feat(mcp,orchestrator,frontend): tool idea_restart_self, redemarrage autonome d'un agent — #288 (tool core self-only via requester MCP handshake, retour immediat {restartId, status: scheduled} puis orchestration detachee: snapshot reprise, stop PTY/structured, liberation Busy/mailbox, relance LaunchAgent meme conversation_id fresh_start=false, injection interne invisible; events domain/wire agentRestartRequested/PhaseChanged/Completed/Failed phases stopping/releasingInput/launching/resuming; CLI custom: separateurs exacts redemarrage de l'agent + etat termine/echoue, deduplication (restartId, event), verrouillage composer; TUI native: overlay AgentRestartOverlay sans injection xterm, progress/annonces projetes jusqu'a idle; QA verte: mcp_server restart_self 1/1, restart-self 3/3, backend self_restart_contract + events wire 2/2, frontend 3 suites 92/92, npm build, cargo check --workspace, fmt --check, diff --check; reserves hors perimetre: web-server 103/110 fixture PTY preexistante, 34 echecs npm test globaux listProjectSettings/web hors #288; scripts/ hors perimetre)

.ideai/tickets/288/carnet.md

@@ -1,8 +1,8 @@
 ---
 issueRef: "#288"
-version: 2
+version: 5
-updatedBy: {"kind":"agent","agent_id":"a6c6ea12-bfc6-4bdc-8031-324102dfa34d"}
+updatedBy: {"kind":"agent","agent_id":"qa"}
-updatedAt: 1788895080146
+updatedAt: 1788897533882
 ---
 #288 — Tool MCP de redemarrage autonome d'un agent
 
@@ -22,5 +22,46 @@ Ajouter un tool MCP permettant a un agent de demander son propre redemarrage apr
 - Invariant: liberer Busy/mailbox meme si la connexion MCP disparait quand l'agent est tue.
 - Memoire durable ajoutee: `ticket288-agent-self-restart-architecture`.
 
+## DevBackend — livre
+- Tool MCP `idea_restart_self({ reason? })` implemente.
+- Identite issue du requester MCP; requester absent/malformed/non live refuse; restart concurrent refuse.
+- Retour immediat `scheduled` puis orchestration detachee avec delai de flush avant arret du bridge.
+- Snapshot node/conversation/dimensions/mode structure; stop PTY/structured; nettoyage mailbox/Busy; relance via LaunchAgent avec meme conversation_id et fresh_start=false; injection interne invisible.
+- Events frontend exposes sur `domain://event`: `agentRestartRequested`, `agentRestartPhaseChanged`, `agentRestartCompleted`, `agentRestartFailed`; phases `stopping`, `releasingInput`, `launching`, `resuming`.
+- Fichiers touches annonces: `crates/domain/src/{events,orchestrator}.rs`, `crates/application/src/{lib,orchestrator/mod,orchestrator/service}.rs`, `crates/infrastructure/src/orchestrator/mcp/tools.rs`, `crates/infrastructure/tests/mcp_server.rs`, `crates/backend/src/{lib,events}.rs`, `crates/app-tauri/src/commands.rs`, `crates/web-server/src/lib.rs`.
+- Validations DevBackend: domaine orchestrateur 45/45, mapping MCP 27/27, serveur MCP 41/41, orchestrateur applicatif 81/81, backend 87 passants + 7 socket ignores, app-tauri 82 passants + 1 socket ignore, `cargo check --workspace`, `cargo fmt --check`, `git diff --check` verts.
+- Reserve: web-server 103/110 en serie; 7 echecs preexistants/fixture PTY `error` au lieu de `terminal.attached`, hors #288 selon DevBackend; un lancement parallele a aussi touche `EMFILE`.
+
 ## Etat
-Ticket cree et passe inProgress par Main. En attente branche Git puis implementation DevBackend/DevFrontend et validation QA.
+Backend et frontend livres. En attente validation QA.
+
+## DevFrontend — livre
+- Ajout des quatre events de restart au `DomainEvent` frontend et de la phase typee.
+- Projection ephemere partagee dans le provider projet, conservee a travers le demontage/remontage de la cellule pendant la relance.
+- CLI custom: separateurs UX exacts requested/completed/failed, message d'echec court, deduplication par `(restartId, event type)` et verrouillage du composer durant le cycle.
+- TUI native: overlay prioritaire sans injection de separateur dans xterm, libelles de phase exacts et annonces/progress conserves jusqu'au signal idle. L'ordre `busy:false` puis `completed` du runtime structure est traite sans overlay bloque.
+- Aucun ajout au transcript: les marqueurs restent un etat de presentation frontend; le prompt interne de reprise n'est pas consomme ni projete par le frontend.
+- Tests: provider/overlay (phases, reprise, idle, echec), CLI custom (separateurs, deduplication, echec), integration LayoutGrid (priorite du voile et absence de separateur TUI).
+- Validations: `npm run test -- --run src/features/announcements/AnnouncementsProvider.test.tsx src/features/agents/CustomAgentChatView.test.tsx src/features/layout/LayoutGrid.cellControlsLayering.test.tsx` -> 92/92; `npm run build` -> OK; `git diff --check` -> OK.
+- Reserve validation globale: `npm test` termine avec 34 echecs hors fichiers #288 (notamment suites web en timeout et tests agents lies au gateway plugin `listProjectSettings` du chantier deja present); les 3 suites ciblees #288 restent vertes.
+
+## QA — validation independante
+
+Verdict: VERT pour #288 sur `feature/288-agent-self-restart-mcp`, avec reserves hors perimetre confirmees.
+
+Commandes executees depuis `/home/anthony/Documents/Projects/IdeA`:
+- `git status --short --branch` -> branche `feature/288-agent-self-restart-mcp`, changements non committes dans le perimetre #288 + metadata ticket.
+- `cargo test -p infrastructure --test mcp_server restart_self` -> 1/1 passant.
+- `cargo test -p infrastructure restart_self` -> 3 tests restart-self passants: mapping/catalogue self-only, requester absent/malforme rejete, payload scheduled via handshake.
+- `cargo test -p backend self_restart_contract_tests` -> 1/1 passant; relance conserve `conversation_id` et `fresh_start=false`.
+- `cargo test -p backend agent_restart_events_expose_stable_camel_case_contract` -> 1/1 passant; events/phases wire `agentRestartPhaseChanged`, `agentRestartFailed`, `releasingInput`, `launching`.
+- `npm run test -- --run src/features/announcements/AnnouncementsProvider.test.tsx src/features/agents/CustomAgentChatView.test.tsx src/features/layout/LayoutGrid.cellControlsLayering.test.tsx` depuis `frontend` -> 3 fichiers / 92 tests passants.
+- `npm run build` depuis `frontend` -> OK.
+- `cargo check --workspace` -> OK.
+- `cargo fmt --check` -> OK.
+- `git diff --check` -> OK.
+
+Reserves verifiees:
+- `cargo test -p web-server` en parallele a echoue avec EMFILE (`Too many open files`) sur 38 tests; ce run n'est pas probant pour #288.
+- `cargo test -p web-server -- --test-threads=1` reproduit la reserve stable: 103/110, 7 echecs WebSocket/PTY `left: "error" right: "terminal.attached"`; aucun test restart/self-restart dans la liste.
+- `npm test` depuis `frontend` reproduit 34 echecs globaux hors fichiers #288: `agents.test.tsx` (`listProjectSettings` absent dans le mock), `ProjectsView.ls7.test.tsx`, `WebAgentCell.test.tsx`, `WebApp.test.tsx`, `WebDesktopWorkspace.test.tsx`, `WebMenus.test.tsx`, `WebTicketsSprints.test.tsx`. Les suites #288 ciblees restent vertes.

.ideai/tickets/288/issue.md

@@ -2,7 +2,7 @@
 id: "3d6c1342-58cc-4bc8-bed5-a176f155b9ef"
 number: 288
 title: "Tool MCP de redémarrage autonome d'un agent"
-status: "inProgress"
+status: "qa"
 priority: "high"
 sprint: null
 links: []
@@ -11,7 +11,7 @@ attachments: []
 createdBy: {"kind":"agent","agent_id":"a6c6ea12-bfc6-4bdc-8031-324102dfa34d"}
 updatedBy: {"kind":"agent","agent_id":"a6c6ea12-bfc6-4bdc-8031-324102dfa34d"}
 createdAt: 1788894923196
-updatedAt: 1788895080146
+updatedAt: 1788897287730
-version: 2
+version: 4
 ---
 Ajouter un outil MCP permettant à un agent de demander son propre redémarrage pour récupérer de nouvelles capacités (ex. plugin ajouté). Comportement attendu : IdeA arrête l'agent demandeur, le relance, lui injecte le contexte/handoff nécessaire pour reprendre son travail, masque le message interne de reprise, affiche dans la CLI custom des séparateurs de redémarrage puis les progress à la suite, et pour la TUI native affiche un overlay pendant le redémarrage puis y projette les progress jusqu'à fin de travail.

