Fix terminal snapshots reflowing after resize

Terminal snapshots now carry soft-wrap row metadata only to clients that advertise support, so restored output can resize like live output without breaking older clients.

packages/app/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "main": "index.ts",
   "scripts": {
-    "start": "npm --prefix ../.. run build:client && concurrently --kill-others --names protocol,client,expo --prefix-colors yellow,blue,magenta \"npm --prefix ../.. run watch:protocol\" \"npm --prefix ../.. run watch:client\" \"npm run start:expo\"",
+    "start": "npm run start:expo",
     "start:expo": "cross-env APP_VARIANT=development expo start",
     "reset-project": "node ./scripts/reset-project.js",
     "eas-build-post-install": "npm --prefix ../.. run build:app-deps && npm run build:terminal-webview",

packages/app/src/terminal/runtime/terminal-resize-repro.browser.test.ts

@@ -0,0 +1,155 @@
+import { page } from "@vitest/browser/context";
+import { afterEach, describe, expect, it } from "vitest";
+import type { TerminalState } from "@getpaseo/protocol/messages";
+import { encodeTerminalOutput, TerminalEmulatorRuntime } from "./terminal-emulator-runtime";
+
+// Regression: "streaming pino log, resized the Paseo terminal, old logs stayed
+// narrow and new logs drew on top of the old ones."
+//
+// A heavy stream overflows MAX_TERMINAL_OUTPUT_FRAME_BYTES, so the server sends a
+// SNAPSHOT mid-stream. The client restores it via renderTerminalSnapshotToAnsi.
+// When the snapshot carries per-row soft-wrap flags, restored long lines must
+// reflow on resize just like live output — not freeze at the snapshot width.
+
+interface Mounted {
+  host: HTMLDivElement;
+  root: HTMLDivElement;
+  runtime: TerminalEmulatorRuntime;
+}
+
+const mounted: Mounted[] = [];
+
+function nextFrame(): Promise<void> {
+  return new Promise((resolve) => requestAnimationFrame(() => resolve()));
+}
+
+async function waitFor(predicate: () => boolean, timeoutMs = 4000): Promise<void> {
+  const start = performance.now();
+  while (!predicate()) {
+    if (performance.now() - start > timeoutMs) throw new Error("timeout waiting for condition");
+    await nextFrame();
+  }
+}
+
+function mount(width: number, height: number): Mounted {
+  const root = document.createElement("div");
+  root.style.cssText = `width:${width}px;height:${height}px;position:fixed;left:0;top:0;overflow:hidden`;
+  const host = document.createElement("div");
+  host.style.cssText = "width:100%;height:100%";
+  root.appendChild(host);
+  document.body.appendChild(root);
+
+  const runtime = new TerminalEmulatorRuntime();
+  runtime.setCallbacks({ callbacks: {} });
+  runtime.mount({
+    root,
+    host,
+    initialSnapshot: null,
+    scrollback: 10_000,
+    theme: { background: "#0b0b0b", foreground: "#e6e6e6", cursor: "#e6e6e6" },
+  });
+  const m = { host, root, runtime };
+  mounted.push(m);
+  return m;
+}
+
+interface Row {
+  text: string;
+  wrapped: boolean;
+}
+
+function dumpRows(): Row[] {
+  const term = window.__paseoTerminal;
+  if (!term) throw new Error("no terminal");
+  const buf = term.buffer.active;
+  const rows: Row[] = [];
+  for (let i = 0; i < buf.length; i++) {
+    const line = buf.getLine(i);
+    if (!line) continue;
+    rows.push({ text: line.translateToString(true).trimEnd(), wrapped: line.isWrapped });
+  }
+  return rows;
+}
+
+function someRowContains(text: string): boolean {
+  return dumpRows().some((r) => r.text.includes(text));
+}
+
+// Build a server-style snapshot of one long pino line that the SERVER soft-wrapped
+// at `cols`, represented as multiple grid rows (exactly what the daemon stores in
+// its headless xterm and ships in a snapshot).
+function buildWrappedSnapshot(cols: number): TerminalState {
+  const longLine = `[server] [15:30:00.123] TRACE: provider.claude.raw_event {"module":"agent","seq":1,"sessionId":"ed8972f4-d3be-45d0-992c-631f8f1ed04e","turnId":"foreground-turn-1","payload":"${"A".repeat(40)}"}`;
+  const grid: TerminalState["grid"] = [];
+  for (let i = 0; i < longLine.length; i += cols) {
+    const chunk = longLine.slice(i, i + cols);
+    grid.push([...chunk].map((char) => ({ char })));
+  }
+  // The fixed daemon ships per-row soft-wrap flags: every row of the logical line
+  // continues onto the next except the last.
+  const gridWrapped = grid.map((_, index) => index < grid.length - 1);
+  // Cursor sits just below the restored content, exactly where the daemon's
+  // headless terminal leaves it after a line break, so streamed output appends
+  // cleanly below instead of overwriting the restored rows.
+  return {
+    rows: 24,
+    cols,
+    scrollback: [],
+    scrollbackWrapped: [],
+    grid,
+    gridWrapped,
+    cursor: { row: grid.length, col: 0 },
+  };
+}
+
+function pinoLine(seq: number): string {
+  return `[server] [15:30:${String(seq % 60).padStart(2, "0")}.123] TRACE: provider.claude.raw_event {"module":"agent","seq":${seq},"sessionId":"ed8972f4-d3be-45d0-992c-631f8f1ed04e","turnId":"foreground-turn-1","payload":"${"A".repeat(40)}"}\r\n`;
+}
+
+afterEach(() => {
+  for (const m of mounted.splice(0)) {
+    m.runtime.unmount();
+    m.root.remove();
+  }
+});
+
+describe("terminal resize reflow repro (Paseo terminal)", () => {
+  it("snapshot-restored rows stay frozen at the snapshot width after the terminal grows", async () => {
+    await page.viewport(1600, 700);
+    const m = mount(560, 360); // ~70 cols
+    await waitFor(() => window.__paseoTerminal !== undefined);
+    const narrowCols = window.__paseoTerminal?.cols ?? 0;
+
+    // 1) Mid-stream snapshot arrives (server overflowed 256KB). It carries the
+    //    long line wrapped at the server width as separate grid rows.
+    m.runtime.renderSnapshot({ state: buildWrappedSnapshot(narrowCols) });
+    await waitFor(() => someRowContains('"seq":1'));
+
+    // 2) Normal post-snapshot streaming resumes (autowrap on -> soft-wrapped).
+    for (let seq = 90; seq <= 96; seq++) {
+      m.runtime.write({ data: encodeTerminalOutput(pinoLine(seq)) });
+    }
+    await waitFor(() => someRowContains('"seq":96'));
+
+    // 3) User resizes the terminal wider.
+    m.root.style.width = "1480px";
+    await nextFrame();
+    m.runtime.resize({ force: true, shouldClaim: true });
+    await nextFrame();
+    await nextFrame();
+    const wideCols = window.__paseoTerminal?.cols ?? 0;
+
+    const rows = dumpRows();
+    const snapshotRowLen =
+      rows.find((r) => r.text.startsWith("[server] [15:30:00"))?.text.length ?? -1;
+    const streamedRowLen =
+      rows.find((r) => r.text.startsWith("[server] [15:30:30"))?.text.length ?? -1;
+
+    expect(wideCols).toBeGreaterThan(narrowCols + 20);
+    // Post-snapshot streamed output reflows to fill the wide terminal.
+    expect(streamedRowLen).toBeGreaterThan(narrowCols + 20);
+    // Snapshot-restored content reflows too, instead of staying frozen at the
+    // snapshot width — the reported bug.
+    expect(snapshotRowLen).toBeGreaterThan(narrowCols + 20);
+  });
+});

