diff --git a/packages/electron/README.md b/packages/electron/README.md
index 2e052833..45722457 100644
--- a/packages/electron/README.md
+++ b/packages/electron/README.md
@@ -85,6 +85,8 @@ After packaging, run `bun run --cwd packages/electron verify:linux-appimage`. Th
 
 Running a packaged Linux AppImage requires FUSE (`libfuse.so.2`, typically `libfuse2` / `libfuse2t64` on Debian/Ubuntu). Without FUSE, start with `APPIMAGE_EXTRACT_AND_RUN=1`. Keep the AppImage on a writable path so in-app updates can replace it.
 
+Desktop clears AppImage `ARGV0` from `process.env` before probing the login shell and starting the in-process server. Leaving it set makes zsh rewrite argv[0] for integrated-terminal and managed-OpenCode child commands to the AppImage path.
+
 Linux updates are supported only when the packaged app is running from a writable AppImage. Update checks, downloads, and installation report an actionable error when `APPIMAGE` is missing, invalid, or read-only; a missing release feed (`latest-linux.yml` 404 before the first Linux publish) is treated as “no update available”. macOS and Windows updater behavior is unchanged. Release builds keep `latest-linux.yml` (x64) and `latest-linux-arm64.yml` separate and validate each manifest against its AppImage before upload. Linux AppImages download full updates (no `.blockmap` differential channel yet).
 
 ### Updater End-to-End Fixture
diff --git a/packages/electron/main.mjs b/packages/electron/main.mjs
index d82fbb3b..46722691 100644
--- a/packages/electron/main.mjs
+++ b/packages/electron/main.mjs
@@ -1374,11 +1374,16 @@ const loadShellEnv = () => {
 
 // Merge the user's login-shell env (PATH, etc.) into this process before we
 import { pathLooksUserConfigured, mergePathValues } from '@openchamber/web/server/lib/opencode/path-utils.js';
+import { stripAppImageArgv0Leak } from '@openchamber/web/server/lib/inherited-env.js';
 
 // import/start the server in-process. The server and its children (opencode
 // CLI, git, etc.) inherit process.env directly now — there is no sidecar
 // subprocess to hand a custom env to.
 const inheritUserShellEnv = () => {
+  // Clear before probing/merging so login-shell snapshots and children never
+  // inherit the AppImage path as argv[0] via zsh's ARGV0 parameter (#2588).
+  stripAppImageArgv0Leak(process.env);
+
   const shellEnv = loadShellEnv();
   if (!shellEnv) return;
 
@@ -1388,7 +1393,7 @@ const inheritUserShellEnv = () => {
   const currentPathLooksUserConfigured = pathLooksUserConfigured(currentPath, homeDir, delimiter);
 
   for (const [key, value] of Object.entries(shellEnv)) {
-    if (key === 'PATH') continue;
+    if (key === 'PATH' || key === 'ARGV0') continue;
     if (typeof process.env[key] === 'undefined') {
       process.env[key] = value;
     }
diff --git a/packages/web/server/lib/inherited-env.js b/packages/web/server/lib/inherited-env.js
new file mode 100644
index 00000000..9cae7f27
--- /dev/null
+++ b/packages/web/server/lib/inherited-env.js
@@ -0,0 +1,23 @@
+/**
+ * Sanitize environment objects inherited by user-facing child processes.
+ *
+ * Linux AppImage runtimes export `ARGV0` as the AppImage path before launching
+ * the packaged app. zsh treats an exported `ARGV0` as the argv[0] for every
+ * external command it spawns, which corrupts Python venv detection and any
+ * other program that reads argv[0]/$0 while leaving `/proc/self/exe` correct.
+ *
+ * See openchamber/openchamber#2588 and pingdotgg/t3code#2509.
+ */
+
+/**
+ * Remove AppImage `ARGV0` from a mutable env object (or `process.env`).
+ * @param {NodeJS.ProcessEnv | Record<string, string | undefined> | null | undefined} env
+ * @returns {typeof env}
+ */
+export function stripAppImageArgv0Leak(env) {
+  if (!env || typeof env !== 'object') return env;
+  if (Object.prototype.hasOwnProperty.call(env, 'ARGV0')) {
+    delete env.ARGV0;
+  }
+  return env;
+}
diff --git a/packages/web/server/lib/inherited-env.test.js b/packages/web/server/lib/inherited-env.test.js
new file mode 100644
index 00000000..e7193190
--- /dev/null
+++ b/packages/web/server/lib/inherited-env.test.js
@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest';
+import { stripAppImageArgv0Leak } from './inherited-env.js';
+
+describe('stripAppImageArgv0Leak', () => {
+  it('removes ARGV0 from a child env object', () => {
+    const env = {
+      PATH: '/usr/bin',
+      ARGV0: '/path/to/OpenChamber-1.17.2-linux-x86_64.AppImage',
+      SHELL: '/bin/zsh',
+    };
+
+    expect(stripAppImageArgv0Leak(env)).toBe(env);
+    expect(env).toEqual({
+      PATH: '/usr/bin',
+      SHELL: '/bin/zsh',
+    });
+  });
+
+  it('is a no-op when ARGV0 is absent', () => {
+    const env = { PATH: '/usr/bin', SHELL: '/bin/bash' };
+    stripAppImageArgv0Leak(env);
+    expect(env).toEqual({ PATH: '/usr/bin', SHELL: '/bin/bash' });
+  });
+
+  it('tolerates nullish env values', () => {
+    expect(stripAppImageArgv0Leak(null)).toBeNull();
+    expect(stripAppImageArgv0Leak(undefined)).toBeUndefined();
+  });
+});
diff --git a/packages/web/server/lib/opencode/DOCUMENTATION.md b/packages/web/server/lib/opencode/DOCUMENTATION.md
index c57ecb8b..bb9fcdfc 100644
--- a/packages/web/server/lib/opencode/DOCUMENTATION.md
+++ b/packages/web/server/lib/opencode/DOCUMENTATION.md
@@ -120,7 +120,9 @@ The runtime maintains active-session count incrementally from idempotent activit
 Managed OpenCode launch also merges the environment returned by the agent-tool
 runtime. PATH and `OPENCODE_SERVER_PASSWORD` remain lifecycle-owned and cannot
 be replaced by injected values. External OpenCode processes receive no
-OpenChamber tool injection.
+OpenChamber tool injection. Managed launch env strips AppImage `ARGV0` before
+spawn so zsh-backed OpenCode tools do not rewrite child argv[0] to the AppImage
+path (#2588).
 