.ideai/tickets/index.json

@@ -3940,7 +3940,7 @@
       "issueRef": "#288",
       "path": "288",
       "title": "Tool MCP de redémarrage autonome d'un agent",
-      "status": "inProgress",
+      "status": "qa",
       "priority": "high",
       "sprint": null,
       "assignedAgentIds": [],
@@ -3948,7 +3948,7 @@
         "kind": "agent",
         "agent_id": "a6c6ea12-bfc6-4bdc-8031-324102dfa34d"
       },
-      "updatedAt": 1788895080146
+      "updatedAt": 1788897287730
     }
   ]
 }

crates/app-tauri/src/commands.rs

@@ -2243,6 +2243,12 @@ pub async fn launch_agent(
                 project: resume_project,
                 rows: request.rows,
                 cols: request.cols,
+                node_id,
+                conversation_id: request
+                    .conversation_id
+                    .clone()
+                    .or_else(|| output.assigned_conversation_id.clone()),
+                require_structured: request.cell_kind == Some(CellKind::Chat),
             },
         );
     }

crates/application/src/lib.rs

@@ -165,10 +165,11 @@ pub use model_server::{
 };
 pub use orchestrator::{
     resolve_rendezvous_ceiling, resolve_rendezvous_window, run_inactivity_watchdog,
-    AgentWakeService, AskLivenessProbe, ContextGuardUseCases, LiveStateProvider,
+    AgentRestartScheduled, AgentSelfRestartScheduler, AgentWakeService, AskLivenessProbe,
-    LiveStateReadProvider, McpRuntimeProvider, OrchestratorOutcome, OrchestratorService,
+    ContextGuardUseCases, LiveStateProvider, LiveStateReadProvider, McpRuntimeProvider,
-    ProposeContext, ReadContext, ReadMemory, RecordTurnProvider, WakeSessionProvider,
+    OrchestratorOutcome, OrchestratorService, ProposeContext, ReadContext, ReadMemory,
-    WatchdogOutcome, WriteMemory, DEFAULT_RENDEZVOUS_CEILING, DEFAULT_RENDEZVOUS_WINDOW,
+    RecordTurnProvider, WakeSessionProvider, WatchdogOutcome, WriteMemory,
+    DEFAULT_RENDEZVOUS_CEILING, DEFAULT_RENDEZVOUS_WINDOW,
 };
 pub use permission::{
     GetProjectPermissions, GetProjectPermissionsInput, GetProjectPermissionsOutput,

crates/application/src/orchestrator/mod.rs

@@ -19,7 +19,8 @@ pub use rendezvous::{
     WatchdogOutcome, DEFAULT_RENDEZVOUS_CEILING, DEFAULT_RENDEZVOUS_WINDOW,
 };
 pub use service::{
-    AskLivenessProbe, ContextGuardUseCases, LiveStateProvider, LiveStateReadProvider,
+    AgentRestartScheduled, AgentSelfRestartScheduler, AskLivenessProbe, ContextGuardUseCases,
-    McpRuntimeProvider, OrchestratorOutcome, OrchestratorService, RecordTurnProvider,
+    LiveStateProvider, LiveStateReadProvider, McpRuntimeProvider, OrchestratorOutcome,
+    OrchestratorService, RecordTurnProvider,
 };
 pub use wake::{AgentWakeService, WakeSessionProvider};

crates/application/src/orchestrator/service.rs

@@ -63,6 +63,25 @@ use crate::workstate::{
     GetLiveStateLean, StopAgentExecutionCascade, UpdateLiveState, UpdateLiveStateInput,
 };
 
+/// Immediate acknowledgement returned after a self-restart has been accepted.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AgentRestartScheduled {
+    /// Correlation id emitted on all subsequent restart events.
+    pub restart_id: String,
+}
+
+/// Composition-root owned scheduler for the destructive, detached restart flow.
+/// The application orchestrator only authenticates and dispatches the intent.
+pub trait AgentSelfRestartScheduler: Send + Sync {
+    /// Validates liveness/concurrency synchronously, then owns the detached work.
+    fn schedule(
+        &self,
+        project: &Project,
+        agent: AgentId,
+        reason: Option<String>,
+    ) -> Result<AgentRestartScheduled, AppError>;
+}
+
 /// Default terminal geometry for an orchestrator-launched agent cell. The UI
 /// resizes the PTY to the real cell size on attach; these are sane starting rows
 /// /cols so the spawn never fails on a zero-sized terminal.
@@ -685,6 +704,8 @@ pub struct OrchestratorService {
     /// Use case B8 qui produit une tâche de fond command-backed depuis la surface
     /// agent MCP `idea_run_in_background`. `None` ⇒ outil non configuré.
     spawn_background_command: Option<Arc<SpawnBackgroundCommand>>,
+    /// Detached self-restart coordinator, wired at the composition root.
+    self_restart: Option<Arc<dyn AgentSelfRestartScheduler>>,
 }
 
 /// Bundle des quatre use cases C7 sous [`domain::fileguard::FileGuard`], injectés
@@ -784,6 +805,7 @@ impl OrchestratorService {
             background_runner: None,
             session_limits: None,
             spawn_background_command: None,
+            self_restart: None,
         }
     }
 
@@ -808,6 +830,13 @@ impl OrchestratorService {
         self
     }
 
+    /// Wires the requester-scoped detached self-restart coordinator.
+    #[must_use]
+    pub fn with_self_restart(mut self, restart: Arc<dyn AgentSelfRestartScheduler>) -> Self {
+        self.self_restart = Some(restart);
+        self
+    }
+
     /// Branche le store des tâches de fond pour tracer les rendez-vous inter-agents
     /// comme [`BackgroundTaskKind::HeadlessRendezvous`] (B6).
     ///
@@ -1456,6 +1485,25 @@ impl OrchestratorService {
         command: OrchestratorCommand,
     ) -> Result<OrchestratorOutcome, AppError> {
         match command {
+            OrchestratorCommand::RestartSelf { agent, reason } => {
+                let scheduled = self
+                    .self_restart
+                    .as_ref()
+                    .ok_or_else(|| {
+                        AppError::Invalid("idea_restart_self not configured".to_owned())
+                    })?
+                    .schedule(project, agent, reason)?;
+                let reply = serde_json::json!({
+                    "restartId": scheduled.restart_id,
+                    "status": "scheduled",
+                    "message": "Agent restart scheduled."
+                })
+                .to_string();
+                Ok(OrchestratorOutcome {
+                    detail: "agent restart scheduled".to_owned(),
+                    reply: Some(reply),
+                })
+            }
             OrchestratorCommand::SpawnAgent {
                 name,
                 profile,

crates/backend/src/events.rs

@@ -113,6 +113,34 @@ pub struct AgentLaunchFailedDto {
 #[derive(Debug, Clone, Serialize)]
 #[serde(tag = "type", rename_all = "camelCase")]
 pub enum DomainEventDto {
+    /// A requester-scoped agent self-restart was accepted.
+    #[serde(rename_all = "camelCase")]
+    AgentRestartRequested {
+        agent_id: String,
+        restart_id: String,
+        reason: Option<String>,
+    },
+    /// A self-restart changed phase.
+    #[serde(rename_all = "camelCase")]
+    AgentRestartPhaseChanged {
+        agent_id: String,
+        restart_id: String,
+        phase: String,
+    },
+    /// A self-restart completed.
+    #[serde(rename_all = "camelCase")]
+    AgentRestartCompleted {
+        agent_id: String,
+        restart_id: String,
+    },
+    /// A self-restart failed after scheduling.
+    #[serde(rename_all = "camelCase")]
+    AgentRestartFailed {
+        agent_id: String,
+        restart_id: String,
+        phase: String,
+        message: String,
+    },
     /// A project was created.
     #[serde(rename_all = "camelCase")]
     ProjectCreated {
@@ -787,6 +815,42 @@ fn rendezvous_conversation_id(rendezvous: &Option<RendezvousContext>) -> Option<
 impl From<&DomainEvent> for DomainEventDto {
     fn from(e: &DomainEvent) -> Self {
         match e {
+            DomainEvent::AgentRestartRequested {
+                agent_id,
+                restart_id,
+                reason,
+            } => Self::AgentRestartRequested {
+                agent_id: agent_id.to_string(),
+                restart_id: restart_id.clone(),
+                reason: reason.clone(),
+            },
+            DomainEvent::AgentRestartPhaseChanged {
+                agent_id,
+                restart_id,
+                phase,
+            } => Self::AgentRestartPhaseChanged {
+                agent_id: agent_id.to_string(),
+                restart_id: restart_id.clone(),
+                phase: restart_phase_label(*phase).to_owned(),
+            },
+            DomainEvent::AgentRestartCompleted {
+                agent_id,
+                restart_id,
+            } => Self::AgentRestartCompleted {
+                agent_id: agent_id.to_string(),
+                restart_id: restart_id.clone(),
+            },
+            DomainEvent::AgentRestartFailed {
+                agent_id,
+                restart_id,
+                phase,
+                message,
+            } => Self::AgentRestartFailed {
+                agent_id: agent_id.to_string(),
+                restart_id: restart_id.clone(),
+                phase: restart_phase_label(*phase).to_owned(),
+                message: message.clone(),
+            },
             DomainEvent::ProjectCreated { project_id } => Self::ProjectCreated {
                 project_id: project_id.to_string(),
             },
@@ -1312,6 +1376,15 @@ impl From<&DomainEvent> for DomainEventDto {
     }
 }
 
+fn restart_phase_label(phase: domain::events::AgentRestartPhase) -> &'static str {
+    match phase {
+        domain::events::AgentRestartPhase::Stopping => "stopping",
+        domain::events::AgentRestartPhase::ReleasingInput => "releasingInput",
+        domain::events::AgentRestartPhase::Launching => "launching",
+        domain::events::AgentRestartPhase::Resuming => "resuming",
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -1336,6 +1409,32 @@ mod tests {
         ConversationId::from_uuid(uuid::Uuid::from_u128(n))
     }
 
