diff --git a/apps/web/src/components/ThreadTerminalDrawer.browser.test.tsx b/apps/web/src/components/ThreadTerminalDrawer.browser.test.tsx
index 9fd2758747533..37fd527142aba 100644
--- a/apps/web/src/components/ThreadTerminalDrawer.browser.test.tsx
+++ b/apps/web/src/components/ThreadTerminalDrawer.browser.test.tsx
@@ -1,10 +1,14 @@
-import { EMPTY_TERMINAL_SESSION_STATE } from "@t3tools/client-runtime/state/terminal";
+import {
+  EMPTY_TERMINAL_SESSION_STATE,
+  type TerminalSessionState,
+} from "@t3tools/client-runtime/state/terminal";
 import {
   EnvironmentId,
   ThreadId,
   type ScopedThreadRef,
   type FilesystemEntryMetadata,
 } from "@t3tools/contracts";
+import { Cause } from "effect";
 import { Atom, AsyncResult } from "effect/reactivity";
 import type { GhosttyTerminalSurfaceOptions } from "~/terminal/ghostty/surface";
 import { AppAtomRegistryProvider, appAtomRegistry } from "../rpc/atomRegistry";
@@ -15,17 +19,29 @@ import ThreadTerminalDrawer from "./ThreadTerminalDrawer";
 
 const fixture = vi.hoisted(() => ({
   statusByThreadId: new Map<string, "running" | "exited">(),
+  sessions: new Map<string, Atom.Writable<TerminalSessionState>>(),
   pendingSurfaces: [] as Array<() => void>,
   surfaceOptions: [] as GhosttyTerminalSurfaceOptions[],
+  reportedSize: null as { cols: number; rows: number } | null,
+  resizeCommand: {},
+  runResize: (_input: unknown): Promise<AsyncResult.AsyncResult<unknown, unknown>> =>
+    Promise.resolve(AsyncResult.success(undefined)),
   metadata: new Map<
     string,
     Atom.Writable<AsyncResult.AsyncResult<FilesystemEntryMetadata | null>>
   >(),
 }));
 
