feat: pass --name to local claude spawns so workers carry their session names as peer names

Version-gated fail-closed at 2.1.224 (the cross-session-messaging release,
flag presence verified against that binary): an unknown or older CLI yields
a spawn command byte-identical to before, because claude aborts startup on
an unknown option and that would kill every session spawn. The value is
allowlist-sanitized ahead of the double-quoted interpolation, and only the
local command carries the flag; docker/remote builders never see it since
their CLI is not the probed binary. Verified E2E on an isolated instance:
cmdline shows --name, ListAgents lists the session name, replies arrive
tagged from-name.

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

src/mux-interface.ts

@@ -97,6 +97,8 @@ export interface RespawnPaneOptions {
   sessionId: string;
   workingDir: string;
   mode: SessionMode;
+  /** Session display name; a respawned claude keeps its `--name` peer name (version-gated, local only). */
+  name?: string;
   niceConfig?: NiceConfig;
   model?: string;
   claudeMode?: ClaudeMode;

src/session-cli-builder.ts

@@ -11,6 +11,7 @@
 import type { ClaudeMode, EffortLevel } from './types.js';
 import { isEffortLevel } from './types.js';
 import { getAugmentedPath } from './utils/index.js';
+import { compareVersions } from './utils/dependency-checker.js';
 import { dataPath } from './config/instance.js';
 
 /**
@@ -52,6 +53,53 @@ export function buildEffortCliArgs(effort?: EffortLevel): string[] {
   return effort === 'ultracode' ? ['--settings', '{"ultracode":true}'] : ['--effort', effort];
 }
 
+/**
+ * Minimum Claude CLI version for passing `--name` at spawn. 2.1.224 is the release
+ * that ships cross-session messaging (the feature that makes the peer name matter),
+ * and the flag's presence at exactly this version was verified against the installed
+ * binary (`2.1.224 --help` lists `-n, --name`). The gate MUST stay fail-closed: an
+ * older or unknown CLI aborts startup on an unknown flag ("error: unknown option"),
+ * which would kill every session spawn — so no version means no flag, and the
+ * command line stays byte-identical to the pre-`--name` one.
+ */
+export const CLAUDE_NAME_FLAG_MIN_VERSION = '2.1.224';
+
+/**
+ * Reduce a Codeman session name to a string safe to pass as the Claude CLI
+ * `--name` value. Allowlist, not escaping: keeps Unicode letters/digits (CJK
+ * session names survive) plus ` . _ : -`, which excludes every character that is
+ * special inside the double-quoted shell interpolation buildSpawnCommand uses
+ * (`"`, `$`, backslash, backtick) as well as newlines. Leading dashes/punctuation
+ * are stripped so the value can never be parsed as another CLI option, and the
+ * result is capped at 64 chars. Returns undefined when nothing safe remains —
+ * callers must then omit the flag entirely (never send `--name ""`).
+ */
+export function sanitizeCliSessionName(name?: string): string | undefined {
+  if (!name) return undefined;
+  const cleaned = name
+    .replace(/[^\p{L}\p{N} ._:-]/gu, '')
+    .replace(/\s+/g, ' ')
+    .replace(/^[\s._:-]+/, '')
+    .trim()
+    .slice(0, 64)
+    .trim();
+  return cleaned.length > 0 ? cleaned : undefined;
+}
+
+/**
+ * Build the `--name <session name>` args pair, version-gated and fail-closed.
+ * Returns [] unless the CLI version is KNOWN to support the flag (>= 2.1.224):
+ * a null/undefined version (probe failed, or running under vitest where
+ * getClaudeCliVersion() is hermetically null) yields [], keeping the spawn
+ * command identical to a Codeman without this feature. The name itself is a
+ * SOFT default, exactly like model and effort: `/rename` in-session still works.
+ */
+export function buildNameCliArgs(sessionName: string | undefined, cliVersion: string | null | undefined): string[] {
+  if (!cliVersion || compareVersions(cliVersion, CLAUDE_NAME_FLAG_MIN_VERSION) < 0) return [];
+  const name = sanitizeCliSessionName(sessionName);
+  return name ? ['--name', name] : [];
+}
+
 /**
  * Build args for an interactive Claude CLI session (direct PTY, non-mux fallback).
  *
@@ -60,6 +108,8 @@ export function buildEffortCliArgs(effort?: EffortLevel): string[] {
  * @param model - Optional model override (e.g., 'opus', 'sonnet')
  * @param allowedTools - Optional comma-separated allowed tools list
  * @param effort - Optional effort level, injected via --settings (overridable in-session)
+ * @param sessionName - Optional Codeman session name, passed as `--name` (version-gated)
+ * @param cliVersion - Installed Claude CLI version for the `--name` gate (null = omit the flag)
  * @returns Array of CLI arguments
  */
 export function buildInteractiveArgs(
@@ -67,11 +117,14 @@ export function buildInteractiveArgs(
   claudeMode: ClaudeMode,
   model?: string,
   allowedTools?: string,
-  effort?: EffortLevel
+  effort?: EffortLevel,
+  sessionName?: string,
+  cliVersion?: string | null
 ): string[] {
   const args = [...buildPermissionArgs(claudeMode, allowedTools), '--session-id', sessionId];
   if (model) args.push('--model', model);
   args.push(...buildEffortCliArgs(effort));
+  args.push(...buildNameCliArgs(sessionName, cliVersion));
   return args;
 }
 

