fix(core): bound compaction request size

packages/core/src/session/compaction.ts

@@ -17,6 +17,8 @@ import { Token } from "../util/token"
 const DEFAULT_BUFFER = 20_000
 const DEFAULT_KEEP_TOKENS = 8_000
 const TOOL_OUTPUT_MAX_CHARS = 2_000
+const COMPACTION_CHUNK_TOKENS = 32_000
+const SUMMARY_OUTPUT_TOKENS = 4_096
 const SUMMARY_TEMPLATE = `Output exactly the Markdown structure shown inside <template> and keep the section order unchanged. Do not include the <template> tags in your response.
 <template>
 ## Objective
@@ -80,7 +82,8 @@ type Plan = {
   readonly sessionID: SessionSchema.ID
   readonly model: Model
   readonly reason: SessionMessage.Compaction["reason"]
-  readonly prompt: string
+  readonly previousSummary?: string
+  readonly context: readonly string[]
   readonly recent: string
   readonly inputID?: SessionMessage.ID
 }
@@ -199,6 +202,14 @@ export const buildPrompt = (input: { readonly previousSummary?: string; readonly
     ...input.context,
   ].join("\n\n")
 
+const chunkContext = (context: readonly string[]) => {
+  const value = context.filter(Boolean).join("\n\n")
+  const size = COMPACTION_CHUNK_TOKENS * 4
+  return Array.from({ length: Math.ceil(value.length / size) }, (_, index) =>
+    value.slice(index * size, (index + 1) * size),
+  )
+}
+
 const planContent = (messages: readonly SessionMessage.Info[], tokens: number) => {
   const selected = select(messages, tokens)
   if (!selected) return
@@ -208,10 +219,8 @@ const planContent = (messages: readonly SessionMessage.Info[], tokens: number) =
   const previousRecent = previousSummary?.type === "compaction" ? previousSummary.recent : ""
   const summarizeRecent = !previousRecent && !selected.head
   return {
-    prompt: buildPrompt({
-      previousSummary: previousSummary?.type === "compaction" ? previousSummary.summary : undefined,
-      context: summarizeRecent ? [selected.recent] : [previousRecent, selected.head].filter(Boolean),
-    }),
+    previousSummary: previousSummary?.type === "compaction" ? previousSummary.summary : undefined,
+    context: chunkContext(summarizeRecent ? [selected.recent] : [previousRecent, selected.head]),
     recent: summarizeRecent ? "" : selected.recent,
   }
 }
@@ -235,62 +244,67 @@ const make = (dependencies: Dependencies) => {
       inputID: plan.inputID,
     })
 
