled");
+
+        assert!(matches!(
+            error.kind(),
+            crate::ErrorKind::NoIndex(package) if package == "validation"
+        ));
+        assert!(
+            server
+                .received_requests()
+                .await
+                .expect("request recording should be enabled")
+                .is_empty()
+        );
+
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn no_index_disables_torch_simple_index() -> Result<(), Error> {
+        let flat_index_dir = tempfile::tempdir()?;
+        let flat_index = Index::from_find_links(IndexUrl::parse(
+            flat_index_dir.path().to_string_lossy().as_ref(),
+            None,
+        )?);
+        let registry_client = RegistryClientBuilder::new(
+            BaseClientBuilder::default().connectivity(Connectivity::Offline),
+            Cache::temp()?,
+        )
+        .index_locations(IndexLocations::new(vec![], vec![flat_index], true))
+        .torch_backend(Some(TorchStrategy::Backend {
+            backend: TorchBackend::Cpu,
+            source: TorchSource::PyTorch,
+        }))
+        .build()?;
+
+        let error = registry_client
+            .simple_detail(
+                &PackageName::from_str("torch")?,
+                None,
+                &IndexCapabilities::default(),
+                &Semaphore::new(1),
+            )
+            .await
+            .expect_err("torch simple index should be disabled");
+
+        assert!(matches!(
+            error.kind(),
+            crate::ErrorKind::NoIndex(package) if package == "torch"
+        ));
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_redirect_to_server_with_credentials() -> Result<(), Error> {
         let username = "user";
diff --git a/crates/uv-distribution-types/src/index_url.rs b/crates/uv-distribution-types/src/index_url.rs
index f1c20b733aeea..a1cc79d2f349d 100644
--- a/crates/uv-distribution-types/src/index_url.rs
+++ b/crates/uv-distribution-types/src/index_url.rs
@@ -617,11 +617,6 @@ impl<'a> IndexUrls {
         self.no_index
     }
 
-    /// Returns `true` if there are no index sources at all (simple indexes disabled and no flat indexes).
-    pub fn no_indexes(&self) -> bool {
-        self.no_index && self.flat_indexes.is_empty()
-    }
-
     /// Return the [`IndexStatusCodeStrategy`] for an [`IndexUrl`].
     pub fn status_code_strategy_for(&self, url: &IndexUrl) -> IndexStatusCodeStrategy {
         for index in &self.indexes {

From b142414b844dbf5d868a8c08aa256f9b1409e1bc Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 23:14:01 -0400
Subject: [PATCH 13/17] Combine candidates from legacy find-links

---
 crates/uv-client/src/registry_client.rs | 18 +++++++----
 crates/uv/tests/it/pip_install.rs       | 43 +++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index 93980dfee4262..e2161790e867a 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -435,17 +435,21 @@ impl RegistryClient {
                 .map(async |index| {
                     let _permit = download_concurrency.acquire().await;
                     let entries = self.flat_single_index(package_name, index.url()).await?;
-                    Ok((index.url(), entries))
+                    Ok::<_, Error>((index.url(), entries))
                 })
                 .buffered(8)
-                .filter_map(async |result: Result<_, Error>| match result {
-                    Ok((_, entries)) if entries.is_empty() => None,
-                    Ok((index, entries)) => Some(Ok((index, MetadataFormat::Flat(entries)))),
-                    Err(err) => Some(Err(err)),
-                })
                 .try_collect::<Vec<_>>()
                 .await?;
-            results.extend(flat_results);
+            let flat_index = flat_results.first().map(|(index, _)| *index);
+            let flat_entries = flat_results
+                .into_iter()
+                .flat_map(|(_, entries)| entries)
+                .collect::<Vec<_>>();
+            if let Some(flat_index) = flat_index
+                && !flat_entries.is_empty()
+            {
+                results.push((flat_index, MetadataFormat::Flat(flat_entries)));
+            }
         }
 
         if results.is_empty() {
diff --git a/crates/uv/tests/it/pip_install.rs b/crates/uv/tests/it/pip_install.rs
index 56f48718059d6..0f8f9f2c05bf9 100644
--- a/crates/uv/tests/it/pip_install.rs
+++ b/crates/uv/tests/it/pip_install.rs
@@ -7518,6 +7518,49 @@ fn find_links() {
     );
 }
 
+/// Install the latest version across multiple `--find-links` directories.
+#[test]
+fn find_links_multiple() -> Result<()> {
+    let context = uv_test::test_context!("3.12");
+    let links_dir = context.workspace_root.join("test/links");
+
+    let first_links_dir = context.temp_dir.child("first-links");
+    first_links_dir.create_dir_all()?;
+    fs::copy(
+        links_dir.join("ok-1.0.0-py3-none-any.whl"),
+        first_links_dir.child("ok-1.0.0-py3-none-any.whl").path(),
+    )?;
+
+    let second_links_dir = context.temp_dir.child("second-links");
+    second_links_dir.create_dir_all()?;
+    fs::copy(
+        links_dir.join("ok-2.0.0-py3-none-any.whl"),
+        second_links_dir.child("ok-2.0.0-py3-none-any.whl").path(),
+    )?;
+
+    uv_snapshot!(context.filters(), context.pip_install()
+        .env_remove(EnvVars::UV_EXCLUDE_NEWER)
+        .arg("ok")
+        .arg("--no-index")
+        .arg("--find-links")
+        .arg(first_links_dir.path())
+        .arg("--find-links")
+        .arg(second_links_dir.path()), @"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
+    Installed 1 package in [TIME]
+     + ok==2.0.0
+    "
+    );
+
+    Ok(())
+}
+
 /// Install from a `--find-links` HTML page with uppercase tag and attribute names.
 #[tokio::test]
 async fn find_links_uppercase_html() -> Result<()> {

