diff --git a/crates/nebula-core/src/harness.rs b/crates/nebula-core/src/harness.rs
index 9b7006ad..5b4b2175 100644
--- a/crates/nebula-core/src/harness.rs
+++ b/crates/nebula-core/src/harness.rs
@@ -160,6 +160,9 @@ pub struct HarnessDescriptor {
     pub label: String,
     /// The CLI nebula launches, resolved on PATH through the login shell.
     pub program: String,
+    /// Arguments before any resume subcommand or per-session options.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub launch_args: Vec<String>,
     /// Whether the picker and presets offer this harness.
     #[serde(default = "default_enabled")]
     pub enabled: bool,
@@ -373,6 +376,7 @@ pub fn builtin(id: &str) -> Option<HarnessDescriptor> {
         id: id.trim().to_string(),
         label: String::new(),
         program: String::new(),
+        launch_args: Vec::new(),
         enabled: true,
         model: ModelSpec::default(),
         effort: EffortSpec::default(),
@@ -419,6 +423,9 @@ pub fn builtin(id: &str) -> Option<HarnessDescriptor> {
         "codex" => HarnessDescriptor {
             label: "Codex".into(),
             program: "codex".into(),
+            // Hooks and tool shells must inherit this PTY's NEBULA_*
+            // environment, not a shared server's startup environment.
+            launch_args: vec!["--no-daemon".into()],
             model: ModelSpec {
                 flag: Some("--model".into()),
                 default: default_model_choice(),
@@ -669,6 +676,8 @@ pub struct HarnessOverride {
     pub effort_offered: Option<bool>,
     #[serde(default, skip_serializing_if = "Clearable::is_keep")]
     pub permissions_flag: Clearable<String>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub launch_args: Option<Vec<String>>,
     #[serde(default, skip_serializing_if = "Clearable::is_keep")]
     pub prompt_flag: Clearable<String>,
     #[serde(default, skip_serializing_if = "Clearable::is_keep")]
@@ -727,6 +736,9 @@ impl HarnessDescriptor {
             self.effort.offered = offered;
         }
         over.permissions_flag.apply_to(&mut self.permissions_flag);
+        if let Some(args) = &over.launch_args {
+            self.launch_args = args.clone();
+        }
         over.prompt_flag.apply_to(&mut self.prompt_flag);
         over.resume_flag.apply_to(&mut self.resume.flag);
         over.resume_subcommand.apply_to(&mut self.resume.subcommand);
@@ -812,6 +824,7 @@ impl CustomHarness {
             id: self.id.clone(),
             label: self.label.clone(),
             program: self.program.clone(),
+            launch_args: Vec::new(),
             enabled: self.enabled,
             model: ModelSpec {
                 flag: Some(self.model_flag.clone()),
@@ -897,6 +910,7 @@ pub fn registry(
             id: id.clone(),
             label: String::new(),
             program: String::new(),
+            launch_args: Vec::new(),
             enabled: true,
             model: ModelSpec::default(),
             effort: EffortSpec::default(),
@@ -996,6 +1010,7 @@ mod tests {
         assert_eq!(claude.resume.flag.as_deref(), Some("--resume"));
         assert!(claude.relocation_prompt);
         let codex = builtin("codex").unwrap();
+        assert_eq!(codex.launch_args, ["--no-daemon"]);
         assert_eq!(codex.model.catalog, Some(HarnessCatalog::Codex));
         assert_eq!(HarnessCatalog::parse("codex"), Some(HarnessCatalog::Codex));
         assert_eq!(HarnessCatalog::Codex.as_str(), "codex");
@@ -1028,6 +1043,31 @@ mod tests {
         assert!(!opencode.claude_like());
     }
 
+    #[test]
+    fn launch_args_follow_registry_overrides_and_can_be_cleared() {
+        let mut codex = builtin("codex").unwrap();
+        codex.apply(&HarnessOverride::default());
+        assert_eq!(codex.launch_args, ["--no-daemon"]);
+        let over: HarnessOverride = serde_json::from_value(serde_json::json!({
+            "launch_args": ["--no-daemon", "--no-alt-screen"]
+        }))
+        .unwrap();
+        codex.apply(&over);
+        assert_eq!(codex.launch_args, ["--no-daemon", "--no-alt-screen"]);
+        let encoded = serde_json::to_value(&over).unwrap();
+        assert_eq!(encoded["launch_args"], serde_json::json!(codex.launch_args));
+        let clear: HarnessOverride = serde_json::from_value(serde_json::json!({
+            "launch_args": []
+        }))
+        .unwrap();
+        codex.apply(&clear);
+        assert!(codex.launch_args.is_empty());
+        // Speaking Codex's hooks alone does not promise its CLI flags.
+        let mut custom = custom("wrapper");
+        custom.hooks = Some("codex".into());
+        assert!(custom.as_descriptor().launch_args.is_empty());
+    }
+
     #[test]
     fn overrides_apply_field_by_field_with_null_clearing() {
         let over: HarnessOverride = serde_json::from_value(serde_json::json!({
diff --git a/crates/nebula-daemon/src/registry.rs b/crates/nebula-daemon/src/registry.rs
index 8fdb7651..c8a4fb10 100644
--- a/crates/nebula-daemon/src/registry.rs
+++ b/crates/nebula-daemon/src/registry.rs
@@ -552,6 +552,10 @@ fn agent_spawn_command_with(
         }
         _ => (Vec::new(), false),
     };
+    // Global launch options precede subcommands too: Codex's --no-daemon
+    // keeps hooks and tools in this session's NEBULA_* environment on
+    // fresh starts, resumes, restarts and worktree relocations alike.
+    args.splice(0..0, harness.launch_args.iter().cloned());
     if let Some(flag) = harness.permissions_flag.as_deref() {
         args.push(flag.to_string());
     }
@@ -1028,6 +1032,41 @@ mod tests {
         assert_eq!(claude_transcript_exists(&[missing], "sid-1"), None);
     }
 