+    #[test]
+    fn agent_restart_events_expose_stable_camel_case_contract() {
+        let id = agent(288);
+        let phase = DomainEventDto::from(&DomainEvent::AgentRestartPhaseChanged {
+            agent_id: id,
+            restart_id: "restart-288".to_owned(),
+            phase: domain::events::AgentRestartPhase::ReleasingInput,
+        });
+        let phase = serde_json::to_value(phase).expect("serialisable");
+        assert_eq!(phase["type"], "agentRestartPhaseChanged");
+        assert_eq!(phase["agentId"], id.to_string());
+        assert_eq!(phase["restartId"], "restart-288");
+        assert_eq!(phase["phase"], "releasingInput");
+
+        let failed = DomainEventDto::from(&DomainEvent::AgentRestartFailed {
+            agent_id: id,
+            restart_id: "restart-288".to_owned(),
+            phase: domain::events::AgentRestartPhase::Launching,
+            message: "launch failed".to_owned(),
+        });
+        let failed = serde_json::to_value(failed).expect("serialisable");
+        assert_eq!(failed["type"], "agentRestartFailed");
+        assert_eq!(failed["phase"], "launching");
+        assert_eq!(failed["message"], "launch failed");
+    }
+
     #[test]
     fn model_server_status_changed_relays_ready_to_dto_and_wire() {
         let dto = DomainEventDto::from(&DomainEvent::ModelServerStatusChanged {

crates/backend/src/lib.rs

@@ -13,16 +13,16 @@ use std::sync::{Arc, Mutex};
 
 use application::orchestrator::UpdateProjectContext as GuardedUpdateProjectContext;
 use application::{
-    AddIssueAttachment, AgentResumer, AgentWakeService, AllocateManagedTemp, AppError,
+    AddIssueAttachment, AgentRestartScheduled, AgentResumer, AgentSelfRestartScheduler,
-    AssignIssueAgent, AssignSkillToAgent, AssignTicketToSprint, AssignedSkillResolver,
+    AgentWakeService, AllocateManagedTemp, AppError, AssignIssueAgent, AssignSkillToAgent,
-    AttachLiveAgent, AuthenticateSession, BackgroundCommandArchive, BulkDeleteIssues,
+    AssignTicketToSprint, AssignedSkillResolver, AttachLiveAgent, AuthenticateSession,
-    BulkUpdateIssuePriority, BulkUpdateIssueStatus, CancelBackgroundTask, ChangeAgentProfile,
+    BackgroundCommandArchive, BulkDeleteIssues, BulkUpdateIssuePriority, BulkUpdateIssueStatus,
-    CheckEmbedderSuggestion, ClearChatDraft, CloneOpenCodeProfileFromSeed, CloneProfileFromSeed,
+    CancelBackgroundTask, ChangeAgentProfile, CheckEmbedderSuggestion, ClearChatDraft,
-    CloseProject, CloseTab, CloseTerminal, CloseTicketAssistant, ConfigureProfiles,
+    CloneOpenCodeProfileFromSeed, CloneProfileFromSeed, CloseProject, CloseTab, CloseTerminal,
-    ContextGuardUseCases, CreateAgentFromScratch, CreateAgentFromTemplate, CreateIssue,
+    CloseTicketAssistant, ConfigureProfiles, ContextGuardUseCases, CreateAgentFromScratch,
-    CreateLayout, CreateMemory, CreateProject, CreateSkill, CreateSprint, CreateTemplate,
+    CreateAgentFromTemplate, CreateIssue, CreateLayout, CreateMemory, CreateProject, CreateSkill,
-    DeleteAgent, DeleteEmbedderProfile, DeleteIssue, DeleteLayout, DeleteMemory,
+    CreateSprint, CreateTemplate, DeleteAgent, DeleteEmbedderProfile, DeleteIssue, DeleteLayout,
-    DeleteModelArtifact, DeleteModelServer, DeleteProfile, DeleteSkill, DeleteSprint,
+    DeleteMemory, DeleteModelArtifact, DeleteModelServer, DeleteProfile, DeleteSkill, DeleteSprint,
     DeleteTemplate, DescribeEmbedderEngines, DetectAgentDrift, DetectProfiles,
     DismissEmbedderSuggestion, EnsureLocalModelServer, ExecuteSlashCommand, FirstRunState,
     GcManagedTemp, GetAppExitWorkGuardState, GetLiveStateLean, GetMemory, GetProjectPermissions,
@@ -64,6 +64,7 @@ use application::{
     WakeSessionProvider, WriteMemory, WriteToTerminal, AGENT_MEMORY_RECALL_BUDGET,
 };
 use async_trait::async_trait;
+use domain::events::AgentRestartPhase;
 use domain::ports::{
     AgentContextStore, AgentRuntime, AgentSession, AgentSessionFactory, AgentToolPolicyStore,
     AgentWakePort, AssistantContextProvider, BackgroundTaskPortError, BackgroundTaskRunner,
@@ -1003,6 +1004,12 @@ pub struct ResumeContext {
     pub rows: u16,
     /// Largeur de la cellule au dernier lancement (colonnes PTY).
     pub cols: u16,
+    /// Exact hosting node supplied by the last driving launch (`None` = background).
+    pub node_id: Option<domain::NodeId>,
+    /// Logical conversation id supplied by the hosting cell.
+    pub conversation_id: Option<String>,
+    /// Whether the last driving launch selected the structured chat runtime.
+    pub require_structured: bool,
 }
 
 /// Registre partagé `(project_id, agent_id) → ResumeContext` (composition root ↔ commande
@@ -1030,6 +1037,265 @@ struct AppAgentResumer {
     contexts: ResumeContexts,
 }
 