-// Every surface method is a no-op; `then` stays undefined so awaiting the surface resolves to it.
+// Every other surface method is a no-op; `then` stays undefined so awaiting the surface resolves to it.
 const fakeSurface: object = new Proxy(
-  { input: document.createElement("textarea") },
+  {
+    input: document.createElement("textarea"),
+    // The real surface re-reports its measured grid.
+    resendSize: () => {
+      const size = fixture.reportedSize;
+      if (size) fixture.surfaceOptions.at(-1)!.onResize(size.cols, size.rows);
+    },
+  },
   {
     get: (target, key) =>
       key === "then" ? undefined : key in target ? Reflect.get(target, key) : () => undefined,
@@ -43,13 +59,15 @@ vi.mock("~/terminal/ghostty/surface", () => ({
 vi.mock("../state/terminalSessions", async () => {
   const Atom = await import("effect/reactivity/Atom");
   const sessions = Atom.family((_environmentId: EnvironmentId) =>
-    Atom.family((threadId: ThreadId) =>
-      Atom.make({
+    Atom.family((threadId: ThreadId) => {
+      const session = Atom.make<TerminalSessionState>({
         ...EMPTY_TERMINAL_SESSION_STATE,
         status: fixture.statusByThreadId.get(threadId) ?? "closed",
         version: 1,
-      }),
-    ),
+      });
+      fixture.sessions.set(threadId, session);
+      return session;
+    }),
   );
   return {
     attachedTerminalSessionAtom: (environmentId: EnvironmentId, terminal: { threadId: ThreadId }) =>
@@ -61,7 +79,8 @@ vi.mock("../state/session", () => ({
   readEnvironmentScope: () => true,
 }));
 vi.mock("../state/use-atom-command", () => ({
-  useAtomCommand: () => async () => ({ _tag: "Success" }),
+  useAtomCommand: (command: object) => async (input: unknown) =>
+    command === fixture.resizeCommand ? fixture.runResize(input) : { _tag: "Success" },
 }));
 // The commands are replaced above; importing their runtime would connect a client.
 vi.mock("../state/server", async () => {
@@ -69,7 +88,9 @@ vi.mock("../state/server", async () => {
   const config = Atom.make(null);
   return { serverEnvironment: { configValueAtom: () => config } };
 });
-vi.mock("../state/terminal", () => ({ terminalEnvironment: { write: {}, resize: {} } }));
+vi.mock("../state/terminal", () => ({
+  terminalEnvironment: { write: {}, resize: fixture.resizeCommand },
+}));
 vi.mock("../state/preview", () => ({ previewEnvironment: { open: {} } }));
 vi.mock("../state/projects", async () => {
   const { Atom, AsyncResult } = await import("effect/reactivity");
@@ -148,6 +169,8 @@ function setup() {
   ]);
   fixture.pendingSurfaces = [];
   fixture.surfaceOptions = [];
+  fixture.reportedSize = null;
+  fixture.runResize = () => Promise.resolve(AsyncResult.success(undefined));
   fixture.metadata.clear();
   return { original, other };
 }
@@ -248,3 +271,46 @@ it("only activates terminal paths confirmed to exist on their environment", asyn
   await hover("~/notes.ts:5:2");
   expect(canActivate("~/notes.ts:5:2")).toBe(true);
 });
+
+it("resends a failed resize once in each writable session", async () => {
+  const { other: threadRef } = setup();
+  const resizes: unknown[] = [];
+  const failure = AsyncResult.failure(Cause.die(new Error("resize rejected")));
+  let failFirstResize = () => {};
+  fixture.runResize = (input) => {
+    resizes.push(input);
+    if (resizes.length > 1) return Promise.resolve(failure);
+    return new Promise((resolve) => {
+      failFirstResize = () => resolve(failure);
+    });
+  };
+  const running = (generation: number): TerminalSessionState => ({
+    ...EMPTY_TERMINAL_SESSION_STATE,
+    status: "running",
+    version: 1,
+    output: { ...EMPTY_TERMINAL_SESSION_STATE.output, generation },
+  });
+  await using _screen = await render(<Drawer threadRef={threadRef} onCloseTerminal={() => {}} />);
+  const session = fixture.sessions.get(threadRef.threadId)!;
+  await act(async () => {
+    fixture.pendingSurfaces.shift()?.();
+  });
+  await act(async () => {
+    fixture.reportedSize = { cols: 57, rows: 41 };
+    fixture.surfaceOptions.at(-1)!.onResize(57, 41);
+  });
+  // The first request fails while the attachment reconnects, so its retry is not sent.
+  await act(async () => {
+    appAtomRegistry.set(session, { ...running(1), version: 0 });
+    failFirstResize();
+  });
+  expect(resizes).toHaveLength(1);
+  await act(async () => {
+    appAtomRegistry.set(session, running(2));
+  });
+  const resize = {
+    environmentId: threadRef.environmentId,
+    input: { threadId: threadRef.threadId, terminalId: "term-1", cols: 57, rows: 41 },
+  };
+  expect(resizes).toEqual([resize, resize, resize]);
+});
diff --git a/apps/web/src/components/ThreadTerminalDrawer.tsx b/apps/web/src/components/ThreadTerminalDrawer.tsx
index 049589d0b671a..134869ea04e0a 100644
--- a/apps/web/src/components/ThreadTerminalDrawer.tsx
+++ b/apps/web/src/components/ThreadTerminalDrawer.tsx
@@ -635,14 +635,22 @@ function TerminalSessionViewport({
       input: { threadId, terminalId, data },
     }),
   );
-  const resizeTerminal = useEffectEvent((cols: number, rows: number) => {
-    if (writableSessionGeneration(readTerminalSession(), hasTerminalWriteAccess()) === null) {
-      return;
-    }
-    return runTerminalResize({
+  // The surface reports a resent grid like any other, so the next report is the retry.
+  const resizeRetryGenerationRef = useRef<number | null>(null);
+  const resizeTerminal = useEffectEvent(async (cols: number, rows: number) => {
+    const generation = writableSessionGeneration(readTerminalSession(), hasTerminalWriteAccess());
+    const retry = generation !== null && generation === resizeRetryGenerationRef.current;
+    resizeRetryGenerationRef.current = null;
+    if (generation === null) return;
+    const result = await runTerminalResize({
       environmentId,
       input: { threadId, terminalId, cols, rows },
     });
+    // Resend the current grid, not this one: a newer resize may already be queued behind it.
+    if (!retry && result._tag === "Failure" && !isAtomCommandInterrupted(result)) {
+      resizeRetryGenerationRef.current = generation;
+      terminalRef.current?.resendSize();
+    }
   });
   const outputCursorRef = useRef<TerminalOutputCursor>(INITIAL_TERMINAL_OUTPUT_CURSOR);
   const synchronizedStatusRef = useRef<TerminalSessionState["status"]>("closed");
diff --git a/packages/client-runtime/src/state/terminal.test.ts b/packages/client-runtime/src/state/terminal.test.ts
index 6fb2d21b19ea1..116fdd3993a0a 100644
--- a/packages/client-runtime/src/state/terminal.test.ts
+++ b/packages/client-runtime/src/state/terminal.test.ts
@@ -1,4 +1,5 @@
 import { EnvironmentId, ThreadId } from "@t3tools/contracts";
+import * as Cause from "effect/Cause";
 import { AsyncResult, Atom, AtomRegistry } from "effect/reactivity";
 import { expect, it } from "vite-plus/test";
 