From 9b796f6b8c07951e79a02b6f6e7b64759008f140 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 23:40:04 -0400
Subject: [PATCH 14/17] Disable explicit flat indexes with no-index

---
 crates/uv-client/src/registry_client.rs | 41 +++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index e2161790e867a..3c814f6c306a0 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -337,9 +337,7 @@ impl RegistryClient {
         } else {
             Either::Right(self.index_urls_for(package_name))
         };
-        let indexes = indexes.filter(|index| {
-            index.format == IndexFormat::Flat || !self.index_urls.simple_indexes_disabled()
-        });
+        let indexes = indexes.filter(|_| !self.index_urls.simple_indexes_disabled());
 
         let mut results = Vec::new();
 
@@ -1794,6 +1792,43 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn no_index_disables_explicit_flat_index() -> Result<(), Error> {
+        let server = MockServer::start().await;
+        let explicit_index = IndexUrl::from_str(&server.uri())?;
+        let registry_client =
+            RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
+                .index_locations(IndexLocations::new(vec![], vec![], true))
+                .build()?;
+
+        let error = registry_client
+            .simple_detail(
+                &PackageName::from_str("validation")?,
+                Some(IndexMetadataRef {
+                    url: &explicit_index,
+                    format: IndexFormat::Flat,
+                }),
+                &IndexCapabilities::default(),
+                &Semaphore::new(1),
+            )
+            .await
+            .expect_err("explicit flat index should be disabled");
+
+        assert!(matches!(
+            error.kind(),
+            crate::ErrorKind::NoIndex(package) if package == "validation"
+        ));
+        assert!(
+            server
+                .received_requests()
+                .await
+                .expect("request recording should be enabled")
+                .is_empty()
+        );
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn no_index_disables_torch_simple_index() -> Result<(), Error> {
         let flat_index_dir = tempfile::tempdir()?;

From 9f36d2b2a2966a063a7aa50e060ad1f63688a105 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 23:42:41 -0400
Subject: [PATCH 15/17] Limit find-links metadata to latest queries

---
 crates/uv-client/src/registry_client.rs | 74 ++++++++++++++++++++++++-
 crates/uv/src/commands/pip/latest.rs    |  2 +-
 2 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index 3c814f6c306a0..92ae4cf0018ee 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -323,13 +323,49 @@ impl RegistryClient {
     /// "Simple" here refers to [PEP 503 – Simple Repository API](https://peps.python.org/pep-0503/)
     /// and [PEP 691 – JSON-based Simple API for Python Package Indexes](https://peps.python.org/pep-0691/),
     /// which the PyPI JSON API implements.
-    #[instrument(skip_all, fields(package = % package_name))]
     pub async fn simple_detail<'index>(
         &'index self,
         package_name: &PackageName,
         index: Option<IndexMetadataRef<'index>>,
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
+    ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
+        self.simple_detail_inner(
+            package_name,
+            index,
+            capabilities,
+            download_concurrency,
+            false,
+        )
+        .await
+    }
+
+    /// Fetch package metadata from an index and the configured legacy `--find-links` locations.
+    pub async fn simple_detail_with_find_links<'index>(
+        &'index self,
+        package_name: &PackageName,
+        index: Option<IndexMetadataRef<'index>>,
+        capabilities: &IndexCapabilities,
+        download_concurrency: &Semaphore,
+    ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
+        self.simple_detail_inner(
+            package_name,
+            index,
+            capabilities,
+            download_concurrency,
+            true,
+        )
+        .await
+    }
+
+    #[instrument(skip_all, fields(package = % package_name))]
+    async fn simple_detail_inner<'index>(
+        &'index self,
+        package_name: &PackageName,
+        index: Option<IndexMetadataRef<'index>>,
+        capabilities: &IndexCapabilities,
+        download_concurrency: &Semaphore,
+        include_find_links: bool,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
         let has_explicit_index = index.is_some();
         let indexes = if let Some(index) = index {
@@ -428,7 +464,7 @@ impl RegistryClient {
             }
         }
 