+const SELF_RESTART_PROMPT: &str =
+    "IdeA vient de te redémarrer. Reprends immédiatement le travail en cours là où tu l'avais laissé.";
+
+struct AppAgentSelfRestarter {
+    launch_agent: Arc<LaunchAgent>,
+    close_terminal: Arc<CloseTerminal>,
+    live: Arc<LiveSessions>,
+    input: Arc<dyn domain::input::InputMediator>,
+    mailbox: Arc<dyn domain::mailbox::AgentMailbox>,
+    events: Arc<dyn EventBus>,
+    contexts: ResumeContexts,
+    active: Arc<Mutex<HashSet<domain::RuntimeAgentKey>>>,
+}
+
+fn self_restart_launch_input(
+    context: ResumeContext,
+    agent_id: AgentId,
+    mcp_runtime: Option<McpRuntime>,
+) -> LaunchAgentInput {
+    LaunchAgentInput {
+        project: context.project,
+        agent_id,
+        rows: context.rows,
+        cols: context.cols,
+        node_id: context.node_id,
+        conversation_id: context.conversation_id,
+        mcp_runtime,
+        allow_structured_alongside_pty: false,
+        require_structured: context.require_structured,
+        fresh_start: false,
+        managed_temp_exposure: application::ManagedTempExposureRequest::default(),
+    }
+}
+
+#[cfg(test)]
+mod self_restart_contract_tests {
+    use super::*;
+
+    #[test]
+    fn relaunch_preserves_conversation_and_never_requests_fresh_start() {
+        let project = Project::new(
+            ProjectId::from_uuid(Uuid::from_u128(288)),
+            "restart",
+            domain::project::ProjectPath::new("/tmp/idea-restart-contract").unwrap(),
+            domain::remote::RemoteRef::local(),
+            0,
+        )
+        .unwrap();
+        let agent = AgentId::from_uuid(Uuid::from_u128(1));
+        let node = domain::NodeId::from_uuid(Uuid::from_u128(2));
+        let input = self_restart_launch_input(
+            ResumeContext {
+                project,
+                rows: 31,
+                cols: 97,
+                node_id: Some(node),
+                conversation_id: Some("conversation-288".to_owned()),
+                require_structured: true,
+            },
+            agent,
+            None,
+        );
+
+        assert_eq!(input.agent_id, agent);
+        assert_eq!(input.node_id, Some(node));
+        assert_eq!(input.conversation_id.as_deref(), Some("conversation-288"));
+        assert!(input.require_structured);
+        assert!(!input.fresh_start);
+    }
+}
+
+impl AgentSelfRestartScheduler for AppAgentSelfRestarter {
+    fn schedule(
+        &self,
+        project: &Project,
+        agent: AgentId,
+        reason: Option<String>,
+    ) -> Result<AgentRestartScheduled, AppError> {
+        let key = domain::RuntimeAgentKey::new(project.id, agent);
+        let snapshots = self.live.live_agent_snapshots_for(project.id, &agent);
+        if snapshots.is_empty() {
+            return Err(AppError::Invalid(format!(
+                "requester agent {agent} is not live"
+            )));
+        }
+        {
+            let mut active = self.active.lock().map_err(|_| {
+                AppError::Internal("agent restart registry lock poisoned".to_owned())
+            })?;
+            if !active.insert(key) {
+                return Err(AppError::Invalid(format!(
+                    "a restart is already scheduled for agent {agent}"
+                )));
+            }
+        }
+
+        let restart_id = Uuid::new_v4().to_string();
+        self.events.publish(DomainEvent::AgentRestartRequested {
+            agent_id: agent,
+            restart_id: restart_id.clone(),
+            reason,
+        });
+
+        let launch_agent = Arc::clone(&self.launch_agent);
+        let close_terminal = Arc::clone(&self.close_terminal);
+        let live = Arc::clone(&self.live);
+        let input = Arc::clone(&self.input);
+        let mailbox = Arc::clone(&self.mailbox);
+        let events = Arc::clone(&self.events);
+        let contexts = Arc::clone(&self.contexts);
+        let active = Arc::clone(&self.active);
+        let restart_id_task = restart_id.clone();
+        let project = project.clone();
+        spawn_detached(async move {
+            // Leave the MCP server enough time to serialize and flush the scheduled
+            // acknowledgement before teardown kills the requester's bridge process.
+            tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+            let publish_phase = |phase| {
+                events.publish(DomainEvent::AgentRestartPhaseChanged {
+                    agent_id: agent,
+                    restart_id: restart_id_task.clone(),
+                    phase,
+                });
+            };
+            let context = contexts.lock().ok().and_then(|map| map.get(&key).cloned());
+            let snapshot = snapshots[0];
+            let context = context.unwrap_or(ResumeContext {
+                project: project.clone(),
+                rows: 24,
+                cols: 80,
+                node_id: None,
+                conversation_id: live
+                    .structured
+                    .meta_for_session(&snapshot.session_id)
+                    .and_then(|(_, _, _, conversation)| conversation),
+                require_structured: snapshot.kind == application::LiveSessionKind::Structured,
+            });
+
+            publish_phase(AgentRestartPhase::Stopping);
+            input.preempt(key);
+            let stop_result = application::terminal::stop_live_agent_runtime_in_project(
+                &project,
+                agent,
+                live.as_ref(),
+                close_terminal.as_ref(),
+            )
+            .await;
+
+            publish_phase(AgentRestartPhase::ReleasingInput);
+            if let Some(ticket) = input.busy_state(key).ticket() {
+                mailbox.cancel_head(key, ticket);
+            }
+            input.mark_idle(key);
+
+            let fail = |phase, error: AppError| {
+                events.publish(DomainEvent::AgentRestartFailed {
+                    agent_id: agent,
+                    restart_id: restart_id_task.clone(),
+                    phase,
+                    message: error.to_string(),
+                });
+            };
+            match stop_result {
+                Ok(stopped) if !stopped.is_empty() => {}
+                Ok(_) => {
+                    fail(
+                        AgentRestartPhase::Stopping,
+                        AppError::NotFound(format!("running runtime for agent {agent}")),
+                    );
+                    active.lock().ok().map(|mut set| set.remove(&key));
+                    return;
+                }
+                Err(error) => {
+                    fail(AgentRestartPhase::Stopping, error);
+                    active.lock().ok().map(|mut set| set.remove(&key));
+                    return;
+                }
+            }
+
+            publish_phase(AgentRestartPhase::Launching);
+            let mcp_runtime = crate::mcp_endpoint::idea_exe_path().map(|exe| McpRuntime {
+                exe,
+                endpoint: crate::mcp_endpoint::mcp_endpoint(&project.id)
+                    .as_cli_arg()
+                    .to_owned(),
+                project_id: project.id.as_uuid().simple().to_string(),
+                requester: agent.to_string(),
+            });
+            let launched = launch_agent
+                .execute(self_restart_launch_input(context, agent, mcp_runtime))
+                .await;
+            let launched = match launched {
+                Ok(output) => output,
+                Err(error) => {
+                    fail(AgentRestartPhase::Launching, error);
+                    active.lock().ok().map(|mut set| set.remove(&key));
+                    return;
+                }
+            };
+
+            publish_phase(AgentRestartPhase::Resuming);
+            let resume_result = if let Some(session) = live
+                .structured
+                .session_for_agent_in_project(project.id, &agent)
+            {
+                let turn = StructuredHumanTurnGuard::start(
+                    Arc::clone(&input),
+                    Arc::clone(&mailbox),
+                    project.id,
+                    agent,
+                    SELF_RESTART_PROMPT,
+                );
+                let result = session
+                    .send(SELF_RESTART_PROMPT)
+                    .await
+                    .map(|stream| stream.for_each(drop))
+                    .map_err(|error| AppError::Process(error.to_string()));
+                turn.finish();
+                result
+            } else if let Some(handle) = live.pty.handle(&launched.session.id) {
+                if let Some(profile) = launched.profile.as_ref() {
+                    input.bind_handle_with_submit(
+                        key,
+                        handle,
+                        domain::input::SubmitConfig::new(
+                            profile.submit_sequence.clone(),
+                            profile.submit_delay_ms,
+                        ),
+                    );
+                } else {
+                    input.bind_handle(key, handle);
+                }
+                let ticket = domain::mailbox::Ticket::new(
+                    domain::mailbox::TicketId::new_random(),
+                    "IdeA",
+                    SELF_RESTART_PROMPT,
+                );
+                let _pending = input.enqueue(key, ticket);
+                Ok(())
+            } else {
+                Err(AppError::Process(format!(
+                    "agent {agent} has no live input after relaunch"
+                )))
+            };
+
+            match resume_result {
+                Ok(()) => events.publish(DomainEvent::AgentRestartCompleted {
+                    agent_id: agent,
+                    restart_id: restart_id_task.clone(),
+                }),
+                Err(error) => fail(AgentRestartPhase::Resuming, error),
+            }
+            active.lock().ok().map(|mut set| set.remove(&key));
+        });
+
+        Ok(AgentRestartScheduled { restart_id })
+    }
+}
+
 /// Guard for a direct human turn sent to a structured agent session.
 ///
 /// Direct chat adapters (`agent_send`, web `chat.send`) still drive the provider
@@ -3230,6 +3496,16 @@ impl BackendCore {
             Arc::clone(&events_port),
             resumer,
         ));
+        let self_restart = Arc::new(AppAgentSelfRestarter {
+            launch_agent: Arc::clone(&launch_agent),
+            close_terminal: Arc::clone(&close_terminal),
+            live: Arc::clone(&live_sessions),
+            input: Arc::clone(&input_mediator),
+            mailbox: Arc::clone(&mailbox),
+            events: Arc::clone(&events_port),
+            contexts: Arc::clone(&resume_contexts),
+            active: Arc::new(Mutex::new(HashSet::new())),
+        }) as Arc<dyn AgentSelfRestartScheduler>;
         // Drain du scheduler (§21.5-b) : à chaque réveil tiré, `TokioScheduler` pousse une
         // `ScheduledTask::ResumeAgent` ; on l'exécute via le service (relance + AgentResumed).
         // Patron `sweep_stalled` : spawner detache (pas `tokio::spawn` — `build`
@@ -3299,6 +3575,7 @@ impl BackendCore {
             .with_project_store(Arc::clone(&store_port))
             .with_conversations(Arc::clone(&conversation_registry))
             .with_events(Arc::clone(&events_port))
+            .with_self_restart(self_restart)
             // Faits OS/runtime (exe $APPIMAGE/current_exe + endpoint loopback) pour
             // que les (re)lancements issus du chemin `ask` écrivent la déclaration MCP
             // réelle ⇒ le pont MCP de la cible se spawne et `idea_reply` débloque le round-trip.

crates/domain/src/events.rs

@@ -49,6 +49,42 @@ pub enum OrchestrationSource {
 /// channel rather than serialised here.
 #[derive(Debug, Clone, PartialEq)]
 pub enum DomainEvent {
+    /// An agent requested a self-restart through its MCP handshake identity.
+    AgentRestartRequested {
+        /// Agent authenticated by the MCP handshake.
+        agent_id: AgentId,
+        /// Correlation id shared by all events in this restart.
+        restart_id: String,
+        /// Optional model-provided diagnostic reason.
+        reason: Option<String>,
+    },
+    /// A scheduled self-restart moved to another runtime phase.
+    AgentRestartPhaseChanged {
+        /// Restarting agent.
+        agent_id: AgentId,
+        /// Restart correlation id.
+        restart_id: String,
+        /// Newly entered phase.
+        phase: AgentRestartPhase,
+    },
+    /// A self-restart relaunched the agent and submitted its internal resume turn.
+    AgentRestartCompleted {
+        /// Restarted agent.
+        agent_id: AgentId,
+        /// Restart correlation id.
+        restart_id: String,
+    },
+    /// A self-restart failed after it had already been acknowledged as scheduled.
+    AgentRestartFailed {
+        /// Agent whose restart failed.
+        agent_id: AgentId,
+        /// Restart correlation id.
+        restart_id: String,
+        /// Phase that failed.
+        phase: AgentRestartPhase,
+        /// Human-readable failure safe to expose in the UI.
+        message: String,
+    },
     /// A project was created.
     ProjectCreated {
         /// The new project.
@@ -667,6 +703,19 @@ pub enum DomainEvent {
     },
 }
 
+/// Stable phases exposed by the agent self-restart event stream.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AgentRestartPhase {
+    /// Existing runtime teardown.
+    Stopping,
+    /// Busy state and mailbox cleanup.
+    ReleasingInput,
+    /// Activation through `LaunchAgent`.
+    Launching,
+    /// Submission of the internal continuation turn.
+    Resuming,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/domain/src/orchestrator.rs

