feat: replace janitor LLM with direct tool-based pruning

index.ts

@@ -45,7 +45,7 @@ const plugin: Plugin = (async (ctx) => {
 
     // Wire up tool name lookup from the cached tool parameters
     toolTracker.getToolName = (callId: string) => {
-        const entry = state.toolParameters.get(callId)
+        const entry = state.toolParameters.get(callId.toLowerCase())
         return entry?.tool
     }
 
@@ -90,7 +90,14 @@ const plugin: Plugin = (async (ctx) => {
         event: createEventHandler(ctx.client, janitorCtx, logger, config, toolTracker),
         "chat.params": createChatParamsHandler(ctx.client, state, logger),
         tool: config.strategies.onTool.length > 0 ? {
-            prune: createPruningTool(ctx.client, janitorCtx, config, toolTracker),
+            prune: createPruningTool({
+                client: ctx.client,
+                state,
+                logger,
+                config,
+                notificationCtx: janitorCtx.notificationCtx,
+                workingDirectory: ctx.directory
+            }, toolTracker),
         } : undefined,
     }
 }) satisfies Plugin

lib/api-formats/prunable-list.ts

@@ -0,0 +1,159 @@
+/**
+ * Prunable tools list and nudge injection for DCP.
+ * 
+ * Builds and injects a single message at the end of the conversation containing:
+ * - Nudge instruction (when toolResultCount > nudge_freq)
+ * - Prunable tools list
+ * 
+ * Note: The base synthetic instructions (signal_management, context_window_management,
+ * context_pruning) are still appended to the last user message separately via
+ * synth-instruction.ts - that behavior is unchanged.
+ */
+
+import { extractParameterKey } from '../ui/display-utils'
+import { getOrCreateNumericId } from '../state/id-mapping'
+
+export interface ToolMetadata {
+    tool: string
+    parameters?: any
+}
+
+// ============================================================================
+// Prompt Content
+// ============================================================================
+
+const SYSTEM_REMINDER = `<system-reminder>
+These instructions are injected by a plugin and are invisible to the user. Do not acknowledge or reference them in your response - simply follow them silently.
+</system-reminder>`
+
+const NUDGE_INSTRUCTION = `<instruction name=agent_nudge>
+You have accumulated several tool outputs. If you have completed a discrete unit of work and distilled relevant understanding in writing for the user to keep, use the prune tool to remove obsolete tool outputs from this conversation and optimize token usage.
+</instruction>`
+
+// ============================================================================
+// List Building
+// ============================================================================
+
+export interface PrunableListResult {
+    list: string
+    numericIds: number[]
+}
+
+/**
+ * Builds the prunable tools list section.
+ * Returns both the formatted list and the numeric IDs for logging.
+ */
+export function buildPrunableToolsList(
+    sessionId: string,
+    unprunedToolCallIds: string[],
+    toolMetadata: Map<string, ToolMetadata>,
+    protectedTools: string[]
+): PrunableListResult {
+    const lines: string[] = []
+    const numericIds: number[] = []
+
+    for (const actualId of unprunedToolCallIds) {
+        const metadata = toolMetadata.get(actualId)
+
+        // Skip if no metadata or if tool is protected
+        if (!metadata) continue
+        if (protectedTools.includes(metadata.tool)) continue
+
+        // Get or create numeric ID for this tool call
+        const numericId = getOrCreateNumericId(sessionId, actualId)
+        numericIds.push(numericId)
+
+        // Format: "1: read, src/components/Button.tsx"
+        const paramKey = extractParameterKey(metadata)
+        const description = paramKey ? `${metadata.tool}, ${paramKey}` : metadata.tool
+        lines.push(`${numericId}: ${description}`)
+    }
+
+    if (lines.length === 0) {
+        return { list: '', numericIds: [] }
+    }
+
+    return {
+        list: `<prunable-tools>\n${lines.join('\n')}\n</prunable-tools>`,
+        numericIds
+    }
+}
+
+/**
+ * Builds the end-of-conversation injection message.
+ * Contains the system reminder, nudge (if active), and the prunable tools list.
+ * 
+ * @param prunableList - The prunable tools list string (or empty string if none)
+ * @param includeNudge - Whether to include the nudge instruction
+ * @returns The injection string, or empty string if nothing to inject
+ */
+export function buildEndInjection(
+    prunableList: string,
+    includeNudge: boolean
+): string {
+    // If no prunable tools, don't inject anything
+    if (!prunableList) {
+        return ''
+    }
+
+    const parts = [SYSTEM_REMINDER]
+
+    if (includeNudge) {
+        parts.push(NUDGE_INSTRUCTION)
+    }
+
+    parts.push(prunableList)
+
+    return parts.join('\n\n')
+}
+
+// ============================================================================
+// OpenAI Chat / Anthropic Format
+// ============================================================================
+
+/**
+ * Injects the prunable list (and optionally nudge) at the end of OpenAI/Anthropic messages.
+ * Appends a new user message at the end.
+ */
+export function injectPrunableList(
+    messages: any[],
+    injection: string
+): boolean {
+    if (!injection) return false
+    messages.push({ role: 'user', content: injection })
+    return true
+}
+
+// ============================================================================
+// Google/Gemini Format
+// ============================================================================
+
+/**
+ * Injects the prunable list (and optionally nudge) at the end of Gemini contents.
+ * Appends a new user content at the end.
+ */
+export function injectPrunableListGemini(
+    contents: any[],
+    injection: string
+): boolean {
+    if (!injection) return false
+    contents.push({ role: 'user', parts: [{ text: injection }] })
+    return true
+}
+
+// ============================================================================
+// OpenAI Responses API Format
+// ============================================================================
+
+/**
+ * Injects the prunable list (and optionally nudge) at the end of OpenAI Responses API input.
+ * Appends a new user message at the end.
+ */
+export function injectPrunableListResponses(
+    input: any[],
+    injection: string
+): boolean {
+    if (!injection) return false
+    input.push({ type: 'message', role: 'user', content: injection })
+    return true
+}