fix(codex): fold a codex session into its own rollout row

Review fixes for #386.

Duplicate rows. A codex conversation showed twice, once live and once as a
past rollout row, because nothing aliased a codex session to its thread id.
That is worse than cosmetic: the stale row still resumes, so clicking it
starts a second `codex resume` on a thread already open in another pane.

  - A RESUMED session knows its thread id up front, so it folds from its own
    side: add `codexConfig.resumeSessionId` to the `claudeSessionId` chain.
    Not only in the constructor — `start()` recomputes that id at two further
    points (the mux branch, and the unconditional "third reset point" whose
    own comment already warned that omitting omp's fallback there stomps the
    mux branch's resolved alias). Both listed Claude's and omp's ids only, so
    for codex every mux reattach and boot recovery reset the alias back to
    the Codeman id and the duplicate returned.
  - A FRESH session has no thread id until codex writes the rollout, so it is
    folded from the other side. The scanner now reports
    `session_meta.originator`, which is `codeman_<sessionId>` for every pane
    Codeman spawns, and `gatherUnifiedInputs()` stamps the matching live and
    persisted rows, newest rollout winning (`/new` inside the TUI leaves
    several rollouts sharing one originator).
  - Persisted rows read `codexConfig.resumeSessionId` too. A resumed session
    demoted to a persisted-only record would otherwise lose its alias, and
    the originator fallback cannot rescue that one: a resumed rollout keeps
    its ORIGINAL session_meta, so it still names the pane that created the
    thread rather than the pane that resumed it.

Identity cache. It was written as soon as the thread id was known, but codex
writes the first user message only when the user submits, so any scan in that
window pinned `firstPrompt: undefined` for the life of the process — and the
home screen, the command palette and the search-index refresh all scan.
`shouldCacheIdentity()` now keeps an identity only once the prompt is known or
the head read filled its whole window.

Also from review: both caps count emitted rows rather than file index, so a
store of sub-agent threads no longer spends the `lastPrompt` budget before the
first row that needed it; the cache is an `LRUMap` sized like the one beside
it; the unreachable filename fallback is gone; a rollout recording no cwd is
dropped rather than emitted with `workingDir: ''`; and the unified-session
module header names all three transcript stores.

Tests. The resume wiring now has cases for a row with a thread id, a row
without one, and a `resumeId` on a non-codex row; the "no continuation is
wired" case narrows to gemini/antigravity, which is no longer true of codex.
`codex-resume-alias-survives-start.test.ts` drives a real Session through
`start()` rather than asserting on pre-stamped inputs — that gap is why the
reset points went unnoticed. Plus the maintainer's own cache repro, the
tail-budget case, a no-cwd case, and merge cases for both folds.

src/codex-transcript.ts

@@ -42,7 +42,9 @@
 
 import { open, readdir, stat } from 'node:fs/promises';
 import { homedir } from 'node:os';
-import { basename, join } from 'node:path';
+import { join } from 'node:path';
+
+import { LRUMap } from './utils/lru-map.js';
 
 /** Covers `session_meta` (~19 KiB) plus the first user message (~69 KiB behind it). */
 const HEAD_BYTES = 131072;
@@ -51,16 +53,19 @@ const HEAD_BYTES = 131072;
 const TAIL_BYTES = 65536;
 
 /**
- * Newest rollouts to report. A store this size is already far more than any list
- * shows, and the cap keeps one enormous `~/.codex` from stalling a request.
+ * Newest rollouts to REPORT. Counted in emitted rows, not files scanned: the
+ * store is mostly sub-agent threads this never returns, so capping files first
+ * would spend the budget on rows nobody sees.
  */
 const MAX_ROLLOUTS = 400;
 
 /**
- * How many of those also get a tail read for `lastPrompt`. The head read is
- * cached forever (see below) but the tail cannot be, because appending to a
- * rollout is exactly what changes it, so this is the one genuinely per-request
- * cost and it stays bounded.
+ * How many emitted rows also get a tail read for `lastPrompt`. The head read is
+ * cached (see below) but the tail cannot be, because appending to a rollout is
+ * exactly what changes it, so this is the one genuinely per-request cost and it
+ * stays bounded. Counted in emitted rows for the same reason as above — against
+ * file index a store of sub-agent threads spends the whole budget before the
+ * first row that needed it.
  */
 const MAX_TAIL_READS = 100;
 