-        if !has_explicit_index {
+        if include_find_links && !has_explicit_index {
             let flat_results = futures::stream::iter(self.index_urls.flat_indexes())
                 .map(async |index| {
                     let _permit = download_concurrency.acquire().await;
@@ -1865,6 +1901,40 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn simple_detail_does_not_fetch_legacy_find_links() -> Result<(), Error> {
+        let server = MockServer::start().await;
+        let flat_index = Index::from_find_links(IndexUrl::from_str(&server.uri())?);
+        let registry_client =
+            RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
+                .index_locations(IndexLocations::new(vec![], vec![flat_index], true))
+                .build()?;
+
+        let error = registry_client
+            .simple_detail(
+                &PackageName::from_str("validation")?,
+                None,
+                &IndexCapabilities::default(),
+                &Semaphore::new(1),
+            )
+            .await
+            .expect_err("legacy find-links should not be fetched");
+
+        assert!(matches!(
+            error.kind(),
+            crate::ErrorKind::NoIndex(package) if package == "validation"
+        ));
+        assert!(
+            server
+                .received_requests()
+                .await
+                .expect("request recording should be enabled")
+                .is_empty()
+        );
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_redirect_to_server_with_credentials() -> Result<(), Error> {
         let username = "user";
diff --git a/crates/uv/src/commands/pip/latest.rs b/crates/uv/src/commands/pip/latest.rs
index 884c293a4105b..7ca89798badc0 100644
--- a/crates/uv/src/commands/pip/latest.rs
+++ b/crates/uv/src/commands/pip/latest.rs
@@ -131,7 +131,7 @@ impl LatestClient<'_> {
 
         let archives = match self
             .client
-            .simple_detail(
+            .simple_detail_with_find_links(
                 package,
                 index.map(IndexMetadataRef::from),
                 self.capabilities,

From 9989be8fc592443027895ce08378b74624b34b3f Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Fri, 5 Jun 2026 23:57:35 -0400
Subject: [PATCH 16/17] Simplify find-links metadata handling

---
 crates/uv-client/src/registry_client.rs       | 168 +++++++-----------
 crates/uv-distribution-types/src/index_url.rs |  40 ++---
 crates/uv/src/commands/pip/latest.rs          |  57 ++----
 crates/uv/src/commands/project/add.rs         |   2 +-
 crates/uv/tests/it/show_settings.rs           |  30 ++--
 5 files changed, 118 insertions(+), 179 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index 92ae4cf0018ee..a341bd27aa0f2 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -21,7 +21,7 @@ use uv_configuration::IndexStrategy;
 use uv_configuration::KeyringProviderType;
 use uv_distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use uv_distribution_types::{
-    BuiltDist, File, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
+    BuiltDist, File, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
     IndexStatusCodeDecision, IndexStatusCodeStrategy, IndexUrl, IndexUrls, Name,
 };
 use uv_git::{GIT_LFS, GitError, GitHttpSettings, GitResolver, Reporter};
@@ -323,6 +323,7 @@ impl RegistryClient {
     /// "Simple" here refers to [PEP 503 – Simple Repository API](https://peps.python.org/pep-0503/)
     /// and [PEP 691 – JSON-based Simple API for Python Package Indexes](https://peps.python.org/pep-0691/),
     /// which the PyPI JSON API implements.
+    #[instrument(skip_all, fields(package = % package_name))]
     pub async fn simple_detail<'index>(
         &'index self,
         package_name: &PackageName,
@@ -341,6 +342,7 @@ impl RegistryClient {
     }
 
     /// Fetch package metadata from an index and the configured legacy `--find-links` locations.
+    #[instrument(skip_all, fields(package = % package_name))]
     pub async fn simple_detail_with_find_links<'index>(
         &'index self,
         package_name: &PackageName,
@@ -358,7 +360,6 @@ impl RegistryClient {
         .await
     }
 
-    #[instrument(skip_all, fields(package = % package_name))]
     async fn simple_detail_inner<'index>(
         &'index self,
         package_name: &PackageName,
@@ -373,7 +374,7 @@ impl RegistryClient {
         } else {
             Either::Right(self.index_urls_for(package_name))
         };
-        let indexes = indexes.filter(|_| !self.index_urls.simple_indexes_disabled());
+        let indexes = indexes.filter(|_| !self.index_urls.no_index());
 
         let mut results = Vec::new();
 
@@ -465,19 +466,17 @@ impl RegistryClient {
         }
 
         if include_find_links && !has_explicit_index {
-            let flat_results = futures::stream::iter(self.index_urls.flat_indexes())
+            let flat_index = self.index_urls.flat_indexes().next().map(Index::url);
+            let flat_entries = futures::stream::iter(self.index_urls.flat_indexes())
                 .map(async |index| {
                     let _permit = download_concurrency.acquire().await;
-                    let entries = self.flat_single_index(package_name, index.url()).await?;
-                    Ok::<_, Error>((index.url(), entries))
+                    self.flat_single_index(package_name, index.url()).await
                 })
                 .buffered(8)
                 .try_collect::<Vec<_>>()
-                .await?;
-            let flat_index = flat_results.first().map(|(index, _)| *index);
-            let flat_entries = flat_results
+                .await?
                 .into_iter()
-                .flat_map(|(_, entries)| entries)
+                .flatten()
                 .collect::<Vec<_>>();
             if let Some(flat_index) = flat_index
                 && !flat_entries.is_empty()
@@ -487,7 +486,7 @@ impl RegistryClient {
         }
 
         if results.is_empty() {
-            if self.index_urls.simple_indexes_disabled() {
+            if self.index_urls.no_index() {
                 return Err(ErrorKind::NoIndex(package_name.to_string()).into());
             }
 
