fix: skip oversized summary diffs individually and drop the dead summary_diffs column

.specgit.yaml

@@ -1,8 +1,8 @@
 version: 1
-delivery: auto-close-linked
+delivery: summary-diff-continue
 context:
   kind: branch
-  branch: feat/519-auto-close-linked
+  branch: fix/525-summary-diff-continue
 issues:
-  - 519
-pr: 520
+  - 525
+pr: 526

packages/core/schema.json

@@ -1,9 +1,9 @@
 {
   "version": "7",
   "dialect": "sqlite",
-  "id": "874d8e74-d354-4dcb-b98c-c893660c9371",
+  "id": "abadf28b-1770-46c6-bbf6-b7800a9ca874",
   "prevIds": [
-    "4142b961-0712-4834-b475-16ea4a74c43c"
+    "874d8e74-d354-4dcb-b98c-c893660c9371"
   ],
   "ddl": [
     {
@@ -1772,16 +1772,6 @@
       "entityType": "columns",
       "table": "session"
     },
-    {
-      "type": "text",
-      "notNull": false,
-      "autoincrement": false,
-      "default": null,
-      "generated": null,
-      "name": "summary_diffs",
-      "entityType": "columns",
-      "table": "session"
-    },
     {
       "type": "text",
       "notNull": false,

packages/core/src/database/migration/20260903044702_drop_session_summary_diffs.ts

@@ -0,0 +1,11 @@
+import { Effect } from "effect"
+import type { DatabaseMigration } from "../migration"
+
+export default {
+  id: "20260903044702_drop_session_summary_diffs",
+  up(tx) {
+    return Effect.gen(function* () {
+      yield* tx.run(`ALTER TABLE \`session\` DROP COLUMN \`summary_diffs\`;`)
+    })
+  },
+} satisfies DatabaseMigration.Migration

packages/core/src/database/schema.gen.ts

@@ -274,7 +274,6 @@ export default {
           \`summary_additions\` integer,
           \`summary_deletions\` integer,
           \`summary_files\` integer,
-          \`summary_diffs\` text,
           \`metadata\` text,
           \`cost\` real DEFAULT 0 NOT NULL,
           \`tokens_input\` integer DEFAULT 0 NOT NULL,

packages/core/src/session/projector.ts

@@ -60,7 +60,6 @@ function sessionRow(info: SessionV1.SessionInfo): typeof SessionTable.$inferInse
     summary_additions: info.summary?.additions,
     summary_deletions: info.summary?.deletions,
     summary_files: info.summary?.files,
-    summary_diffs: info.summary?.diffs ? [...info.summary.diffs] : undefined,
     metadata: info.metadata,
     cost: info.cost ?? 0,
     tokens_input: (info.tokens ?? { input: 0 }).input,

packages/core/src/session/sql.ts

@@ -4,7 +4,6 @@ import { ProjectTable } from "../project/sql"
 import type { SessionMessage } from "./message"
 import type { Prompt } from "./prompt"
 import type { SessionInput } from "./input"
-import type { Snapshot } from "../snapshot"
 import { PermissionV1 } from "../v1/permission"
 import { ProjectV2 } from "../project"
 import type { SessionSchema } from "./schema"
@@ -38,7 +37,6 @@ export const SessionTable = sqliteTable(
     summary_additions: integer(),
     summary_deletions: integer(),
     summary_files: integer(),
-    summary_diffs: text({ mode: "json" }).$type<Snapshot.LegacyFileDiff[]>(),
     metadata: text({ mode: "json" }).$type<Record<string, unknown>>(),
     cost: real().notNull().default(0),
     tokens_input: integer().notNull().default(0),

packages/core/test/database-migration.test.ts

@@ -18,6 +18,7 @@ import simplifySessionInputMigration from "@opencode-ai/core/database/migration/
 import capturedOutputMigration from "@opencode-ai/core/database/migration/20260715035022_captured_output"
 import fearlessCammiMigration from "@opencode-ai/core/database/migration/20260717034735_fearless_cammi"
 import dagWorkflowNodeIdentityMigration from "@opencode-ai/core/database/migration/20260720013828_dag-workflow-node-identity"
+import dropSessionSummaryDiffsMigration from "@opencode-ai/core/database/migration/20260903044702_drop_session_summary_diffs"
 import { EventV2 } from "@opencode-ai/core/event"
 import { ProjectV2 } from "@opencode-ai/core/project"
 import { ProjectTable } from "@opencode-ai/core/project/sql"
@@ -100,6 +101,39 @@ describe("DatabaseMigration", () => {
     )
   })
 
