diff --git a/apps/decodex/src/orchestrator/execution.rs b/apps/decodex/src/orchestrator/execution.rs
index 2d05323c..87090fcc 100644
--- a/apps/decodex/src/orchestrator/execution.rs
+++ b/apps/decodex/src/orchestrator/execution.rs
@@ -65,6 +65,13 @@ where
 	run_result: &'a AppServerRunResult,
 }
 
+struct ThreadArchiveCandidate {
+	run_id: String,
+	attempt_number: i64,
+	thread_id: String,
+	sequence_number: i64,
+}
+
 fn execute_issue_run<T>(
 	tracker: &T,
 	project: &ServiceConfig,
@@ -564,7 +571,7 @@ where
 		run.issue_run,
 		run.tracker_tool_bridge,
 	)?;
-	archive_completed_app_server_thread_best_effort(
+	archive_completed_issue_threads_best_effort(
 		run.project,
 		run.state_store,
 		run.issue_run,
@@ -576,22 +583,133 @@ where
 	Ok(run_summary_from_issue_run(run.project.service_id(), run.issue_run))
 }
 
-fn archive_completed_app_server_thread_best_effort(
+fn archive_completed_issue_threads_best_effort(
 	project: &ServiceConfig,
 	state_store: &StateStore,
 	issue_run: &IssueRunPlan,
 	process_env: &AppServerProcessEnv,
 	transport: &str,
 	run_result: &AppServerRunResult,
+) {
+	let candidates =
+		match completed_issue_thread_archive_candidates(state_store, issue_run, run_result) {
+			Ok(candidates) => candidates,
+			Err(error) => {
+				tracing::warn!(
+					?error,
+					project_id = project.service_id(),
+					issue_id = issue_run.issue.id,
+					issue = issue_run.issue.identifier,
+					run_id = issue_run.run_id,
+					attempt = issue_run.attempt_number,
+					thread_id = %run_result.thread_id,
+					"Failed to list completed issue threads for archive; archiving current thread only."
+				);
+
+				vec![ThreadArchiveCandidate {
+					run_id: issue_run.run_id.clone(),
+					attempt_number: issue_run.attempt_number,
+					thread_id: run_result.thread_id.clone(),
+					sequence_number: run_result.event_count.saturating_add(1),
+				}]
+			},
+		};
+
+	for candidate in candidates {
+		archive_completed_issue_thread_best_effort(
+			project,
+			state_store,
+			issue_run,
+			process_env,
+			transport,
+			&candidate,
+		);
+	}
+}
+
+fn completed_issue_thread_archive_candidates(
+	state_store: &StateStore,
+	issue_run: &IssueRunPlan,
+	run_result: &AppServerRunResult,
+) -> Result<Vec<ThreadArchiveCandidate>> {
+	let mut seen_thread_ids = HashSet::new();
+	let mut candidates = Vec::new();
+
+	push_thread_archive_candidate(
+		state_store,
+		&mut candidates,
+		&mut seen_thread_ids,
+		&issue_run.run_id,
+		issue_run.attempt_number,
+		&run_result.thread_id,
+	)?;
+
+	for attempt in state_store.list_run_attempts_for_issue(&issue_run.issue.id)? {
+		if attempt.run_id() == issue_run.run_id
+			|| !completed_issue_archive_attempt_status(attempt.status())
+		{
+			continue;
+		}
+
+		if let Some(thread_id) = attempt.thread_id() {
+			push_thread_archive_candidate(
+				state_store,
+				&mut candidates,
+				&mut seen_thread_ids,
+				attempt.run_id(),
+				attempt.attempt_number(),
+				thread_id,
+			)?;
+		}
+	}
+
+	Ok(candidates)
+}
+
+fn completed_issue_archive_attempt_status(status: &str) -> bool {
+	matches!(status, "succeeded" | "failed" | "interrupted" | TERMINAL_GUARDED_RUN_STATUS)
+}
+
+fn push_thread_archive_candidate(
+	state_store: &StateStore,
+	candidates: &mut Vec<ThreadArchiveCandidate>,
+	seen_thread_ids: &mut HashSet<String>,
+	run_id: &str,
+	attempt_number: i64,
+	thread_id: &str,
+) -> Result<()> {
+	if !seen_thread_ids.insert(thread_id.to_owned())
+		|| state_store.run_has_protocol_event(run_id, "thread/archive")?
+	{
+		return Ok(());
+	}
+
+	candidates.push(ThreadArchiveCandidate {
+		run_id: run_id.to_owned(),
+		attempt_number,
+		thread_id: thread_id.to_owned(),
+		sequence_number: state_store.event_count(run_id)?.saturating_add(1),
+	});
+
+	Ok(())
+}
+
+fn archive_completed_issue_thread_best_effort(
+	project: &ServiceConfig,
+	state_store: &StateStore,
+	issue_run: &IssueRunPlan,
+	process_env: &AppServerProcessEnv,
+	transport: &str,
+	candidate: &ThreadArchiveCandidate,
 ) {
 	let archive_request = AppServerThreadArchiveRequest {
-		run_id: &issue_run.run_id,
+		run_id: &candidate.run_id,
 		issue_id: &issue_run.issue.id,
-		attempt_number: issue_run.attempt_number,
+		attempt_number: candidate.attempt_number,
 		listen: transport,
 		process_env,
-		thread_id: &run_result.thread_id,
-		sequence_number: run_result.event_count.saturating_add(1),
+		thread_id: &candidate.thread_id,
+		sequence_number: candidate.sequence_number,
 	};
 