@@ -1757,11 +1756,9 @@ mod tests {
     use uv_torch::{TorchBackend, TorchSource, TorchStrategy};
 
     use crate::{
-        BaseClientBuilder, Connectivity, SimpleDetailMetadata, SimpleDetailMetadatum,
-        html::SimpleDetailHTML,
+        BaseClientBuilder, Connectivity, RegistryClient, RegistryClientBuilder,
+        SimpleDetailMetadata, SimpleDetailMetadatum, html::SimpleDetailHTML,
     };
-
-    use crate::RegistryClientBuilder;
     use uv_cache::Cache;
     use uv_distribution_types::{
         FileLocation, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
@@ -1790,33 +1787,37 @@ mod tests {
         server
     }
 
-    #[tokio::test]
-    async fn no_index_disables_explicit_simple_index() -> Result<(), Error> {
-        let server = MockServer::start().await;
-        let explicit_index = IndexUrl::from_str(&format!("{}/simple", server.uri()))?;
-        let flat_index = Index::from_find_links(IndexUrl::from_str("https://example.com/flat")?);
-        let registry_client =
+    fn no_index_client(flat_indexes: Vec<Index>) -> Result<RegistryClient, Error> {
+        Ok(
             RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
-                .index_locations(IndexLocations::new(vec![], vec![flat_index], true))
-                .build()?;
+                .index_locations(IndexLocations::new(vec![], flat_indexes, true))
+                .build()?,
+        )
+    }
 
-        let error = registry_client
+    async fn assert_no_index(
+        client: &RegistryClient,
+        package: &str,
+        index: Option<IndexMetadataRef<'_>>,
+    ) -> Result<(), Error> {
+        let error = client
             .simple_detail(
-                &PackageName::from_str("validation")?,
-                Some(IndexMetadataRef {
-                    url: &explicit_index,
-                    format: IndexFormat::Simple,
-                }),
+                &PackageName::from_str(package)?,
+                index,
                 &IndexCapabilities::default(),
                 &Semaphore::new(1),
             )
             .await
-            .expect_err("explicit simple index should be disabled");
+            .expect_err("index lookup should be disabled");
 
         assert!(matches!(
             error.kind(),
-            crate::ErrorKind::NoIndex(package) if package == "validation"
+            crate::ErrorKind::NoIndex(error_package) if error_package == package
         ));
+        Ok(())
+    }
+
+    async fn assert_no_requests(server: &MockServer) {
         assert!(
             server
                 .received_requests()
@@ -1824,7 +1825,25 @@ mod tests {
                 .expect("request recording should be enabled")
                 .is_empty()
         );
+    }
 
+    #[tokio::test]
+    async fn no_index_disables_explicit_simple_index() -> Result<(), Error> {
+        let server = MockServer::start().await;
+        let explicit_index = IndexUrl::from_str(&format!("{}/simple", server.uri()))?;
+        let flat_index = Index::from_find_links(IndexUrl::from_str("https://example.com/flat")?);
+        let registry_client = no_index_client(vec![flat_index])?;
+
+        assert_no_index(
+            &registry_client,
+            "validation",
+            Some(IndexMetadataRef {
+                url: &explicit_index,
+                format: IndexFormat::Simple,
+            }),
+        )
+        .await?;
+        assert_no_requests(&server).await;
         Ok(())
     }
 
@@ -1832,36 +1851,18 @@ mod tests {
     async fn no_index_disables_explicit_flat_index() -> Result<(), Error> {
         let server = MockServer::start().await;
         let explicit_index = IndexUrl::from_str(&server.uri())?;
-        let registry_client =
-            RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
-                .index_locations(IndexLocations::new(vec![], vec![], true))
-                .build()?;
-
-        let error = registry_client
-            .simple_detail(
-                &PackageName::from_str("validation")?,
-                Some(IndexMetadataRef {
-                    url: &explicit_index,
-                    format: IndexFormat::Flat,
-                }),
-                &IndexCapabilities::default(),
-                &Semaphore::new(1),
-            )
-            .await
-            .expect_err("explicit flat index should be disabled");
-
-        assert!(matches!(
-            error.kind(),
-            crate::ErrorKind::NoIndex(package) if package == "validation"
-        ));
-        assert!(
-            server
-                .received_requests()
-                .await
-                .expect("request recording should be enabled")
-                .is_empty()
-        );
-
+        let registry_client = no_index_client(vec![])?;
+
+        assert_no_index(
+            &registry_client,
+            "validation",
+            Some(IndexMetadataRef {
+                url: &explicit_index,
+                format: IndexFormat::Flat,
+            }),
+        )
+        .await?;
+        assert_no_requests(&server).await;
         Ok(())
     }
 
@@ -1883,21 +1884,7 @@ mod tests {
         }))
         .build()?;
 
-        let error = registry_client
-            .simple_detail(
-                &PackageName::from_str("torch")?,
-                None,
-                &IndexCapabilities::default(),
-                &Semaphore::new(1),
-            )
-            .await
-            .expect_err("torch simple index should be disabled");
-
-        assert!(matches!(
-            error.kind(),
-            crate::ErrorKind::NoIndex(package) if package == "torch"
-        ));
-
+        assert_no_index(&registry_client, "torch", None).await?;
         Ok(())
     }
 