+  test("drops the legacy session summary_diffs column", async () => {
+    await run(
+      Effect.gen(function* () {
+        const db = yield* makeDb
+        // Legacy install: the column still exists with data, and only the drop migration is pending.
+        yield* db.run(sql`CREATE TABLE session (id text PRIMARY KEY, summary_diffs text)`)
+        yield* db.run(
+          sql`INSERT INTO session (id, summary_diffs) VALUES ('ses_legacy', '[{"file":"a.txt","patch":"p","additions":1,"deletions":0,"status":"modified"}]')`,
+        )
+
+        yield* DatabaseMigration.applyOnly(db, [dropSessionSummaryDiffsMigration])
+
+        expect(
+          yield* db.get(sql`SELECT name FROM pragma_table_info('session') WHERE name = 'summary_diffs'`),
+        ).toBeUndefined()
+        expect(yield* db.get(sql`SELECT id FROM session WHERE id = 'ses_legacy'`)).toEqual({ id: "ses_legacy" })
+        expect(yield* db.get(sql`SELECT id FROM migration WHERE id = ${dropSessionSummaryDiffsMigration.id}`)).toEqual({
+          id: dropSessionSummaryDiffsMigration.id,
+        })
+      }),
+    )
+
+    await run(
+      Effect.gen(function* () {
+        const db = yield* makeDb
+        yield* DatabaseMigration.apply(db)
+        expect(
+          yield* db.get(sql`SELECT name FROM pragma_table_info('session') WHERE name = 'summary_diffs'`),
+        ).toBeUndefined()
+      }),
+    )
+  })
+
   test("upgrades DAG node storage without duplicate columns or cross-workflow collisions", async () => {
     await run(
       Effect.gen(function* () {

packages/opencode/src/session/session.ts

@@ -68,33 +68,28 @@ export const MAX_SUMMARY_DIFF_BYTES = 256 * 1024
 
 // Byte accounting mirrors the JSON serialization: 2 bytes for the "[]" wrapper,
 // +1 per comma separator, so kept output never exceeds MAX_SUMMARY_DIFF_BYTES.
+// Entries that do not fit are skipped individually so later, smaller entries
+// are still kept.
 export function truncateSummaryDiffs(diffs: Snapshot.FileDiff[] | undefined) {
   if (!diffs) return undefined
   let total = 2
   const kept: Snapshot.FileDiff[] = []
   for (const item of diffs) {
     const size = Buffer.byteLength(JSON.stringify(item)) + (kept.length > 0 ? 1 : 0)
-    if (total + size > MAX_SUMMARY_DIFF_BYTES) break
+    if (total + size > MAX_SUMMARY_DIFF_BYTES) continue
     total += size
     kept.push(item)
   }
   return kept
 }
 
-function stripOversizedDiffs<T>(diffs: T[] | null | undefined) {
-  if (!diffs) return undefined
-  if (Buffer.byteLength(JSON.stringify(diffs)) > MAX_SUMMARY_DIFF_BYTES) return undefined
-  return diffs
-}
-
 export function fromRow(row: SessionRow): Info {
   const summary =
     row.summary_additions !== null || row.summary_deletions !== null || row.summary_files !== null
       ? {
           additions: row.summary_additions ?? 0,
           deletions: row.summary_deletions ?? 0,
           files: row.summary_files ?? 0,
-          diffs: stripOversizedDiffs(row.summary_diffs),
         }
       : undefined
   const share = row.share_url ? { url: row.share_url } : undefined
@@ -165,7 +160,6 @@ export function toRow(info: Info) {
     summary_additions: info.summary?.additions,
     summary_deletions: info.summary?.deletions,
     summary_files: info.summary?.files,
-    summary_diffs: truncateSummaryDiffs(info.summary?.diffs),
     metadata: info.metadata,
     cost: info.cost ?? 0,
     tokens_input: (info.tokens ?? EmptyTokens).input,

packages/opencode/test/server/httpapi-session.test.ts

@@ -182,22 +182,6 @@ const insertCorruptV2Message = (sessionID: SessionIDType, time = 1) =>
       .pipe(Effect.orDie)
   })
 