 	match agent::archive_app_server_thread_after_success(&archive_request, state_store) {
@@ -599,20 +717,20 @@ fn archive_completed_app_server_thread_best_effort(
 			project_id = project.service_id(),
 			issue_id = issue_run.issue.id,
 			issue = issue_run.issue.identifier,
-			run_id = issue_run.run_id,
-			attempt = issue_run.attempt_number,
-			thread_id = %run_result.thread_id,
-			"Archived completed app-server thread."
+			run_id = candidate.run_id,
+			attempt = candidate.attempt_number,
+			thread_id = %candidate.thread_id,
+			"Archived completed issue app-server thread."
 		),
 		Err(error) => tracing::warn!(
 			?error,
 			project_id = project.service_id(),
 			issue_id = issue_run.issue.id,
 			issue = issue_run.issue.identifier,
-			run_id = issue_run.run_id,
-			attempt = issue_run.attempt_number,
-			thread_id = %run_result.thread_id,
-			"Failed to archive completed app-server thread; leaving completed run intact."
+			run_id = candidate.run_id,
+			attempt = candidate.attempt_number,
+			thread_id = %candidate.thread_id,
+			"Failed to archive completed issue app-server thread; leaving completed run intact."
 		),
 	}
 }
diff --git a/apps/decodex/src/orchestrator/tests.rs b/apps/decodex/src/orchestrator/tests.rs
index 20189322..bd5380f0 100644
--- a/apps/decodex/src/orchestrator/tests.rs
+++ b/apps/decodex/src/orchestrator/tests.rs
@@ -71,6 +71,8 @@ include!("tests/runtime/repo_gate.rs");
 
 include!("tests/runtime/failure.rs");
 
+include!("tests/runtime/thread_archive.rs");
+
 include!("tests/recovery/reconciliation.rs");
 