-    const chunks: string[] = []
-    let failure: SessionError.Error | undefined
-    yield* dependencies.llm
-      .stream(
-        LLM.request({
-          model: plan.model,
-          messages: [Message.user(plan.prompt)],
-          tools: [],
-        }),
-      )
-      .pipe(
-        Stream.runForEach((event) => {
-          if (LLMEvent.is.providerError(event))
-            failure = {
-              type: event.classification === "context-overflow" ? "provider.invalid-request" : "provider.error",
-              message: event.message,
-            }
-          if (LLMEvent.is.textDelta(event)) {
-            chunks.push(event.text)
-            return dependencies.events.publish(SessionEvent.Compaction.Delta, {
-              sessionID: plan.sessionID,
-              text: event.text,
-            })
-          }
-          return Effect.void
-        }),
-        Effect.catchTag("LLM.Error", (error) =>
-          Effect.sync(() => {
-            failure = toSessionError(error)
+    let summary = plan.previousSummary
+    for (const [index, context] of plan.context.entries()) {
+      const chunks: string[] = []
+      let failure: SessionError.Error | undefined
+      const publish = index === plan.context.length - 1
+      yield* dependencies.llm
+        .stream(
+          LLM.request({
+            model: plan.model,
+            messages: [Message.user(buildPrompt({ previousSummary: summary, context: [context] }))],
+            tools: [],
+            generation: { maxTokens: SUMMARY_OUTPUT_TOKENS },
           }),
-        ),
-        Effect.onInterrupt(() =>
-          plan.reason === "auto"
-            ? failed({
-                sessionID: plan.sessionID,
-                reason: plan.reason,
-                error: { type: "compaction.interrupted", message: "Compaction was interrupted" },
-                inputID: plan.inputID,
-              }).pipe(Effect.asVoid)
-            : Effect.void,
-        ),
-      )
-    const summary = chunks.join("")
-    if (failure || !summary.trim()) {
-      const error = failure ?? { type: "compaction.failed" as const, message: "Compaction produced no summary" }
-      return yield* failed({
-        sessionID: plan.sessionID,
-        reason: plan.reason,
-        error,
-        inputID: plan.inputID,
-      })
+        )
+        .pipe(
+          Stream.runForEach((event) => {
+            if (LLMEvent.is.providerError(event))
+              failure = {
+                type: event.classification === "context-overflow" ? "provider.invalid-request" : "provider.error",
+                message: event.message,
+              }
+            if (LLMEvent.is.textDelta(event)) {
+              chunks.push(event.text)
+              if (publish)
+                return dependencies.events.publish(SessionEvent.Compaction.Delta, {
+                  sessionID: plan.sessionID,
+                  text: event.text,
+                })
+            }
+            return Effect.void
+          }),
+          Effect.catchTag("LLM.Error", (error) =>
+            Effect.sync(() => {
+              failure = toSessionError(error)
+            }),
+          ),
+          Effect.onInterrupt(() =>
+            plan.reason === "auto"
+              ? failed({
+                  sessionID: plan.sessionID,
+                  reason: plan.reason,
+                  error: { type: "compaction.interrupted", message: "Compaction was interrupted" },
+                  inputID: plan.inputID,
+                }).pipe(Effect.asVoid)
+              : Effect.void,
+          ),
+        )
+      const next = chunks.join("")
+      if (failure || !next.trim())
+        return yield* failed({
+          sessionID: plan.sessionID,
+          reason: plan.reason,
+          error: failure ?? { type: "compaction.failed", message: "Compaction produced no summary" },
+          inputID: plan.inputID,
+        })
+      summary = next
     }
     yield* dependencies.events.publish(SessionEvent.Compaction.Ended, {
       sessionID: plan.sessionID,
       reason: plan.reason,
-      text: summary,
+      text: summary ?? "",
       recent: plan.recent,
     })
     return { status: "completed" as const }

packages/core/test/session-compaction.test.ts

@@ -151,7 +151,7 @@ it.effect("manual compaction summarizes short context instead of no-op", () =>
     expect(Array.from(yield* Fiber.join(delta)).map((event) => event.data.text)).toEqual(["manual summary"])
 
     expect(requests).toHaveLength(1)
-    expect(requests[0]?.generation).toBeUndefined()
+    expect(requests[0]?.generation?.maxTokens).toBe(4_096)
     expect(JSON.stringify(requests[0]?.messages)).toContain("Manual compaction should include this short conversation.")
     expect(yield* store.context(sessionID)).toMatchObject([
       { type: "compaction", reason: "manual", summary: "manual summary", recent: "" },
@@ -170,3 +170,53 @@ it.effect("manual compaction summarizes short context instead of no-op", () =>
     ])
   }),
 )
+
+it.effect("manual compaction rolls large histories through bounded requests", () =>
+  Effect.gen(function* () {
+    requests = []
+    const db = (yield* Database.Service).db
+    const compaction = yield* SessionCompaction.Service
+    const store = yield* SessionStore.Service
+    const sessionID = SessionV2.ID.make("ses_bounded_compaction")
+    yield* db
+      .insert(ProjectTable)
+      .values({ id: Project.ID.global, worktree: AbsolutePath.make("/project"), sandboxes: [] })
+      .onConflictDoNothing()
+      .run()
+      .pipe(Effect.orDie)
+    yield* db
+      .insert(SessionTable)
+      .values({
+        id: sessionID,
+        project_id: Project.ID.global,
+        slug: "bounded-compaction",
+        directory: "/project",
+        title: "Bounded compaction",
+        version: "test",
+      })
+      .run()
+      .pipe(Effect.orDie)
+    const session = yield* store
+      .get(sessionID)
+      .pipe(Effect.flatMap((value) => (value ? Effect.succeed(value) : Effect.die("test session missing"))))
+
+    expect(
+      yield* compaction.compactManual({
+        session,
+        messages: [
+          {
+            id: SessionMessage.ID.create(),
+            type: "user",
+            text: "a".repeat(300_000),
+            time: { created: DateTime.makeUnsafe(0) },
+          },
+        ],
+        inputID: SessionMessage.ID.make("msg_bounded_compaction"),
+      }),
+    ).toEqual({ status: "completed" })
+
+    expect(requests.length).toBeGreaterThan(1)
+    expect(requests.every((request) => JSON.stringify(request.messages).length < 150_000)).toBe(true)
+    expect(JSON.stringify(requests[1]?.messages)).toContain("manual summary")
+  }),
+)

