fix(session): probe the Claude CLI version over ssh for remote sessions

Remote Claude sessions were the one backend left relying on the
startup-banner scrape for cliVersion (the unreliable path #154 was filed
for: newer Claude Code builds print no banner and resumed sessions never
do), so wheel/touch forwarding silently stayed off for them. Mirror the
docker approach: a deferred best-effort probe at session start, running
claude --version on the remote host through the same
buildSshConnectionArgs + login-shell wrapper as the real launch, parsing
the first semver in stdout (an interactive login shell may echo rc-file
noise around it).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/remote-hosts.ts

@@ -256,6 +256,69 @@ export async function checkRemoteTmuxAvailable(
   }
 }
 
+/**
+ * The CLI binary each session mode runs on the remote host. Antigravity's
+ * binary is `agy` (the mode name is not the command); shell has no CLI to
+ * probe, so it is absent.
+ */
+const REMOTE_CLI_BIN: Partial<Record<SessionMode, string>> = {
+  claude: 'claude',
+  opencode: 'opencode',
+  codex: 'codex',
+  gemini: 'gemini',
+  antigravity: 'agy',
+};
+
+/**
+ * Build the SSH command that reads the remote CLI's version (`claude --version`
+ * on the remote host). The version query is routed through
+ * `remoteLoginShellCommand` (the SAME `$SHELL -i -l -c` wrapper the real
+ * launch uses), because agent CLIs live on PATH only after the remote user's
+ * interactive-login startup files run (see defaultRemoteCommandForMode); a bare
+ * `claude --version` over ssh exits 127. Connection options come from the
+ * shared `buildSshConnectionArgs`, so the probe reaches exactly the hosts the
+ * launch can reach. Returns null for modes with no CLI (shell).
+ */
+export function buildRemoteCliVersionProbeCommand(
+  host: Pick<RemoteHost, 'username' | 'host' | 'port'> & RemoteSshOptions,
+  mode: SessionMode
+): string | null {
+  const bin = REMOTE_CLI_BIN[mode];
+  if (!bin) return null;
+  return [
+    ...buildSshConnectionArgs(host),
+    remoteSshTarget(host),
+    shellescape(remoteLoginShellCommand(`${bin} --version`)),
+  ].join(' ');
+}
+
+/**
+ * Read the CLI version installed ON THE REMOTE HOST. Feeds Session.cliVersion
+ * for remote sessions: the deterministic local probe deliberately skips them
+ * (it would report the LOCAL host's claude), and the startup-banner scrape is
+ * unreliable (newer Claude Code builds print no banner; resumed sessions never
+ * do), which left cliVersion undefined and silently disabled wheel-forwarding
+ * to the CLI transcript (residual #154, noted in the #205 analysis). The
+ * version is parsed as the first semver in stdout, never raw output: an
+ * interactive-login shell may echo rc-file noise around it. Returns undefined
+ * on any failure. No-op under VITEST (mirrors checkRemoteTmuxAvailable).
+ */
+export async function probeRemoteCliVersion(
+  host: Pick<RemoteHost, 'username' | 'host' | 'port'> & RemoteSshOptions,
+  mode: SessionMode
+): Promise<string | undefined> {
+  if (process.env.VITEST) return undefined;
+  const command = buildRemoteCliVersionProbeCommand(host, mode);
+  if (!command) return undefined;
+  try {
+    const { stdout } = await execAsync(command, { timeout: 15_000 });
+    const match = stdout.match(/\d+\.\d+\.\d+/);
+    return match ? match[0] : undefined;
+  } catch {
+    return undefined;
+  }
+}
+
 /**
  * COD-105 — build the SSH command that lists `codeman-*` tmux sessions on a
  * remote host's canonical `-L codeman` socket.

src/session.ts

@@ -54,6 +54,7 @@ import {
   type SessionDocker,
 } from './types.js';
 import { probeDockerCliVersion } from './docker-hosts.js';
+import { probeRemoteCliVersion } from './remote-hosts.js';
 import type { TerminalMultiplexer, MuxSession } from './mux-interface.js';
 import { TaskTracker, type BackgroundTask } from './task-tracker.js';
 import { RalphTracker } from './ralph-tracker.js';
@@ -226,6 +227,8 @@ const IS_TEST_MODE = !!process.env.VITEST;
 const TEST_PTY_SCRIPT = 'if (process.stdin.isTTY) process.stdin.setRawMode(true); process.stdin.pipe(process.stdout);';
 /** Delay before the in-container Claude CLI version probe (lets the container start). */
 const DOCKER_CLI_VERSION_PROBE_DELAY_MS = 3000;
+/** Delay before the over-ssh Claude CLI version probe (keeps session start off the ssh round-trip). */
+const REMOTE_CLI_VERSION_PROBE_DELAY_MS = 3000;
 