@@ -73,6 +78,13 @@ const MIN_ROLLOUT_BYTES = 100;
 export interface CodexHistorySession {
   /** The rollout's own thread id — the token `codex resume <id>` expects. */
   sessionId: string;
+  /**
+   * `session_meta.originator`, which codex stamps from
+   * CODEX_INTERNAL_ORIGINATOR_OVERRIDE — `codeman_<sessionId>` for every pane
+   * Codeman spawns. The only link between a FRESH codex pane and the rollout it
+   * is writing, since such a pane knows no thread id of its own.
+   */
+  originator?: string;
   workingDir: string;
   sizeBytes: number;
   /** ISO timestamp, from the file's own mtime. */
@@ -87,17 +99,40 @@ interface RolloutIdentity {
   cwd?: string;
   /** `'subagent'` marks a thread codex spawned for itself. */
   threadSource?: string;
+  /** `codeman_<sessionId>` for a pane Codeman spawned; codex's own default otherwise. */
+  originator?: string;
   firstPrompt?: string;
 }
 
 /**
  * `session_meta` is written once and never rewritten — the same fact
- * `readCodexRolloutMetaCached()` in session-routes.ts relies on — and the first
- * user message cannot change either. So a path's identity is cached for the life
- * of the process, and a rescan costs a `stat` per file plus head reads for
+ * `readCodexRolloutMetaCached()` in session-routes.ts relies on — so a path's
+ * identity is cached, and a rescan costs a `stat` per file plus head reads for
  * rollouts this process has not seen before.
+ *
+ * ⚠️ The first user message is NOT written up front: codex writes it when the
+ * user submits. Caching before then pins `firstPrompt: undefined` for the life
+ * of the process, and every scan of the home screen, the command palette and the
+ * search-index refresh can land in that window — so the row reads as having no
+ * prompt until a restart. `shouldCacheIdentity()` is the guard.
+ *
+ * Bounded, unlike a plain Map: this process runs for days and every sub-agent
+ * rollout adds an entry. Same reason and same size as `codexRolloutMetaCache`.
  */
-const identityCache = new Map<string, RolloutIdentity>();
+const identityCache = new LRUMap<string, RolloutIdentity>({ maxSize: 4096 });
+
+/**
+ * Is this identity settled enough to keep?
+ *
+ * A known `firstPrompt` settles it. So does a head read that FILLED its window,
+ * which means the prompt is genuinely not in the first `HEAD_BYTES` rather than
+ * not written yet. A short file with no prompt is the ambiguous case — codex is
+ * still to write one — so that one is re-read next scan.
+ */
+function shouldCacheIdentity(identity: RolloutIdentity, fileSize: number): boolean {
+  if (!identity.threadId) return false;
+  return identity.firstPrompt !== undefined || fileSize >= HEAD_BYTES;
+}
 
 function codexSessionsRoot(): string {
   const home = process.env.CODEX_HOME || join(homedir(), '.codex');
@@ -211,6 +246,7 @@ function parseIdentity(head: string): RolloutIdentity {
         session_id?: string;
         cwd?: string;
         thread_source?: string;
+        originator?: string;
         type?: string;
         role?: string;
         content?: unknown;
@@ -228,6 +264,7 @@ function parseIdentity(head: string): RolloutIdentity {
       out.threadId ??= p.id || p.session_id;
       out.cwd ??= p.cwd;
       out.threadSource ??= p.thread_source;
+      out.originator ??= p.originator;
     } else if (entry.type === 'turn_context' && p) {
       out.cwd ??= p.cwd;
     }
@@ -294,34 +331,29 @@ async function listRollouts(root: string): Promise<Array<{ path: string; mtimeMs
  * threads that are.
  */
 export async function scanCodexSessionsHistory(): Promise<CodexHistorySession[]> {
-  const files = (await listRollouts(codexSessionsRoot())).slice(0, MAX_ROLLOUTS);
+  const files = await listRollouts(codexSessionsRoot());
   const out: CodexHistorySession[] = [];
 
-  for (const [index, file] of files.entries()) {
+  for (const file of files) {
+    if (out.length >= MAX_ROLLOUTS) break;
+
     let identity = identityCache.get(file.path);
     if (!identity) {
       identity = parseIdentity(await readHead(file.path, HEAD_BYTES));
-      // A rollout still being created may not have flushed session_meta yet;
-      // caching that would pin an empty identity for the life of the process.
-      if (identity.threadId) identityCache.set(file.path, identity);
+      if (shouldCacheIdentity(identity, file.size)) identityCache.set(file.path, identity);
     }
     if (!identity.threadId || identity.threadSource === 'subagent') continue;
-
-    // The filename ends in the thread id, so a rollout whose head window was too
-    // small to reach session_meta still yields an id worth resuming.
-    const fromName = basename(file.path)
-      .replace(/\.jsonl$/, '')
-      .split('-')
-      .slice(-5)
-      .join('-');
-    const sessionId = identity.threadId || fromName;
+    // A row with no directory has nowhere to resume INTO, and emitting an empty
+    // one makes a click post `workingDir: ''`. omp drops such a row; so does this.
+    if (!identity.cwd) continue;
 