@@ -260,6 +260,13 @@ pub struct OrchestratorRequest {
 /// proof the request was well-formed (Parse, don't validate).
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum OrchestratorCommand {
+    /// Schedule a restart of the MCP requester itself.
+    RestartSelf {
+        /// Requesting agent, strictly parsed from the MCP handshake identity.
+        agent: AgentId,
+        /// Optional diagnostic reason. It is never used as an identity or target.
+        reason: Option<String>,
+    },
     /// Create the agent if unknown (with `profile` + optional initial context),
     /// then launch it — exactly as the UI would.
     SpawnAgent {
@@ -476,6 +483,15 @@ impl OrchestratorRequest {
     pub fn validate(&self) -> Result<OrchestratorCommand, OrchestratorError> {
         let action = self.action_name()?;
         match action {
+            "agent.restart_self" => Ok(OrchestratorCommand::RestartSelf {
+                agent: self.require_from(action)?,
+                reason: self
+                    .task
+                    .as_deref()
+                    .map(str::trim)
+                    .filter(|value| !value.is_empty())
+                    .map(str::to_owned),
+            }),
             "spawn_agent" => Ok(OrchestratorCommand::SpawnAgent {
                 name: self.require_name(action)?,
                 profile: Some(self.require("profile", action, self.profile.as_deref())?),

crates/infrastructure/src/orchestrator/mcp/tools.rs

@@ -72,6 +72,7 @@ pub const WRITE_ACTION_TOOLS: &[&str] = &[
     "idea_run_in_background",
     "idea_launch_agent",
     "idea_stop_agent",
+    "idea_restart_self",
     "idea_update_context",
     "idea_context_propose",
     "idea_context_update",
@@ -155,6 +156,7 @@ pub fn tool_returns_reply(tool: &str) -> bool {
             | "idea_memory_read"
             | "idea_skill_read"
             | "idea_run_in_background"
+            | "idea_restart_self"
             | "idea_workstate_read"
     ) || is_ticket_tool(tool)
         || is_template_tool(tool)
@@ -193,6 +195,17 @@ pub fn is_plugin_tool(tool: &str) -> bool {
 #[must_use]
 pub fn catalogue() -> Vec<ToolDef> {
     let mut tools = vec![
+        ToolDef {
+            name: "idea_restart_self",
+            description: "Restart this requesting agent and resume its current work with freshly resolved capabilities.",
+            input_schema: json!({
+                "type": "object",
+                "properties": {
+                    "reason": { "type": "string" }
+                },
+                "additionalProperties": false
+            }),
+        },
         ToolDef {
             name: "idea_project_list",
             description: "List known IdeA projects for cross-project agent discovery.",
@@ -543,6 +556,15 @@ pub fn map_tool_call(
     // Translate the tool into the wire-level request shape the watcher already
     // uses (v2 `type`), then let `validate` enforce the invariants once.
     let request = match name {
+        "idea_restart_self" => {
+            reject_unknown_keys(name, args, &["reason"])?;
+            OrchestratorRequest {
+                request_type: Some("agent.restart_self".to_owned()),
+                requested_by: Some(requester.to_owned()),
+                task: s("reason"),
+                ..base()
+            }
+        }
         "idea_list_agents" => OrchestratorRequest {
             request_type: Some("agent.list".to_owned()),
             ..base()
@@ -845,6 +867,51 @@ mod tests {
         assert!(tool_returns_reply("idea_ask_agents"));
     }
 
+    #[test]
+    fn restart_self_is_catalogued_and_uses_only_handshake_requester() {
+        let definition = catalogue()
+            .into_iter()
+            .find(|tool| tool.name == "idea_restart_self")
+            .expect("restart-self tool advertised");
+        assert_eq!(
+            tool_access(definition.name),
+            Some(McpToolAccess::WriteAction)
+        );
+        assert!(tool_returns_reply(definition.name));
+
+        let expected = domain::AgentId::from_uuid(uuid::Uuid::parse_str(REQ).unwrap());
+        assert_eq!(
+            map_tool_call(
+                "idea_restart_self",
+                &json!({ "reason": "plugin installed" }),
+                REQ,
+            )
+            .unwrap(),
+            OrchestratorCommand::RestartSelf {
+                agent: expected,
+                reason: Some("plugin installed".to_owned()),
+            }
+        );
+        assert_eq!(
+            map_tool_call(
+                "idea_restart_self",
+                &json!({ "target": "someone-else" }),
+                REQ,
+            ),
+            Err(ToolMapError::BadArguments("idea_restart_self".to_owned()))
+        );
+    }
+
+    #[test]
+    fn restart_self_rejects_missing_or_malformed_requester() {
+        for requester in ["", "not-an-agent-id"] {
+            assert!(matches!(
+                map_tool_call("idea_restart_self", &json!({}), requester),
+                Err(ToolMapError::Invalid(_))
+            ));
+        }
+    }
+
     #[test]
     fn project_tools_are_classified_and_return_inline_replies() {
         for tool in [

crates/infrastructure/tests/mcp_server.rs

@@ -53,8 +53,9 @@ use domain::{
 use uuid::Uuid;
 
 use application::{
-    CloseTerminal, CreateAgentFromScratch, CreateSkill, LaunchAgent, ListAgents,
+    AgentRestartScheduled, AgentSelfRestartScheduler, AppError, CloseTerminal,
-    OrchestratorService, StructuredSessions, TerminalSessions, UpdateAgentContext,
+    CreateAgentFromScratch, CreateSkill, LaunchAgent, ListAgents, OrchestratorService,
+    StructuredSessions, TerminalSessions, UpdateAgentContext,
 };
 use infrastructure::orchestrator::mcp::jsonrpc::error_codes;
 use infrastructure::orchestrator::mcp::tools::classified_tool_names;
@@ -578,6 +579,25 @@ fn capturing_events() -> (
     (publish, captured)
 }
 
+#[derive(Default)]
+struct FakeSelfRestart {
+    calls: Mutex<Vec<(ProjectId, AgentId, Option<String>)>>,
+}
+
+impl AgentSelfRestartScheduler for FakeSelfRestart {
+    fn schedule(
+        &self,
+        project: &Project,
+        agent: AgentId,
+        reason: Option<String>,
+    ) -> Result<AgentRestartScheduled, AppError> {
+        self.calls.lock().unwrap().push((project.id, agent, reason));
+        Ok(AgentRestartScheduled {
+            restart_id: "restart-test-1".to_owned(),
+        })
+    }
+}
+
 // --- JSON-RPC framing helpers ---------------------------------------------
 
 /// A `tools/call` request envelope for `tool` with `arguments`.
@@ -762,6 +782,7 @@ async fn tools_list_advertises_the_idea_tools_with_schemas() {
         "idea_ask_agent",
         "idea_ask_agents",
         "idea_run_in_background",
+        "idea_restart_self",
         "idea_launch_agent",
         "idea_stop_agent",
         "idea_update_context",
@@ -812,8 +833,8 @@ async fn tools_list_advertises_the_idea_tools_with_schemas() {
     assert!(!names.contains(&"idea_reply"));
     assert_eq!(
         tools.len(),
-        49,
+        50,
-        "exactly the forty-nine exposed idea_* tools; got {names:?}"
+        "exactly the fifty exposed idea_* tools; got {names:?}"
     );
 
     // Every tool advertises an object input schema.
@@ -988,6 +1009,33 @@ async fn cross_project_actions_are_advertised_only_when_allowed_and_denial_is_ac
 // 2. tools/call → the right OrchestratorCommand (observed through the fakes)
 // ---------------------------------------------------------------------------
 
+#[tokio::test]
+async fn restart_self_returns_scheduled_payload_and_uses_handshake_identity() {
+    let (base, _sessions) = build_service(FakeContexts::new());
+    let restart = Arc::new(FakeSelfRestart::default());
+    let service = Arc::try_unwrap(base)
+        .unwrap_or_else(|_| panic!("freshly built service must be uniquely owned"))
+        .with_self_restart(Arc::clone(&restart) as Arc<dyn AgentSelfRestartScheduler>);
+    let requester = AgentId::from_uuid(Uuid::from_u128(288));
+    let response = server(Arc::new(service))
+        .for_requester(requester.to_string())
+        .handle_raw(&tools_call(
+            288,
+            "idea_restart_self",
+            json!({ "reason": "new plugin" }),
+        ))
+        .await
+        .expect("restart call replies before detached teardown");
+    let result = response.result.expect("successful tool result");
+    let payload: Value = serde_json::from_str(result_text(&result)).unwrap();
+    assert_eq!(payload["restartId"], "restart-test-1");
+    assert_eq!(payload["status"], "scheduled");
+    assert_eq!(
+        restart.calls.lock().unwrap().as_slice(),
+        &[(project().id, requester, Some("new plugin".to_owned()))]
+    );
+}
+
 #[tokio::test]
 async fn general_agent_without_mcp_override_is_read_only_for_tools_call() {
     let contexts = FakeContexts::new();

crates/web-server/src/lib.rs

@@ -1658,6 +1658,12 @@ async fn execute_launch_agent_for_ws(
                 project: resume_project,
                 rows: request.rows,
                 cols: request.cols,
+                node_id,
+                conversation_id: request
+                    .conversation_id
+                    .clone()
+                    .or_else(|| output.assigned_conversation_id.clone()),
+                require_structured: request.cell_kind == Some(backend::dto::CellKind::Chat),
             },
         );
     }