packages/client/src/daemon-client.ts

@@ -4279,6 +4279,7 @@ export class DaemonClient {
           capabilities: {
             [CLIENT_CAPS.customModeIcons]: true,
             [CLIENT_CAPS.reasoningMergeEnum]: true,
+            [CLIENT_CAPS.terminalReflowableSnapshot]: true,
           },
           ...(this.config.appVersion ? { appVersion: this.config.appVersion } : {}),
         }),

packages/protocol/src/binary-frames/file-transfer.test.ts

@@ -102,7 +102,7 @@ describe("file transfer binary frames", () => {
     });
   });
 
-  it("rejects malformed metadata and unknown metadata fields", () => {
+  it("rejects malformed metadata but ignores unknown metadata fields", () => {
     expect(
       decodeFileTransferFrame(
         encodeFileTransferFrame({
@@ -135,7 +135,18 @@ describe("file transfer binary frames", () => {
     new DataView(encoded.buffer).setUint16(2 + requestId.byteLength, json.byteLength);
     encoded.set(json, 4 + requestId.byteLength);
 
-    expect(decodeFileTransferFrame(encoded)).toBeNull();
+    // Non-strict: the unknown `extra` key is stripped and the frame still decodes.
+    expect(decodeFileTransferFrame(encoded)).toEqual({
+      opcode: FileTransferOpcode.FileBegin,
+      requestId: "req-1",
+      metadata: {
+        mime: "image/png",
+        size: 1,
+        encoding: "binary",
+        modifiedAt: "2026-05-02T00:00:00.000Z",
+      },
+      payload: new Uint8Array(),
+    });
   });
 
   it("rejects malformed request id prefixes and frame tails", () => {

packages/protocol/src/binary-frames/file-transfer.ts

@@ -9,14 +9,12 @@ export const FileTransferOpcode = {
 
 export type FileTransferOpcode = (typeof FileTransferOpcode)[keyof typeof FileTransferOpcode];
 