     const lastPrompt =
-      index < MAX_TAIL_READS ? parseLastPrompt(await readTail(file.path, file.size, TAIL_BYTES)) : undefined;
+      out.length < MAX_TAIL_READS ? parseLastPrompt(await readTail(file.path, file.size, TAIL_BYTES)) : undefined;
 
     out.push({
-      sessionId,
-      workingDir: identity.cwd || '',
+      sessionId: identity.threadId,
+      originator: identity.originator,
+      workingDir: identity.cwd,
       sizeBytes: file.size,
       lastModified: new Date(file.mtimeMs).toISOString(),
       firstPrompt: identity.firstPrompt,
@@ -332,6 +364,29 @@ export async function scanCodexSessionsHistory(): Promise<CodexHistorySession[]>
   return out;
 }
 
+/**
+ * Which codex thread each Codeman-spawned pane is writing, keyed by Codeman
+ * session id.
+ *
+ * Codeman spawns every codex pane with
+ * CODEX_INTERNAL_ORIGINATOR_OVERRIDE=codeman_<sessionId>, and codex stamps that
+ * into `session_meta.originator`. That is the ONLY link between a fresh codex
+ * pane and the rollout it is writing: such a pane knows no thread id of its own,
+ * so it cannot be folded into its own Past-Sessions row from its own side.
+ *
+ * Newest wins. `/new` typed inside the codex TUI leaves several rollouts sharing
+ * one originator, and the pane is on the most recent — so this expects `rows`
+ * newest-first, as `scanCodexSessionsHistory()` returns them.
+ */
+export function codexThreadBySessionId(rows: CodexHistorySession[]): Map<string, string> {
+  const out = new Map<string, string>();
+  for (const row of rows) {
+    const owner = /^codeman_(.+)$/.exec(row.originator ?? '')?.[1];
+    if (owner && !out.has(owner)) out.set(owner, row.sessionId);
+  }
+  return out;
+}
+
 /** Test seam: drop the per-path identity cache. */
 export function __clearCodexIdentityCache(): void {
   identityCache.clear();

src/services/unified-session-service.ts

@@ -2,12 +2,16 @@
  * @fileoverview Pure merge/filter logic for the unified session list (COD-121).
  *
  * Combines four read-only views of a session — live (in-memory `Session`),
- * persisted (`state.json`), transcript history (`~/.claude/projects`), and the
- * lifecycle audit log — plus mux process stats, into one de-duplicated list
- * keyed by sessionId. Transcript-history rows are keyed by the Claude
- * conversation UUID (the `.jsonl` filename stem), which diverges from the
- * Codeman id for resumed sessions — an alias map (claudeSessionId → Codeman id,
- * built from the live/persisted views) folds them into the owning session item.
+ * persisted (`state.json`), transcript history, and the lifecycle audit log —
+ * plus mux process stats, into one de-duplicated list keyed by sessionId.
+ *
+ * Transcript history is not one source but three, because the CLIs keep their
+ * conversations in their own stores: Claude's `~/.claude/projects`, omp's
+ * `~/.omp/agent/sessions` and codex's `~/.codex/sessions`. Each row is keyed by
+ * whatever id that CLI names the conversation with, which diverges from the
+ * Codeman id for a resumed session and for every non-Claude one — an alias map
+ * (claudeSessionId → Codeman id, built from the live/persisted views) folds them
+ * into the owning session item.
  * Higher-precedence sources overwrite scalar fields when present
  * (history < lifecycle < persisted < live), while the `sources` array
  * always accumulates every contributing view. A "meaningfulness floor" drops