frontend/src/domain/index.ts

@@ -280,6 +280,12 @@ export interface EmbeddedServerStatus {
 }
 
 /** A domain event relayed from the backend (tagged union on `type`). */
+export type AgentRestartPhase =
+  | "stopping"
+  | "releasingInput"
+  | "launching"
+  | "resuming";
+
 export type DomainEvent =
   | { type: "projectCreated"; projectId: string }
   | { type: "pluginInstalled"; pluginId: string; version: string }
@@ -317,6 +323,26 @@ export type DomainEvent =
     }
   | { type: "agentProfileChanged"; agentId: string; profileId: string }
   | { type: "agentBusyChanged"; agentId: string; busy: boolean }
+  | {
+      type: "agentRestartRequested";
+      agentId: string;
+      restartId: string;
+      reason: string | null;
+    }
+  | {
+      type: "agentRestartPhaseChanged";
+      agentId: string;
+      restartId: string;
+      phase: AgentRestartPhase;
+    }
+  | { type: "agentRestartCompleted"; agentId: string; restartId: string }
+  | {
+      type: "agentRestartFailed";
+      agentId: string;
+      restartId: string;
+      phase: AgentRestartPhase;
+      message: string;
+    }
   | {
       type: "backgroundTaskChanged";
       projectId: string;

frontend/src/features/agents/CustomAgentChatView.test.tsx

@@ -5,6 +5,7 @@ import { beforeEach, describe, expect, it, vi } from "vitest";
 import { DIProvider } from "@/app/di";
 import type { AgentProfile, ReplyChunk } from "@/domain";
 import { MockSystemGateway, MockWorkStateGateway } from "@/adapters/mock";
+import { AnnouncementsProvider } from "@/features/announcements";
 import { PluginRuntimeProvider } from "@/features/plugins";
 import {
   __resetProjectCliInteractionActivityForTests,
@@ -145,6 +146,91 @@ describe("CustomAgentChatView", () => {
     __resetProjectCliInteractionActivityForTests();
   });
 
+  it("projects self-restart lifecycle separators in the custom CLI only once", async () => {
+    const system = new MockSystemGateway();
+    const agent = {
+      launchAgentChat: vi.fn(async () => ({ sessionId: "chat-session-restart" })),
+      reattachAgentChat: vi.fn(async (sessionId: string) => ({
+        sessionId,
+        scrollback: [],
+      })),
+      sendAgentChat: vi.fn(async () => {}),
+      cancelAgentChat: vi.fn(async () => {}),
+      closeAgentChat: vi.fn(async () => {}),
+    };
+
+    render(
+      <DIProvider gateways={{ agent, system } as unknown as Gateways}>
+        <AnnouncementsProvider projectId="project-1">
+          <CustomAgentChatView
+            projectId="project-1"
+            agentId="agent-1"
+            agentName="Worker"
+            profile={profile}
+            cwd="/repo"
+            nodeId="node-1"
+            sessionId={null}
+            conversationId="conversation-1"
+            onSessionId={vi.fn()}
+            onConversationId={vi.fn()}
+          />
+        </AnnouncementsProvider>
+      </DIProvider>,
+    );
+    await waitFor(() => expect(agent.launchAgentChat).toHaveBeenCalled());
+
+    act(() => {
+      system.emit({
+        type: "agentRestartRequested",
+        agentId: "agent-1",
+        restartId: "restart-1",
+        reason: null,
+      });
+      system.emit({
+        type: "agentRestartCompleted",
+        agentId: "agent-1",
+        restartId: "restart-1",
+      });
+    });
+
+    expect(
+      await screen.findByText("------- redemarrage de l'agent -------"),
+    ).not.toBeNull();
+    expect(
+      screen.getByText("------- redemarrage de l'agent termine -------"),
+    ).not.toBeNull();
+    expect(screen.getAllByTestId("agent-restart-separator")).toHaveLength(2);
+
+    act(() => {
+      system.emit({
+        type: "agentRestartCompleted",
+        agentId: "agent-1",
+        restartId: "restart-1",
+      });
+    });
+    expect(screen.getAllByTestId("agent-restart-separator")).toHaveLength(2);
+
+    act(() => {
+      system.emit({
+        type: "agentRestartRequested",
+        agentId: "agent-1",
+        restartId: "restart-2",
+        reason: "new capability",
+      });
+      system.emit({
+        type: "agentRestartFailed",
+        agentId: "agent-1",
+        restartId: "restart-2",
+        phase: "launching",
+        message: "runtime unavailable",
+      });
+    });
+    expect(
+      screen.getByText("------- redemarrage de l'agent echoue -------"),
+    ).not.toBeNull();
+    expect(screen.getByText("runtime unavailable")).not.toBeNull();
+  });
+
   it("shows the technical open failure on mobile with retry and native TUI fallback", async () => {
     const openNativeTui = vi.fn();
     const agent = {

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -31,7 +31,11 @@ import type {
   SlashCommand,
 } from "@/domain";
 import { useGateways } from "@/app/di";
-import { AnnouncementsPreview } from "@/features/announcements";
+import {
+  AnnouncementsPreview,
+  shortRestartFailure,
+  useAgentRestart,
+} from "@/features/announcements";
 import { usePluginRuntime } from "@/features/plugins/PluginRuntimeProvider";
 import {
   markProjectCliInteractionFinished,
@@ -68,6 +72,7 @@ type ChatTurn =
   | { role: "progress"; progress: ReplyProgress; settled?: boolean; progressKey?: string }
   | { role: "final"; text: string; receivedAtMs?: number }
   | { role: "error"; text: string; receivedAtMs?: number }
+  | { role: "restart"; key: string; text: string; message?: string; failed?: boolean }
   | { role: "unknown"; text: string; receivedAtMs?: number };
 
 interface CachedChatView {
@@ -1127,9 +1132,14 @@ export function CustomAgentChatView({
       currentAgentBusy: false,
       delegationTargetName: null,
     });
+  const { restart, events: restartEvents } = useAgentRestart(agentId);
   const delegationActive = requesterDelegation.delegationTargetName !== null;
   const effectiveBusy =
-    busy || stopping || requesterDelegation.currentAgentBusy || delegationActive;
+    busy ||
+    stopping ||
+    Boolean(restart && restart.outcome !== "failed") ||
+    requesterDelegation.currentAgentBusy ||
+    delegationActive;
   const delegationFallbackText = requesterDelegation.delegationTargetName
     ? `${agentName} attend ${requesterDelegation.delegationTargetName}`
     : "Délégation en cours.";
@@ -1303,6 +1313,45 @@ export function CustomAgentChatView({
     };
   }, [agentId, projectId, refreshRequesterDelegation, system]);
 
+  useEffect(() => {
+    if (restartEvents.length === 0) return;
+    updateChatViewState((previous) => {
+      const nextTurns = [...previous.turns];
+      let changed = false;
+      for (const event of restartEvents) {
+        const key = `${event.restartId}:${event.type}`;
+        if (nextTurns.some((turn) => turn.role === "restart" && turn.key === key)) {
+          continue;
+        }
+        if (event.type === "agentRestartRequested") {
+          changed = true;
+          nextTurns.push({
+            role: "restart",
+            key,
+            text: "------- redemarrage de l'agent -------",
+          });
+        } else if (event.type === "agentRestartCompleted") {
+          changed = true;
+          nextTurns.push({
+            role: "restart",
+            key,
+            text: "------- redemarrage de l'agent termine -------",
+          });
+        } else {
+          changed = true;
+          nextTurns.push({
+            role: "restart",
+            key,
+            text: "------- redemarrage de l'agent echoue -------",
+            message: shortRestartFailure(event.message),
+            failed: true,
+          });
+        }
+      }
+      return changed ? { ...previous, turns: nextTurns } : previous;
+    });
+  }, [restartEvents, updateChatViewState]);
+
   useEffect(() => {
     mountedRef.current = true;
     return () => {
@@ -2577,6 +2626,20 @@ function ChatBubble({
   expandedProgressKeys: Set<string>;
   onToggleProgressExpanded: (key: string) => void;
 }) {
+  if (turn.role === "restart") {
+    return (
+      <div
+        data-testid="agent-restart-separator"
+        className={cn(
+          "flex min-w-0 flex-col items-center gap-1 py-1 text-xs",
+          turn.failed ? "text-danger" : "text-muted",
+        )}
+      >
+        <span className="whitespace-pre-wrap text-center">{turn.text}</span>
+        {turn.message && <span className="max-w-[86%] text-center">{turn.message}</span>}
+      </div>
+    );
+  }
   if (turn.role === "tool") {
     return (
       <div className="flex min-w-0 justify-center">