+    #[test]
+    fn codex_sessions_keep_the_nebula_environment_on_cold_launch_and_resume() {
+        let all = test_registry();
+        let codex = test_harness(&all, AgentKind::Codex);
+        // The shared Codex server can predate this PTY and has none of its
+        // NEBULA_* variables. Both hooks and `nebula rename` need this
+        // invocation's environment, including when no model/effort override
+        // happens to force Codex into embedded mode on its own.
+        for sid in [None, Some("sid")] {
+            for prompt in [None, Some("fix the login redirect")] {
+                let (_, args, resumed) = agent_spawn_command_with(
+                    &codex,
+                    sid,
+                    Some(Path::new(TEST_CWD)),
+                    None,
+                    None,
+                    None,
+                    prompt,
+                    None,
+                    true,
+                );
+                assert_eq!(resumed, sid.is_some());
+                assert_eq!(args.first().map(String::as_str), Some("--no-daemon"));
+                if let Some(prompt) = prompt {
+                    assert_eq!(args.last().map(String::as_str), Some(prompt));
+                }
+            }
+        }
+        // A test stand-in is a complete command, never a Codex invocation.
+        assert_eq!(
+            agent_spawn_command(AgentKind::Codex, None, None, None, Some("/bin/cat")),
+            ("/bin/cat".into(), Vec::new(), false)
+        );
+    }
+
     #[test]
     fn spawn_command_per_kind_resume_shapes() {
         // Fresh sessions: bare CLI (Claude plus its system-prompt guidance).
@@ -1042,7 +1081,11 @@ mod tests {
         // Codex/cursor always run in skip-permissions mode.
         assert_eq!(
             agent_spawn_command(AgentKind::Codex, None, None, None, None),
-            ("codex".into(), vec!["--yolo".to_string()], false)
+            (
+                "codex".into(),
+                vec!["--no-daemon".to_string(), "--yolo".to_string()],
+                false
+            )
         );
         // Cursor's agent CLI is `cursor-agent`, not `cursor` (the editor).
         assert_eq!(
@@ -1108,6 +1151,7 @@ mod tests {
             (
                 "codex".into(),
                 vec![
+                    "--no-daemon".to_string(),
                     "resume".to_string(),
                     "sid-2".to_string(),
                     "--cd".to_string(),
@@ -1174,6 +1218,7 @@ mod tests {
             (
                 "codex".into(),
                 vec![
+                    "--no-daemon".to_string(),
                     "--yolo".to_string(),
                     "--model".to_string(),
                     "gpt-5.5".to_string(),
@@ -1590,7 +1635,15 @@ mod tests {
                 true,
             )
             .1,
-            vec!["resume", "sid", "--cd", TEST_CWD, "--yolo", "carry on"]
+            vec![
+                "--no-daemon",
+                "resume",
+                "sid",
+                "--cd",
+                TEST_CWD,
+                "--yolo",
+                "carry on"
+            ]
         );
         assert_eq!(
             agent_spawn_command_with(
@@ -1643,6 +1696,7 @@ mod tests {
             )
             .1,
             vec![
+                "--no-daemon",
                 "--yolo",
                 "--model",
                 "gpt-5.5",
@@ -1797,6 +1851,7 @@ mod tests {
         assert_eq!(
             args,
             vec![
+                "--no-daemon",
                 "resume",
                 "sid",
                 "--cd",
diff --git a/docs/configuration.md b/docs/configuration.md
index f6bbe41e..0e7cc461 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -180,6 +180,15 @@ including ones a later nebula adds. Like every other object key, a `harnesses` m
 `config.local.json` replaces the whole map from `config.json` rather than merging per harness,
 so keep machine-specific overrides in one layer.
 
+`launch_args` is an array of arguments placed before resume subcommands and session options.
+Codex defaults to `["--no-daemon"]`: its hooks and tool shells need the current session's
+`NEBULA_*` environment for status updates and automatic naming. A shared Codex background server
+keeps its own startup environment, which can belong to another session or have no Nebula context.
+Other harnesses default to `[]`; Codex-compatible wrappers can opt in explicitly. Setting
+`"codex": {"launch_args": []}` removes the flag for older CLIs, with the risk of missing or
+misdirected hooks when a shared server is used. Hook trust review still applies; Nebula does not
+bypass it.
+
 Grok Build is enabled by default and launches `grok`. Its Enabled toggle is stored under
 `harnesses.grok.enabled`. Set `harnesses.grok.model_default` and `effort_default` in config.json
 to pass `--model` and `--reasoning-effort`; unset values use the CLI defaults. The picker offers