src/session.ts

@@ -703,13 +703,20 @@ export class Session extends EventEmitter {
     this._wireActivityAt = config.lastActivityAt || Date.now();
     this._wireActivitySettleUntil = config.lastActivityAt ? Date.now() + WIRE_ACTIVITY_SETTLE_MS : 0;
     // Set claudeSessionId — when resuming, the Claude conversation ID is the resumed one.
-    // For omp, `claudeSessionId` doubles as the generic "external transcript id"
-    // alias key mergeUnifiedSessions() folds a history row into its owning
-    // session by: omp mints its OWN uuid, unrelated to this Codeman id, so
-    // without this an omp conversation's Past-Sessions row (keyed by omp's
-    // id) would never merge with its own live/persisted row (keyed by this
-    // id) — it would just show up a second time.
-    this._claudeSessionId = config.resumeSessionId || config.ompConfig?.resumeSessionId || this.id;
+    // For omp and codex, `claudeSessionId` doubles as the generic "external
+    // transcript id" alias key mergeUnifiedSessions() folds a history row into
+    // its owning session by: each mints its OWN thread id, unrelated to this
+    // Codeman id, so without this the conversation's Past-Sessions row (keyed by
+    // that thread id) would never merge with its own live/persisted row (keyed
+    // by this id) — it would just show up a second time. For codex a duplicate
+    // is worse than cosmetic: the stale row still resumes, so clicking it starts
+    // a SECOND `codex resume` on a thread already open in another pane.
+    //
+    // This covers a RESUMED codex session, which knows its thread id up front. A
+    // fresh one learns its id only once codex writes the rollout, so it is folded
+    // from the other side — see the originator stamping in `gatherUnifiedInputs()`.
+    this._claudeSessionId =
+      config.resumeSessionId || config.ompConfig?.resumeSessionId || config.codexConfig?.resumeSessionId || this.id;
     // Restored from state.json on boot recovery. start() resets _claudeSessionId
     // to the launch id even when re-attaching to a mux session whose CLI has
     // moved on (a `/clear` before the restart), so this anchor is what lets the
@@ -1988,8 +1995,12 @@ export class Session extends EventEmitter {
         // this to omp's own session uuid — that already-resolved id must win
         // over the generic `this.id` fallback, or this line clobbers it back
         // to the Codeman id
-        // on every single respawn.
-        this._claudeSessionId = this._resumeSessionId || this._ompConfig?.resumeSessionId || this.id;
+        // on every single respawn. codex needs the same fallback for the same
+        // reason: its thread id lives in `_codexConfig`, so without it every
+        // respawn drops a resumed codex session's alias and its Past-Sessions
+        // row springs back as a duplicate that still resumes.
+        this._claudeSessionId =
+          this._resumeSessionId || this._ompConfig?.resumeSessionId || this._codexConfig?.resumeSessionId || this.id;
 
         // For NEW mux sessions: wait for readiness then clean buffer
         // For RESTORED mux sessions: don't do anything - client will fetch buffer on tab switch
@@ -2090,10 +2101,11 @@ export class Session extends EventEmitter {
     // Set claudeSessionId — when resuming, the Claude conversation ID is the resumed one.
     // Mirrors the mux branch above and must not clobber it: this line runs
     // unconditionally after both the mux and direct-PTY paths, so it also needs
-    // the ompConfig fallback or it stomps the mux branch's correctly-resolved
-    // OMP alias back to this.id on every mux/plain-reattach boot recovery
-    // (the "third reset point" — see DECISIONS.md).
-    this._claudeSessionId = this._resumeSessionId || this._ompConfig?.resumeSessionId || this.id;
+    // the ompConfig and codexConfig fallbacks or it stomps the mux branch's
+    // correctly-resolved OMP/codex alias back to this.id on every mux/plain-
+    // reattach boot recovery (the "third reset point" — see DECISIONS.md).
+    this._claudeSessionId =
+      this._resumeSessionId || this._ompConfig?.resumeSessionId || this._codexConfig?.resumeSessionId || this.id;
 
     this._pid = this.ptyProcess.pid;
     console.log('[Session] Interactive PTY spawned with PID:', this._pid);

src/web/public/terminal-ui.js

@@ -2990,11 +2990,16 @@ Object.assign(CodemanApp.prototype, {
       // as a duplicate — click it 3 times, see the same name 3 times. Claude
       // rows are left alone: `sessionId` there is a claudeSessionId, which
       // usually has no live/persisted Codeman session of its own to delete.
-      // Gated on `continuesSomething`: for codex/gemini/antigravity (no
-      // continuation wired above), this is really a FRESH session with no
+      // Gated on `continuesSomething`: for gemini/antigravity, and for a codex
+      // row carrying no `resumeId`, this is really a FRESH session with no
       // relation to the old row's conversation, so retiring it would discard
       // the old conversation with no recovery — worse than the duplicate row
       // this guard exists to prevent for the modes that DO continue.
+      //
+      // A codex row that DOES continue passes this gate, but the DELETE is a
+      // no-op for it: `sessionId` there is codex's thread id and no Codeman
+      // session carries that id. Its duplicate is cleared from the other side
+      // instead, by the alias fold in gatherUnifiedInputs()/Session.
       if (effectiveMode !== 'claude' && continuesSomething && sessionId !== newSessionId) {
         fetch(`/api/sessions/${sessionId}?killMux=true`, { method: 'DELETE' }).catch(() => {});
       }