@@ -1905,33 +1892,10 @@ mod tests {
     async fn simple_detail_does_not_fetch_legacy_find_links() -> Result<(), Error> {
         let server = MockServer::start().await;
         let flat_index = Index::from_find_links(IndexUrl::from_str(&server.uri())?);
-        let registry_client =
-            RegistryClientBuilder::new(BaseClientBuilder::default(), Cache::temp()?)
-                .index_locations(IndexLocations::new(vec![], vec![flat_index], true))
-                .build()?;
-
-        let error = registry_client
-            .simple_detail(
-                &PackageName::from_str("validation")?,
-                None,
-                &IndexCapabilities::default(),
-                &Semaphore::new(1),
-            )
-            .await
-            .expect_err("legacy find-links should not be fetched");
-
-        assert!(matches!(
-            error.kind(),
-            crate::ErrorKind::NoIndex(package) if package == "validation"
-        ));
-        assert!(
-            server
-                .received_requests()
-                .await
-                .expect("request recording should be enabled")
-                .is_empty()
-        );
+        let registry_client = no_index_client(vec![flat_index])?;
 
+        assert_no_index(&registry_client, "validation", None).await?;
+        assert_no_requests(&server).await;
         Ok(())
     }
 
diff --git a/crates/uv-distribution-types/src/index_url.rs b/crates/uv-distribution-types/src/index_url.rs
index a1cc79d2f349d..ab55a43cce58f 100644
--- a/crates/uv-distribution-types/src/index_url.rs
+++ b/crates/uv-distribution-types/src/index_url.rs
@@ -256,16 +256,16 @@ impl Deref for IndexUrl {
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 pub struct IndexLocations {
     indexes: Vec<Index>,
-    flat_indexes: Vec<Index>,
+    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_indexes: Vec<Index>, no_index: bool) -> Self {
+    pub fn new(indexes: Vec<Index>, flat_index: Vec<Index>, no_index: bool) -> Self {
         Self {
             indexes,
-            flat_indexes,
+            flat_index,
             no_index,
         }
     }
@@ -277,10 +277,10 @@ impl IndexLocations {
     ///
     /// If the current index location has an `index` set, it will be preserved.
     #[must_use]
-    pub fn combine(self, indexes: Vec<Index>, flat_indexes: Vec<Index>, no_index: bool) -> Self {
+    pub fn combine(self, indexes: Vec<Index>, flat_index: Vec<Index>, no_index: bool) -> Self {
         Self {
             indexes: self.indexes.into_iter().chain(indexes).collect(),
-            flat_indexes: self.flat_indexes.into_iter().chain(flat_indexes).collect(),
+            flat_index: self.flat_index.into_iter().chain(flat_index).collect(),
             no_index: self.no_index || no_index,
         }
     }
@@ -383,7 +383,7 @@ impl<'a> IndexLocations {
 
     /// Return an iterator over the [`FlatIndexLocation`] entries.
     pub fn flat_indexes(&'a self) -> impl Iterator<Item = &'a Index> + 'a {
-        self.flat_indexes.iter()
+        self.flat_index.iter()
     }
 
     /// Return the `--no-index` flag.
@@ -395,7 +395,7 @@ impl<'a> IndexLocations {
     pub fn index_urls(&'a self) -> IndexUrls {
         IndexUrls {
             indexes: self.indexes.clone(),
-            flat_indexes: self.flat_indexes.clone(),
+            flat_indexes: self.flat_index.clone(),
             no_index: self.no_index,
         }
     }
@@ -408,7 +408,7 @@ impl<'a> IndexLocations {
     /// that the last-defined index is the first item in the vector.
     pub fn allowed_indexes(&'a self) -> Vec<&'a Index> {
         if self.no_index {
-            self.flat_indexes.iter().rev().collect()
+            self.flat_index.iter().rev().collect()
         } else {
             let mut indexes = vec![];
 
@@ -417,7 +417,7 @@ impl<'a> IndexLocations {
             for index in {
                 self.indexes
                     .iter()
-                    .chain(self.flat_indexes.iter())
+                    .chain(self.flat_index.iter())
                     .filter(move |index| index.name.as_ref().is_none_or(|name| seen.insert(name)))
             } {
                 if index.default {
@@ -447,11 +447,11 @@ impl<'a> IndexLocations {
     /// that the last-defined index is the first item in the vector.
     pub fn known_indexes(&'a self) -> impl Iterator<Item = &'a Index> {
         if self.no_index {
-            Either::Left(self.flat_indexes.iter().rev())
+            Either::Left(self.flat_index.iter().rev())
         } else {
             Either::Right(
                 std::iter::once(&*DEFAULT_INDEX)
-                    .chain(self.flat_indexes.iter().rev())
+                    .chain(self.flat_index.iter().rev())
                     .chain(self.indexes.iter().rev()),
             )
         }
@@ -518,10 +518,10 @@ pub struct IndexUrls {
 }
 
 impl<'a> IndexUrls {
-    pub fn from_indexes(indexes: Vec<Index>, flat_indexes: Vec<Index>) -> Self {
+    pub fn from_indexes(indexes: Vec<Index>) -> Self {
         Self {
             indexes,
-            flat_indexes,
+            flat_indexes: Vec::new(),
             no_index: false,
         }
     }
@@ -578,7 +578,7 @@ impl<'a> IndexUrls {
         self.implicit_indexes()
             .chain(self.default_index())
             .filter(|index| !index.explicit)
-            .filter(move |index| seen.insert(index.raw_url()))
+            .filter(move |index| seen.insert(index.raw_url())) // Filter out redundant raw URLs
     }
 