frontend/src/features/announcements/AgentRestartOverlay.tsx

@@ -0,0 +1,80 @@
+import { useEffect, useRef } from "react";
+
+import { Spinner } from "@/shared";
+import { useAgentRestart, useTargetAnnouncements } from "./AnnouncementsProvider";
+
+export interface AgentRestartOverlayProps {
+  agentId: string;
+}
+
+export function restartOverlayLabel(
+  phase: "requested" | "stopping" | "releasingInput" | "launching" | "resuming",
+): string {
+  switch (phase) {
+    case "stopping":
+    case "releasingInput":
+      return "Arret de l'agent en cours...";
+    case "launching":
+      return "Relance de l'agent...";
+    case "resuming":
+      return "Reprise du travail...";
+    default:
+      return "Redemarrage de l'agent...";
+  }
+}
+
+export function shortRestartFailure(message: string): string {
+  const normalized = message.trim().replace(/\s+/g, " ");
+  if (!normalized) return "Cause technique non disponible.";
+  return normalized.length <= 160 ? normalized : `${normalized.slice(0, 157)}...`;
+}
+
+export function AgentRestartOverlay({ agentId }: AgentRestartOverlayProps) {
+  const { restart } = useAgentRestart(agentId);
+  const { announcements } = useTargetAnnouncements(agentId);
+  const feedRef = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    const element = feedRef.current;
+    if (element) element.scrollTop = element.scrollHeight;
+  }, [announcements]);
+
+  if (!restart) return null;
+
+  const failed = restart.outcome === "failed";
+  return (
+    <div
+      data-testid="agent-restart-overlay"
+      role="status"
+      aria-live="polite"
+      className="pointer-events-none absolute inset-0 z-[4] flex flex-col bg-canvas/90 backdrop-blur-sm"
+    >
+      <div className="flex shrink-0 items-center gap-2 border-b border-border/60 bg-surface/85 px-4 py-2">
+        {!failed && <Spinner size={14} />}
+        <span className={failed ? "text-sm font-medium text-danger" : "text-sm font-medium text-content"}>
+          {failed ? "Redemarrage de l'agent echoue" : restartOverlayLabel(restart.phase)}
+        </span>
+      </div>
+      <div
+        ref={feedRef}
+        className="flex flex-1 flex-col justify-end gap-1.5 overflow-hidden px-6 py-4"
+      >
+        {failed ? (
+          <div className="rounded-md border border-danger/40 bg-danger/10 px-3 py-2 text-sm text-danger">
+            {shortRestartFailure(restart.message ?? "")}
+          </div>
+        ) : announcements.length === 0 ? (
+          <div className="flex items-center justify-center rounded-md border border-border/70 bg-surface/70 px-3 py-2 text-sm text-muted">
+            {restartOverlayLabel(restart.phase)}
+          </div>
+        ) : (
+          announcements.map((announcement) => (
+            <div key={announcement.seq} className="text-sm text-content/90">
+              <span className="whitespace-pre-wrap break-words">{announcement.text}</span>
+            </div>
+          ))
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/features/announcements/AnnouncementsProvider.test.tsx

@@ -21,6 +21,7 @@ import { DIProvider } from "@/app/di";
 import { AnnouncementsProvider } from "./AnnouncementsProvider";
 import { AnnouncementsPreview } from "./AnnouncementsPreview";
 import { TargetAnnouncementsOverlay } from "./TargetAnnouncementsOverlay";
+import { AgentRestartOverlay } from "./AgentRestartOverlay";
 
 function setup(
   node: React.ReactNode,
@@ -304,6 +305,91 @@ describe("F3 — overlay lifecycle is the target's busy state", () => {
   });
 });
 
+describe("#288 — native TUI restart overlay", () => {
+  it("tracks restart phases, keeps progress after resume, then retracts at idle", async () => {
+    const { system } = setup(<AgentRestartOverlay agentId="agent-T" />);
+    await flush();
+
+    act(() => {
+      system.emit({
+        type: "agentRestartRequested",
+        agentId: "agent-T",
+        restartId: "restart-1",
+        reason: null,
+      });
+    });
+    expect(screen.getAllByText("Redemarrage de l'agent...").length).toBeGreaterThan(0);
+
+    act(() => {
+      system.emit({
+        type: "agentRestartPhaseChanged",
+        agentId: "agent-T",
+        restartId: "restart-1",
+        phase: "launching",
+      });
+    });
+    expect(screen.getAllByText("Relance de l'agent...").length).toBeGreaterThan(0);
+
+    act(() => {
+      system.emit(busy("agent-T", true));
+      system.emit({
+        type: "agentRestartCompleted",
+        agentId: "agent-T",
+        restartId: "restart-1",
+      });
+      system.emit(announcement({ target: "agent-T", text: "travail repris" }));
+    });
+    expect(screen.getByText("Reprise du travail...")).not.toBeNull();
+    expect(screen.getByText("travail repris")).not.toBeNull();
+
+    act(() => system.emit(busy("agent-T", false)));
+    expect(screen.queryByTestId("agent-restart-overlay")).toBeNull();
+  });
+
+  it("shows a short failure without CLI separators", async () => {
+    const { system } = setup(<AgentRestartOverlay agentId="agent-T" />);
+    await flush();
+    act(() => {
+      system.emit({
+        type: "agentRestartRequested",
+        agentId: "agent-T",
+        restartId: "restart-2",
+        reason: "new plugin",
+      });
+      system.emit({
+        type: "agentRestartFailed",
+        agentId: "agent-T",
+        restartId: "restart-2",
+        phase: "launching",
+        message: "runtime unavailable",
+      });
+    });
+    expect(screen.getByText("Redemarrage de l'agent echoue")).not.toBeNull();
+    expect(screen.getByText("runtime unavailable")).not.toBeNull();
+    expect(screen.queryByText(/-------/)).toBeNull();
+  });
+
+  it("does not stick when the structured resumed turn becomes idle before completed", async () => {
+    const { system } = setup(<AgentRestartOverlay agentId="agent-T" />);
+    await flush();
+    act(() => {
+      system.emit({
+        type: "agentRestartRequested",
+        agentId: "agent-T",
+        restartId: "restart-structured",
+        reason: null,
+      });
+      system.emit(busy("agent-T", false));
+      system.emit({
+        type: "agentRestartCompleted",
+        agentId: "agent-T",
+        restartId: "restart-structured",
+      });
+    });
+    expect(screen.queryByTestId("agent-restart-overlay")).toBeNull();
+  });
+});
+
 describe("F2 — AnnouncementsPreview (requester filter)", () => {
   it("shows a requester-side fallback while waiting without live text", async () => {
     setup(

frontend/src/features/announcements/AnnouncementsProvider.tsx

@@ -11,6 +11,10 @@
  *      2026-07-04). Fed live by `agentBusyChanged { agentId, busy }` and hydrated
  *      from the reconciled read-model `ProjectWorkState.agents[].busy` at mount /
  *      reboot (via {@link useHydrateAgentBusy}).
+ *   3. **Self-restart presentation** — the live restart phase plus a small,
+ *      deduplicated journal used by the native-TUI overlay and custom-CLI
+ *      separators. It is deliberately presentation-only and never persisted to
+ *      the human conversation transcript.
  *
  * Why busy — not "there are announcements" — drives F3: a turn can end **without**
  * any completion event (interruption / error / crash / rate-limit). The mediator's
@@ -33,11 +37,13 @@ import {
   useContext,
   useEffect,
   useMemo,
+  useRef,
   useState,
   type ReactNode,
 } from "react";
 
 import { useGateways } from "@/app/di";
+import type { AgentRestartPhase, DomainEvent } from "@/domain";
 import {
   announcementsForRequester,
   announcementsForTarget,
@@ -51,11 +57,33 @@ import {
 /** Per-agent busy map: `true` while the agent owns a turn (drives the overlay). */
 type BusyMap = Record<string, boolean>;
 
+export type AgentRestartJournalEvent = Extract<
+  DomainEvent,
+  {
+    type:
+      | "agentRestartRequested"
+      | "agentRestartCompleted"
+      | "agentRestartFailed";
+  }
+>;
+
+export interface AgentRestartPresentation {
+  restartId: string;
+  phase: AgentRestartPhase | "requested";
+  outcome: "running" | "completed" | "failed";
+  message?: string;
+}
+
+type RestartMap = Record<string, AgentRestartPresentation>;
+type RestartJournal = Record<string, AgentRestartJournalEvent[]>;
+
 interface AnnouncementsStore {
   /** Bounded announcement content, indexed by `(target, ticketId)`. */
   index: AnnouncementIndex;
   /** Per-agent busy state — the overlay's lifecycle authority. */
   busy: BusyMap;
+  restarts: RestartMap;
+  restartJournal: RestartJournal;
   /**
    * Seeds an agent's busy state from the read-model, but only when no live signal
    * is yet known for it: live `agentBusyChanged` events always win over a
@@ -67,11 +95,15 @@ interface AnnouncementsStore {
 const noopSeed = () => {};
 const EMPTY_INDEX = emptyAnnouncementIndex();
 const EMPTY_BUSY: BusyMap = {};
+const EMPTY_RESTARTS: RestartMap = {};
+const EMPTY_RESTART_JOURNAL: RestartJournal = {};
 
 /** Store shape read outside a provider — a silent, inert default (never throws). */
 const DEFAULT_STORE: AnnouncementsStore = {
   index: EMPTY_INDEX,
   busy: EMPTY_BUSY,
+  restarts: EMPTY_RESTARTS,
+  restartJournal: EMPTY_RESTART_JOURNAL,
   seedBusy: noopSeed,
 };
 
@@ -87,16 +119,24 @@ export function AnnouncementsProvider({
   const { system } = useGateways();
   const [index, setIndex] = useState<AnnouncementIndex>(emptyAnnouncementIndex);
   const [busy, setBusy] = useState<BusyMap>({});
+  const busyRef = useRef<BusyMap>({});
+  const [restarts, setRestarts] = useState<RestartMap>({});
+  const [restartJournal, setRestartJournal] = useState<RestartJournal>({});
 
