Fetch Requirements from cloud (#10167)

Load requirements from Codex Backend. It only does this for enterprise
customers signed in with ChatGPT.

Todo in follow-up PRs:
* Add to app-server and exec too
* Switch from fail-open to fail-closed on failure

codex-rs/core/src/config_loader/README.md

@@ -10,7 +10,7 @@ This module is the canonical place to **load and describe Codex configuration la
 
 Exported from `codex_core::config_loader`:
 
-- `load_config_layers_state(codex_home, cwd_opt, cli_overrides, overrides) -> ConfigLayerStack`
+- `load_config_layers_state(codex_home, cwd_opt, cli_overrides, overrides, cloud_requirements) -> ConfigLayerStack`
 - `ConfigLayerStack`
   - `effective_config() -> toml::Value`
   - `origins() -> HashMap<String, ConfigLayerMetadata>`
@@ -49,6 +49,7 @@ let layers = load_config_layers_state(
     Some(cwd),
     &cli_overrides,
     LoaderOverrides::default(),
+    None,
 ).await?;
 
 let effective = layers.effective_config();

codex-rs/core/src/config_loader/cloud_requirements.rs

@@ -0,0 +1,56 @@
+use crate::config_loader::ConfigRequirementsToml;
+use futures::future::BoxFuture;
+use futures::future::FutureExt;
+use futures::future::Shared;
+use std::fmt;
+use std::future::Future;
+
+#[derive(Clone)]
+pub struct CloudRequirementsLoader {
+    // TODO(gt): This should return a Result once we can fail-closed.
+    fut: Shared<BoxFuture<'static, Option<ConfigRequirementsToml>>>,
+}
+
+impl CloudRequirementsLoader {
+    pub fn new<F>(fut: F) -> Self
+    where
+        F: Future<Output = Option<ConfigRequirementsToml>> + Send + 'static,
+    {
+        Self {
+            fut: fut.boxed().shared(),
+        }
+    }
+
+    pub async fn get(&self) -> Option<ConfigRequirementsToml> {
+        self.fut.clone().await
+    }
+}
+
+impl fmt::Debug for CloudRequirementsLoader {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("CloudRequirementsLoader").finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+    use std::sync::Arc;
+    use std::sync::atomic::AtomicUsize;
+    use std::sync::atomic::Ordering;
+
+    #[tokio::test]
+    async fn shared_future_runs_once() {
+        let counter = Arc::new(AtomicUsize::new(0));
+        let counter_clone = Arc::clone(&counter);
+        let loader = CloudRequirementsLoader::new(async move {
+            counter_clone.fetch_add(1, Ordering::SeqCst);
+            Some(ConfigRequirementsToml::default())
+        });
+
+        let (first, second) = tokio::join!(loader.get(), loader.get());
+        assert_eq!(first, second);
+        assert_eq!(counter.load(Ordering::SeqCst), 1);
+    }
+}

codex-rs/core/src/config_loader/config_requirements.rs

@@ -13,6 +13,7 @@ use crate::config::ConstraintError;
 pub enum RequirementSource {
     Unknown,
     MdmManagedPreferences { domain: String, key: String },
+    CloudRequirements,
     SystemRequirementsToml { file: AbsolutePathBuf },
     LegacyManagedConfigTomlFromFile { file: AbsolutePathBuf },
     LegacyManagedConfigTomlFromMdm,
@@ -25,6 +26,9 @@ impl fmt::Display for RequirementSource {
             RequirementSource::MdmManagedPreferences { domain, key } => {
                 write!(f, "MDM {domain}:{key}")
             }
+            RequirementSource::CloudRequirements => {
+                write!(f, "cloud requirements")
+            }
             RequirementSource::SystemRequirementsToml { file } => {
                 write!(f, "{}", file.as_path().display())
             }
@@ -448,6 +452,33 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn constraint_error_includes_cloud_requirements_source() -> Result<()> {
+        let source: ConfigRequirementsToml = from_str(
+            r#"
+                allowed_approval_policies = ["on-request"]
+            "#,
+        )?;
+
+        let source_location = RequirementSource::CloudRequirements;
+
+        let mut target = ConfigRequirementsWithSources::default();
+        target.merge_unset_fields(source_location.clone(), source);
+        let requirements = ConfigRequirements::try_from(target)?;
+
+        assert_eq!(
+            requirements.approval_policy.can_set(&AskForApproval::Never),
+            Err(ConstraintError::InvalidValue {
+                field_name: "approval_policy",
+                candidate: "Never".into(),
+                allowed: "[OnRequest]".into(),
+                requirement_source: source_location,
+            })
+        );
+
+        Ok(())
+    }
+
     #[test]
     fn deserialize_allowed_approval_policies() -> Result<()> {
         let toml_str = r#"

codex-rs/core/src/config_loader/mod.rs

@@ -1,3 +1,4 @@
+mod cloud_requirements;
 mod config_requirements;
 mod diagnostics;
 mod fingerprint;
@@ -30,6 +31,7 @@ use std::io;
 use std::path::Path;
 use toml::Value as TomlValue;
 