@@ -9,6 +10,7 @@ import {
   type TerminalLifecycleEvent,
   type TerminalSessionMode,
 } from "./terminal.ts";
+import type { AtomCommandResult } from "./runtime.ts";
 import { EMPTY_TERMINAL_BUFFER_STATE, type TerminalBufferState } from "./terminalSession.ts";
 
 function run(events: ReadonlyArray<TerminalLifecycleEvent>) {
@@ -79,13 +81,22 @@ function setup(options: { readonly initialInput?: string } = {}) {
   );
   const access = { canOperate: true };
   const calls: Array<{ readonly command: string; readonly input: unknown }> = [];
+  // Resize requests stay in flight until the test settles them.
+  const resizeResults: Array<(result: AtomCommandResult<void, string>) => void> = [];
   const command = (name: string) => ({
     label: name,
-    run: async (_registry: AtomRegistry.AtomRegistry, value: { readonly input: unknown }) => {
+    run: (_registry: AtomRegistry.AtomRegistry, value: { readonly input: unknown }) => {
       calls.push({ command: name, input: value.input });
-      return AsyncResult.success(undefined);
+      if (name !== "resize") return Promise.resolve(AsyncResult.success(undefined));
+      return new Promise<AtomCommandResult<void, string>>((resolve) => resizeResults.push(resolve));
     },
   });
+  // The session sees a settled result within a fixed number of microtasks.
+  const failResize = async (index: number) => {
+    resizeResults[index]!(AsyncResult.failure(Cause.fail("offline")));
+    // No promise marks the retry decision, so flush the command's continuation chain.
+    for (let tick = 0; tick < 10; tick++) await Promise.resolve();
+  };
   const exits: Array<true> = [];
   const live: Array<boolean> = [];
   const session = createTerminalSession(
@@ -126,7 +137,21 @@ function setup(options: { readonly initialInput?: string } = {}) {
     registry.set(observation, snapshot(state));
   const mount = (mode: TerminalSessionMode) => registry.mount(session.driver(mode));
   const of = (name: string) => calls.filter((call) => call.command === name).map((c) => c.input);
-  return { session, attached, access, flush, detach, emit, observe, mount, calls, of, exits, live };
+  return {
+    session,
+    attached,
+    access,
+    failResize,
+    flush,
+    detach,
+    emit,
+    observe,
+    mount,
+    calls,
+    of,
+    exits,
+    live,
+  };
 }
 
 it("replays the measured grid on every new attachment generation", () => {
@@ -154,6 +179,30 @@ it("replays the measured grid on every new attachment generation", () => {
   ]);
 });
 
+it("sends each failed resize again once, in every attachment generation", async () => {
+  const { session, attached, failResize, emit, detach, mount, of } = setup();
+  mount(attached);
+  emit({ status: "running", version: 1 });
+  detach();
+  await failResize(0);
+  expect(of("resize")).toHaveLength(1);
+
+  emit({ status: "running", version: 1, generation: 2 });
+  await failResize(1);
+  expect(of("resize")).toHaveLength(3);
+  await failResize(2);
+  session.reportGridSize({ cols: 100, rows: 30 });
+  await failResize(3);
+  await failResize(4);
+  expect(of("resize")).toEqual([
+    { threadId, terminalId: "term-1", cols: 120, rows: 40 },
+    { threadId, terminalId: "term-1", cols: 120, rows: 40 },
+    { threadId, terminalId: "term-1", cols: 120, rows: 40 },
+    { threadId, terminalId: "term-1", cols: 100, rows: 30 },
+    { threadId, terminalId: "term-1", cols: 100, rows: 30 },
+  ]);
+});
+
 it("writes the launch's initial input once the first snapshot lands", () => {
   const { attached, emit, mount, calls, of } = setup({ initialInput: "pnpm dev\r" });
   mount(attached);
diff --git a/packages/client-runtime/src/state/terminal.ts b/packages/client-runtime/src/state/terminal.ts
index a39e47b1340b4..26d319f1e88d1 100644
--- a/packages/client-runtime/src/state/terminal.ts
+++ b/packages/client-runtime/src/state/terminal.ts
@@ -18,6 +18,7 @@ import {
   createAtomCommandScheduler,
   createEnvironmentRpcCommand,
   createEnvironmentSubscriptionAtomFamily,
+  isAtomCommandInterrupted,
   runAtomCommand,
 } from "./runtime.ts";
 import type { EnvironmentRegistry } from "../connection/registry.ts";
@@ -263,11 +264,17 @@ export function createTerminalSession(
   let loggedFirstOutput = false;
   let resizeRegistry: AtomRegistry.AtomRegistry | null = null;
 
-  const sendResize = () => {
+  const sendResize = (retry = false) => {
     if (generation === null || resizeRegistry === null || !options.canOperate()) return;
     void runAtomCommand(resizeRegistry, atoms.resize, {
       environmentId,
       input: { threadId, terminalId, cols: gridSize.cols, rows: gridSize.rows },
+    }).then((result) => {
+      // Only a new grid or generation sends again, so retry a failure once. Resend the current
+      // grid, not this one: a newer resize may already be queued behind it.
+      if (!retry && result._tag === "Failure" && !isAtomCommandInterrupted(result)) {
+        sendResize(true);
+      }
     });
   };