-export const FileBeginMetadataSchema = z
-  .object({
-    mime: z.string().min(1),
-    size: z.number().int().nonnegative(),
-    encoding: z.enum(["utf-8", "binary"]),
-    modifiedAt: z.string(),
-  })
-  .strict();
+export const FileBeginMetadataSchema = z.object({
+  mime: z.string().min(1),
+  size: z.number().int().nonnegative(),
+  encoding: z.enum(["utf-8", "binary"]),
+  modifiedAt: z.string(),
+});
 
 export interface FileBegin {
   opcode: typeof FileTransferOpcode.FileBegin;

packages/protocol/src/binary-frames/terminal.test.ts

@@ -91,24 +91,26 @@ describe("terminal binary frames", () => {
     ).toBeNull();
   });
 
-  it("rejects unknown fields in resize and snapshot payloads", () => {
+  it("ignores unknown fields in resize and snapshot payloads", () => {
+    // Protocol schemas are non-strict: unknown keys are stripped, not rejected, so a
+    // new daemon can add fields without breaking an old client's parse.
     expect(
       decodeTerminalResizePayload(
         new TextEncoder().encode(JSON.stringify({ rows: 24, cols: 80, extra: true })),
       ),
-    ).toBeNull();
-    expect(
-      decodeTerminalSnapshotPayload(
-        new TextEncoder().encode(
-          JSON.stringify({
-            rows: 1,
-            cols: 1,
-            grid: [[{ char: "A", extra: true }]],
-            scrollback: [],
-            cursor: { row: 0, col: 1 },
-          }),
-        ),
+    ).toEqual({ rows: 24, cols: 80 });
+
+    const snapshot = decodeTerminalSnapshotPayload(
+      new TextEncoder().encode(
+        JSON.stringify({
+          rows: 1,
+          cols: 1,
+          grid: [[{ char: "A", extra: true }]],
+          scrollback: [],
+          cursor: { row: 0, col: 1 },
+        }),
       ),
-    ).toBeNull();
+    );
+    expect(snapshot?.grid[0]?.[0]).toEqual({ char: "A" });
   });
 });

packages/protocol/src/binary-frames/terminal.ts

@@ -1,12 +1,10 @@
 import { z } from "zod";
 import { TerminalStateSchema } from "../messages.js";
 
-export const TerminalStreamResizeSchema = z
-  .object({
-    rows: z.number().int().positive(),
-    cols: z.number().int().positive(),
-  })
-  .strict();
+export const TerminalStreamResizeSchema = z.object({
+  rows: z.number().int().positive(),
+  cols: z.number().int().positive(),
+});
 
 export const TerminalStreamOpcode = {
   Output: 0x01,

packages/protocol/src/client-capabilities.ts

@@ -5,6 +5,12 @@ export const CLIENT_CAPS = {
   // outside the legacy set to "ShieldCheck" when this cap is absent. Drop the
   // gate when floor >= v0.1.84.
   customModeIcons: "custom_mode_icons",
+  // COMPAT(terminalReflowableSnapshot): added in v0.1.88. The daemon attaches
+  // per-row soft-wrap flags (gridWrapped/scrollbackWrapped) to terminal snapshots
+  // only when the client advertises this, so restored content can reflow on resize.
+  // Old clients use a strict TerminalState schema and would reject the extra fields.
+  // Drop the gate (always send the flags) when floor >= v0.1.88.
+  terminalReflowableSnapshot: "terminal_reflowable_snapshot",
 } as const;
 
 export type ClientCapability = (typeof CLIENT_CAPS)[keyof typeof CLIENT_CAPS];

packages/protocol/src/messages.tool-call-schema.test.ts

@@ -64,7 +64,13 @@ describe("shared messages tool_call schema", () => {
       error: null,
     });
 
-    const withTopLevelInputOutput = AgentTimelineItemPayloadSchema.safeParse({
+    expect(missingCallId.success).toBe(false);
+    expect(unknownStatus.success).toBe(false);
+  });
+
+  it("ignores unknown top-level fields on tool_call payloads", () => {
+    // Non-strict protocol: extra top-level keys are stripped, not rejected.
+    const parsed = AgentTimelineItemPayloadSchema.safeParse({
       ...canonicalBase(),
       status: "running",
       error: null,
@@ -72,9 +78,7 @@ describe("shared messages tool_call schema", () => {
       output: { exitCode: 0 },
     });
 
-    expect(missingCallId.success).toBe(false);
-    expect(unknownStatus.success).toBe(false);
-    expect(withTopLevelInputOutput.success).toBe(false);
+    expect(parsed.success).toBe(true);
   });
 
   it("rejects legacy status/error combinations without normalization", () => {

packages/protocol/src/messages.ts

@@ -485,15 +485,13 @@ const ToolCallDetailPayloadSchema: z.ZodType<ToolCallDetail, z.ZodTypeDef, unkno
     }),
   ]);
 