+pub use cloud_requirements::CloudRequirementsLoader;
 pub use config_requirements::ConfigRequirements;
 pub use config_requirements::ConfigRequirementsToml;
 pub use config_requirements::McpServerIdentity;
@@ -69,6 +71,7 @@ const DEFAULT_PROJECT_ROOT_MARKERS: &[&str] = &[".git"];
 /// earlier layer cannot be overridden by a later layer:
 ///
 /// - admin:    managed preferences (*)
+/// - cloud:    managed cloud requirements
 /// - system    `/etc/codex/requirements.toml`
 ///
 /// For backwards compatibility, we also load from
@@ -98,6 +101,7 @@ pub async fn load_config_layers_state(
     cwd: Option<AbsolutePathBuf>,
     cli_overrides: &[(String, TomlValue)],
     overrides: LoaderOverrides,
+    cloud_requirements: Option<CloudRequirementsLoader>, // TODO(gt): Once exec and app-server are wired up, we can remove the option.
 ) -> io::Result<ConfigLayerStack> {
     let mut config_requirements_toml = ConfigRequirementsWithSources::default();
 
@@ -110,6 +114,13 @@ pub async fn load_config_layers_state(
     )
     .await?;
 
+    if let Some(loader) = cloud_requirements
+        && let Some(requirements) = loader.get().await
+    {
+        config_requirements_toml
+            .merge_unset_fields(RequirementSource::CloudRequirements, requirements);
+    }
+
     // Honor /etc/codex/requirements.toml.
     if cfg!(unix) {
         load_requirements_toml(

codex-rs/core/src/config_loader/tests.rs

@@ -4,11 +4,15 @@ use crate::config::CONFIG_TOML_FILE;
 use crate::config::ConfigBuilder;
 use crate::config::ConfigOverrides;
 use crate::config::ConfigToml;
+use crate::config::ConstraintError;
 use crate::config::ProjectConfig;
+use crate::config_loader::CloudRequirementsLoader;
 use crate::config_loader::ConfigLayerEntry;
 use crate::config_loader::ConfigLoadError;
 use crate::config_loader::ConfigRequirements;
+use crate::config_loader::ConfigRequirementsToml;
 use crate::config_loader::config_requirements::ConfigRequirementsWithSources;
+use crate::config_loader::config_requirements::RequirementSource;
 use crate::config_loader::fingerprint::version_for_toml;
 use crate::config_loader::load_requirements_toml;
 use codex_protocol::config_types::TrustLevel;
@@ -65,6 +69,7 @@ async fn returns_config_error_for_invalid_user_config_toml() {
         Some(cwd),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await
     .expect_err("expected error");
@@ -94,6 +99,7 @@ async fn returns_config_error_for_invalid_managed_config_toml() {
         Some(cwd),
         &[] as &[(String, TomlValue)],
         overrides,
+        None,
     )
     .await
     .expect_err("expected error");
@@ -182,6 +188,7 @@ extra = true
         Some(cwd),
         &[] as &[(String, TomlValue)],
         overrides,
+        None,
     )
     .await
     .expect("load config");
@@ -218,6 +225,7 @@ async fn returns_empty_when_all_layers_missing() {
         Some(cwd),
         &[] as &[(String, TomlValue)],
         overrides,
+        None,
     )
     .await
     .expect("load layers");
@@ -315,6 +323,7 @@ flag = false
         Some(cwd),
         &[] as &[(String, TomlValue)],
         overrides,
+        None,
     )
     .await
     .expect("load config");
@@ -354,6 +363,7 @@ allowed_sandbox_modes = ["read-only"]
                 ),
             ),
         },
+        None,
     )
     .await?;
 
@@ -414,6 +424,7 @@ allowed_approval_policies = ["never"]
                 ),
             ),
         },
+        None,
     )
     .await?;
 
@@ -472,6 +483,91 @@ allowed_approval_policies = ["never", "on-request"]
     Ok(())
 }
 