-const setLegacySummaryDiff = (sessionID: SessionIDType) =>
-  Effect.gen(function* () {
-    const { db } = yield* Database.Service
-    yield* db
-      .update(SessionTable)
-      .set({
-        summary_additions: 1,
-        summary_deletions: 0,
-        summary_files: 1,
-        summary_diffs: [{ additions: 1, deletions: 0 }],
-      })
-      .where(eq(SessionTable.id, sessionID))
-      .run()
-      .pipe(Effect.orDie)
-  })
-
 const getWorkspaceID = (sessionID: SessionIDType) =>
   Effect.gen(function* () {
     const { db } = yield* Database.Service
@@ -690,24 +674,6 @@ describe("session HttpApi", () => {
     { git: true, config: { formatter: false, lsp: false } },
   )
 
-  it.instance(
-    "serves sessions with migrated summary diffs missing file details",
-    () =>
-      Effect.gen(function* () {
-        const test = yield* TestInstance
-        const session = yield* createSession({ title: "legacy diff" })
-        yield* setLegacySummaryDiff(session.id)
-
-        const response = yield* request(pathFor(SessionPaths.get, { sessionID: session.id }), {
-          headers: { "x-opencode-directory": test.directory },
-        })
-
-        expect(response.status).toBe(200)
-        expect((yield* json<Session.Info>(response)).summary?.diffs).toEqual([{ additions: 1, deletions: 0 }])
-      }),
-    { git: true, config: { formatter: false, lsp: false } },
-  )
-
   it.instance(
     "serves lifecycle mutation routes",
     () =>

packages/opencode/test/session/summary-diff-guard.test.ts

@@ -3,12 +3,10 @@ import { Database } from "@opencode-ai/core/database/database"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import { SessionProjector } from "@opencode-ai/core/session/projector"
-import { SessionTable } from "@opencode-ai/core/session/sql"
 import { SessionV1 } from "@opencode-ai/core/v1/session"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { Effect, Layer } from "effect"
-import { eq } from "drizzle-orm"
 import { Snapshot } from "@/snapshot"
 import { Session as SessionNs, truncateSummaryDiffs, MAX_SUMMARY_DIFF_BYTES } from "@/session/session"
 import { SessionSummary } from "@/session/summary"
@@ -48,22 +46,6 @@ const giantDiffs = (count: number) =>
     status: "modified" as const,
   }))
 
-const setSummaryRow = (sessionID: SessionID, summary: { additions: number; deletions: number; files: number; diffs: Snapshot.FileDiff[] }) =>
-  Effect.gen(function* () {
-    const database = yield* Database.Service
-    yield* database.db
-      .update(SessionTable)
-      .set({
-        summary_additions: summary.additions,
-        summary_deletions: summary.deletions,
-        summary_files: summary.files,
-        summary_diffs: summary.diffs,
-      })
-      .where(eq(SessionTable.id, sessionID))
-      .run()
-      .pipe(Effect.orDie)
-  })
-
 const seedUserTurn = Effect.fnUntraced(function* (sessionID: SessionID) {
   const sessions = yield* SessionNs.Service
   const userMessageID = MessageID.ascending()
@@ -140,34 +122,6 @@ describe("summary.diffs source truncation", () => {
   )
 })
 
-describe("summary_diffs read guard", () => {
-  it.instance("strips oversized legacy summary_diffs on read and keeps stats", () =>
-    Effect.gen(function* () {
-      const sessions = yield* SessionNs.Service
-      const database = yield* Database.Service
-      const session = yield* sessions.create({ title: "legacy-giant-diffs" })
-
-      yield* database.db
-        .update(SessionTable)
-        .set({
-          summary_additions: 12,
-          summary_deletions: 34,
-          summary_files: 56,
-          summary_diffs: giantDiffs(300),
-        })
-        .where(eq(SessionTable.id, session.id))
-        .run()
-        .pipe(Effect.orDie)
-
-      const info = yield* sessions.get(session.id)
-      expect(info.summary?.additions).toBe(12)
-      expect(info.summary?.deletions).toBe(34)
-      expect(info.summary?.files).toBe(56)
-      expect(info.summary?.diffs).toBeUndefined()
-    }),
-  )
-})
-
 describe("truncateSummaryDiffs boundaries", () => {
   const item = {
     file: "a.txt",
@@ -194,45 +148,31 @@ describe("truncateSummaryDiffs boundaries", () => {
     expect(kept?.length).toBe(count)
     expect(Buffer.byteLength(JSON.stringify(kept))).toBeLessThanOrEqual(MAX_SUMMARY_DIFF_BYTES)
   })
-})
 