 include!("tests/recovery/terminal_support.rs");
diff --git a/apps/decodex/src/orchestrator/tests/runtime/thread_archive.rs b/apps/decodex/src/orchestrator/tests/runtime/thread_archive.rs
new file mode 100644
index 00000000..77cd39e8
--- /dev/null
+++ b/apps/decodex/src/orchestrator/tests/runtime/thread_archive.rs
@@ -0,0 +1,75 @@
+use crate::agent::AppServerRunResult;
+
+#[test]
+fn completed_issue_thread_archive_candidates_include_prior_terminal_attempts() {
+	let temp_dir = TempDir::new().expect("tempdir should create");
+	let state_store = StateStore::open_in_memory().expect("state store should open");
+	let issue = sample_issue("In Progress", &[]);
+
+	state_store
+		.record_run_attempt("run-old", &issue.id, 1, "failed")
+		.expect("old attempt should record");
+	state_store.update_run_thread("run-old", "thread-old").expect("old thread should attach");
+	state_store
+		.append_event("run-old", 1, "turn/completed", "{}")
+		.expect("old event should record");
+	state_store
+		.record_run_attempt("run-current", &issue.id, 2, "succeeded")
+		.expect("current attempt should record");
+	state_store
+		.update_run_thread("run-current", "thread-current")
+		.expect("current thread should attach");
+	state_store
+		.append_event("run-current", 1, "turn/completed", "{}")
+		.expect("current event should record");
+	state_store
+		.record_run_attempt("run-active", &issue.id, 3, "running")
+		.expect("active attempt should record");
+	state_store.update_run_thread("run-active", "thread-active").expect("active thread should attach");
+	state_store
+		.record_run_attempt("run-archived", &issue.id, 4, TERMINAL_GUARDED_RUN_STATUS)
+		.expect("archived attempt should record");
+	state_store
+		.update_run_thread("run-archived", "thread-archived")
+		.expect("archived thread should attach");
+	state_store
+		.append_event("run-archived", 1, "thread/archive", "{}")
+		.expect("archive event should record");
+
+	let issue_run = IssueRunPlan {
+		issue,
+		issue_state: String::from("In Progress"),
+		initial_issue_state: String::from("Todo"),
+		worktree: WorktreeSpec {
+			branch_name: String::from("xy/test"),
+			issue_identifier: String::from("PUB-101"),
+			path: temp_dir.path().join("PUB-101"),
+			reused_existing: false,
+		},
+		retry_project_slug: String::from("pubfi"),
+		dispatch_mode: IssueDispatchMode::Normal,
+		attempt_number: 2,
+			run_id: String::from("run-current"),
+			retry_budget_base: 0,
+		};
+	let run_result = AppServerRunResult {
+		user_agent: String::from("codex-test"),
+		thread_id: String::from("thread-current"),
+		turn_id: String::from("turn-current"),
+		turn_count: 1,
+		event_count: 1,
+		final_output: String::new(),
+		continuation_pending: false,
+	};
+	let candidates =
+		super::completed_issue_thread_archive_candidates(&state_store, &issue_run, &run_result)
+			.expect("archive candidates should load");
+	let candidate_threads = candidates
+		.iter()
+		.map(|candidate| candidate.thread_id.as_str())
+		.collect::<Vec<_>>();
+
+	assert_eq!(candidate_threads, vec!["thread-current", "thread-old"]);
+	assert_eq!(candidates[0].sequence_number, 2);
+	assert_eq!(candidates[1].sequence_number, 2);
+}
diff --git a/apps/decodex/src/state/store.rs b/apps/decodex/src/state/store.rs
index 94294161..1f1cb7ba 100644
--- a/apps/decodex/src/state/store.rs
+++ b/apps/decodex/src/state/store.rs
@@ -826,6 +826,34 @@ impl StateStore {
 		Ok(attempt)
 	}
 
+	/// List all locally recorded run attempts for one issue.
+	pub fn list_run_attempts_for_issue(&self, issue_id: &str) -> Result<Vec<RunAttempt>> {
+		let state = self.lock()?;
+		let mut attempts = state
+			.run_attempts
+			.values()
+			.filter(|attempt| attempt.issue_id == issue_id)
+			.map(RunAttemptRecord::as_public)
+			.collect::<Vec<_>>();
+
+		attempts.sort_by(|left, right| {
+			left.attempt_number()
+				.cmp(&right.attempt_number())
+				.then_with(|| left.run_id().cmp(right.run_id()))
+		});
+
+		Ok(attempts)
+	}
+
+	/// Return whether one run already has a matching protocol event.
+	pub fn run_has_protocol_event(&self, run_id: &str, event_type: &str) -> Result<bool> {
+		let state = self.lock()?;
+
+		Ok(state.events.get(run_id).is_some_and(|events| {
+			events.iter().any(|event| event.event_type == event_type)
+		}))
+	}
+
 	/// List recent run attempts for one project, including lease and protocol summary fields.
 	pub fn list_recent_runs(
 		&self,
diff --git a/apps/decodex/src/state/tests.rs b/apps/decodex/src/state/tests.rs
index bd2ebeef..89869786 100644
--- a/apps/decodex/src/state/tests.rs
+++ b/apps/decodex/src/state/tests.rs
@@ -1026,6 +1026,38 @@ fn records_run_attempts_and_events() {
 	);
 }
 