packages/tui/src/routes/home.tsx

@@ -95,9 +95,17 @@ export function Home() {
           {(_) => {
             const form = forms()[0]
             return form ? (
-              <box position="absolute" zIndex={2000} left={0} right={0} bottom={1} paddingLeft={2} paddingRight={2}>
+              <box
+                position="absolute"
+                zIndex={2000}
+                left={0}
+                right={0}
+                bottom={1}
+                paddingLeft={2}
+                paddingRight={2}
+              >
                 <box width="100%">
-                  <FormPrompt form={form} onNotFound={() => data.session.form.refresh(form.sessionID, form.location)} />
+                  <FormPrompt form={form} />
                 </box>
               </box>
             ) : null

packages/tui/src/routes/session/form.tsx

@@ -4,7 +4,7 @@ import { useRenderer, useTerminalDimensions } from "@opentui/solid"
 import type { ScrollBoxRenderable, TextareaRenderable } from "@opentui/core"
 import open from "open"
 import { selectedForeground, tint, useTheme } from "../../context/theme"
-import { isFormNotFoundError, type FormField, type FormValue } from "@opencode-ai/client"
+import type { FormField, FormValue } from "@opencode-ai/client"
 import type { FormWithLocation } from "../../context/data"
 import { useSDK } from "../../context/sdk"
 import { useClipboard } from "../../context/clipboard"
@@ -144,7 +144,7 @@ function requestOptions(form: FormWithLocation) {
   }
 }
 
-export function FormPrompt(props: { form: FormWithLocation; onNotFound: () => Promise<void> }) {
+export function FormPrompt(props: { form: FormWithLocation }) {
   const sdk = useSDK()
   const { theme } = useTheme()
   const renderer = useRenderer()
@@ -295,19 +295,6 @@ export function FormPrompt(props: { form: FormWithLocation; onNotFound: () => Pr
     setStore("error", "")
   }
 
-  function replyFailed(error: unknown) {
-    if (isFormNotFoundError(error)) {
-      void props.onNotFound().catch(() => setStore("error", error.message))
-      return
-    }
-    setStore(
-      "error",
-      typeof error === "object" && error !== null && "message" in error && typeof error.message === "string"
-        ? error.message
-        : "Invalid answer",
-    )
-  }
-
   function replySingle(field: Field, value: FormValue) {
     sdk.api.form
       .reply(
@@ -318,7 +305,14 @@ export function FormPrompt(props: { form: FormWithLocation; onNotFound: () => Pr
         },
         requestOptions(props.form),
       )
-      .catch(replyFailed)
+      .catch((error: unknown) => {
+        setStore(
+          "error",
+          typeof error === "object" && error !== null && "message" in error && typeof error.message === "string"
+            ? error.message
+            : "Invalid answer",
+        )
+      })
   }
 
   function pick(value: FormValue, customValue?: string) {
@@ -550,7 +544,14 @@ export function FormPrompt(props: { form: FormWithLocation; onNotFound: () => Pr
         },
         requestOptions(props.form),
       )
-      .catch(replyFailed)
+      .catch((error: unknown) => {
+        setStore(
+          "error",
+          typeof error === "object" && error !== null && "message" in error && typeof error.message === "string"
+            ? error.message
+            : "Invalid answer",
+        )
+      })
   }
 
   onMount(() => onCleanup(modeStack.push(FORM_MODE)))

packages/tui/src/routes/session/index.tsx

@@ -918,12 +918,7 @@ export function Session() {
                     <Show when={forms()[0]?.id} keyed>
                       {(_) => {
                         const form = forms()[0]
-                        return form ? (
-                          <FormPrompt
-                            form={form}
-                            onNotFound={() => data.session.form.refresh(form.sessionID, form.location)}
-                          />
-                        ) : null
+                        return form ? <FormPrompt form={form} /> : null
                       }}
                     </Show>
                   </Match>

