feat: activationThreshold

index.ts

@@ -33,15 +33,22 @@ const plugin: Plugin = (async (ctx) => {
             const discardEnabled = config.tools.discard.enabled
             const extractEnabled = config.tools.extract.enabled
 
+            if (!discardEnabled && !extractEnabled) {
+                return
+            }
+
+            const threshold = config.tools.settings.activationThreshold
+            if (state.thresholdState < threshold) {
+                return
+            }
+
             let promptName: string
             if (discardEnabled && extractEnabled) {
                 promptName = "user/system/system-prompt-both"
             } else if (discardEnabled) {
                 promptName = "user/system/system-prompt-discard"
-            } else if (extractEnabled) {
-                promptName = "user/system/system-prompt-extract"
             } else {
-                return
+                promptName = "user/system/system-prompt-extract"
             }
 
             const syntheticPrompt = loadPrompt(promptName)

lib/config.ts

@@ -30,6 +30,7 @@ export interface ToolSettings {
     nudgeEnabled: boolean
     nudgeFrequency: number
     protectedTools: string[]
+    activationThreshold: number
 }
 
 export interface Tools {
@@ -84,6 +85,7 @@ export const VALID_CONFIG_KEYS = new Set([
     "tools.settings.nudgeEnabled",
     "tools.settings.nudgeFrequency",
     "tools.settings.protectedTools",
+    "tools.settings.activationThreshold",
     "tools.discard",
     "tools.discard.enabled",
     "tools.extract",
@@ -216,6 +218,16 @@ function validateConfigTypes(config: Record<string, any>): ValidationError[] {
                     actual: typeof tools.settings.protectedTools,
                 })
             }
+            if (
+                tools.settings.minToolOutputTokens !== undefined &&
+                typeof tools.settings.minToolOutputTokens !== "number"
+            ) {
+                errors.push({
+                    key: "tools.settings.minToolOutputTokens",
+                    expected: "number",
+                    actual: typeof tools.settings.minToolOutputTokens,
+                })
+            }
         }
         if (tools.discard) {
             if (tools.discard.enabled !== undefined && typeof tools.discard.enabled !== "boolean") {
@@ -437,6 +449,7 @@ const defaultConfig: PluginConfig = {
             nudgeEnabled: true,
             nudgeFrequency: 10,
             protectedTools: [...DEFAULT_PROTECTED_TOOLS],
+            activationThreshold: 5000,
         },
         discard: {
             enabled: true,
@@ -555,7 +568,9 @@ function createDefaultConfig(): void {
       "nudgeEnabled": true,
       "nudgeFrequency": 10,
       // Additional tools to protect from pruning
-      "protectedTools": []
+      "protectedTools": [],
+      // Minimum tool output tokens before injecting prune context
+      "activationThreshold": 5000
     },
     // Removes tool content from context without preservation (for completed tasks or noise)
     "discard": {
@@ -693,6 +708,8 @@ function mergeTools(
                     ...(override.settings?.protectedTools ?? []),
                 ]),
             ],
+            activationThreshold:
+                override.settings?.activationThreshold ?? base.settings.activationThreshold,
         },
         discard: {
             enabled: override.discard?.enabled ?? base.discard.enabled,

lib/hooks.ts

@@ -6,6 +6,7 @@ import { deduplicate, supersedeWrites, purgeErrors } from "./strategies"
 import { prune, insertPruneToolContext } from "./messages"
 import { checkSession } from "./state"
 import { runOnIdle } from "./strategies/on-idle"
+import { getThreshold } from "./shared-utils"
 
 export function createChatMessageTransformHandler(
     client: any,
@@ -28,6 +29,8 @@ export function createChatMessageTransformHandler(
 
         prune(state, logger, config, output.messages)
 
+        state.thresholdState = getThreshold(state, output.messages)
+
         insertPruneToolContext(state, config, logger, output.messages)
 
         if (state.sessionId) {

lib/messages/prune.ts

@@ -102,6 +102,14 @@ export const insertPruneToolContext = (
         return
     }
 
+    const threshold = config.tools.settings.activationThreshold
+    if (state.thresholdState < threshold) {
+        logger.debug(
+            `Skipping prune context injection: ${state.thresholdState} tokens < ${threshold} threshold`,
+        )
+        return
+    }
+
     let prunableToolsContent: string
 
     if (state.lastToolPrune) {

lib/shared-utils.ts

@@ -1,9 +1,38 @@
+import { encode } from "gpt-tokenizer"
 import { SessionState, WithParts } from "./state"
 
 export const isMessageCompacted = (state: SessionState, msg: WithParts): boolean => {
     return msg.info.time.created < state.lastCompaction
 }
 
+export const getThreshold = (state: SessionState, messages: WithParts[]): number => {
+    let totalTokens = 0
+
+    for (const msg of messages) {
+        if (isMessageCompacted(state, msg)) {
+            continue
+        }
+
+        for (const part of msg.parts) {
+            if (part.type !== "tool") {
+                continue
+            }
+            if (state.prune.toolIds.includes(part.callID)) {
+                continue
+            }
+            if (part.state.status === "completed") {
+                const output = part.state.output
+                if (output) {
+                    const outputStr = typeof output === "string" ? output : JSON.stringify(output)
+                    totalTokens += encode(outputStr).length
+                }
+            }
+        }
+    }
+
+    return totalTokens
+}
+
 export const getLastUserMessage = (messages: WithParts[]): WithParts | null => {
     for (let i = messages.length - 1; i >= 0; i--) {
         const msg = messages[i]

lib/state/state.ts

@@ -55,6 +55,7 @@ export function createSessionState(): SessionState {
         lastToolPrune: false,
         lastCompaction: 0,
         currentTurn: 0,
+        thresholdState: 0,
     }
 }
 
@@ -73,6 +74,7 @@ export function resetSessionState(state: SessionState): void {
     state.lastToolPrune = false
     state.lastCompaction = 0
     state.currentTurn = 0
+    state.thresholdState = 0
 }
 
 export async function ensureSessionInitialized(

lib/state/types.ts

@@ -33,5 +33,6 @@ export interface SessionState {
     nudgeCounter: number
     lastToolPrune: boolean
     lastCompaction: number
-    currentTurn: number // Current turn count derived from step-start parts
+    currentTurn: number
+    thresholdState: number
 }