     /// Return an iterator over all user-defined [`Index`] entries in order.
@@ -612,8 +612,8 @@ impl<'a> IndexUrls {
         Either::Right(non_default.into_iter().chain(default))
     }
 
-    /// Returns `true` if simple indexes (e.g., PyPI or `--extra-index-url`) are disabled via `--no-index`.
-    pub fn simple_indexes_disabled(&self) -> bool {
+    /// Return the `--no-index` flag.
+    pub fn no_index(&self) -> bool {
         self.no_index
     }
 
@@ -806,7 +806,7 @@ mod tests {
             },
         ];
 
-        let index_urls = IndexUrls::from_indexes(indexes, Vec::new());
+        let index_urls = IndexUrls::from_indexes(indexes);
 
         let url1 = IndexUrl::from_str("https://index1.example.com/simple").unwrap();
         assert_eq!(
@@ -844,7 +844,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
+        let index_urls = IndexUrls::from_indexes(indexes.clone());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let pytorch_url = IndexUrl::from_str("https://download.pytorch.org/whl/cu118").unwrap();
@@ -891,7 +891,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
+        let index_urls = IndexUrls::from_indexes(indexes.clone());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let pytorch_url = IndexUrl::from_str("https://download.pytorch.org/whl/cu118").unwrap();
@@ -934,7 +934,7 @@ mod tests {
             exclude_newer: None,
         }];
 
-        let index_urls = IndexUrls::from_indexes(indexes.clone(), Vec::new());
+        let index_urls = IndexUrls::from_indexes(indexes.clone());
         let index_locations = IndexLocations::new(indexes, Vec::new(), false);
 
         let nvidia_url = IndexUrl::from_str("https://pypi.nvidia.com").unwrap();
diff --git a/crates/uv/src/commands/pip/latest.rs b/crates/uv/src/commands/pip/latest.rs
index 7ca89798badc0..f6ba132776ac3 100644
--- a/crates/uv/src/commands/pip/latest.rs
+++ b/crates/uv/src/commands/pip/latest.rs
@@ -60,10 +60,8 @@ impl LatestClient<'_> {
         }
 
         // Unless explicitly allowed, skip pre-release artifacts.
-        if !filename.version().is_stable() {
-            if !matches!(self.prerelease, PrereleaseMode::Allow) {
-                return false;
-            }
+        if !filename.version().is_stable() && !matches!(self.prerelease, PrereleaseMode::Allow) {
+            return false;
         }
 
         // Avoid yanked or otherwise withdrawn files.
@@ -88,13 +86,12 @@ impl LatestClient<'_> {
         }
 
         // Skip wheels that aren't compatible with the current platform.
-        if let DistFilename::WheelFilename(filename) = filename {
-            if self
+        if let DistFilename::WheelFilename(filename) = filename
+            && self
                 .tags
                 .is_some_and(|tags| !filename.compatibility(tags).is_compatible())
-            {
-                return false;
-            }
+        {
+            return false;
         }
 
         true
@@ -112,20 +109,14 @@ impl LatestClient<'_> {
         let mut latest: Option<DistFilename> = None;
 
         let mut update_latest = |candidate: DistFilename| {
-            match latest.as_ref() {
-                Some(current) => {
-                    // Prefer higher versions, and prefer wheels over sdists at parity.
-                    if candidate.version() > current.version()
-                        || (candidate.version() == current.version()
-                            && matches!(candidate, DistFilename::WheelFilename(_))
-                            && matches!(current, DistFilename::SourceDistFilename(_)))
-                    {
-                        latest = Some(candidate);
-                    }
-                }
-                None => {
-                    latest = Some(candidate);
-                }
+            // Prefer higher versions, and prefer wheels over sdists at parity.
+            if latest.as_ref().is_none_or(|current| {
+                candidate.version() > current.version()
+                    || (candidate.version() == current.version()
+                        && matches!(candidate, DistFilename::WheelFilename(_))
+                        && matches!(current, DistFilename::SourceDistFilename(_)))
+            }) {
+                latest = Some(candidate);
             }
         };
 
@@ -160,27 +151,11 @@ impl LatestClient<'_> {
                             rkyv::deserialize::<VersionFiles, rkyv::rancor::Error>(&datum.files)
                                 .expect("archived version files always deserializes");
 
-                        let mut best: Option<DistFilename> = None;
                         for (filename, file) in files.all() {
-                            if !self.consider_candidate(&filename, &file, exclude_newer.as_ref()) {
-                                continue;
-                            }
-
-                            match filename {
-                                DistFilename::WheelFilename(_) => {
-                                    best = Some(filename);
-                                    break;
-                                }
-                                DistFilename::SourceDistFilename(_) if best.is_none() => {
-                                    best = Some(filename);
-                                }
-                                DistFilename::SourceDistFilename(_) => {}
+                            if self.consider_candidate(&filename, &file, exclude_newer.as_ref()) {
+                                update_latest(filename);
                             }
                         }
-
-                        if let Some(best) = best {
-                            update_latest(best);
-                        }
                     }
                 }
                 MetadataFormat::Flat(entries) => {
diff --git a/crates/uv/src/commands/project/add.rs b/crates/uv/src/commands/project/add.rs
index 0a04d8e12e814..1ebcb879d84d3 100644
--- a/crates/uv/src/commands/project/add.rs
+++ b/crates/uv/src/commands/project/add.rs
@@ -686,7 +686,7 @@ pub(crate) async fn add(
 