+#[tokio::test(flavor = "current_thread")]
+async fn cloud_requirements_are_not_overwritten_by_system_requirements() -> anyhow::Result<()> {
+    let tmp = tempdir()?;
+    let requirements_file = tmp.path().join("requirements.toml");
+    tokio::fs::write(
+        &requirements_file,
+        r#"
+allowed_approval_policies = ["on-request"]
+"#,
+    )
+    .await?;
+
+    let mut config_requirements_toml = ConfigRequirementsWithSources::default();
+    config_requirements_toml.merge_unset_fields(
+        RequirementSource::CloudRequirements,
+        ConfigRequirementsToml {
+            allowed_approval_policies: Some(vec![AskForApproval::Never]),
+            allowed_sandbox_modes: None,
+            mcp_servers: None,
+        },
+    );
+    load_requirements_toml(&mut config_requirements_toml, &requirements_file).await?;
+
+    assert_eq!(
+        config_requirements_toml
+            .allowed_approval_policies
+            .as_ref()
+            .map(|sourced| sourced.value.clone()),
+        Some(vec![AskForApproval::Never])
+    );
+    assert_eq!(
+        config_requirements_toml
+            .allowed_approval_policies
+            .as_ref()
+            .map(|sourced| sourced.source.clone()),
+        Some(RequirementSource::CloudRequirements)
+    );
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn load_config_layers_includes_cloud_requirements() -> anyhow::Result<()> {
+    let tmp = tempdir()?;
+    let codex_home = tmp.path().join("home");
+    tokio::fs::create_dir_all(&codex_home).await?;
+    let cwd = AbsolutePathBuf::from_absolute_path(tmp.path())?;
+
+    let requirements = ConfigRequirementsToml {
+        allowed_approval_policies: Some(vec![AskForApproval::Never]),
+        allowed_sandbox_modes: None,
+        mcp_servers: None,
+    };
+    let expected = requirements.clone();
+    let cloud_requirements = CloudRequirementsLoader::new(async move { Some(requirements) });
+
+    let layers = load_config_layers_state(
+        &codex_home,
+        Some(cwd),
+        &[] as &[(String, TomlValue)],
+        LoaderOverrides::default(),
+        Some(cloud_requirements),
+    )
+    .await?;
+
+    assert_eq!(
+        layers.requirements_toml().allowed_approval_policies,
+        expected.allowed_approval_policies
+    );
+    assert_eq!(
+        layers
+            .requirements()
+            .approval_policy
+            .can_set(&AskForApproval::OnRequest),
+        Err(ConstraintError::InvalidValue {
+            field_name: "approval_policy",
+            candidate: "OnRequest".into(),
+            allowed: "[Never]".into(),
+            requirement_source: RequirementSource::CloudRequirements,
+        })
+    );
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn project_layers_prefer_closest_cwd() -> std::io::Result<()> {
     let tmp = tempdir()?;
@@ -501,6 +597,7 @@ async fn project_layers_prefer_closest_cwd() -> std::io::Result<()> {
         Some(cwd),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await?;
 
@@ -632,6 +729,7 @@ async fn project_layer_is_added_when_dot_codex_exists_without_config_toml() -> s
         Some(cwd),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await?;
 
@@ -691,6 +789,7 @@ async fn project_layers_disabled_when_untrusted_or_unknown() -> std::io::Result<
         Some(cwd.clone()),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await?;
     let project_layers_untrusted: Vec<_> = layers_untrusted
@@ -728,6 +827,7 @@ async fn project_layers_disabled_when_untrusted_or_unknown() -> std::io::Result<
         Some(cwd),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await?;
     let project_layers_unknown: Vec<_> = layers_unknown
@@ -788,6 +888,7 @@ async fn invalid_project_config_ignored_when_untrusted_or_unknown() -> std::io::
             Some(cwd.clone()),
             &[] as &[(String, TomlValue)],
             LoaderOverrides::default(),
+            None,
         )
         .await?;
         let project_layers: Vec<_> = layers
@@ -843,6 +944,7 @@ async fn cli_overrides_with_relative_paths_do_not_break_trust_check() -> std::io
         Some(cwd),
         &cli_overrides,
         LoaderOverrides::default(),
+        None,
     )
     .await?;
 
@@ -884,6 +986,7 @@ async fn project_root_markers_supports_alternate_markers() -> std::io::Result<()
         Some(cwd),
         &[] as &[(String, TomlValue)],
         LoaderOverrides::default(),
+        None,
     )
     .await?;