Add constraint dependencies to pyproject.toml (#5248)

Resolves #4467.

## Summary

This PR implements the following

1. Add `tool.uv.constraint-dependencies` to pyproject.toml
1. Support to refer `tool.uv.constraint-dependencies` in `uv lock`
1. Support to refer `tool.uv.constraint-dependencies` in `uv pip
compile/install`

These are analogues of the override features implemented in #3839 and
#4369.

## Test Plan

Add test.

crates/uv-settings/src/settings.rs

@@ -48,6 +48,7 @@ pub struct Options {
         )
     )]
     pub override_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
+    pub constraint_dependencies: Option<Vec<Requirement<VerbatimParsedUrl>>>,
 }
 
 /// Global settings, relevant to all invocations.

crates/uv-workspace/src/pyproject.rs

@@ -104,6 +104,7 @@ pub struct ToolUv {
         )
     )]
     pub override_dependencies: Option<Vec<pep508_rs::Requirement<VerbatimParsedUrl>>>,
+    pub constraint_dependencies: Option<Vec<pep508_rs::Requirement<VerbatimParsedUrl>>>,
 }
 
 #[derive(Serialize, Deserialize, OptionsMetadata, Default, Debug, Clone, PartialEq, Eq)]

crates/uv-workspace/src/workspace.rs

@@ -254,6 +254,38 @@ impl Workspace {
             .collect()
     }
 
+    /// Returns the set of constraints for the workspace.
+    pub fn constraints(&self) -> Vec<Requirement> {
+        let Some(workspace_package) = self
+            .packages
+            .values()
+            .find(|workspace_package| workspace_package.root() == self.install_path())
+        else {
+            return vec![];
+        };
+
+        let Some(constraints) = workspace_package
+            .pyproject_toml()
+            .tool
+            .as_ref()
+            .and_then(|tool| tool.uv.as_ref())
+            .and_then(|uv| uv.constraint_dependencies.as_ref())
+        else {
+            return vec![];
+        };
+
+        constraints
+            .iter()
+            .map(|requirement| {
+                Requirement::from(
+                    requirement
+                        .clone()
+                        .with_origin(RequirementOrigin::Workspace),
+                )
+            })
+            .collect()
+    }
+
     /// The path to the workspace root, the directory containing the top level `pyproject.toml` with
     /// the `uv.tool.workspace`, or the `pyproject.toml` in an implicit single workspace project.
     pub fn install_path(&self) -> &PathBuf {

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

@@ -48,6 +48,7 @@ pub(crate) async fn pip_compile(
     requirements: &[RequirementsSource],
     constraints: &[RequirementsSource],
     overrides: &[RequirementsSource],
+    constraints_from_workspace: Vec<Requirement>,
     overrides_from_workspace: Vec<Requirement>,
     extras: ExtrasSpecification,
     output_file: Option<&Path>,
@@ -126,6 +127,12 @@ pub(crate) async fn pip_compile(
     )
     .await?;
 
+    let constraints = constraints
+        .iter()
+        .cloned()
+        .chain(constraints_from_workspace.into_iter())
+        .collect();
+
     let overrides: Vec<UnresolvedRequirementSpecification> = overrides
         .iter()
         .cloned()

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

@@ -40,6 +40,7 @@ pub(crate) async fn pip_install(
     requirements: &[RequirementsSource],
     constraints: &[RequirementsSource],
     overrides: &[RequirementsSource],
+    constraints_from_workspace: Vec<Requirement>,
     overrides_from_workspace: Vec<Requirement>,
     extras: &ExtrasSpecification,
     resolution_mode: ResolutionMode,
@@ -104,6 +105,12 @@ pub(crate) async fn pip_install(
     )
     .await?;
 
+    let constraints: Vec<Requirement> = constraints
+        .iter()
+        .cloned()
+        .chain(constraints_from_workspace.into_iter())
+        .collect();
+
     let overrides: Vec<UnresolvedRequirementSpecification> = overrides
         .iter()
         .cloned()

