diff --git a/.github/scripts/verify_cargo_workspace_manifests.py b/.github/scripts/verify_cargo_workspace_manifests.py
index 69320cb14..410685792 100644
--- a/.github/scripts/verify_cargo_workspace_manifests.py
+++ b/.github/scripts/verify_cargo_workspace_manifests.py
@@ -27,11 +27,6 @@ UTILITY_NAME_EXCEPTIONS = {
     "path-utils": "codex-utils-path",
 }
 MANIFEST_FEATURE_EXCEPTIONS = {
-    "codex-rs/cloud-tasks-client/Cargo.toml": {
-        "default": ("online",),
-        "online": ("dep:codex-backend-client",),
-        "mock": (),
-    },
     "codex-rs/otel/Cargo.toml": {
         "disable-default-metrics-exporter": (),
     },
@@ -43,11 +38,6 @@ MANIFEST_FEATURE_EXCEPTIONS = {
     },
 }
 OPTIONAL_DEPENDENCY_EXCEPTIONS = {
-    (
-        "codex-rs/cloud-tasks-client/Cargo.toml",
-        "dependencies",
-        "codex-backend-client",
-    ),
     (
         "codex-rs/tui/Cargo.toml",
         'target.cfg(not(target_os = "linux")).dependencies',
@@ -55,11 +45,6 @@ OPTIONAL_DEPENDENCY_EXCEPTIONS = {
     ),
 }
 INTERNAL_DEPENDENCY_FEATURE_EXCEPTIONS = {
-    (
-        "codex-rs/cloud-tasks/Cargo.toml",
-        "dependencies",
-        "codex-cloud-tasks-client",
-    ): ("mock", "online"),
     (
         "codex-rs/core/Cargo.toml",
         "dev-dependencies",
diff --git a/codex-rs/Cargo.lock b/codex-rs/Cargo.lock
index 967b020d1..4eb2c3e5f 100644
--- a/codex-rs/Cargo.lock
+++ b/codex-rs/Cargo.lock
@@ -1721,6 +1721,7 @@ dependencies = [
  "clap",
  "codex-client",
  "codex-cloud-tasks-client",
+ "codex-cloud-tasks-mock-client",
  "codex-core",
  "codex-git-utils",
  "codex-login",
@@ -1750,12 +1751,21 @@ dependencies = [
  "chrono",
  "codex-backend-client",
  "codex-git-utils",
- "diffy",
  "serde",
  "serde_json",
  "thiserror 2.0.18",
 ]
 