+#[test]
+fn lists_issue_attempts_and_protocol_event_presence() {
+	let store = StateStore::open_in_memory().expect("in-memory state store should open");
+
+	store
+		.record_run_attempt("run-2", "PUB-101", 2, "succeeded")
+		.expect("second run attempt should record");
+	store
+		.record_run_attempt("run-1", "PUB-101", 1, "failed")
+		.expect("first run attempt should record");
+	store
+		.record_run_attempt("run-other", "PUB-102", 1, "succeeded")
+		.expect("other issue run attempt should record");
+	store.update_run_thread("run-1", "thread-1").expect("first thread should attach");
+	store.update_run_thread("run-2", "thread-2").expect("second thread should attach");
+	store.append_event("run-1", 1, "thread/archive", "{}").expect("archive event should record");
+
+	let attempts =
+		store.list_run_attempts_for_issue("PUB-101").expect("issue attempts should load");
+
+	assert_eq!(attempts.len(), 2);
+	assert_eq!(attempts[0].run_id(), "run-1");
+	assert_eq!(attempts[0].thread_id(), Some("thread-1"));
+	assert_eq!(attempts[1].run_id(), "run-2");
+	assert!(store.run_has_protocol_event("run-1", "thread/archive").expect("event should load"));
+	assert!(
+		!store
+			.run_has_protocol_event("run-2", "thread/archive")
+			.expect("missing event should load")
+	);
+}
+
 #[test]
 fn run_activity_marker_round_trips_marker_surfaces() {
 	assert_run_activity_marker_round_trips_clearable_auxiliary_fields();
diff --git a/docs/spec/app-server.md b/docs/spec/app-server.md
index 934420d0..cea3d063 100644
--- a/docs/spec/app-server.md
+++ b/docs/spec/app-server.md
@@ -65,6 +65,9 @@ codex app-server generate-json-schema --experimental --out target/decodex-app-se
   - `thread/start`
   - `thread/resume` when retrying a persisted same-thread continuation
   - `turn/start`
+  - `thread/archive` after successful completion writeback, for every locally
+    recorded terminal attempt thread on the issue that has not already recorded a
+    successful archive event
 - Required notifications for the MVP:
   - `thread/started`
   - `thread/status/changed`
@@ -98,6 +101,9 @@ unless an existing lifecycle event summarizes them.
 7. Consume notifications until that turn reaches a terminal outcome.
 8. If the project-owned continuation policy allows another same-thread turn, send another `turn/start` on the same thread.
 9. Persist the local run journal and classify the bounded run result.
+10. After successful completion writeback, best-effort archive all locally recorded
+    terminal attempt threads for the issue so prior failed retry attempts do not keep
+    the Codex conversation list visible.
 
 The capability preflight is observational. It may inspect the effective app-server
 config, model inventory, provider capabilities, skill inventory, plugin inventory,
diff --git a/docs/spec/runtime.md b/docs/spec/runtime.md
index bf5ce569..5e7ac9c3 100644
--- a/docs/spec/runtime.md
+++ b/docs/spec/runtime.md
@@ -220,6 +220,7 @@ If the label is recorded without the required explanatory comment, `decodex` mus
 If the resolved terminal path is not explicitly finalized through `issue_terminal_finalize`, the app-server wrapper must fail the turn before `decodex` records the attempt as successful.
 The explanatory public summary for `manual_attention` must describe the exact observed blocker and should include the failed command plus raw error text only when those values are public-safe, instead of speculating about unverified capability limits.
 Execution-state checkpoints are durable progress overlays only. Their phase, focus, next action, blockers, evidence, or verification fields are never a substitute for the explicit terminal-finalization call.
+After successful completion writeback, Decodex must best-effort archive every locally recorded terminal Codex thread for the issue, including earlier failed retry attempts, so old attempts do not keep the issue visible in the Codex conversation list.
 
 ### Progress checkpoint writeback