feat(core): Land AgentHistoryProvider. (#23978)

packages/cli/src/config/config.ts

@@ -975,6 +975,14 @@ export async function loadCliConfig(
     disabledSkills: settings.skills?.disabled,
     experimentalJitContext: settings.experimental?.jitContext,
     experimentalMemoryManager: settings.experimental?.memoryManager,
+    experimentalAgentHistoryTruncation:
+      settings.experimental?.agentHistoryTruncation,
+    experimentalAgentHistoryTruncationThreshold:
+      settings.experimental?.agentHistoryTruncationThreshold,
+    experimentalAgentHistoryRetainedMessages:
+      settings.experimental?.agentHistoryRetainedMessages,
+    experimentalAgentHistorySummarization:
+      settings.experimental?.agentHistorySummarization,
     modelSteering: settings.experimental?.modelSteering,
     topicUpdateNarration: settings.experimental?.topicUpdateNarration,
     toolOutputMasking: settings.experimental?.toolOutputMasking,

packages/cli/src/config/settingsSchema.ts

@@ -2141,6 +2141,46 @@ const SETTINGS_SCHEMA = {
           'Replace the built-in save_memory tool with a memory manager subagent that supports adding, removing, de-duplicating, and organizing memories.',
         showInDialog: true,
       },
+      agentHistoryTruncation: {
+        type: 'boolean',
+        label: 'Agent History Truncation',
+        category: 'Experimental',
+        requiresRestart: true,
+        default: false,
+        description:
+          'Enable truncation window logic for the Agent History Provider.',
+        showInDialog: true,
+      },
+      agentHistoryTruncationThreshold: {
+        type: 'number',
+        label: 'Agent History Truncation Threshold',
+        category: 'Experimental',
+        requiresRestart: true,
+        default: 30,
+        description:
+          'The maximum number of messages before history is truncated.',
+        showInDialog: true,
+      },
+      agentHistoryRetainedMessages: {
+        type: 'number',
+        label: 'Agent History Retained Messages',
+        category: 'Experimental',
+        requiresRestart: true,
+        default: 15,
+        description:
+          'The number of recent messages to retain after truncation.',
+        showInDialog: true,
+      },
+      agentHistorySummarization: {
+        type: 'boolean',
+        label: 'Agent History Summarization',
+        category: 'Experimental',
+        requiresRestart: true,
+        default: false,
+        description:
+          'Enable summarization of truncated content via a small model for the Agent History Provider.',
+        showInDialog: true,
+      },
       topicUpdateNarration: {
         type: 'boolean',
         label: 'Topic & Update Narration',