feat: session history compaction support via SDK ^0.1.26

package.json

@@ -15,7 +15,7 @@
     "test:watch": "vitest"
   },
   "dependencies": {
-    "@github/copilot-sdk": "^0.1.24",
+    "@github/copilot-sdk": "^0.1.26",
     "ink": "^5.1.0",
     "ink-select-input": "^6.0.0",
     "ink-spinner": "^5.0.0",

src/components/status-bar.tsx

@@ -7,16 +7,18 @@ interface StatusBarProps {
   screen: string;
   hint?: string;
   model?: string;
+  extra?: string;
 }
 
-export default function StatusBar({ screen, hint, model }: StatusBarProps): React.ReactElement {
+export default function StatusBar({ screen, hint, model, extra }: StatusBarProps): React.ReactElement {
   const displayModel = model || getModelLabel();
   const { stdout } = useStdout();
   // Parent App uses padding={1} → 2 cols consumed; border chars │…│ take 2 more
   const innerWidth = (stdout?.columns ?? 80) - 4;
 
-  // Build right-side content: "model  hint  q: quit"
+  // Build right-side content: "model  extra  hint  q: quit"
   const rightParts: string[] = [displayModel];
+  if (extra) rightParts.push(extra);
   if (hint) rightParts.push(hint);
   rightParts.push('q: quit');
   const rightText = rightParts.join('  ');

src/screens/clarify.tsx

@@ -26,6 +26,7 @@ export default function ClarifyScreen({ onScopeConfirmed, onBack }: ClarifyScree
   const [codebaseContext, setCodebaseContext] = useState('');
   const [inspecting, setInspecting] = useState(false);
   const [inspectDone, setInspectDone] = useState(false);
+  const [compactionMsg, setCompactionMsg] = useState('');
 
   useEffect(() => {
     loadHistory().then(setHistory);
@@ -108,6 +109,19 @@ export default function ClarifyScreen({ onScopeConfirmed, onBack }: ClarifyScree
           ]);
           setStreaming(false);
         },
+        onSessionEvent: (event) => {
+          if (event.type === 'session.compaction_start') {
+            setCompactionMsg('⟳ Compacting session history…');
+          } else if (event.type === 'session.compaction_complete') {
+            if (event.data.success) {
+              const removed = event.data.messagesRemoved ?? 0;
+              setCompactionMsg(`✓ Session history compacted (${removed} messages removed)`);
+            } else {
+              setCompactionMsg(`⚠ Compaction failed: ${event.data.error ?? 'unknown error'}`);
+            }
+            setTimeout(() => setCompactionMsg(''), 5000);
+          }
+        },
       }, codebaseContext || undefined).catch((error: Error) => {
         setMessages((prev) => [
           ...prev,
@@ -232,6 +246,13 @@ export default function ClarifyScreen({ onScopeConfirmed, onBack }: ClarifyScree
         </Box>
       )}
 
+      {/* Compaction notification */}
+      {compactionMsg !== '' && (
+        <Box marginBottom={1}>
+          <Text color="magenta">{compactionMsg}</Text>
+        </Box>
+      )}
+
       <StatusBar
         screen="Clarify"
         hint={

src/screens/execute.tsx

@@ -48,6 +48,8 @@ export default function ExecuteScreen({
   const [summarized, setSummarized] = useState('');
   const [sessionEvents, setSessionEvents] = useState<SessionEventWithTask[]>([]);
   const [taskContexts, setTaskContexts] = useState<Record<string, { cwd?: string; repository?: string; branch?: string }>>({});
+  const [tokenUsage, setTokenUsage] = useState<{ tokenLimit: number; currentTokens: number } | null>(null);
+  const [compactionMsg, setCompactionMsg] = useState('');
 