packages/tui/test/cli/tui/form.test.tsx

@@ -4,7 +4,7 @@ import { testRender, useRenderer } from "@opentui/solid"
 import { expect, test } from "bun:test"
 import { mkdir } from "node:fs/promises"
 import path from "node:path"
-import { createSignal, onCleanup, Show } from "solid-js"
+import { onCleanup } from "solid-js"
 import { ClipboardProvider } from "../../../src/context/clipboard"
 import type { FormWithLocation } from "../../../src/context/data"
 import { KVProvider } from "../../../src/context/kv"
@@ -18,13 +18,12 @@ import { TestTuiContexts } from "../../fixture/tui-environment"
 import { createTuiResolvedConfig } from "../../fixture/tui-runtime"
 import { createApi, createClient, createEventStream, createFetch } from "../../fixture/tui-sdk"
 
-async function mountForm(root: string, width = 80, missing = false) {
+async function mountForm(root: string, width = 80) {
   const state = path.join(root, "state")
   await mkdir(state, { recursive: true })
   await Bun.write(path.join(state, "kv.json"), "{}")
 
   const replies: unknown[] = []
-  const notFound: string[] = []
   const copied: string[] = []
   const events = createEventStream()
   const transport = createFetch(
@@ -32,11 +31,6 @@ async function mountForm(root: string, width = 80, missing = false) {
       url.pathname === "/api/session/ses_test/form/frm_test/reply"
         ? request.json().then((answer) => {
             replies.push(answer)
-            if (missing)
-              return Response.json(
-                { _tag: "FormNotFoundError", id: "frm_test", message: "Form not found: frm_test" },
-                { status: 404 },
-              )
             return new Response(null, { status: 204 })
           })
         : undefined,
@@ -63,7 +57,6 @@ async function mountForm(root: string, width = 80, missing = false) {
     const keymap = createDefaultOpenTuiKeymap(renderer)
     const off = registerOpencodeKeymap(keymap, renderer, config)
     onCleanup(off)
-    const [visible, setVisible] = createSignal(true)
 
     return (
       <TestTuiContexts
@@ -88,16 +81,7 @@ async function mountForm(root: string, width = 80, missing = false) {
                 <KVProvider>
                   <ThemeProvider mode="dark" source={{ discover: () => Promise.resolve({}) }}>
                     <ToastProvider>
-                      <Show when={visible()}>
-                        <FormPrompt
-                          form={form}
-                          onNotFound={() => {
-                            notFound.push(form.id)
-                            setVisible(false)
-                            return Promise.resolve()
-                          }}
-                        />
-                      </Show>
+                      <FormPrompt form={form} />
                     </ToastProvider>
                   </ThemeProvider>
                 </KVProvider>
@@ -112,28 +96,9 @@ async function mountForm(root: string, width = 80, missing = false) {
   const app = await testRender(() => <Harness />, { width, height: 20, kittyKeyboard: true })
   app.renderer.start()
   await app.waitForFrame((frame) => frame.includes("Authorization required"))
-  return { app, copied, notFound, replies }
+  return { app, copied, replies }
 }
 
-test("dismisses a form that no longer exists when submitting", async () => {
-  await using tmp = await tmpdir()
-  const prompt = await mountForm(tmp.path, 80, true)
-  try {
-    prompt.app.mockInput.pressKey("right")
-    prompt.app.mockInput.pressKey("left")
-    prompt.app.mockInput.pressKey("c")
-    await prompt.app.waitForFrame((frame) => frame.includes("press enter to confirm"))
-    prompt.app.mockInput.pressEnter()
-    await prompt.app.waitForFrame((frame) => frame.includes("Acknowledged"))
-    prompt.app.mockInput.pressEnter()
-
-    await prompt.app.waitForFrame((frame) => !frame.includes("Authorization required"))
-    expect(prompt.notFound).toEqual(["frm_test"])
-  } finally {
-    prompt.app.renderer.destroy()
-  }
-})
-
 test("requires explicit acknowledgement before submitting an external field", async () => {
   await using tmp = await tmpdir()
   const prompt = await mountForm(tmp.path)