Merge pull request #178 from Opencode-DCP/feat/split-prune-into-discard-and-extract

Split prune tool into discard and extract

Author: Tarquinen

README.md

@@ -29,7 +29,9 @@ DCP uses multiple strategies to reduce context size:
 
 **Supersede Writes** — Prunes write tool inputs for files that have subsequently been read. When a file is written and later read, the original write content becomes redundant since the current file state is captured in the read result. Runs automatically on every request with zero LLM cost.
 
-**Prune Tool** — Exposes a `prune` tool that the AI can call to manually trigger pruning when it determines context cleanup is needed.
+**Discard Tool** — Exposes a `discard` tool that the AI can call to remove completed or noisy tool outputs from context. Use this for task completion cleanup and removing irrelevant outputs.
+
+**Extract Tool** — Exposes an `extract` tool that the AI can call to distill valuable context into concise summaries before removing the raw outputs. Use this when you need to preserve key findings while reducing context size.
 
 **On Idle Analysis** — Uses a language model to semantically analyze conversation context during idle periods and identify tool outputs that are no longer relevant.
 
@@ -72,8 +74,8 @@ DCP uses its own config file:
     "supersedeWrites": {
       "enabled": true
     },
-    // Exposes a prune tool to your LLM to call when it determines pruning is necessary
-    "pruneTool": {
+    // Removes tool content from context without preservation (for completed tasks or noise)
+    "discardTool": {
       "enabled": true,
       // Additional tools to protect from pruning
       "protectedTools": [],
@@ -82,12 +84,30 @@ DCP uses its own config file:
         "enabled": false,
         "turns": 4
       },
-      // Nudge the LLM to use the prune tool (every <frequency> tool results)
+      // Nudge the LLM to use the discard tool (every <frequency> tool results)
       "nudge": {
         "enabled": true,
         "frequency": 10
       }
     },
+    // Distills key findings into preserved knowledge before removing raw content
+    "extractTool": {
+      "enabled": true,
+      // Additional tools to protect from pruning
+      "protectedTools": [],
+      // Protect from pruning for <turn protection> message turns
+      "turnProtection": {
+        "enabled": false,
+        "turns": 4
+      },
+      // Nudge the LLM to use the extract tool (every <frequency> tool results)
+      "nudge": {
+        "enabled": true,
+        "frequency": 10
+      },
+      // Show distillation content as an ignored message notification
+      "showDistillation": false
+    },
     // (Legacy) Run an LLM to analyze what tool calls are no longer relevant on idle
     "onIdle": {
       "enabled": false,
@@ -109,7 +129,7 @@ DCP uses its own config file:
 ### Protected Tools
 
 By default, these tools are always protected from pruning across all strategies:
-`task`, `todowrite`, `todoread`, `prune`, `batch`
+`task`, `todowrite`, `todoread`, `discard`, `extract`, `batch`
 
 The `protectedTools` arrays in each strategy add to this default list.
 

index.ts

@@ -3,7 +3,7 @@ import { getConfig } from "./lib/config"
 import { Logger } from "./lib/logger"
 import { loadPrompt } from "./lib/prompt"
 import { createSessionState } from "./lib/state"
-import { createPruneTool } from "./lib/strategies"
+import { createDiscardTool, createExtractTool } from "./lib/strategies"
 import { createChatMessageTransformHandler, createEventHandler } from "./lib/hooks"
 
 const plugin: Plugin = (async (ctx) => {
@@ -18,18 +18,30 @@ const plugin: Plugin = (async (ctx) => {
         (globalThis as any).AI_SDK_LOG_WARNINGS = false
     }
 
-    // Initialize core components
     const logger = new Logger(config.debug)
     const state = createSessionState()
 
-    // Log initialization
     logger.info("DCP initialized", {
         strategies: config.strategies,
     })
 
     return {
         "experimental.chat.system.transform": async (_input: unknown, output: { system: string[] }) => {
-            const syntheticPrompt = loadPrompt("prune-system-prompt")
+            const discardEnabled = config.strategies.discardTool.enabled
+            const extractEnabled = config.strategies.extractTool.enabled
+
+            let promptName: string
+            if (discardEnabled && extractEnabled) {
+                promptName = "system/system-prompt-both"
+            } else if (discardEnabled) {
+                promptName = "system/system-prompt-discard"
+            } else if (extractEnabled) {
+                promptName = "system/system-prompt-extract"
+            } else {
+                return
+            }
+
+            const syntheticPrompt = loadPrompt(promptName)
             output.system.push(syntheticPrompt)
         },
         "experimental.chat.messages.transform": createChatMessageTransformHandler(
@@ -38,25 +50,40 @@ const plugin: Plugin = (async (ctx) => {
             logger,
             config
         ),
-        tool: config.strategies.pruneTool.enabled ? {
-            prune: createPruneTool({
-                client: ctx.client,
-                state,
-                logger,
-                config,
-                workingDirectory: ctx.directory
+        tool: {
+            ...(config.strategies.discardTool.enabled && {
+                discard: createDiscardTool({
+                    client: ctx.client,
+                    state,
+                    logger,
+                    config,
+                    workingDirectory: ctx.directory
+                }),
             }),
-        } : undefined,
+            ...(config.strategies.extractTool.enabled && {
+                extract: createExtractTool({
+                    client: ctx.client,
+                    state,
+                    logger,
+                    config,
+                    workingDirectory: ctx.directory
+                }),
+            }),
+        },
         config: async (opencodeConfig) => {
-            // Add prune to primary_tools by mutating the opencode config
+            // Add enabled tools to primary_tools by mutating the opencode config
             // This works because config is cached and passed by reference
-            if (config.strategies.pruneTool.enabled) {
+            const toolsToAdd: string[] = []
+            if (config.strategies.discardTool.enabled) toolsToAdd.push("discard")
+            if (config.strategies.extractTool.enabled) toolsToAdd.push("extract")
+
+            if (toolsToAdd.length > 0) {
                 const existingPrimaryTools = opencodeConfig.experimental?.primary_tools ?? []
                 opencodeConfig.experimental = {
                     ...opencodeConfig.experimental,
-                    primary_tools: [...existingPrimaryTools, "prune"],
+                    primary_tools: [...existingPrimaryTools, ...toolsToAdd],
                 }
-                logger.info("Added 'prune' to experimental.primary_tools via config mutation")
+                logger.info(`Added ${toolsToAdd.map(t => `'${t}'`).join(" and ")} to experimental.primary_tools via config mutation`)
             }
         },
         event: createEventHandler(ctx.client, config, state, logger, ctx.directory),