 Set `OPENCHAMBER_STARTUP_PERF=1` to emit bounded startup phase records for server listen, managed OpenCode preparation/readiness, and proxy readiness holds. Every OpenCode bootstrap emits one terminal `opencode.bootstrap.ready` or `opencode.bootstrap.error` event, including reused and external server paths. Records contain controlled phase/outcome/route labels and timing values only; they never contain request URLs, runtime keys, directories, session IDs, credentials, or content.
 
diff --git a/packages/web/server/lib/opencode/env-runtime.js b/packages/web/server/lib/opencode/env-runtime.js
index 0bd65b50..5ed52956 100644
--- a/packages/web/server/lib/opencode/env-runtime.js
+++ b/packages/web/server/lib/opencode/env-runtime.js
@@ -232,7 +232,7 @@ export const createOpenCodeEnvRuntime = (deps) => {
       return;
     }
 
-    const skipKeys = new Set(['PWD', 'OLDPWD', 'SHLVL', '_']);
+    const skipKeys = new Set(['PWD', 'OLDPWD', 'SHLVL', '_', 'ARGV0']);
     for (const [key, value] of Object.entries(snapshot)) {
       if (skipKeys.has(key)) {
         continue;
@@ -244,6 +244,9 @@ export const createOpenCodeEnvRuntime = (deps) => {
       process.env[key] = value;
     }
 
+    // AppImage ARGV0 must never remain on process.env (zsh rewrites argv[0]; #2588).
+    delete process.env.ARGV0;
+
     const currentPath = process.env.PATH || '';
     const shellPath = snapshot.PATH || '';
     if (!shellPath) {
diff --git a/packages/web/server/lib/opencode/env-runtime.test.js b/packages/web/server/lib/opencode/env-runtime.test.js
index 52ce6908..96386db3 100644
--- a/packages/web/server/lib/opencode/env-runtime.test.js
+++ b/packages/web/server/lib/opencode/env-runtime.test.js
@@ -131,6 +131,28 @@ describe('OpenCode env runtime', () => {
     expect(process.env.PATH).toBe(defaultDir);
   });
 
+  it('clears AppImage ARGV0 when applying a login-shell env snapshot', () => {
+    const previousArgv0 = process.env.ARGV0;
+    process.env.ARGV0 = '/path/to/OpenChamber.AppImage';
+    delete process.env.OPENCHAMBER_ARGV0_TEST_MARKER;
+    const { runtime, state } = createRuntime({});
+    state.cachedLoginShellEnvSnapshot = {
+      PATH: '/usr/bin',
+      ARGV0: '/leaked/from/shell.AppImage',
+      OPENCHAMBER_ARGV0_TEST_MARKER: '1',
+    };
+
+    try {
+      runtime.applyLoginShellEnvSnapshot();
+      expect(process.env.ARGV0).toBeUndefined();
+      expect(process.env.OPENCHAMBER_ARGV0_TEST_MARKER).toBe('1');
+    } finally {
+      delete process.env.OPENCHAMBER_ARGV0_TEST_MARKER;
+      if (previousArgv0 === undefined) delete process.env.ARGV0;
+      else process.env.ARGV0 = previousArgv0;
+    }
+  });
+
   it('throws a specific error for a missing configured OpenCode binary in strict mode', async () => {
     const { runtime } = createRuntime({ opencodeBinary: '/missing/opencode' });
 