+[[package]]
+name = "codex-cloud-tasks-mock-client"
+version = "0.0.0"
+dependencies = [
+ "async-trait",
+ "chrono",
+ "codex-cloud-tasks-client",
+ "diffy",
+]
+
 [[package]]
 name = "codex-code-mode"
 version = "0.0.0"
diff --git a/codex-rs/Cargo.toml b/codex-rs/Cargo.toml
index d5a4baa4d..7fc120031 100644
--- a/codex-rs/Cargo.toml
+++ b/codex-rs/Cargo.toml
@@ -18,6 +18,7 @@ members = [
     "cloud-requirements",
     "cloud-tasks",
     "cloud-tasks-client",
+    "cloud-tasks-mock-client",
     "cli",
     "connectors",
     "config",
@@ -96,10 +97,9 @@ license = "Apache-2.0"
 [workspace.dependencies]
 # Internal
 app_test_support = { path = "app-server/tests/common" }
-codex-ansi-escape = { path = "ansi-escape" }
 codex-analytics = { path = "analytics" }
+codex-ansi-escape = { path = "ansi-escape" }
 codex-api = { path = "codex-api" }
-codex-code-mode = { path = "code-mode" }
 codex-app-server = { path = "app-server" }
 codex-app-server-client = { path = "app-server-client" }
 codex-app-server-protocol = { path = "app-server-protocol" }
@@ -112,16 +112,19 @@ codex-chatgpt = { path = "chatgpt" }
 codex-cli = { path = "cli" }
 codex-client = { path = "codex-client" }
 codex-cloud-requirements = { path = "cloud-requirements" }
-codex-connectors = { path = "connectors" }
+codex-cloud-tasks-client = { path = "cloud-tasks-client" }
+codex-cloud-tasks-mock-client = { path = "cloud-tasks-mock-client" }
+codex-code-mode = { path = "code-mode" }
 codex-config = { path = "config" }
+codex-connectors = { path = "connectors" }
 codex-core = { path = "core" }
 codex-core-skills = { path = "core-skills" }
 codex-exec = { path = "exec" }
 codex-exec-server = { path = "exec-server" }
 codex-execpolicy = { path = "execpolicy" }
 codex-experimental-api-macros = { path = "codex-experimental-api-macros" }
-codex-feedback = { path = "feedback" }
 codex-features = { path = "features" }
+codex-feedback = { path = "feedback" }
 codex-file-search = { path = "file-search" }
 codex-git-utils = { path = "git-utils" }
 codex-hooks = { path = "hooks" }
@@ -137,9 +140,9 @@ codex-otel = { path = "otel" }
 codex-plugin = { path = "plugin" }
 codex-process-hardening = { path = "process-hardening" }
 codex-protocol = { path = "protocol" }
-codex-rollout = { path = "rollout" }
 codex-responses-api-proxy = { path = "responses-api-proxy" }
 codex-rmcp-client = { path = "rmcp-client" }
+codex-rollout = { path = "rollout" }
 codex-sandboxing = { path = "sandboxing" }
 codex-secrets = { path = "secrets" }
 codex-shell-command = { path = "shell-command" }
@@ -150,7 +153,6 @@ codex-stdio-to-uds = { path = "stdio-to-uds" }
 codex-terminal-detection = { path = "terminal-detection" }
 codex-tools = { path = "tools" }
 codex-tui = { path = "tui" }
-codex-v8-poc = { path = "v8-poc" }
 codex-utils-absolute-path = { path = "utils/absolute-path" }
 codex-utils-approval-presets = { path = "utils/approval-presets" }
 codex-utils-cache = { path = "utils/cache" }
@@ -171,8 +173,9 @@ codex-utils-rustls-provider = { path = "utils/rustls-provider" }
 codex-utils-sandbox-summary = { path = "utils/sandbox-summary" }
 codex-utils-sleep-inhibitor = { path = "utils/sleep-inhibitor" }
 codex-utils-stream-parser = { path = "utils/stream-parser" }
-codex-utils-template = { path = "utils/template" }
 codex-utils-string = { path = "utils/string" }
+codex-utils-template = { path = "utils/template" }
+codex-v8-poc = { path = "v8-poc" }
 codex-windows-sandbox = { path = "windows-sandbox-rs" }
 core_test_support = { path = "core/tests/common" }
 mcp_test_support = { path = "mcp-server/tests/common" }
@@ -217,12 +220,12 @@ gethostname = "1.1.0"
 globset = "0.4"
 hmac = "0.12.1"
 http = "1.3.1"
+iana-time-zone = "0.1.64"
 icu_decimal = "2.1"
 icu_locale_core = "2.1"
 icu_provider = { version = "2.1", features = ["sync"] }
 ignore = "0.4.23"
 image = { version = "^0.25.9", default-features = false }
-iana-time-zone = "0.1.64"
 include_dir = "0.7.4"
 indexmap = "2.12.0"
 insta = "1.46.3"
@@ -264,7 +267,6 @@ regex-lite = "0.1.8"
 reqwest = "0.12"
 rmcp = { version = "0.15.0", default-features = false }
 runfiles = { git = "https://github.com/dzbarsky/rules_rust", rev = "b56cbaa8465e74127f1ea216f813cd377295ad81" }
-v8 = "=146.4.0"
 rustls = { version = "0.23", default-features = false, features = [
     "ring",
     "std",
@@ -333,6 +335,7 @@ unicode-width = "0.2"
 url = "2"
 urlencoding = "2.1"
 uuid = "1"
+v8 = "=146.4.0"
 vt100 = "0.16.2"
 walkdir = "2.5.0"
 webbrowser = "1.0"
diff --git a/codex-rs/cloud-tasks-client/BUILD.bazel b/codex-rs/cloud-tasks-client/BUILD.bazel
index cbbd47b76..83157266a 100644
--- a/codex-rs/cloud-tasks-client/BUILD.bazel
+++ b/codex-rs/cloud-tasks-client/BUILD.bazel
@@ -3,8 +3,4 @@ load("//:defs.bzl", "codex_rust_crate")
 codex_rust_crate(
     name = "cloud-tasks-client",
     crate_name = "codex_cloud_tasks_client",
-    crate_features = [
-        "mock",
-        "online",
-    ],
 )
diff --git a/codex-rs/cloud-tasks-client/Cargo.toml b/codex-rs/cloud-tasks-client/Cargo.toml
index 6774d46fd..cdfcba47b 100644
--- a/codex-rs/cloud-tasks-client/Cargo.toml
+++ b/codex-rs/cloud-tasks-client/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
-name = "codex-cloud-tasks-client"
-version.workspace = true
 edition.workspace = true
 license.workspace = true
+name = "codex-cloud-tasks-client"
+version.workspace = true
 