     // Add any indexes that were provided on the command-line, in priority order.
     if !raw {
-        let urls = IndexUrls::from_indexes(indexes, Vec::new());
+        let urls = IndexUrls::from_indexes(indexes);
         let mut indexes = urls.defined_indexes().collect::<Vec<_>>();
         indexes.reverse();
         for index in indexes {
diff --git a/crates/uv/tests/it/show_settings.rs b/crates/uv/tests/it/show_settings.rs
index 08cf0e1fc52bf..01a592ba1ce22 100644
--- a/crates/uv/tests/it/show_settings.rs
+++ b/crates/uv/tests/it/show_settings.rs
@@ -106,7 +106,7 @@ fn pip_compile_baseline() {
         settings: PipSettings {
             index_locations: IndexLocations {
                 indexes: [],
-                flat_indexes: [],
+                flat_index: [],
                 no_index: false,
             },
             python: None,
@@ -291,7 +291,7 @@ fn pip_install_baseline() {
         settings: PipSettings {
             index_locations: IndexLocations {
                 indexes: [],
-                flat_indexes: [],
+                flat_index: [],
                 no_index: false,
             },
             python: None,
@@ -488,7 +488,7 @@ fn lock_baseline() {
             fork_strategy: RequiresPython,
             index_locations: IndexLocations {
                 indexes: [],
-                flat_indexes: [],
+                flat_index: [],
                 no_index: false,
             },
             index_strategy: FirstIndex,
@@ -617,7 +617,7 @@ fn version_baseline() {
                 fork_strategy: RequiresPython,
                 index_locations: IndexLocations {
                     indexes: [],
-                    flat_indexes: [],
+                    flat_index: [],
                     no_index: false,
                 },
                 index_strategy: FirstIndex,
@@ -784,7 +784,7 @@ fn tool_install_baseline() {
                 fork_strategy: RequiresPython,
                 index_locations: IndexLocations {
                     indexes: [],
-                    flat_indexes: [],
+                    flat_index: [],
                     no_index: false,
                 },
                 index_strategy: FirstIndex,
@@ -902,7 +902,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -1058,7 +1058,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -1251,7 +1251,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     "#
@@ -1357,9 +1357,9 @@ fn resolve_find_links() -> anyhow::Result<()> {
          settings: PipSettings {
              index_locations: IndexLocations {
                  indexes: [],
-    -            flat_indexes: [],
+    -            flat_index: [],
     -            no_index: false,
-    +            flat_indexes: [
+    +            flat_index: [
     +                Index {
     +                    name: None,
     +                    url: Url(
@@ -1554,7 +1554,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     "#
@@ -1973,7 +1973,7 @@ fn resolve_both() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -2105,7 +2105,7 @@ fn resolve_both_special_fields() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     @@ -120,7 +158,7 @@
@@ -2318,7 +2318,7 @@ fn resolve_config_file() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     @@ -120,7 +156,7 @@
@@ -2656,7 +2656,7 @@ fn index_priority() -> anyhow::Result<()> {
     +                    exclude_newer: None,
     +                },
     +            ],
-                 flat_indexes: [],
+                 flat_index: [],
                  no_index: false,
              },
     "#

From 3d0365f8c9feba67f2cc167bc818700508cadb61 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Sat, 6 Jun 2026 00:14:15 -0400
Subject: [PATCH 17/17] Separate find-links metadata fetching

---
 crates/uv-client/src/registry_client.rs | 89 ++++++++-----------------
 crates/uv/src/commands/pip/latest.rs    | 33 ++++++---
 2 files changed, 51 insertions(+), 71 deletions(-)

diff --git a/crates/uv-client/src/registry_client.rs b/crates/uv-client/src/registry_client.rs
index a341bd27aa0f2..28f4b11fb04bf 100644
--- a/crates/uv-client/src/registry_client.rs
+++ b/crates/uv-client/src/registry_client.rs
@@ -21,7 +21,7 @@ use uv_configuration::IndexStrategy;
 use uv_configuration::KeyringProviderType;
 use uv_distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use uv_distribution_types::{
-    BuiltDist, File, Index, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
+    BuiltDist, File, IndexCapabilities, IndexFormat, IndexLocations, IndexMetadataRef,
     IndexStatusCodeDecision, IndexStatusCodeStrategy, IndexUrl, IndexUrls, Name,
 };
 use uv_git::{GIT_LFS, GitError, GitHttpSettings, GitResolver, Reporter};
@@ -331,50 +331,17 @@ impl RegistryClient {
         capabilities: &IndexCapabilities,
         download_concurrency: &Semaphore,
     ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        self.simple_detail_inner(
-            package_name,
-            index,
-            capabilities,
-            download_concurrency,
-            false,
-        )
-        .await
-    }
-
-    /// Fetch package metadata from an index and the configured legacy `--find-links` locations.
-    #[instrument(skip_all, fields(package = % package_name))]
-    pub async fn simple_detail_with_find_links<'index>(
-        &'index self,
-        package_name: &PackageName,
-        index: Option<IndexMetadataRef<'index>>,
-        capabilities: &IndexCapabilities,
-        download_concurrency: &Semaphore,
-    ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        self.simple_detail_inner(
-            package_name,
-            index,
-            capabilities,
-            download_concurrency,
-            true,
-        )
-        .await
-    }
+        // If `--no-index` is specified, avoid fetching regardless of whether the index is implicit,
+        // explicit, etc.
+        if self.index_urls.no_index() {
+            return Err(ErrorKind::NoIndex(package_name.to_string()).into());
+        }
 