diff --git a/packages/web/server/lib/opencode/lifecycle.js b/packages/web/server/lib/opencode/lifecycle.js
index 046a710e..77cb3f4d 100644
--- a/packages/web/server/lib/opencode/lifecycle.js
+++ b/packages/web/server/lib/opencode/lifecycle.js
@@ -1,5 +1,6 @@
 import { spawn, spawnSync } from 'node:child_process';
 import net from 'node:net';
+import { stripAppImageArgv0Leak } from '../inherited-env.js';
 import { registerManagedProcess, unregisterManagedProcess, reapOrphanedProcesses } from './managed-process-registry.js';
 import { recordStartupPerformance } from './startup-performance.js';
 
@@ -518,13 +519,13 @@ export const createOpenCodeLifecycleRuntime = (deps) => {
         timeout: 30000,
         cwd: state.openCodeWorkingDirectory,
         shellEnvKeysCount: Object.keys(shellEnv).length,
-        env: {
+        env: stripAppImageArgv0Leak({
           ...shellEnv,
           ...process.env,
           ...managedOpenCodeEnv,
           PATH: envPath,
           OPENCODE_SERVER_PASSWORD: openCodePassword,
-        },
+        }),
       });
 
       if (!serverInstance || !serverInstance.url) {
diff --git a/packages/web/server/lib/opencode/lifecycle.test.js b/packages/web/server/lib/opencode/lifecycle.test.js
index aadb5483..1a1c1b21 100644
--- a/packages/web/server/lib/opencode/lifecycle.test.js
+++ b/packages/web/server/lib/opencode/lifecycle.test.js
@@ -285,6 +285,40 @@ describe('OpenCode lifecycle', () => {
     await server.close();
   });
 
+  it('strips AppImage ARGV0 from managed OpenCode launch env', async () => {
+    delete process.env.OPENCODE_BINARY;
+    const previousArgv0 = process.env.ARGV0;
+    process.env.ARGV0 = '/path/to/OpenChamber/OpenChamber-1.17.2-linux-x86_64.AppImage';
+    const child = createMockChild();
+    spawnMock.mockImplementationOnce(() => {
+      queueMicrotask(() => {
+        child.stdout.emit('data', 'opencode server listening on http://127.0.0.1:45678\n');
+      });
+      return child;
+    });
+
+    try {
+      const runtime = createRuntime({
+        getManagedOpenCodeShellEnvSnapshot: vi.fn(() => ({
+          PATH: '/home/user/.bun/bin:/usr/local/bin:/usr/bin',
+          ARGV0: '/leaked/from/shell/snapshot.AppImage',
+          SHELL_ONLY: 'yes',
+        })),
+      });
+      const server = await runtime.startOpenCode();
+      const [, , options] = spawnMock.mock.calls[0];
+
+      expect(options.env).not.toHaveProperty('ARGV0');
+      expect(options.env.SHELL_ONLY).toBe('yes');
+      expect(options.env.PATH).toBe('/home/user/.bun/bin:/usr/local/bin:/usr/bin');
+
+      await server.close();
+    } finally {
+      if (previousArgv0 === undefined) delete process.env.ARGV0;
+      else process.env.ARGV0 = previousArgv0;
+    }
+  });
+
   it('adds managed OpenChamber tool environment without allowing it to replace launch invariants', async () => {
     const child = createMockChild();
     spawnMock.mockImplementationOnce(() => {
diff --git a/packages/web/server/lib/terminal/DOCUMENTATION.md b/packages/web/server/lib/terminal/DOCUMENTATION.md
index ffc27411..d662c060 100644
--- a/packages/web/server/lib/terminal/DOCUMENTATION.md
+++ b/packages/web/server/lib/terminal/DOCUMENTATION.md
@@ -24,6 +24,7 @@ HTTP remains the authenticated command plane for create, resize, appearance upda
 - Concurrent creates for one ID are single-flight only when working directory and shell preference match. Existing IDs cannot be reused for another working directory.
 - Dimensions are bounded to 1-1000 columns and 1-500 rows; input is capped at 64 KiB.
 - PTY children explicitly clear `NODE_CHANNEL_FD`; daemon IPC descriptors are host-private and invalid after PTY descriptor cleanup.
+- PTY children also strip AppImage `ARGV0` (and other host-private shell vars such as `ELECTRON_RUN_AS_NODE`, `BASH_ENV`, `ENV`, `BASH_XTRACEFD`). An exported `ARGV0` makes zsh rewrite argv[0] for every external command, which breaks Python venv detection and other argv[0]/$0 consumers while leaving `/proc/self/exe` correct.
 - `GET /api/terminal/shells` reports shell IDs available on the active server using the same augmented PATH provided to spawned PTYs, plus whether each executable has a supported login-mode argument. `auto` preserves environment/platform fallback order; an explicit unavailable shell fails creation instead of silently running a different shell. Login mode is opt-in and uses only built-in arguments for known shells. Preference changes affect new sessions and explicit restarts, not running PTYs.
 - PTY data and exit callbacks enter one FIFO queue. Stale callbacks from replaced processes are ignored.
 - Scrollback is retained on the server and capped at 512 KiB with UTF-8-safe trimming. Device-status, device-attribute, cursor-position reply, and color-query exchanges are removed from replay history with incomplete control sequences carried across PTY chunks; live output remains byte-for-byte unchanged.
diff --git a/packages/web/server/lib/terminal/runtime.js b/packages/web/server/lib/terminal/runtime.js
index f717cb7a..3d036ff0 100644
--- a/packages/web/server/lib/terminal/runtime.js
+++ b/packages/web/server/lib/terminal/runtime.js
@@ -10,6 +10,7 @@ import {
 import { sanitizeTerminalHistoryChunk } from './history.js';
 import { consumeTerminalThemeQueries, terminalThemeModeReport } from './theme-response.js';
 import { createTerminalShellResolver, getTerminalShellLoginArgs, normalizeTerminalShell } from './shells.js';
+import { stripAppImageArgv0Leak } from '../inherited-env.js';
 
