fix(session): check for context overflow mid-turn in finish-step (#6480)

packages/opencode/src/session/processor.ts

@@ -13,6 +13,7 @@ import { Plugin } from "@/plugin"
 import type { Provider } from "@/provider/provider"
 import { LLM } from "./llm"
 import { Config } from "@/config/config"
+import { SessionCompaction } from "./compaction"
 
 export namespace SessionProcessor {
   const DOOM_LOOP_THRESHOLD = 3
@@ -31,6 +32,7 @@ export namespace SessionProcessor {
     let snapshot: string | undefined
     let blocked = false
     let attempt = 0
+    let needsCompaction = false
 
     const result = {
       get message() {
@@ -41,6 +43,7 @@ export namespace SessionProcessor {
       },
       async process(streamInput: LLM.StreamInput) {
         log.info("process")
+        needsCompaction = false
         const shouldBreak = (await Config.get()).experimental?.continue_loop_on_deny !== true
         while (true) {
           try {
@@ -279,6 +282,9 @@ export namespace SessionProcessor {
                     sessionID: input.sessionID,
                     messageID: input.assistantMessage.parentID,
                   })
+                  if (await SessionCompaction.isOverflow({ tokens: usage.tokens, model: input.model })) {
+                    needsCompaction = true
+                  }
                   break
 
                 case "text-start":
@@ -339,6 +345,7 @@ export namespace SessionProcessor {
                   })
                   continue
               }
+              if (needsCompaction) break
             }
           } catch (e: any) {
             log.error("process", {
@@ -398,6 +405,7 @@ export namespace SessionProcessor {
           }
           input.assistantMessage.time.completed = Date.now()
           await Session.updateMessage(input.assistantMessage)
+          if (needsCompaction) return "compact"
           if (blocked) return "stop"
           if (input.assistantMessage.error) return "stop"
           return "continue"

packages/opencode/src/session/prompt.ts

@@ -549,6 +549,14 @@ export namespace SessionPrompt {
         model,
       })
       if (result === "stop") break
+      if (result === "compact") {
+        await SessionCompaction.create({
+          sessionID,
+          agent: lastUser.agent,
+          model: lastUser.model,
+          auto: true,
+        })
+      }
       continue
     }
     SessionCompaction.prune({ sessionID })