 /**
  * Ask tmux for the current window geometry of `muxName` so a re-attaching PTY
@@ -1534,8 +1537,8 @@ export class Session extends EventEmitter {
     // never show it — which left cliVersion undefined and silently disabled
     // wheel-forwarding to Claude's own transcript (the only route to history in
     // repaint/alt-screen mode; issue #154). Remote sessions run claude on
-    // another host, so a local probe wouldn't reflect their version — skip them
-    // and let the banner scrape handle those. Cached process-wide, best-effort.
+    // another host, so a local probe wouldn't reflect their version; they get
+    // their own over-ssh probe below. Cached process-wide, best-effort.
     if (this.mode === 'claude' && !this._remote && !this._docker && !this._cliVersion) {
       const probedVersion = getClaudeCliVersion();
       if (probedVersion) {
@@ -1574,6 +1577,32 @@ export class Session extends EventEmitter {
       }, DOCKER_CLI_VERSION_PROBE_DELAY_MS);
     }
 
+    // Remote sessions run claude on ANOTHER HOST, so neither the local nor the
+    // docker probe applies, and the banner-scrape fallback they were left with
+    // is the unreliable path #154 was filed for, so remote Claude cases silently
+    // never got wheel-forwarding (noted in the #205 analysis). Probe over ssh,
+    // deferred so session start never waits on the ssh round-trip.
+    if (this.mode === 'claude' && this._remote && !this._cliVersion) {
+      const remoteMeta = this._remote;
+      setTimeout(() => {
+        if (this._isStopped || this._cliVersion) return;
+        void probeRemoteCliVersion(remoteMeta, this.mode)
+          .then((version) => {
+            if (!version || this._isStopped || this._cliVersion) return;
+            this._cliVersion = version;
+            this.emit('cliInfoUpdated', {
+              version: this._cliVersion,
+              model: this._cliModel,
+              accountType: this._cliAccountType,
+              latestVersion: this._cliLatestVersion,
+            });
+          })
+          .catch(() => {
+            /* best-effort */
+          });
+      }, REMOTE_CLI_VERSION_PROBE_DELAY_MS);
+    }
+
     // If mux wrapping is enabled, create or attach to a mux session
     if (this._useMux && this._mux) {
       try {

test/remote-ssh-options.test.ts

@@ -20,7 +20,12 @@
 
 import { homedir } from 'node:os';
 import { describe, it, expect } from 'vitest';
-import { buildSshConnectionArgs, buildRemoteTmuxCheckCommand, remoteSshTarget } from '../src/remote-hosts.js';
+import {
+  buildSshConnectionArgs,
+  buildRemoteTmuxCheckCommand,
+  buildRemoteCliVersionProbeCommand,
+  remoteSshTarget,
+} from '../src/remote-hosts.js';
 import { buildRemoteLaunchCommand } from '../src/tmux-manager.js';
 import type { SessionRemote } from '../src/types.js';
 
@@ -198,3 +203,29 @@ describe('COD-107 buildRemoteTmuxCheckCommand — same connection options as the
     expect(buildRemoteTmuxCheckCommand({ username: 'ubuntu', host: '10.0.0.42', port: 2222 })).toContain('-p 2222');
   });
 });
+
+describe('buildRemoteCliVersionProbeCommand: remote CLI version over the same connection (#205)', () => {
+  it('routes the version query through the interactive-login shell wrapper, like the launch', () => {
+    const cmd = buildRemoteCliVersionProbeCommand(baseRemote, 'claude');
+    // Same PATH-resolution wrapper as defaultRemoteCommandForMode: a bare
+    // `claude --version` over ssh sees only sshd's minimal PATH (exit 127).
+    expect(cmd).toBe(
+      'ssh -o BatchMode=yes -o ConnectTimeout=10 ubuntu@10.0.0.42 ' +
+        `'exec "\${SHELL:-/bin/sh}" -i -l -c '\\''claude --version'\\'''`
+    );
+  });
+
+  it('uses the shared connection args (proxy/identity/port), so it reaches what the launch reaches', () => {
+    const cmd = buildRemoteCliVersionProbeCommand(aaDesktop, 'claude');
+    expect(cmd).toContain('-o BatchMode=yes');
+    expect(cmd).toContain('-p 2222');
+    expect(cmd).toContain(`-i '${HOME}/.ssh/remote_ed25519'`);
+    expect(cmd).toContain("-o 'ProxyCommand=nc -X 5 -x 127.0.0.1:1080 %h %p'");
+    expect(cmd).toContain('aakht@192.168.55.170');
+  });
+
+  it('maps antigravity to its real binary name and shell to no probe at all', () => {
+    expect(buildRemoteCliVersionProbeCommand(baseRemote, 'antigravity')).toContain('agy --version');
+    expect(buildRemoteCliVersionProbeCommand(baseRemote, 'shell')).toBeNull();
+  });
+});