-const ToolCallBasePayloadSchema = z
-  .object({
-    type: z.literal("tool_call"),
-    callId: z.string(),
-    name: z.string(),
-    detail: ToolCallDetailPayloadSchema,
-    metadata: z.record(z.string(), z.unknown()).optional(),
-  })
-  .strict();
+const ToolCallBasePayloadSchema = z.object({
+  type: z.literal("tool_call"),
+  callId: z.string(),
+  name: z.string(),
+  detail: ToolCallDetailPayloadSchema,
+  metadata: z.record(z.string(), z.unknown()).optional(),
+});
 
 const ToolCallRunningPayloadSchema = ToolCallBasePayloadSchema.extend({
   status: z.literal("running"),
@@ -1808,10 +1806,8 @@ export const SubscribeTerminalRequestSchema = z.object({
           rows: z.number().int().positive(),
           cols: z.number().int().positive(),
         })
-        .strict()
         .optional(),
     })
-    .strict()
     .optional(),
 });
 
@@ -3540,44 +3536,45 @@ const TerminalInfoSchema = z.object({
   title: z.string().optional(),
 });
 
-export const TerminalCellSchema = z
-  .object({
-    char: z.string(),
-    fg: z.number().optional(),
-    bg: z.number().optional(),
-    fgMode: z.number().optional(),
-    bgMode: z.number().optional(),
-    bold: z.boolean().optional(),
-    italic: z.boolean().optional(),
-    underline: z.boolean().optional(),
-    dim: z.boolean().optional(),
-    inverse: z.boolean().optional(),
-    strikethrough: z.boolean().optional(),
-  })
-  .strict();
+export const TerminalCellSchema = z.object({
+  char: z.string(),
+  fg: z.number().optional(),
+  bg: z.number().optional(),
+  fgMode: z.number().optional(),
+  bgMode: z.number().optional(),
+  bold: z.boolean().optional(),
+  italic: z.boolean().optional(),
+  underline: z.boolean().optional(),
+  dim: z.boolean().optional(),
+  inverse: z.boolean().optional(),
+  strikethrough: z.boolean().optional(),
+});
 
 export const TerminalCursorStyleSchema = z.enum(["block", "underline", "bar"]);
 
-export const TerminalCursorSchema = z
-  .object({
-    row: z.number(),
-    col: z.number(),
-    hidden: z.boolean().optional(),
-    style: TerminalCursorStyleSchema.optional(),
-    blink: z.boolean().optional(),
-  })
-  .strict();
+export const TerminalCursorSchema = z.object({
+  row: z.number(),
+  col: z.number(),
+  hidden: z.boolean().optional(),
+  style: TerminalCursorStyleSchema.optional(),
+  blink: z.boolean().optional(),
+});
 
-export const TerminalStateSchema = z
-  .object({
-    rows: z.number(),
-    cols: z.number(),
-    grid: z.array(z.array(TerminalCellSchema)),
-    scrollback: z.array(z.array(TerminalCellSchema)),
-    cursor: TerminalCursorSchema,
-    title: z.string().optional(),
-  })
-  .strict();
+export const TerminalStateSchema = z.object({
+  rows: z.number(),
+  cols: z.number(),
+  grid: z.array(z.array(TerminalCellSchema)),
+  scrollback: z.array(z.array(TerminalCellSchema)),
+  cursor: TerminalCursorSchema,
+  title: z.string().optional(),
+  // Per-row soft-wrap flags aligned 1:1 with `grid` / `scrollback`. `true` means
+  // the row continued onto the next row (xterm's GRID_LINE_WRAPPED equivalent),
+  // so the client can re-wrap the logical line on resize instead of freezing it
+  // at the snapshot width. Optional: only sent to clients that advertise the
+  // `terminalReflowableSnapshot` capability, so old daemons/clients are unaffected.
+  gridWrapped: z.array(z.boolean()).optional(),
+  scrollbackWrapped: z.array(z.boolean()).optional(),
+});
 
 export const ListTerminalsResponseSchema = z.object({
   type: z.literal("list_terminals_response"),
@@ -4108,6 +4105,7 @@ export const WSHelloMessageSchema = z.object({
       pushNotifications: z.boolean().optional(),
       [CLIENT_CAPS.reasoningMergeEnum]: z.boolean().optional(),
       [CLIENT_CAPS.customModeIcons]: z.boolean().optional(),
+      [CLIENT_CAPS.terminalReflowableSnapshot]: z.boolean().optional(),
     })
     .passthrough()
     .optional(),

packages/protocol/src/provider-config.ts

@@ -2,25 +2,19 @@ import { z } from "zod";
 import type { AgentProvider } from "./agent-types.js";
 import { AgentProviderSchema } from "./provider-manifest.js";
 
-const ProviderCommandDefaultSchema = z
-  .object({
-    mode: z.literal("default"),
-  })
-  .strict();
+const ProviderCommandDefaultSchema = z.object({
+  mode: z.literal("default"),
+});
 
-const ProviderCommandAppendSchema = z
-  .object({
-    mode: z.literal("append"),
-    args: z.array(z.string()).optional(),
-  })
-  .strict();
+const ProviderCommandAppendSchema = z.object({
+  mode: z.literal("append"),
+  args: z.array(z.string()).optional(),
+});
 