-    async fn simple_detail_inner<'index>(
-        &'index self,
-        package_name: &PackageName,
-        index: Option<IndexMetadataRef<'index>>,
-        capabilities: &IndexCapabilities,
-        download_concurrency: &Semaphore,
-        include_find_links: bool,
-    ) -> Result<Vec<(&'index IndexUrl, MetadataFormat)>, Error> {
-        let has_explicit_index = index.is_some();
         let indexes = if let Some(index) = index {
             Either::Left(std::iter::once(index))
         } else {
             Either::Right(self.index_urls_for(package_name))
         };
-        let indexes = indexes.filter(|_| !self.index_urls.no_index());
 
         let mut results = Vec::new();
 
@@ -465,31 +432,7 @@ impl RegistryClient {
             }
         }
 
-        if include_find_links && !has_explicit_index {
-            let flat_index = self.index_urls.flat_indexes().next().map(Index::url);
-            let flat_entries = futures::stream::iter(self.index_urls.flat_indexes())
-                .map(async |index| {
-                    let _permit = download_concurrency.acquire().await;
-                    self.flat_single_index(package_name, index.url()).await
-                })
-                .buffered(8)
-                .try_collect::<Vec<_>>()
-                .await?
-                .into_iter()
-                .flatten()
-                .collect::<Vec<_>>();
-            if let Some(flat_index) = flat_index
-                && !flat_entries.is_empty()
-            {
-                results.push((flat_index, MetadataFormat::Flat(flat_entries)));
-            }
-        }
-
         if results.is_empty() {
-            if self.index_urls.no_index() {
-                return Err(ErrorKind::NoIndex(package_name.to_string()).into());
-            }
-
             return match self.connectivity {
                 Connectivity::Online => {
                     Err(ErrorKind::RemotePackageNotFound(package_name.clone()).into())
@@ -501,6 +444,26 @@ impl RegistryClient {
         Ok(results)
     }
 
+    /// Fetch and combine entries for a package from the configured legacy `--find-links` locations.
+    #[instrument(skip_all, fields(package = % package_name))]
+    pub async fn find_links_entries(
+        &self,
+        package_name: &PackageName,
+        download_concurrency: &Semaphore,
+    ) -> Result<Vec<FlatIndexEntry>, Error> {
+        Ok(futures::stream::iter(self.index_urls.flat_indexes())
+            .map(async |index| {
+                let _permit = download_concurrency.acquire().await;
+                self.flat_single_index(package_name, index.url()).await
+            })
+            .buffered(8)
+            .try_collect::<Vec<_>>()
+            .await?
+            .into_iter()
+            .flatten()
+            .collect::<Vec<_>>())
+    }
+
     /// Fetch the [`FlatIndexEntry`] entries for a given package from a single `--find-links` index.
     async fn flat_single_index(
         &self,
diff --git a/crates/uv/src/commands/pip/latest.rs b/crates/uv/src/commands/pip/latest.rs
index f6ba132776ac3..8768af37b72ae 100644
--- a/crates/uv/src/commands/pip/latest.rs
+++ b/crates/uv/src/commands/pip/latest.rs
@@ -122,7 +122,7 @@ impl LatestClient<'_> {
 
         let archives = match self
             .client
-            .simple_detail_with_find_links(
+            .simple_detail(
                 package,
                 index.map(IndexMetadataRef::from),
                 self.capabilities,
@@ -131,14 +131,17 @@ impl LatestClient<'_> {
             .await
         {
             Ok(archives) => archives,
-            Err(err) => {
-                return match err.kind() {
-                    uv_client::ErrorKind::RemotePackageNotFound(_) => Ok(None),
-                    uv_client::ErrorKind::NoIndex(_) => Ok(None),
-                    uv_client::ErrorKind::Offline(_) => Ok(None),
-                    _ => Err(err),
-                };
+            Err(err)
+                if matches!(
+                    err.kind(),
+                    uv_client::ErrorKind::RemotePackageNotFound(_)
+                        | uv_client::ErrorKind::NoIndex(_)
+                        | uv_client::ErrorKind::Offline(_)
+                ) =>
+            {
+                Vec::new()
             }
+            Err(err) => return Err(err),
         };
 
         for (index, archive) in archives {
@@ -169,6 +172,20 @@ impl LatestClient<'_> {
             }
         }
 
+        if index.is_none() {
+            for entry in self
+                .client
+                .find_links_entries(package, download_concurrency)
+                .await?
+            {
+                let (filename, file, index) = entry.into_parts();
+                let exclude_newer = self.effective_exclude_newer(package, &index);
+                if self.consider_candidate(&filename, &file, exclude_newer.as_ref()) {
+                    update_latest(filename);
+                }
+            }
+        }
+
         Ok(latest)
     }
 }