src/web/routes/session-routes.ts

@@ -145,7 +145,7 @@ import {
 import { LRUMap } from '../../utils/lru-map.js';
 import { findLatestOmpSessionId } from '../../utils/omp-session-resolver.js';
 import { scanOmpSessionsHistory } from '../../omp-transcript.js';
-import { scanCodexSessionsHistory } from '../../codex-transcript.js';
+import { scanCodexSessionsHistory, codexThreadBySessionId } from '../../codex-transcript.js';
 import {
   getLastTranscriptResponse,
   isExternalCliTranscriptMode,
@@ -4062,6 +4062,13 @@ export function registerSessionRoutes(
     // Persisted sessions (state.json). resumeSessionId is the Claude
     // conversation UUID a resumed session continues — feed it to the merge's
     // alias map so its transcript row folds into this session.
+    //
+    // codex keeps its thread id in `codexConfig` instead, and state.json stores
+    // that, so read it here as well. Without it a resumed codex session that has
+    // been demoted to a persisted-only record loses its alias and duplicates: the
+    // originator fallback below cannot rescue that one, because a RESUMED rollout
+    // keeps the original session_meta (see findActiveCodexFile) and so still
+    // names whichever pane first created the thread.
     const persisted: PersistedSessionInput[] = Object.values(ctx.store.getState().sessions).map((p) => ({
       id: p.id,
       name: p.name,
@@ -4070,7 +4077,7 @@ export function registerSessionRoutes(
       workingDir: p.workingDir,
       createdAt: p.createdAt,
       lastActivityAt: p.lastActivityAt,
-      claudeSessionId: p.resumeSessionId,
+      claudeSessionId: p.resumeSessionId || p.codexConfig?.resumeSessionId,
       pinned: p.pinned,
       pinnedAt: p.pinnedAt,
     }));
@@ -4144,7 +4151,8 @@ export function registerSessionRoutes(
     // session record does. `resumeId` is the rollout's own thread id, which is
     // what `codex resume` takes; see codex-transcript.ts.
     try {
-      for (const h of await scanCodexSessionsHistory()) {
+      const codexRows = await scanCodexSessionsHistory();
+      for (const h of codexRows) {
         history.push({
           sessionId: h.sessionId,
           workingDir: h.workingDir,
@@ -4156,6 +4164,26 @@ export function registerSessionRoutes(
           resumeId: h.sessionId,
         });
       }
+
+      // Fold a FRESH codex pane into its own rollout row. A resumed one already
+      // folds, because Session sets `claudeSessionId` from the resume id it was
+      // given; a fresh one has no thread id until codex writes the rollout, so
+      // the link has to come from the other side. Codeman spawns every codex pane
+      // with CODEX_INTERNAL_ORIGINATOR_OVERRIDE=codeman_<sessionId>, and codex
+      // stamps that into session_meta.originator, so the rollout names the pane.
+      //
+      // Newest rollout wins: `/new` typed inside the TUI leaves several rollouts
+      // carrying the same originator, and the pane is on the most recent one.
+      // Rows arrive newest-first, so the first match is it.
+      //
+      // Never overwrites an id a session already knows — that one came from the
+      // resume path and is authoritative.
+      const codexThreads = codexThreadBySessionId(codexRows);
+      for (const row of [...live, ...persisted]) {
+        if (row.claudeSessionId && row.claudeSessionId !== row.id) continue;
+        const threadId = codexThreads.get(row.id);
+        if (threadId) row.claudeSessionId = threadId;
+      }
     } catch {
       // Best-effort, same as the two scans above.
     }