 [lib]
 name = "codex_cloud_tasks_client"
@@ -11,18 +11,12 @@ path = "src/lib.rs"
 [lints]
 workspace = true
 
-[features]
-default = ["online"]
-online = ["dep:codex-backend-client"]
-mock = []
-
 [dependencies]
-anyhow = "1"
-async-trait = "0.1"
-chrono = { version = "0.4", features = ["serde"] }
-diffy = "0.4.2"
-serde = { version = "1", features = ["derive"] }
-serde_json = "1"
-thiserror = "2.0.17"
-codex-backend-client = { path = "../backend-client", optional = true }
+anyhow = { workspace = true }
+async-trait = { workspace = true }
+chrono = { workspace = true, features = ["serde"] }
+codex-backend-client = { workspace = true }
 codex-git-utils = { workspace = true }
+serde = { version = "1", features = ["derive"] }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
diff --git a/codex-rs/cloud-tasks-client/src/lib.rs b/codex-rs/cloud-tasks-client/src/lib.rs
index 9519050ba..8ed6469a5 100644
--- a/codex-rs/cloud-tasks-client/src/lib.rs
+++ b/codex-rs/cloud-tasks-client/src/lib.rs
@@ -15,16 +15,5 @@ pub use api::TaskSummary;
 pub use api::TaskText;
 pub use api::TurnAttempt;
 
-#[cfg(feature = "mock")]
-mod mock;
-
-#[cfg(feature = "online")]
 mod http;
-
-#[cfg(feature = "mock")]
-pub use mock::MockClient;
-
-#[cfg(feature = "online")]
 pub use http::HttpClient;
-
-// Reusable apply engine now lives in the shared crate `codex-git-utils`.
diff --git a/codex-rs/cloud-tasks-mock-client/BUILD.bazel b/codex-rs/cloud-tasks-mock-client/BUILD.bazel
new file mode 100644
index 000000000..4d54dab57
--- /dev/null
+++ b/codex-rs/cloud-tasks-mock-client/BUILD.bazel
@@ -0,0 +1,6 @@
+load("//:defs.bzl", "codex_rust_crate")
+
+codex_rust_crate(
+    name = "cloud-tasks-mock-client",
+    crate_name = "codex_cloud_tasks_mock_client",
+)
diff --git a/codex-rs/cloud-tasks-mock-client/Cargo.toml b/codex-rs/cloud-tasks-mock-client/Cargo.toml
new file mode 100644
index 000000000..728292938
--- /dev/null
+++ b/codex-rs/cloud-tasks-mock-client/Cargo.toml
@@ -0,0 +1,19 @@
+
+[package]
+edition.workspace = true
+license.workspace = true
+name = "codex-cloud-tasks-mock-client"
+version.workspace = true
+
+[lib]
+name = "codex_cloud_tasks_mock_client"
+path = "src/lib.rs"
+
+[lints]
+workspace = true
+
+[dependencies]
+async-trait = { workspace = true }
+chrono = { workspace = true }
+codex-cloud-tasks-client = { workspace = true }
+diffy = { workspace = true }
diff --git a/codex-rs/cloud-tasks-mock-client/src/lib.rs b/codex-rs/cloud-tasks-mock-client/src/lib.rs
new file mode 100644
index 000000000..833ea5e1f
--- /dev/null
+++ b/codex-rs/cloud-tasks-mock-client/src/lib.rs
@@ -0,0 +1,3 @@
+mod mock;
+
+pub use mock::MockClient;
diff --git a/codex-rs/cloud-tasks-client/src/mock.rs b/codex-rs/cloud-tasks-mock-client/src/mock.rs
similarity index 88%
rename from codex-rs/cloud-tasks-client/src/mock.rs
rename to codex-rs/cloud-tasks-mock-client/src/mock.rs
index a679f617b..4bde0e93b 100644
--- a/codex-rs/cloud-tasks-client/src/mock.rs
+++ b/codex-rs/cloud-tasks-mock-client/src/mock.rs
@@ -1,15 +1,18 @@
-use crate::ApplyOutcome;
-use crate::AttemptStatus;
-use crate::CloudBackend;
-use crate::CloudTaskError;
-use crate::DiffSummary;
-use crate::Result;
-use crate::TaskId;
-use crate::TaskStatus;
-use crate::TaskSummary;
-use crate::TurnAttempt;
-use crate::api::TaskText;
 use chrono::Utc;
+use codex_cloud_tasks_client::ApplyOutcome;
+use codex_cloud_tasks_client::ApplyStatus;
+use codex_cloud_tasks_client::AttemptStatus;
+use codex_cloud_tasks_client::CloudBackend;
+use codex_cloud_tasks_client::CloudTaskError;
+use codex_cloud_tasks_client::CreatedTask;
+use codex_cloud_tasks_client::DiffSummary;
+use codex_cloud_tasks_client::Result;
+use codex_cloud_tasks_client::TaskId;
+use codex_cloud_tasks_client::TaskListPage;
+use codex_cloud_tasks_client::TaskStatus;
+use codex_cloud_tasks_client::TaskSummary;
+use codex_cloud_tasks_client::TaskText;
+use codex_cloud_tasks_client::TurnAttempt;
 