-const ProviderCommandReplaceSchema = z
-  .object({
-    mode: z.literal("replace"),
-    argv: z.array(z.string().min(1)).min(1),
-  })
-  .strict();
+const ProviderCommandReplaceSchema = z.object({
+  mode: z.literal("replace"),
+  argv: z.array(z.string().min(1)).min(1),
+});
 
 export const ProviderCommandSchema = z.discriminatedUnion("mode", [
   ProviderCommandDefaultSchema,
@@ -28,47 +22,39 @@ export const ProviderCommandSchema = z.discriminatedUnion("mode", [
   ProviderCommandReplaceSchema,
 ]);
 
-export const ProviderRuntimeSettingsSchema = z
-  .object({
-    command: ProviderCommandSchema.optional(),
-    env: z.record(z.string()).optional(),
-    disallowedTools: z.array(z.string()).optional(),
-  })
-  .strict();
+export const ProviderRuntimeSettingsSchema = z.object({
+  command: ProviderCommandSchema.optional(),
+  env: z.record(z.string()).optional(),
+  disallowedTools: z.array(z.string()).optional(),
+});
 
-const ProviderProfileThinkingOptionSchema = z
-  .object({
-    id: z.string(),
-    label: z.string(),
-    description: z.string().optional(),
-    isDefault: z.boolean().optional(),
-  })
-  .strict();
+const ProviderProfileThinkingOptionSchema = z.object({
+  id: z.string(),
+  label: z.string(),
+  description: z.string().optional(),
+  isDefault: z.boolean().optional(),
+});
 
-export const ProviderProfileModelSchema = z
-  .object({
-    id: z.string().min(1),
-    label: z.string().min(1),
-    description: z.string().optional(),
-    isDefault: z.boolean().optional(),
-    thinkingOptions: z.array(ProviderProfileThinkingOptionSchema).optional(),
-  })
-  .strict();
+export const ProviderProfileModelSchema = z.object({
+  id: z.string().min(1),
+  label: z.string().min(1),
+  description: z.string().optional(),
+  isDefault: z.boolean().optional(),
+  thinkingOptions: z.array(ProviderProfileThinkingOptionSchema).optional(),
+});
 
-export const ProviderOverrideSchema = z
-  .object({
-    extends: z.string().optional(),
-    label: z.string().optional(),
-    description: z.string().optional(),
-    command: z.array(z.string().min(1)).min(1).optional(),
-    env: z.record(z.string()).optional(),
-    models: z.array(ProviderProfileModelSchema).optional(),
-    additionalModels: z.array(ProviderProfileModelSchema).optional(),
-    disallowedTools: z.array(z.string()).optional(),
-    enabled: z.boolean().optional(),
-    order: z.number().optional(),
-  })
-  .strict();
+export const ProviderOverrideSchema = z.object({
+  extends: z.string().optional(),
+  label: z.string().optional(),
+  description: z.string().optional(),
+  command: z.array(z.string().min(1)).min(1).optional(),
+  env: z.record(z.string()).optional(),
+  models: z.array(ProviderProfileModelSchema).optional(),
+  additionalModels: z.array(ProviderProfileModelSchema).optional(),
+  disallowedTools: z.array(z.string()).optional(),
+  enabled: z.boolean().optional(),
+  order: z.number().optional(),
+});
 
 const BUILTIN_PROVIDER_IDS = ["claude", "codex", "copilot", "opencode", "pi"] as const;
 const PROVIDER_ID_PATTERN = /^[a-z][a-z0-9-]*$/;

packages/protocol/src/terminal-snapshot.test.ts

@@ -0,0 +1,49 @@
+import { describe, it, expect } from "vitest";
+import { renderTerminalSnapshotToAnsi } from "./terminal-snapshot";
+import type { TerminalState } from "./messages";
+
+function cells(text: string): TerminalState["grid"][number] {
+  return [...text].map((char) => ({ char }));
+}
+
+describe("renderTerminalSnapshotToAnsi", () => {
+  it("renders soft-wrapped rows as one contiguous logical line when wrap flags are present", () => {
+    // The server soft-wrapped one logical line "ABCDEFGHIJKLMNOP" at 10 cols into
+    // two grid rows. gridWrapped[0] = true marks row 0 as continuing into row 1.
+    const state: TerminalState = {
+      rows: 2,
+      cols: 10,
+      scrollback: [],
+      scrollbackWrapped: [],
+      grid: [cells("ABCDEFGHIJ"), cells("KLMNOP")],
+      gridWrapped: [true, false],
+      cursor: { row: 1, col: 6 },
+    };
+
+    const ansi = renderTerminalSnapshotToAnsi(state);
+
+    // The rows must arrive unbroken so xterm re-wraps them itself (and can later
+    // reflow them) — no hard newline injected between "...IJ" and "KL...".
+    expect(ansi).toContain("ABCDEFGHIJKLMNOP");
+    // Auto-wrap must stay enabled; disabling it (ESC[?7l) is what makes xterm mark
+    // the rows non-wrapped and refuse to reflow them on resize.
+    expect(ansi).not.toContain("[?7l");
+  });
+
+  it("falls back to verbatim per-row replay when wrap flags are absent (old daemon)", () => {
+    // No gridWrapped/scrollbackWrapped: the client cannot tell soft-wraps from hard
+    // newlines, so it must keep today's exact behaviour rather than guess.
+    const state: TerminalState = {
+      rows: 2,
+      cols: 10,
+      scrollback: [],
+      grid: [cells("ABCDEFGHIJ"), cells("KLMNOP")],
+      cursor: { row: 1, col: 6 },
+    };
+
+    const ansi = renderTerminalSnapshotToAnsi(state);
+
+    expect(ansi).toContain("[?7l");
+    expect(ansi).toContain("ABCDEFGHIJ\r\nKLMNOP");
+  });
+});