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

@@ -211,7 +211,7 @@ pub(super) async fn do_lock(
         .into_iter()
         .map(UnresolvedRequirementSpecification::from)
         .collect::<Vec<_>>();
-    let constraints = vec![];
+    let constraints = workspace.constraints();
     let dev = vec![DEV_DEPENDENCIES.clone()];
     let source_trees = vec![];
 

crates/uv/src/lib.rs

@@ -200,6 +200,7 @@ async fn run(cli: Cli) -> Result<ExitStatus> {
                 &requirements,
                 &constraints,
                 &overrides,
+                args.constraints_from_workspace,
                 args.overrides_from_workspace,
                 args.settings.extras,
                 args.settings.output_file.as_deref(),
@@ -349,6 +350,7 @@ async fn run(cli: Cli) -> Result<ExitStatus> {
                 &requirements,
                 &constraints,
                 &overrides,
+                args.constraints_from_workspace,
                 args.overrides_from_workspace,
                 &args.settings.extras,
                 args.settings.resolution,

crates/uv/src/settings.rs

@@ -763,6 +763,7 @@ pub(crate) struct PipCompileSettings {
     pub(crate) src_file: Vec<PathBuf>,
     pub(crate) constraint: Vec<PathBuf>,
     pub(crate) r#override: Vec<PathBuf>,
+    pub(crate) constraints_from_workspace: Vec<Requirement>,
     pub(crate) overrides_from_workspace: Vec<Requirement>,
     pub(crate) refresh: Refresh,
     pub(crate) settings: PipSettings,
@@ -824,6 +825,20 @@ impl PipCompileSettings {
             compat_args: _,
         } = args;
 
+        let constraints_from_workspace = if let Some(configuration) = &filesystem {
+            configuration
+                .constraint_dependencies
+                .clone()
+                .unwrap_or_default()
+                .into_iter()
+                .map(|requirement| {
+                    Requirement::from(requirement.with_origin(RequirementOrigin::Workspace))
+                })
+                .collect()
+        } else {
+            Vec::new()
+        };
+
         let overrides_from_workspace = if let Some(configuration) = &filesystem {
             configuration
                 .override_dependencies
@@ -848,6 +863,7 @@ impl PipCompileSettings {
                 .into_iter()
                 .filter_map(Maybe::into_option)
                 .collect(),
+            constraints_from_workspace,
             overrides_from_workspace,
             refresh: Refresh::from(refresh),
             settings: PipSettings::combine(
@@ -988,6 +1004,7 @@ pub(crate) struct PipInstallSettings {
     pub(crate) constraint: Vec<PathBuf>,
     pub(crate) r#override: Vec<PathBuf>,
     pub(crate) dry_run: bool,
+    pub(crate) constraints_from_workspace: Vec<Requirement>,
     pub(crate) overrides_from_workspace: Vec<Requirement>,
     pub(crate) refresh: Refresh,
     pub(crate) settings: PipSettings,
@@ -1036,6 +1053,20 @@ impl PipInstallSettings {
             compat_args: _,
         } = args;
 
+        let constraints_from_workspace = if let Some(configuration) = &filesystem {
+            configuration
+                .constraint_dependencies
+                .clone()
+                .unwrap_or_default()
+                .into_iter()
+                .map(|requirement| {
+                    Requirement::from(requirement.with_origin(RequirementOrigin::Workspace))
+                })
+                .collect()
+        } else {
+            Vec::new()
+        };
+
         let overrides_from_workspace = if let Some(configuration) = &filesystem {
             configuration
                 .override_dependencies
@@ -1063,6 +1094,7 @@ impl PipInstallSettings {
                 .filter_map(Maybe::into_option)
                 .collect(),
             dry_run,
+            constraints_from_workspace,
             overrides_from_workspace,
             refresh: Refresh::from(refresh),
             settings: PipSettings::combine(

crates/uv/tests/lock.rs

@@ -644,6 +644,55 @@ fn lock_project_with_overrides() -> Result<()> {
 
     Ok(())
 }
+
+/// Lock a project with a uv.tool.constraint-dependencies.
+#[test]
+fn lock_project_with_constraints() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"
+        [project]
+        name = "project"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["anyio==3.7.0"]
+
+        [tool.uv]
+        constraint-dependencies = ["idna<3.4"]
+        "#,
+    )?;
+
+    uv_snapshot!(context.filters(), context.lock(), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv lock` is experimental and may change without warning
+    Resolved 4 packages in [TIME]
+    "###);
+
+    // Install the base dependencies from the lockfile.
+    uv_snapshot!(context.filters(), context.sync().arg("--frozen"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv sync` is experimental and may change without warning
+    Prepared 4 packages in [TIME]
+    Installed 4 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.3
+     + project==0.1.0 (from file://[TEMP_DIR]/)
+     + sniffio==1.3.1
+    "###);
+
+    Ok(())
+}
+
 /// Lock a project with a dependency that has an extra.
 #[test]
 fn lock_dependency_extra() -> Result<()> {

crates/uv/tests/pip_compile.rs

@@ -3043,6 +3043,50 @@ fn override_dependency_from_pyproject() -> Result<()> {
     Ok(())
 }
 
