Preserve legacy goal prompt handling

codex-rs/core/src/context/contextual_user_message.rs

@@ -8,6 +8,7 @@ use super::ExtensionContext;
 use super::FragmentRegistration;
 use super::FragmentRegistrationProxy;
 use super::LegacyApplyPatchExecCommandWarning;
+use super::LegacyGoalContext;
 use super::LegacyModelMismatchWarning;
 use super::LegacyUnifiedExecProcessLimitWarning;
 use super::SkillInstructions;
@@ -38,6 +39,8 @@ static LEGACY_UNIFIED_EXEC_PROCESS_LIMIT_WARNING_REGISTRATION: FragmentRegistrat
 static LEGACY_APPLY_PATCH_EXEC_COMMAND_WARNING_REGISTRATION: FragmentRegistrationProxy<
     LegacyApplyPatchExecCommandWarning,
 > = FragmentRegistrationProxy::new();
+static LEGACY_GOAL_CONTEXT_REGISTRATION: FragmentRegistrationProxy<LegacyGoalContext> =
+    FragmentRegistrationProxy::new();
 static LEGACY_MODEL_MISMATCH_WARNING_REGISTRATION: FragmentRegistrationProxy<
     LegacyModelMismatchWarning,
 > = FragmentRegistrationProxy::new();
@@ -53,6 +56,7 @@ static CONTEXTUAL_USER_FRAGMENTS: &[&dyn FragmentRegistration] = &[
     &SUBAGENT_NOTIFICATION_REGISTRATION,
     &LEGACY_UNIFIED_EXEC_PROCESS_LIMIT_WARNING_REGISTRATION,
     &LEGACY_APPLY_PATCH_EXEC_COMMAND_WARNING_REGISTRATION,
+    &LEGACY_GOAL_CONTEXT_REGISTRATION,
     &LEGACY_MODEL_MISMATCH_WARNING_REGISTRATION,
 ];
 

codex-rs/core/src/context/contextual_user_message_tests.rs

@@ -20,6 +20,13 @@ fn detects_extension_context_fragment() {
     }));
 }
 
+#[test]
+fn detects_legacy_goal_context_fragment() {
+    assert!(is_contextual_user_fragment(&ContentItem::InputText {
+        text: "<goal_context>\nlegacy hidden goal prompt\n</goal_context>".to_string(),
+    }));
+}
+
 #[test]
 fn detects_agents_instructions_fragment() {
     assert!(is_contextual_user_fragment(&ContentItem::InputText {

codex-rs/core/src/context/legacy_goal_context.rs

@@ -0,0 +1,26 @@
+use super::ContextualUserFragment;
+
+/// Legacy hidden goal-context fragment.
+///
+/// Goal prompts are now owned by the goal extension and wrapped as extension
+/// context. This keeps older hidden goal prompts from being surfaced as visible
+/// user text when stored conversation history is replayed.
+pub(crate) struct LegacyGoalContext;
+
+impl ContextualUserFragment for LegacyGoalContext {
+    fn role() -> &'static str {
+        "user"
+    }
+
+    fn markers(&self) -> (&'static str, &'static str) {
+        Self::type_markers()
+    }
+
+    fn type_markers() -> (&'static str, &'static str) {
+        ("<goal_context>", "</goal_context>")
+    }
+
+    fn body(&self) -> String {
+        String::new()
+    }
+}

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

@@ -14,6 +14,7 @@ mod guardian_followup_review_reminder;
 mod hook_additional_context;
 mod image_generation_instructions;
 mod legacy_apply_patch_exec_command_warning;
+mod legacy_goal_context;
 mod legacy_model_mismatch_warning;
 mod legacy_unified_exec_process_limit_warning;
 mod model_switch_instructions;
@@ -48,6 +49,7 @@ pub(crate) use guardian_followup_review_reminder::GuardianFollowupReviewReminder
 pub(crate) use hook_additional_context::HookAdditionalContext;
 pub(crate) use image_generation_instructions::ImageGenerationInstructions;
 pub(crate) use legacy_apply_patch_exec_command_warning::LegacyApplyPatchExecCommandWarning;
+pub(crate) use legacy_goal_context::LegacyGoalContext;
 pub(crate) use legacy_model_mismatch_warning::LegacyModelMismatchWarning;
 pub(crate) use legacy_unified_exec_process_limit_warning::LegacyUnifiedExecProcessLimitWarning;
 pub(crate) use model_switch_instructions::ModelSwitchInstructions;