test/codex-resume-alias-survives-start.test.ts

@@ -0,0 +1,82 @@
+/**
+ * @fileoverview A resumed codex session must keep its thread-id alias across
+ * `start()`, not just at construction.
+ *
+ * `claudeSessionId` doubles as the generic "external transcript id" the unified
+ * list folds a Past-Sessions row into its owning session by. For codex that id
+ * is the rollout's thread id, and losing it is not cosmetic: the stale row stays
+ * in PAST and still resumes, so clicking it starts a SECOND `codex resume` on a
+ * thread already open in the live pane.
+ *
+ * The bug this pins: the alias was wired into the constructor only. `start()`
+ * recomputes `claudeSessionId` at two further points — the mux branch and the
+ * unconditional "third reset point" that runs after both the mux and direct-PTY
+ * paths — and both listed only Claude's `resumeSessionId` and omp's. For codex
+ * both are undefined, so every mux reattach and every boot recovery reset the
+ * alias back to the Codeman id and the duplicate came back. The existing comment
+ * at the third reset point already warned that omitting omp's fallback there
+ * "stomps the mux branch's correctly-resolved OMP alias"; codex needed the same.
+ *
+ * Mirrors `test/omp-fresh-run-no-resume.test.ts`, which drives a real `Session`
+ * against the in-memory tmux layer that vitest substitutes.
+ */
+import { mkdirSync, rmSync } from 'node:fs';
+import { homedir } from 'node:os';
+import { join } from 'node:path';
+import { afterEach, describe, expect, it } from 'vitest';
+
+import { Session } from '../src/session.js';
+import { TmuxManager } from '../src/tmux-manager.js';
+
+describe('codex: a resumed thread id survives start()', () => {
+  const workingDir = join(homedir(), 'codeman-cases', 'codex-resume-alias');
+  const THREAD_ID = '01a060f0-0361-7f91-abde-b283020db0d7';
+  const sessions: Session[] = [];
+
+  afterEach(() => {
+    for (const s of sessions.splice(0)) s.stop();
+    rmSync(workingDir, { recursive: true, force: true });
+  });
+
+  function makeSession(useMux: boolean): Session {
+    mkdirSync(workingDir, { recursive: true });
+    const session = new Session({
+      workingDir,
+      mode: 'codex',
+      codexConfig: { resumeSessionId: THREAD_ID },
+      mux: new TmuxManager(),
+      useMux,
+    });
+    sessions.push(session);
+    return session;
+  }
+
+  it('carries the thread id from construction', () => {
+    expect(makeSession(true).claudeSessionId).toBe(THREAD_ID);
+  });
+
+  it('still carries it after starting under mux', async () => {
+    const session = makeSession(true);
+    await session.startInteractive();
+    expect(session.claudeSessionId).toBe(THREAD_ID);
+  });
+
+  it('refuses to start without mux at all, so the mux path is the only one to cover', async () => {
+    // codex declares `requiresMux`, so there is no direct-PTY codex session for
+    // the third reset point to run against on its own — the assertion above is
+    // the whole surface.
+    await expect(makeSession(false).startInteractive()).rejects.toThrow(/require tmux/i);
+  });
+
+  it('a fresh codex session keeps the Codeman id, having no thread of its own', async () => {
+    mkdirSync(workingDir, { recursive: true });
+    const session = new Session({ workingDir, mode: 'codex', mux: new TmuxManager(), useMux: true });
+    sessions.push(session);
+
+    await session.startInteractive();
+
+    // Nothing to alias to yet — codex has not written the rollout. Such a
+    // session is folded from the other side, by originator (codexThreadBySessionId).
+    expect(session.claudeSessionId).toBe(session.id);
+  });
+});

test/codex-transcript.test.ts

@@ -16,25 +16,29 @@
  *   outnumbered the threads a person can actually resume.
  */
 import { describe, expect, it, beforeEach, afterEach } from 'vitest';
-import { mkdtemp, mkdir, writeFile, rm, utimes } from 'node:fs/promises';
+import { appendFile, mkdtemp, mkdir, writeFile, rm, utimes } from 'node:fs/promises';
 import { join } from 'node:path';
 import { tmpdir } from 'node:os';
 
-import { scanCodexSessionsHistory, __clearCodexIdentityCache } from '../src/codex-transcript.js';
+import {
+  scanCodexSessionsHistory,
+  codexThreadBySessionId,
+  __clearCodexIdentityCache,
+} from '../src/codex-transcript.js';
 
 let home: string;
 let prevCodexHome: string | undefined;
 
 /** A rollout's opening line, as codex writes it. */
-const sessionMeta = (opts: { id: string; cwd: string; threadSource?: string }) =>
+const sessionMeta = (opts: { id: string; cwd?: string; threadSource?: string; originator?: string }) =>
   JSON.stringify({
     timestamp: '2026-09-02T07:05:37.421Z',
     type: 'session_meta',
     payload: {
       id: opts.id,
       session_id: opts.id,
-      cwd: opts.cwd,
-      originator: 'codex-tui',
+      ...(opts.cwd ? { cwd: opts.cwd } : {}),
+      originator: opts.originator ?? 'codex-tui',
       ...(opts.threadSource ? { thread_source: opts.threadSource } : {}),
       // The real thing embeds full base instructions here; padded so the file
       // clears the size floor and exercises the head window.
@@ -194,6 +198,76 @@ describe('scanCodexSessionsHistory', () => {
     expect(rows[0].firstPrompt).toBe('still found me');
   });
 