src/session.ts

@@ -1406,6 +1406,7 @@ export class Session extends EventEmitter {
       sessionId: this.id,
       workingDir: this.workingDir,
       mode: this.mode,
+      name: this._name,
       niceConfig: this._niceConfig,
       model: this._model,
       claudeMode: this._claudeMode,
@@ -1710,7 +1711,15 @@ export class Session extends EventEmitter {
       try {
         // Pass --session-id to use the SAME ID as the Codeman session
         // This ensures subagents can be directly matched to the correct tab
-        const args = buildInteractiveArgs(this.id, this._claudeMode, this._model, this._allowedTools, this._effort);
+        const args = buildInteractiveArgs(
+          this.id,
+          this._claudeMode,
+          this._model,
+          this._allowedTools,
+          this._effort,
+          this._name,
+          getClaudeCliVersion()
+        );
         this.ptyProcess = spawnPtyWithHelperRepair(() =>
           pty.spawn(getClaudeBinaryPath(), args, {
             name: 'xterm-256color',

src/tmux-manager.ts

@@ -49,7 +49,7 @@ import {
   type SessionDocker,
   type DockerCommandMode,
 } from './types.js';
-import { buildEffortCliArgs } from './session-cli-builder.js';
+import { buildEffortCliArgs, buildNameCliArgs } from './session-cli-builder.js';
 import {
   buildSshConnectionArgs,
   defaultRemoteCommandForMode,
@@ -73,6 +73,7 @@ import {
   wrapWithNice,
   SAFE_PATH_PATTERN,
   findClaudeDir,
+  getClaudeCliVersion,
   resolveOpenCodeDir,
   resolveCodexDir,
   resolveGeminiDir,
@@ -752,6 +753,20 @@ function buildEffortSettingsFlag(effort?: EffortLevel): string {
   return flag && value ? ` ${flag} '${value}'` : '';
 }
 