packages/protocol/src/terminal-snapshot.ts

@@ -28,12 +28,22 @@ const DEFAULT_STYLE: TerminalStyle = {
 
 export function renderTerminalSnapshotToAnsi(state: TerminalState): string {
   const rows = [...state.scrollback, ...state.grid];
-  const lines: string[] = ["\u001b[?7l"];
+  const wrapFlags = [...(state.scrollbackWrapped ?? []), ...(state.gridWrapped ?? [])];
+  // Soft-wrapped lines can only be re-wrapped on resize when we know which rows
+  // were continuations. With that per-row flag we replay each logical line as one
+  // unbroken run (autowrap on) so xterm marks the continuations wrapped and reflows
+  // them. Without it (old daemon) we keep the verbatim per-row replay: autowrap off
+  // plus a hard newline per row.
+  const hasWrapInfo = wrapFlags.length === rows.length;
+  const lines: string[] = hasWrapInfo ? [] : ["\u001b[?7l"];
 
   for (let rowIndex = 0; rowIndex < rows.length; rowIndex += 1) {
     const row = rows[rowIndex] ?? [];
-    lines.push(renderTerminalRow(row));
-    if (rowIndex < rows.length - 1) {
+    const continuesToNextRow = hasWrapInfo && wrapFlags[rowIndex] === true;
+    // A continuation row must fill the full width so the next row first cell
+    // triggers xterm auto-wrap, which is what marks the row wrapped/reflowable.
+    lines.push(renderTerminalRow(row, continuesToNextRow ? state.cols : undefined));
+    if (rowIndex < rows.length - 1 && !continuesToNextRow) {
       lines.push("\r\n");
     }
   }
@@ -45,7 +55,9 @@ export function renderTerminalSnapshotToAnsi(state: TerminalState): string {
   }
   lines.push(`\u001b[${state.cursor.row + 1};${state.cursor.col + 1}H`);
   lines.push(state.cursor.hidden ? "\u001b[?25l" : "\u001b[?25h");
-  lines.push("\u001b[?7h");
+  if (!hasWrapInfo) {
+    lines.push("\u001b[?7h");
+  }
   return lines.join("");
 }
 
@@ -67,9 +79,10 @@ function renderCursorPresentationToAnsi(cursor: TerminalState["cursor"]): string
   return `\u001b[${cursorStyleCode} q`;
 }
 
-function renderTerminalRow(row: TerminalCell[]): string {
+function renderTerminalRow(row: TerminalCell[], padToCols?: number): string {
   const output: string[] = [];
-  const length = getTerminalRowLength(row);
+  const contentLength = getTerminalRowLength(row);
+  const length = padToCols !== undefined ? Math.max(contentLength, padToCols) : contentLength;
   let previousStyle = DEFAULT_STYLE;
 
   for (let index = 0; index < length; index += 1) {

packages/server/src/server/session.ts

@@ -914,6 +914,8 @@ export class Session {
       hasBinaryChannel: () => this.onBinaryMessage !== null,
       isPathWithinRoot: (rootPath, candidatePath) => this.isPathWithinRoot(rootPath, candidatePath),
       sessionLogger: this.sessionLogger,
+      clientSupportsWrapReflow: () =>
+        this.clientCapabilities.has(CLIENT_CAPS.terminalReflowableSnapshot),
     });
     this.createAgentLifecycleDispatch = new CreateAgentLifecycleDispatch({
       paseoHome: this.paseoHome,

packages/server/src/terminal/terminal-session-controller.test.ts

@@ -168,6 +168,91 @@ async function flushMicrotasks(): Promise<void> {
   await new Promise((resolve) => setTimeout(resolve, 0));
 }
 