+  it('reports the originator, which is how a fresh pane finds its own rollout', async () => {
+    await writeRollout('bbbbbbbb-bbbb-7bbb-8bbb-bbbbbbbbbbbb', [
+      sessionMeta({
+        id: 'bbbbbbbb-bbbb-7bbb-8bbb-bbbbbbbbbbbb',
+        cwd: '/repo/nine',
+        originator: 'codeman_2f1c9a44-1111-2222-3333-444455556666',
+      }),
+      itemCompletedUser('hello'),
+    ]);
+
+    const rows = await scanCodexSessionsHistory();
+    expect(rows[0].originator).toBe('codeman_2f1c9a44-1111-2222-3333-444455556666');
+  });
+
+  it('drops a rollout that records no working directory', async () => {
+    // Emitting workingDir: '' would make a click post an empty directory.
+    await writeRollout('cccccccc-cccc-7ccc-8ccc-cccccccccccc', [
+      sessionMeta({ id: 'cccccccc-cccc-7ccc-8ccc-cccccccccccc' }),
+      itemCompletedUser('nowhere to resume into'),
+    ]);
+
+    expect(await scanCodexSessionsHistory()).toEqual([]);
+  });
+
+  it('picks up a prompt written after an earlier scan saw none', async () => {
+    // The bug this pins: the identity cache was written as soon as the thread id
+    // was known, but codex writes the first UserMessage only when the user
+    // submits. Any scan in that window — the home screen, the command palette,
+    // the search-index refresh — pinned `firstPrompt: undefined` until restart.
+    const id = 'dddddddd-dddd-7ddd-8ddd-dddddddddddd';
+    const path = await writeRollout(id, [sessionMeta({ id, cwd: '/repo/ten' })]);
+
+    const before = await scanCodexSessionsHistory();
+    expect(before).toHaveLength(1);
+    expect(before[0].firstPrompt).toBeUndefined();
+
+    await appendFile(path, itemCompletedUser('the prompt, typed a moment later') + '\n', 'utf-8');
+
+    const after = await scanCodexSessionsHistory();
+    expect(after[0].firstPrompt).toBe('the prompt, typed a moment later');
+  });
+
+  it('does not spend the lastPrompt budget on rollouts it never returns', async () => {
+    // The budget used to count file index, so a store whose newest files are all
+    // sub-agent threads exhausted it before the first row that needed it.
+    for (let i = 0; i < 3; i++) {
+      await writeRollout(
+        `eeeeeeee-eeee-7eee-8eee-00000000000${i}`,
+        [
+          sessionMeta({ id: `eeeeeeee-eeee-7eee-8eee-00000000000${i}`, cwd: '/repo/sub', threadSource: 'subagent' }),
+          itemCompletedUser('subagent work'),
+        ],
+        new Date('2026-09-05T00:00:00Z')
+      );
+    }
+    await writeRollout(
+      'ffffffff-ffff-7fff-8fff-ffffffffffff',
+      [
+        sessionMeta({ id: 'ffffffff-ffff-7fff-8fff-ffffffffffff', cwd: '/repo/real' }),
+        itemCompletedUser('opening'),
+        itemCompletedUser('the latest thing asked'),
+      ],
+      new Date('2026-09-04T00:00:00Z')
+    );
+
+    const rows = await scanCodexSessionsHistory();
+    expect(rows).toHaveLength(1);
+    expect(rows[0].lastPrompt).toBe('the latest thing asked');
+  });
+
   it('collapses a long prompt to a single capped line', async () => {
     await writeRollout('aaaaaaaa-aaaa-7aaa-8aaa-aaaaaaaaaaaa', [
       sessionMeta({ id: 'aaaaaaaa-aaaa-7aaa-8aaa-aaaaaaaaaaaa', cwd: '/repo/eight' }),
@@ -206,3 +280,25 @@ describe('scanCodexSessionsHistory', () => {
     expect(rows[0].firstPrompt!.endsWith('…')).toBe(true);
   });
 });
+
+describe('codexThreadBySessionId', () => {
+  const row = (sessionId: string, originator?: string) =>
+    ({ sessionId, originator, workingDir: '/w', sizeBytes: 1, lastModified: '2026-09-02T00:00:00.000Z' }) as never;
+
+  it('maps a Codeman-spawned pane to the thread it is writing', () => {
+    const map = codexThreadBySessionId([row('thread-a', 'codeman_sess-1')]);
+    expect(map.get('sess-1')).toBe('thread-a');
+  });
+
+  it('ignores a rollout codex started on its own', () => {
+    expect(codexThreadBySessionId([row('thread-a', 'codex-tui')]).size).toBe(0);
+    expect(codexThreadBySessionId([row('thread-a', undefined)]).size).toBe(0);
+  });
+
+  it('keeps the newest rollout when a pane has several', () => {
+    // `/new` inside the codex TUI leaves the pane's originator on more than one
+    // rollout; the pane is on the most recent, and rows arrive newest-first.
+    const map = codexThreadBySessionId([row('thread-new', 'codeman_sess-1'), row('thread-old', 'codeman_sess-1')]);
+    expect(map.get('sess-1')).toBe('thread-new');
+  });
+});

test/resume-history-mode-fidelity.test.ts

@@ -90,7 +90,7 @@ describe('resumeHistorySession: row retirement is gated on actual continuation',
     fetchMock = stubFetch('new-session-id');
   });
 
-  it.each(['codex', 'gemini', 'antigravity'])(
+  it.each(['gemini', 'antigravity'])(
     'does NOT retire the old row for %s (no continuation is wired for it)',
     async (mode) => {
       const app = makeApp();
@@ -104,6 +104,44 @@ describe('resumeHistorySession: row retirement is gated on actual continuation',
     }
   );
 