 #[derive(Clone, Default)]
 pub struct MockClient;
@@ -21,7 +24,7 @@ impl CloudBackend for MockClient {
         _env: Option<&str>,
         _limit: Option<i64>,
         _cursor: Option<&str>,
-    ) -> Result<crate::TaskListPage> {
+    ) -> Result<TaskListPage> {
         // Slightly vary content by env to aid tests that rely on the mock
         let rows = match _env {
             Some("env-A") => vec![("T-2000", "A: First", TaskStatus::Ready)],
@@ -63,7 +66,7 @@ impl CloudBackend for MockClient {
                 attempt_total: Some(if id_str == "T-1000" { 2 } else { 1 }),
             });
         }
-        Ok(crate::TaskListPage {
+        Ok(TaskListPage {
             tasks: out,
             cursor: None,
         })
@@ -104,7 +107,7 @@ impl CloudBackend for MockClient {
     async fn apply_task(&self, id: TaskId, _diff_override: Option<String>) -> Result<ApplyOutcome> {
         Ok(ApplyOutcome {
             applied: true,
-            status: crate::ApplyStatus::Success,
+            status: ApplyStatus::Success,
             message: format!("Applied task {} locally (mock)", id.0),
             skipped_paths: Vec::new(),
             conflict_paths: Vec::new(),
@@ -118,7 +121,7 @@ impl CloudBackend for MockClient {
     ) -> Result<ApplyOutcome> {
         Ok(ApplyOutcome {
             applied: false,
-            status: crate::ApplyStatus::Success,
+            status: ApplyStatus::Success,
             message: format!("Preflight passed for task {} (mock)", id.0),
             skipped_paths: Vec::new(),
             conflict_paths: Vec::new(),
@@ -150,10 +153,10 @@ impl CloudBackend for MockClient {
         git_ref: &str,
         qa_mode: bool,
         best_of_n: usize,
-    ) -> Result<crate::CreatedTask> {
+    ) -> Result<CreatedTask> {
         let _ = (env_id, prompt, git_ref, qa_mode, best_of_n);
         let id = format!("task_local_{}", chrono::Utc::now().timestamp_millis());
-        Ok(crate::CreatedTask { id: TaskId(id) })
+        Ok(CreatedTask { id: TaskId(id) })
     }
 }
 
diff --git a/codex-rs/cloud-tasks/Cargo.toml b/codex-rs/cloud-tasks/Cargo.toml
index 7587b341b..30e8b73a8 100644
--- a/codex-rs/cloud-tasks/Cargo.toml
+++ b/codex-rs/cloud-tasks/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
-name = "codex-cloud-tasks"
-version.workspace = true
 edition.workspace = true
 license.workspace = true
+name = "codex-cloud-tasks"
+version.workspace = true
 