+/// Check that `tool.uv.constraint-dependencies` in `pyproject.toml` is respected.
+#[test]
+fn constraint_dependency_from_pyproject() -> Result<()> {
+    let context = TestContext::new("3.12");
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+    name = "example"
+    version = "0.0.0"
+    dependencies = [
+      "anyio==3.7.0"
+    ]
+
+    [tool.uv]
+    constraint-dependencies = [
+      "idna<3.4"
+    ]
+    "#,
+    )?;
+
+    uv_snapshot!(context.pip_compile()
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    # This file was autogenerated by uv via the following command:
+    #    uv pip compile --cache-dir [CACHE_DIR] pyproject.toml
+    anyio==3.7.0
+        # via example (pyproject.toml)
+    idna==3.3
+        # via
+        #   -c (workspace)
+        #   anyio
+    sniffio==1.3.1
+        # via anyio
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    "###
+    );
+
+    Ok(())
+}
+
 /// Check that `override-dependencies` in `uv.toml` is respected.
 #[test]
 fn override_dependency_from_specific_uv_toml() -> Result<()> {

crates/uv/tests/pip_install.rs

@@ -2429,6 +2429,46 @@ fn install_constraints_txt() -> Result<()> {
     Ok(())
 }
 
+/// Check that `tool.uv.constraint-dependencies` in `pyproject.toml` is respected.
+#[test]
+fn install_constraints_from_pyproject() -> Result<()> {
+    let context = TestContext::new("3.12");
+    let pyproject_toml = context.temp_dir.child("pyproject.toml");
+    pyproject_toml.write_str(
+        r#"[project]
+    name = "example"
+    version = "0.0.0"
+    dependencies = [
+      "anyio==3.7.0"
+    ]
+
+    [tool.uv]
+    constraint-dependencies = [
+      "idna<3.4"
+    ]
+    "#,
+    )?;
+
+    uv_snapshot!(context.pip_install()
+            .arg("-r")
+            .arg("pyproject.toml"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Prepared 3 packages in [TIME]
+    Installed 3 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.3
+     + sniffio==1.3.1
+    "###
+    );
+
+    Ok(())
+}
+
 /// Install a package from a `requirements.txt` file, with an inline constraint.
 #[test]
 fn install_constraints_inline() -> Result<()> {

crates/uv/tests/show_settings.rs

@@ -73,6 +73,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -206,6 +207,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -340,6 +342,7 @@ fn resolve_uv_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -506,6 +509,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -641,6 +645,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -762,6 +767,7 @@ fn resolve_pyproject_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -920,6 +926,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1078,6 +1085,7 @@ fn resolve_index_url() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1281,6 +1289,7 @@ fn resolve_find_links() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1438,6 +1447,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1565,6 +1575,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1720,6 +1731,7 @@ fn resolve_top_level() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -1899,6 +1911,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -2016,6 +2029,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -2133,6 +2147,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -2252,6 +2267,7 @@ fn resolve_user_configuration() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -2396,6 +2412,7 @@ fn resolve_poetry_toml() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(
@@ -2541,6 +2558,7 @@ fn resolve_both() -> anyhow::Result<()> {
         ],
         constraint: [],
         override: [],
+        constraints_from_workspace: [],
         overrides_from_workspace: [],
         refresh: None(
             Timestamp(

uv.schema.json

@@ -29,6 +29,15 @@
         }
       ]
     },
+    "constraint-dependencies": {
+      "type": [
+        "array",
+        "null"
+      ],
+      "items": {
+        "$ref": "#/definitions/Requirement"
+      }
+    },
     "dev-dependencies": {
       "description": "PEP 508-style requirements, e.g., `ruff==0.5.0`, or `ruff @ https://...`.",
       "type": [