+describe("terminal-session-controller wrap-flag gating", () => {
+  function setup(clientSupportsWrapReflow?: () => boolean): {
+    controller: TerminalSessionController;
+    getTerminalState: ReturnType<typeof vi.fn>;
+  } {
+    const terminal: TerminalSession = {
+      id: "term-1",
+      name: "Terminal",
+      cwd: "/tmp",
+      send: vi.fn(),
+      subscribe: (listener) => {
+        queueMicrotask(() => listener({ type: "snapshotReady", revision: 1 }));
+        return vi.fn();
+      },
+      onExit: () => vi.fn(),
+      onCommandFinished: () => vi.fn(),
+      onTitleChange: () => vi.fn(),
+      getSize: () => ({ rows: 1, cols: 80 }),
+      getState: () => terminalState("hello"),
+      getStateSnapshot: () => ({ state: terminalState("hello"), revision: 1 }),
+      getReplayPreamble: () => "",
+      getTitle: () => undefined,
+      setTitle: vi.fn(),
+      getExitInfo: () => null,
+      kill: vi.fn(),
+      killAndWait: vi.fn(),
+    };
+    const getTerminalState = vi.fn(() =>
+      Promise.resolve<TerminalStateSnapshot>({ state: terminalState("hello"), revision: 1 }),
+    );
+    const terminalManager = {
+      getTerminals: vi.fn(),
+      createTerminal: vi.fn(),
+      registerCwdEnv: vi.fn(),
+      getTerminal: vi.fn(() => terminal),
+      getTerminalState,
+      setTerminalTitle: vi.fn(),
+      killTerminal: vi.fn(),
+      killTerminalAndWait: vi.fn(),
+      captureTerminal: vi.fn(),
+      listDirectories: vi.fn(() => []),
+      killAll: vi.fn(),
+      subscribeTerminalsChanged: vi.fn(() => vi.fn()),
+    } as unknown as TerminalManager;
+    const controller = new TerminalSessionController({
+      terminalManager,
+      emit: vi.fn(),
+      emitBinary: vi.fn(),
+      hasBinaryChannel: () => true,
+      isPathWithinRoot: () => false,
+      sessionLogger: createLogger(),
+      ...(clientSupportsWrapReflow ? { clientSupportsWrapReflow } : {}),
+    });
+    return { controller, getTerminalState };
+  }
+
+  async function subscribe(controller: TerminalSessionController): Promise<void> {
+    await controller.dispatch({
+      type: "subscribe_terminal_request",
+      terminalId: "term-1",
+      requestId: "req-1",
+      restore: { mode: "visible-snapshot", scrollbackLines: 200 },
+    });
+    await flushMicrotasks();
+  }
+
+  test("requests wrap flags when the client supports reflowable snapshots", async () => {
+    const { controller, getTerminalState } = setup(() => true);
+    await subscribe(controller);
+    expect(getTerminalState).toHaveBeenCalledWith(
+      "term-1",
+      expect.objectContaining({ includeWrapFlags: true }),
+    );
+  });
+
+  test("omits wrap flags when the client does not advertise support", async () => {
+    const { controller, getTerminalState } = setup();
+    await subscribe(controller);
+    expect(getTerminalState).toHaveBeenCalledWith(
+      "term-1",
+      expect.objectContaining({ includeWrapFlags: false }),
+    );
+  });
+});
+
 describe("terminal-session-controller subdirectory aggregation", () => {
   test("delivers a subdirectory change to a root subscriber as an aggregated, root-keyed snapshot", async () => {
     const rootCwd = "/work/repo";

packages/server/src/terminal/terminal-session-controller.ts

@@ -65,6 +65,10 @@ export interface TerminalSessionControllerOptions {
   hasBinaryChannel: () => boolean;
   isPathWithinRoot: (rootPath: string, candidatePath: string) => boolean;
   sessionLogger: pino.Logger;
+  // Whether the connected client can reflow restored snapshots. When true the
+  // daemon attaches per-row soft-wrap flags to snapshots; otherwise it omits them
+  // so old (strict-schema) clients still parse the snapshot.
+  clientSupportsWrapReflow?: () => boolean;
 }
 
 export interface TerminalSessionControllerMetrics {
@@ -104,6 +108,7 @@ export class TerminalSessionController {
   private readonly hasBinaryChannel: () => boolean;
   private readonly isPathWithinRoot: (rootPath: string, candidatePath: string) => boolean;
   private readonly sessionLogger: pino.Logger;
+  private readonly clientSupportsWrapReflow: () => boolean;
 
   private readonly subscribedDirectories = new Set<string>();
   private unsubscribeTerminalsChanged: (() => void) | null = null;
@@ -119,6 +124,7 @@ export class TerminalSessionController {
     this.hasBinaryChannel = options.hasBinaryChannel;
     this.isPathWithinRoot = options.isPathWithinRoot;
     this.sessionLogger = options.sessionLogger;
+    this.clientSupportsWrapReflow = options.clientSupportsWrapReflow ?? (() => false);
   }
 
   start(): void {
@@ -801,7 +807,9 @@ export class TerminalSessionController {
     activeStream: ActiveTerminalStream,
     terminalManager: TerminalManager,
   ): Promise<SnapshotSendResult> {
-    const snapshot = await terminalManager.getTerminalState(activeStream.terminalId);
+    const snapshot = await terminalManager.getTerminalState(activeStream.terminalId, {
+      includeWrapFlags: this.clientSupportsWrapReflow(),
+    });
     if (this.activeStreams.get(activeStream.slot) !== activeStream) {
       return { shouldContinue: false };
     }
@@ -829,10 +837,10 @@ export class TerminalSessionController {
       return { shouldContinue: true };
     }
 