+  // codex continues only when the row carried its thread id. A row without one
+  // is a live session's row, whose sessionId is Codeman's own uuid — sending
+  // THAT to `codex resume` asks for a thread that does not exist, so it must
+  // stay a fresh session and must not retire the row it came from.
+  it('does NOT continue or retire a codex row that carries no resumeId', async () => {
+    const app = makeApp();
+    await app.resumeHistorySession.call(app, 'codeman-uuid', '/repo', 'w1-repo', 'codex');
+
+    expect(createBody(fetchMock)).toMatchObject({ mode: 'codex' });
+    expect(createBody(fetchMock).codexConfig).toBeUndefined();
+    expect(deleteCalls(fetchMock)).toEqual([]);
+  });
+
+  it('resumes a codex row by the thread id the row carried', async () => {
+    const app = makeApp();
+    await app.resumeHistorySession.call(
+      app,
+      '01a060f0-0361-7f91-abde-b283020db0d7',
+      '/repo',
+      'w1-repo',
+      'codex',
+      '01a060f0-0361-7f91-abde-b283020db0d7'
+    );
+
+    expect(createBody(fetchMock)).toMatchObject({
+      mode: 'codex',
+      codexConfig: { resumeSessionId: '01a060f0-0361-7f91-abde-b283020db0d7' },
+    });
+  });
+
+  it('ignores a resumeId on a row that is not codex', async () => {
+    const app = makeApp();
+    await app.resumeHistorySession.call(app, 'old-id', '/repo', 'w1-repo', 'gemini', 'some-thread-id');
+
+    expect(createBody(fetchMock).codexConfig).toBeUndefined();
+    expect(deleteCalls(fetchMock)).toEqual([]);
+  });
+
   it.each([
     ['opencode', 'openCodeConfig'],
     ['pi', 'piConfig'],

test/services/unified-session-service.test.ts

@@ -14,6 +14,70 @@ import {
 } from '../../src/services/unified-session-service.js';
 
 describe('mergeUnifiedSessions', () => {
+  // A codex conversation showing twice is worse than cosmetic: the stale PAST row
+  // still resumes, so clicking it starts a SECOND `codex resume` on a thread
+  // already open in another pane. Both folds below are what prevent that.
+  it('folds a RESUMED codex session into its own rollout row', () => {
+    // Session sets claudeSessionId from codexConfig.resumeSessionId, so the live
+    // row already names the thread the rollout is keyed by.
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-uuid', status: 'idle', mode: 'codex', claudeSessionId: 'codex-thread-id' }],
+      history: [
+        {
+          sessionId: 'codex-thread-id',
+          workingDir: '/w',
+          sizeBytes: 4000,
+          lastModified: '2026-09-02T00:00:00.000Z',
+          mode: 'codex',
+          resumeId: 'codex-thread-id',
+        },
+      ],
+    });
+    expect(merged).toHaveLength(1);
+    expect(merged[0].sessionId).toBe('codeman-uuid');
+    expect([...merged[0].sources].sort()).toEqual(['history', 'live']);
+  });
+
+  it('folds a FRESH codex session once its rollout has been matched by originator', () => {
+    // A fresh pane knows no thread id, so gatherUnifiedInputs() stamps one onto
+    // the live row from session_meta.originator (see codexThreadBySessionId).
+    // This is that stamped row.
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-uuid', status: 'busy', mode: 'codex', claudeSessionId: 'fresh-thread-id' }],
+      persisted: [{ id: 'codeman-uuid', status: 'idle', mode: 'codex', claudeSessionId: 'fresh-thread-id' }],
+      history: [
+        {
+          sessionId: 'fresh-thread-id',
+          workingDir: '/w',
+          sizeBytes: 900,
+          lastModified: '2026-09-02T00:00:00.000Z',
+          mode: 'codex',
+          resumeId: 'fresh-thread-id',
+        },
+      ],
+    });
+    expect(merged).toHaveLength(1);
+    expect(merged[0].sessionId).toBe('codeman-uuid');
+    expect(merged[0].status).toBe('busy');
+  });
+
+  it('leaves an unrelated codex rollout as its own row', () => {
+    const merged = mergeUnifiedSessions({
+      live: [{ id: 'codeman-uuid', status: 'idle', mode: 'codex', claudeSessionId: 'thread-one' }],
+      history: [
+        {
+          sessionId: 'thread-two',
+          workingDir: '/w',
+          sizeBytes: 4000,
+          lastModified: '2026-09-02T00:00:00.000Z',
+          mode: 'codex',
+          resumeId: 'thread-two',
+        },
+      ],
+    });
+    expect(merged.map((m) => m.sessionId).sort()).toEqual(['codeman-uuid', 'thread-two']);
+  });
+
   it("carries a transcript row's own resume token, and stamps none on a live row", () => {
     // codex names a thread by an id in its rollout, not by Codeman's session id.
     // The scanner sets `resumeId`; a live session never does, which is what stops