 [lib]
 name = "codex_cloud_tasks"
@@ -16,32 +16,30 @@ anyhow = { workspace = true }
 base64 = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
 clap = { workspace = true, features = ["derive"] }
-codex-cloud-tasks-client = { path = "../cloud-tasks-client", features = [
-    "mock",
-    "online",
-] }
 codex-client = { workspace = true }
-codex-core = { path = "../core" }
+codex-cloud-tasks-client = { workspace = true }
+# TODO: codex-cloud-tasks-mock-client should be in dev-dependencies.
+codex-cloud-tasks-mock-client = { workspace = true }
+codex-core = { workspace = true }
 codex-git-utils = { workspace = true }
 codex-login = { path = "../login" }
 codex-tui = { workspace = true }
 codex-utils-cli = { workspace = true }
 crossterm = { workspace = true, features = ["event-stream"] }
+owo-colors = { workspace = true, features = ["supports-colors"] }
 ratatui = { workspace = true }
 reqwest = { workspace = true, features = ["json"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+supports-color = { workspace = true }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 tokio-stream = { workspace = true }
 tracing = { workspace = true, features = ["log"] }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
 unicode-width = { workspace = true }
-owo-colors = { workspace = true, features = ["supports-colors"] }
-supports-color = { workspace = true }
 
 [dependencies.async-trait]
 workspace = true
 
 [dev-dependencies]
-async-trait = { workspace = true }
 pretty_assertions = { workspace = true }
diff --git a/codex-rs/cloud-tasks/src/lib.rs b/codex-rs/cloud-tasks/src/lib.rs
index f11eca38f..f7698a300 100644
--- a/codex-rs/cloud-tasks/src/lib.rs
+++ b/codex-rs/cloud-tasks/src/lib.rs
@@ -40,6 +40,7 @@ struct BackendContext {
 }
 
 async fn init_backend(user_agent_suffix: &str) -> anyhow::Result<BackendContext> {
+    #[cfg(debug_assertions)]
     let use_mock = matches!(
         std::env::var("CODEX_CLOUD_TASKS_MODE").ok().as_deref(),
         Some("mock") | Some("MOCK")
@@ -49,9 +50,10 @@ async fn init_backend(user_agent_suffix: &str) -> anyhow::Result<BackendContext>
 
     set_user_agent_suffix(user_agent_suffix);
 
+    #[cfg(debug_assertions)]
     if use_mock {
         return Ok(BackendContext {
-            backend: Arc::new(codex_cloud_tasks_client::MockClient),
+            backend: Arc::new(codex_cloud_tasks_mock_client::MockClient),
             base_url,
         });
     }
@@ -2132,10 +2134,10 @@ mod tests {
     use super::*;
     use crate::resolve_git_ref_with_git_info;
     use codex_cloud_tasks_client::DiffSummary;
-    use codex_cloud_tasks_client::MockClient;
     use codex_cloud_tasks_client::TaskId;
     use codex_cloud_tasks_client::TaskStatus;
     use codex_cloud_tasks_client::TaskSummary;
+    use codex_cloud_tasks_mock_client::MockClient;
     use codex_tui::ComposerAction;
     use codex_tui::ComposerInput;
     use crossterm::event::KeyCode;
diff --git a/codex-rs/cloud-tasks/tests/env_filter.rs b/codex-rs/cloud-tasks/tests/env_filter.rs
index 89bd2fc71..716e4f05e 100644
--- a/codex-rs/cloud-tasks/tests/env_filter.rs
+++ b/codex-rs/cloud-tasks/tests/env_filter.rs
@@ -1,5 +1,5 @@
 use codex_cloud_tasks_client::CloudBackend;
-use codex_cloud_tasks_client::MockClient;
+use codex_cloud_tasks_mock_client::MockClient;
 
 #[tokio::test]
 async fn mock_backend_varies_by_env() {