-    const snapshot = await terminalManager.getTerminalState(
-      activeStream.terminalId,
-      snapshotOptions,
-    );
+    const snapshot = await terminalManager.getTerminalState(activeStream.terminalId, {
+      ...snapshotOptions,
+      includeWrapFlags: this.clientSupportsWrapReflow(),
+    });
     if (this.activeStreams.get(activeStream.slot) !== activeStream) {
       return { shouldContinue: false };
     }

packages/server/src/terminal/terminal.test.ts

@@ -279,6 +279,37 @@ describe("createTerminal", () => {
     expect(state.cols).toBe(120);
   });
 
+  it("reports per-row soft-wrap flags only when wrap flags are requested", async () => {
+    const session = trackSession(
+      await createTerminal({
+        cwd: realpathSync(tmpdir()),
+        cols: 40,
+        rows: 10,
+        command: process.execPath,
+        // 100 chars with no newline soft-wraps across three rows at 40 cols.
+        args: ["-e", "process.stdout.write('A'.repeat(100)); setInterval(() => {}, 100000);"],
+      }),
+    );
+
+    const start = Date.now();
+    while (Date.now() - start < 5000) {
+      if (rowToText(session.getState().grid[2]).startsWith("A")) {
+        break;
+      }
+      await new Promise((resolve) => setTimeout(resolve, 50));
+    }
+
+    // Rows 0 and 1 continue onto the next row; row 2 is the end of the logical line.
+    const withFlags = session.getState({ includeWrapFlags: true });
+    expect(withFlags.gridWrapped?.slice(0, 3)).toEqual([true, true, false]);
+
+    // Back-compat gate: without the capability the daemon must not attach the new
+    // fields, so an old strict-schema client still parses the snapshot.
+    const withoutFlags = session.getState();
+    expect(withoutFlags.gridWrapped).toBeUndefined();
+    expect(withoutFlags.scrollbackWrapped).toBeUndefined();
+  });
+
   it("captures exit diagnostics from the terminal buffer", async () => {
     const session = trackSession(
       await createTerminal({

packages/server/src/terminal/terminal.ts

@@ -40,6 +40,10 @@ export interface TerminalStateSnapshot {
 
 export interface TerminalStateSnapshotOptions {
   scrollbackLines?: number;
+  // Include per-row soft-wrap flags (gridWrapped/scrollbackWrapped) so the client
+  // can reflow restored content on resize. Gated on a client capability, so old
+  // clients never receive the extra fields.
+  includeWrapFlags?: boolean;
 }
 
 export interface TerminalSubscribeOptions {
@@ -359,6 +363,39 @@ function extractScrollback(
   return scrollback;
 }
 
+// xterm marks a line `isWrapped` when it is a continuation of the PREVIOUS line.
+// The snapshot carries the inverse, tmux-style flag — "this row continues onto the
+// next row" — so the client can rejoin and reflow logical lines. So row y's flag is
+// whether line y+1 is a wrapped continuation.
+function lineContinuesToNext(terminal: TerminalType, absoluteRow: number): boolean {
+  return terminal.buffer.active.getLine(absoluteRow + 1)?.isWrapped === true;
+}
+
+function extractGridWrapped(terminal: TerminalType): boolean[] {
+  const baseY = terminal.buffer.active.baseY;
+  const wrapped: boolean[] = [];
+  for (let row = 0; row < terminal.rows; row++) {
+    wrapped.push(lineContinuesToNext(terminal, baseY + row));
+  }
+  return wrapped;
+}
+
+function extractScrollbackWrapped(
+  terminal: TerminalType,
+  options?: { scrollbackLines?: number },
+): boolean[] {
+  const scrollbackLines = terminal.buffer.active.baseY;
+  const startRow =
+    typeof options?.scrollbackLines === "number"
+      ? Math.max(0, scrollbackLines - options.scrollbackLines)
+      : 0;
+  const wrapped: boolean[] = [];
+  for (let row = startRow; row < scrollbackLines; row++) {
+    wrapped.push(lineContinuesToNext(terminal, row));
+  }
+  return wrapped;
+}
+
 function extractCursorState(terminal: TerminalType): TerminalState["cursor"] {
   const coreService = (terminal as unknown as { _core?: { coreService?: Record<string, unknown> } })
     ._core?.coreService as
@@ -853,6 +890,14 @@ export async function createTerminal(options: CreateTerminalOptions): Promise<Te
       }),
       cursor: extractCursorState(terminal),
       ...(title ? { title } : {}),
+      ...(snapshotOptions?.includeWrapFlags
+        ? {
+            gridWrapped: extractGridWrapped(terminal),
+            scrollbackWrapped: extractScrollbackWrapped(terminal, {
+              scrollbackLines: snapshotOptions?.scrollbackLines,
+            }),
+          }
+        : {}),
     };
   }