   // Hydration seed: apply only when the agent is unknown, so a live event that
   // already landed (or lands before the async read-model resolves) is not clobbered.
   const seedBusy = useCallback((agentId: string, value: boolean) => {
-    setBusy((prev) => (agentId in prev ? prev : { ...prev, [agentId]: value }));
+    if (agentId in busyRef.current) return;
+    busyRef.current = { ...busyRef.current, [agentId]: value };
+    setBusy((prev) => ({ ...prev, [agentId]: value }));
   }, []);
 
   useEffect(() => {
     setIndex(emptyAnnouncementIndex());
     setBusy({});
+    busyRef.current = {};
+    setRestarts({});
+    setRestartJournal({});
   }, [projectId]);
 
   useEffect(() => {
@@ -124,8 +164,71 @@ export function AnnouncementsProvider({
           // it (idle) and clears the target's content so a next turn starts fresh —
           // even when no completion event was ever emitted (the sticking case).
           const { agentId, busy: isBusy } = event;
+          busyRef.current = { ...busyRef.current, [agentId]: isBusy };
           setBusy((prev) => ({ ...prev, [agentId]: isBusy }));
           if (!isBusy) setIndex((prev) => purgeAllForTarget(prev, agentId));
+          if (!isBusy) {
+            setRestarts((prev) => {
+              const restart = prev[agentId];
+              if (!restart || restart.outcome !== "completed") return prev;
+              const next = { ...prev };
+              delete next[agentId];
+              return next;
+            });
+          }
+        } else if (event.type === "agentRestartRequested") {
+          setRestarts((prev) => ({
+            ...prev,
+            [event.agentId]: {
+              restartId: event.restartId,
+              phase: "requested",
+              outcome: "running",
+            },
+          }));
+          setRestartJournal((prev) => appendRestartJournal(prev, event));
+        } else if (event.type === "agentRestartPhaseChanged") {
+          setRestarts((prev) => {
+            const current = prev[event.agentId];
+            if (!current || current.restartId !== event.restartId) return prev;
+            return {
+              ...prev,
+              [event.agentId]: { ...current, phase: event.phase },
+            };
+          });
+        } else if (event.type === "agentRestartCompleted") {
+          setRestarts((prev) => {
+            const current = prev[event.agentId];
+            if (!current || current.restartId !== event.restartId) return prev;
+            if (busyRef.current[event.agentId] === false) {
+              const next = { ...prev };
+              delete next[event.agentId];
+              return next;
+            }
+            return {
+              ...prev,
+              [event.agentId]: {
+                ...current,
+                phase: "resuming",
+                outcome: "completed",
+              },
+            };
+          });
+          setRestartJournal((prev) => appendRestartJournal(prev, event));
+        } else if (event.type === "agentRestartFailed") {
+          setRestarts((prev) => {
+            const current = prev[event.agentId];
+            if (!current || current.restartId !== event.restartId) return prev;
+            return {
+              ...prev,
+              [event.agentId]: {
+                ...current,
+                phase: event.phase,
+                outcome: "failed",
+                message: event.message,
+              },
+            };
+          });
+          setRestartJournal((prev) => appendRestartJournal(prev, event));
         }
       })
       .then((un) => {
@@ -143,8 +246,8 @@ export function AnnouncementsProvider({
   }, [system, projectId]);
 
   const store = useMemo<AnnouncementsStore>(
-    () => ({ index, busy, seedBusy }),
+    () => ({ index, busy, restarts, restartJournal, seedBusy }),
-    [index, busy, seedBusy],
+    [index, busy, restarts, restartJournal, seedBusy],
   );
 
   return (
@@ -154,6 +257,19 @@ export function AnnouncementsProvider({
   );
 }
 
+function appendRestartJournal(
+  journal: RestartJournal,
+  event: AgentRestartJournalEvent,
+): RestartJournal {
+  const key = `${event.restartId}:${event.type}`;
+  const previous = journal[event.agentId] ?? [];
+  if (previous.some((item) => `${item.restartId}:${item.type}` === key)) return journal;
+  return {
+    ...journal,
+    [event.agentId]: [...previous, event].slice(-12),
+  };
+}
+
 /** The store, or an inert default when read outside a provider. */
 function useStore(): AnnouncementsStore {
   return useContext(AnnouncementsContext) ?? DEFAULT_STORE;
@@ -183,6 +299,20 @@ export function useTargetAnnouncements(target: string): {
   );
 }
 
+export function useAgentRestart(agentId: string): {
+  restart: AgentRestartPresentation | null;
+  events: AgentRestartJournalEvent[];
+} {
+  const { restarts, restartJournal } = useStore();
+  return useMemo(
+    () => ({
+      restart: restarts[agentId] ?? null,
+      events: restartJournal[agentId] ?? [],
+    }),
+    [agentId, restartJournal, restarts],
+  );
+}
+
 /**
  * Hydrates the target's busy state from the reconciled read-model at mount/reboot,
  * so an overlay mounts for a turn already in flight when its cell appears — no live

frontend/src/features/announcements/index.ts

@@ -7,7 +7,18 @@ export {
   AnnouncementsProvider,
   useTargetAnnouncements,
   useRequesterAnnouncements,
+  useAgentRestart,
 } from "./AnnouncementsProvider";
+export type {
+  AgentRestartJournalEvent,
+  AgentRestartPresentation,
+} from "./AnnouncementsProvider";
+export {
+  AgentRestartOverlay,
+  restartOverlayLabel,
+  shortRestartFailure,
+  type AgentRestartOverlayProps,
+} from "./AgentRestartOverlay";
 export {
   TargetAnnouncementsOverlay,
   type TargetAnnouncementsOverlayProps,

frontend/src/features/layout/LayoutGrid.cellControlsLayering.test.tsx

@@ -367,4 +367,26 @@ describe("LayoutGrid — ticket #48 cell control layering", () => {
       );
     },
   );
+
+  it("gives the native TUI restart overlay priority over other cell veils", async () => {
+    const setup = await makeSplitAgentGrid();
+    renderGrid(setup.gateways);
+    await flush();
+
+    act(() => {
+      setup.system.emit(busy(setup.agentId, true));
+      setup.system.emit({
+        type: "agentRestartRequested",
+        agentId: setup.agentId,
+        restartId: "restart-1",
+        reason: null,
+      });
+    });
+
+    const overlay = await screen.findByTestId("agent-restart-overlay");
+    expect(overlay.className).toContain("z-[4]");
+    expect(screen.queryByTestId("target-announcements-overlay")).toBeNull();
+    expect(screen.queryByText("------- redemarrage de l'agent -------")).toBeNull();
+    expect(controlsFor(setup.bId).controls.style.zIndex).toBe("5");
+  });
 });

frontend/src/features/layout/LayoutGrid.tsx

@@ -30,7 +30,9 @@ import { TerminalView, useWritePortal } from "@/features/terminals";
 import { useGateways } from "@/app/di";
 import { useProjectWorkState } from "@/features/workstate/useProjectWorkState";
 import {
+  AgentRestartOverlay,
   TargetAnnouncementsOverlay,
+  useAgentRestart,
   useTargetAnnouncements,
 } from "@/features/announcements";
 import { PluginLayoutCellView } from "@/features/plugins";
@@ -623,6 +625,7 @@ function LeafView({
   // write-portal veil can be mutually excluded with the F3 overlay (exactly one
   // full-cell veil at a time, F3 first). Same source the overlay itself reads.
   const { active: announcementBusyActive } = useTargetAnnouncements(agentId ?? "");
+  const { restart: agentRestart } = useAgentRestart(agentId ?? "");
   // Ticket #54 — local model-server launch state for this cell's pinned agent.
   // Correlated `agentId → profileId → opencode.localModelServerId → status` via
   // the shared hook (same reduction as `useAgents`). While the bound server is
@@ -1466,7 +1469,8 @@ function LeafView({
             is being injected into the agent's PTY, a grey veil with a centred
             message sits above the terminal. Only ever shown for an agent cell —
             and never together with the F3 overlay (exactly one veil, F3 first). */}
-        {!modelServerOverlay &&
+        {!agentRestart &&
+          !modelServerOverlay &&
           cellMode !== "custom" &&
           shouldShowWritePortalVeil(agentId != null, Boolean(overlay), busyActive) && (
           <div
@@ -1504,7 +1508,7 @@ function LeafView({
             an availability veil showing its live réflexions. Native TUI cells
             need the full-cell guard; custom CLI cells keep the canonical busy
             badge and composer lock only, matching their normal chat turn flow. */}
-        {!modelServerOverlay && cellMode !== "custom" && agentId != null && (
+        {!agentRestart && !modelServerOverlay && cellMode !== "custom" && agentId != null && (
           <TargetAnnouncementsOverlay
             projectId={projectId}
             agentId={agentId}
@@ -1517,7 +1521,7 @@ function LeafView({
             agent's bound local server is downloading its model / starting /
             probing, the empty terminal is covered rather than left to time out.
             Retracts at `ready`/`failed` (the predicate returns null then). */}
-        {modelServerOverlay && (
+        {!agentRestart && modelServerOverlay && (
           <div
             data-testid="model-server-overlay"
             role="status"
@@ -1634,6 +1638,9 @@ function LeafView({
             </div>
           </div>
         )}
+        {cellMode !== "custom" && agentId != null && agentRestart && (
+          <AgentRestartOverlay agentId={agentId} />
+        )}
       </div>
       {busyNotice && (
         <div