 const MAX_SESSIONS = 20;
 const MAX_HISTORY_BYTES = 512 * 1024;
@@ -66,6 +67,8 @@ export function createTerminalRuntime({
         // required because bun-pty also inherits Bun's native process environment.
         env.NODE_CHANNEL_FD = '';
         delete env.BASH_XTRACEFD; delete env.BASH_ENV; delete env.ENV; delete env.ELECTRON_RUN_AS_NODE;
+        // AppImage exports ARGV0; zsh would otherwise rewrite argv[0] for every command (#2588).
+        stripAppImageArgv0Leak(env);
         const options = { name: 'xterm-256color', cwd, cols, rows, env, ...(process.platform === 'win32' ? { useConpty: true } : {}) };
         return { process: provider.spawn(executable, args, options), backend: provider.backend, shell: resolvedShell.id, loginShell };
       } catch (error) { lastError = error; }
diff --git a/packages/web/server/lib/terminal/runtime.test.js b/packages/web/server/lib/terminal/runtime.test.js
index 4bc21420..4a39225f 100644
--- a/packages/web/server/lib/terminal/runtime.test.js
+++ b/packages/web/server/lib/terminal/runtime.test.js
@@ -154,6 +154,8 @@ describe('terminal runtime', () => {
       expect(harness.processes[0].options.cwd).toBe('/repo');
       expect(harness.processes[0].options.env.COLORFGBG).toBe('0;15');
       expect(harness.processes[0].options.env.NODE_CHANNEL_FD).toBe('');
+      expect(harness.processes[0].options.env).not.toHaveProperty('ARGV0');
+      expect(harness.processes[0].options.env).not.toHaveProperty('ELECTRON_RUN_AS_NODE');
       harness.processes[0].emitData('\u001b[?2031h\u001b]10;?\u0007\u001b]11;?\u0007');
       expect(harness.processes[0].writes).toEqual(['\u001b]10;rgb:1b1b/1b1b/1b1b\u001b\\', '\u001b]11;rgb:fafa/f8f8/f0f0\u001b\\']);
 
@@ -173,6 +175,22 @@ describe('terminal runtime', () => {
     } finally { await harness.runtime.shutdown(); }
   });
 
+  it('strips AppImage ARGV0 from PTY child environments', async () => {
+    const previousArgv0 = process.env.ARGV0;
+    process.env.ARGV0 = '/path/to/OpenChamber/OpenChamber-1.17.2-linux-x86_64.AppImage';
+    const harness = createHarness();
+    try {
+      const response = createResponse();
+      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-argv0', cwd: '/repo', cols: 80, rows: 24 } }, response);
+      expect(response.statusCode).toBe(200);
+      expect(harness.processes[0].options.env).not.toHaveProperty('ARGV0');
+    } finally {
+      if (previousArgv0 === undefined) delete process.env.ARGV0;
+      else process.env.ARGV0 = previousArgv0;
+      await harness.runtime.shutdown();
+    }
+  });
+
   it('lists available shells and uses the selected shell for create and restart', async () => {
     const executables = new Set(['/bin/zsh', '/bin/bash', '/bin/sh']);
     const harness = createHarness({