   const { batches } = computeBatches(plan.tasks);
   // Total display batches: init batch (index 0) + real batches
@@ -211,6 +213,20 @@ export default function ExecuteScreen({
             ...prev,
             [taskId]: { cwd, repository, branch },
           }));
+        } else if (event.type === 'session.usage_info') {
+          setTokenUsage({ tokenLimit: event.data.tokenLimit, currentTokens: event.data.currentTokens });
+        } else if (event.type === 'session.compaction_start') {
+          setCompactionMsg('⟳ Compacting session history…');
+        } else if (event.type === 'session.compaction_complete') {
+          if (event.data.success) {
+            const removed = event.data.messagesRemoved ?? 0;
+            const pre = event.data.preCompactionTokens ?? 0;
+            const post = event.data.postCompactionTokens ?? 0;
+            setCompactionMsg(`✓ Compacted: ${removed} messages removed (${pre}→${post} tokens)`);
+          } else {
+            setCompactionMsg(`⚠ Compaction failed: ${event.data.error ?? 'unknown error'}`);
+          }
+          setTimeout(() => setCompactionMsg(''), 5000);
         }
       },
     }, execOptions);
@@ -456,6 +472,13 @@ export default function ExecuteScreen({
         </Box>
       )}
 
+      {/* Compaction notification */}
+      {compactionMsg !== '' && (
+        <Box marginBottom={1}>
+          <Text color="magenta">{compactionMsg}</Text>
+        </Box>
+      )}
+
       <StatusBar
         screen="Execute"
         hint={
@@ -469,6 +492,7 @@ export default function ExecuteScreen({
                   ? '←→: switch batch  ↑↓: select task  z: summarize  esc: back'
                   : 'x: start  esc: back'
         }
+        extra={tokenUsage ? `ctx: ${Math.round((tokenUsage.currentTokens / tokenUsage.tokenLimit) * 100)}%` : undefined}
       />
     </Box>
   );

src/screens/refine.tsx

@@ -41,6 +41,7 @@ export default function RefineScreen({
   const [viewMode, setViewMode] = useState<ViewMode>('tree');
   const [editingTask, setEditingTask] = useState<Task | null>(null);
   const [commandMode, setCommandMode] = useState(false);
+  const [compactionMsg, setCompactionMsg] = useState('');
 
   const toggleSkill = useCallback(
     (skillName: string) => {
@@ -164,7 +165,19 @@ export default function RefineScreen({
         .then((skillOptions) => 
           refineWBS(currentPlan.tasks, value, (_delta, fullText) => {
             setStreamText(fullText);
-          }, skillOptions)
+          }, skillOptions, (event) => {
+            if (event.type === 'session.compaction_start') {
+              setCompactionMsg('⟳ Compacting session history…');
+            } else if (event.type === 'session.compaction_complete') {
+              if (event.data.success) {
+                const removed = event.data.messagesRemoved ?? 0;
+                setCompactionMsg(`✓ Session history compacted (${removed} messages removed)`);
+              } else {
+                setCompactionMsg(`⚠ Compaction failed: ${event.data.error ?? 'unknown error'}`);
+              }
+              setTimeout(() => setCompactionMsg(''), 5000);
+            }
+          })
         )
         .then((tasks) => {
           const updated = { ...currentPlan, tasks, updatedAt: new Date().toISOString() };
@@ -301,6 +314,13 @@ export default function RefineScreen({
 
       {saved && <Text color="green">✓ Plan saved</Text>}
 
+      {/* Compaction notification */}
+      {compactionMsg !== '' && (
+        <Box marginBottom={1}>
+          <Text color="magenta">{compactionMsg}</Text>
+        </Box>
+      )}
+
       <StatusBar
         screen="Refine"
         hint={viewMode === 'skills' 

src/services/copilot.ts

@@ -177,6 +177,9 @@ export async function stopClient(): Promise<void> {
   }
 }
 
+/** Default context utilization threshold (0.0–1.0) at which background compaction starts. */
+export const COMPACTION_THRESHOLD = 0.8;
+
 export interface StreamCallbacks {
   onDelta: (text: string) => void;
   onDone: (fullText: string) => void;
@@ -205,11 +208,13 @@ export async function sendPrompt(
       streaming: boolean;
       skillDirectories?: string[];
       disabledSkills?: string[];
+      infiniteSessions?: { backgroundCompactionThreshold?: number };
     }
 
     const sessionConfig: SessionConfigWithSkills = {
       model: currentModel,
       streaming: true,
+      infiniteSessions: { backgroundCompactionThreshold: COMPACTION_THRESHOLD },
     };
 
     if (skillOptions?.skillDirectories && skillOptions.skillDirectories.length > 0) {