+/**
+ * Build the ` --name "<session name>"` shell fragment, or '' when it must be
+ * omitted. Version-gated FAIL-CLOSED in buildNameCliArgs (an older/unknown CLI
+ * aborts startup on an unknown flag, which would kill every claude spawn), and
+ * the value is allowlist-sanitized there, so it contains none of the characters
+ * that are special inside this double-quoted interpolation. The peer name is a
+ * soft default (in-session /rename still wins), which is why this rides the
+ * spawn command rather than any persisted config.
+ */
+function buildClaudeNameFlag(sessionName: string | undefined, cliVersion: string | null): string {
+  const [flag, value] = buildNameCliArgs(sessionName, cliVersion);
+  return flag && value ? ` ${flag} "${value}"` : '';
+}
+
 export function buildSpawnCommand(options: {
   mode: SessionMode;
   sessionId: string;
@@ -764,12 +779,25 @@ export function buildSpawnCommand(options: {
   antigravityConfig?: AntigravityConfig;
   resumeSessionId?: string;
   effort?: EffortLevel;
+  /** Codeman session name, passed to claude as `--name` (version-gated, sanitized; local spawns only). */
+  sessionName?: string;
+  /**
+   * Claude CLI version for the `--name` gate. Omitted = probe the local CLI
+   * (getClaudeCliVersion; null under vitest). Tests inject a value here; the
+   * docker/remote paths never see this builder's output, which is what keeps the
+   * gate measuring the RIGHT binary — the local one.
+   */
+  claudeCliVersion?: string | null;
 }): string {
   if (options.mode === 'claude') {
     // Validate model to prevent command injection
     const safeModel = options.model && /^[a-zA-Z0-9._\-[\]]+$/.test(options.model) ? options.model : undefined;
     const modelFlag = safeModel ? ` --model "${safeModel}"` : '';
     const effortFlag = buildEffortSettingsFlag(options.effort);
+    const nameFlag = buildClaudeNameFlag(
+      options.sessionName,
+      options.claudeCliVersion !== undefined ? options.claudeCliVersion : getClaudeCliVersion()
+    );
     // Use --resume to restore a previous conversation, otherwise --session-id for new sessions.
     // Wrap --resume in a fallback: if it exits non-zero (session not found, corrupt, etc.),
     // fall back to a new session with --session-id so the pane doesn't die.
@@ -777,11 +805,11 @@ export function buildSpawnCommand(options: {
       options.resumeSessionId && /^[a-f0-9-]+$/.test(options.resumeSessionId) ? options.resumeSessionId : undefined;
     const permFlags = buildClaudePermissionFlags(options.claudeMode, options.allowedTools);
     if (safeResumeId) {
-      const resumeCmd = `claude${permFlags} --resume "${safeResumeId}"${modelFlag}${effortFlag}`;
-      const fallbackCmd = `claude${permFlags} --session-id "${options.sessionId}"${modelFlag}${effortFlag}`;
+      const resumeCmd = `claude${permFlags} --resume "${safeResumeId}"${modelFlag}${effortFlag}${nameFlag}`;
+      const fallbackCmd = `claude${permFlags} --session-id "${options.sessionId}"${modelFlag}${effortFlag}${nameFlag}`;
       return `${resumeCmd} || ${fallbackCmd}`;
     }
-    return `claude${permFlags} --session-id "${options.sessionId}"${modelFlag}${effortFlag}`;
+    return `claude${permFlags} --session-id "${options.sessionId}"${modelFlag}${effortFlag}${nameFlag}`;
   }
   if (options.mode === 'opencode') {
     return buildOpenCodeCommand(options.openCodeConfig);
@@ -1789,6 +1817,7 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       antigravityConfig,
       resumeSessionId,
       effort,
+      sessionName: name,
     });
 
     const config = niceConfig || DEFAULT_NICE_CONFIG;
@@ -2016,6 +2045,7 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       historyLimit = DEFAULT_TMUX_HISTORY_LIMIT,
       remote,
       docker,
+      name,
     } = options;
     const session = this.sessions.get(sessionId);
     if (!session) return null;
@@ -2050,6 +2080,7 @@ export class TmuxManager extends EventEmitter implements TerminalMultiplexer {
       antigravityConfig,
       resumeSessionId,
       effort,
+      sessionName: name,
     });
     const config = niceConfig || DEFAULT_NICE_CONFIG;
     const cmd = wrapWithNice(baseCmd, config);