-describe("summary diffs budget boundary", () => {
-  it.instance("keeps diffs at just under the budget on write and read", () =>
-    Effect.gen(function* () {
-      const sessions = yield* SessionNs.Service
-      const session = yield* sessions.create({ title: "under-budget" })
-      const info = yield* sessions.get(session.id)
-
-      const diffs = giantDiffs(100)
-      expect(Buffer.byteLength(JSON.stringify(diffs))).toBeLessThan(SessionNs.MAX_SUMMARY_DIFF_BYTES)
-      const row = SessionNs.toRow({ ...info, summary: { additions: 5, deletions: 6, files: 100, diffs } })
-      expect(row.summary_diffs).toEqual(diffs)
-
-      yield* setSummaryRow(session.id, { additions: 5, deletions: 6, files: 100, diffs })
-      const back = yield* sessions.get(session.id)
-      expect(back.summary?.diffs).toEqual(diffs)
-      expect(back.summary?.additions).toBe(5)
-      expect(back.summary?.deletions).toBe(6)
-      expect(back.summary?.files).toBe(100)
-    }),
-  )
+  test("skips an oversized entry and keeps later entries that still fit", () => {
+    const huge = { ...item, file: "huge.txt", patch: "x".repeat(MAX_SUMMARY_DIFF_BYTES) }
+    const smallA = { ...item, file: "small-a.txt", patch: "y".repeat(64) }
+    const smallB = { ...item, file: "small-b.txt", patch: "z".repeat(64) }
+    const kept = truncateSummaryDiffs([huge, smallA, smallB])
+    expect(kept).toEqual([smallA, smallB])
+    expect(Buffer.byteLength(JSON.stringify(kept))).toBeLessThanOrEqual(MAX_SUMMARY_DIFF_BYTES)
+  })
 
-  it.instance("truncates oversized diffs on write within the budget", () =>
-    Effect.gen(function* () {
-      const sessions = yield* SessionNs.Service
-      const session = yield* sessions.create({ title: "over-budget-write" })
-      const info = yield* sessions.get(session.id)
-
-      const row = SessionNs.toRow({
-        ...info,
-        summary: { additions: 5, deletions: 6, files: 300, diffs: giantDiffs(300) },
-      })
-      const kept = row.summary_diffs
-      expect(kept?.length).toBeGreaterThan(0)
-      expect(kept?.length).toBeLessThan(300)
-      expect(Buffer.byteLength(JSON.stringify(kept))).toBeLessThanOrEqual(SessionNs.MAX_SUMMARY_DIFF_BYTES)
-      expect(kept?.[0]?.file).toBe("f000.txt")
-      expect(kept?.at(-1)?.file).toBe(`f${String((kept?.length ?? 1) - 1).padStart(3, "0")}.txt`)
-    }),
-  )
+  test("keeps serialized output within the budget for mixed oversized inputs", () => {
+    const huge = { ...item, patch: "x".repeat(MAX_SUMMARY_DIFF_BYTES) }
+    const nearBudget = { ...item, patch: "x".repeat(MAX_SUMMARY_DIFF_BYTES - 120) }
+    const shapes = [
+      [huge, item, item],
+      [item, huge, item],
+      [item, item, huge],
+      [nearBudget, item, nearBudget, item],
+      [huge, nearBudget, huge, item],
+      [nearBudget, nearBudget],
+      [item, nearBudget, item, huge, item],
+    ]
+    shapes.forEach((shape) => {
+      const kept = truncateSummaryDiffs(shape)
+      expect(Buffer.byteLength(JSON.stringify(kept))).toBeLessThanOrEqual(MAX_SUMMARY_DIFF_BYTES)
+    })
+  })
 })