diff --git a/plugins/career/routes.py b/plugins/career/routes.py
index f53a5104..45d20565 100644
--- a/plugins/career/routes.py
+++ b/plugins/career/routes.py
@@ -672,6 +672,9 @@ def get_state():
                 "installed": _installed(v["id"]),
                 "bundled": _bundled(v["id"]),
                 "has_pack": _bundled(v["id"]) or _pack_published(v.get("pack")),
+                # Size of the downloadable pack (for the "Download (~343 MB)"
+                # disclosure); None when there's nothing to download.
+                "pack_bytes": (v.get("pack") or {}).get("bytes") or None,
                 "download": dl,
             })
         return {
diff --git a/plugins/career/screen.js b/plugins/career/screen.js
index 4e47db1d..572441b1 100644
--- a/plugins/career/screen.js
+++ b/plugins/career/screen.js
@@ -29,6 +29,27 @@
     const PP_LABELS = { guitar: 'Guitar', bass: 'Bass', keys: 'Keys', drums: 'Drums' };
     const PP_BROCHURE_ART = ['🎸', '🎷', '🎹', '🥁', '🎺', '🎻', '🎤', '🪕'];
 
+    // Career achievements — DESIGN INTENT (for other contributors):
+    // These reward *real musician learning*, not game busywork. The whole point
+    // of the slim/opt-in content model is that the player grows into it, and the
+    // achievements mark the milestones of that growth on the real-world path:
+    //   - starting a career (committing to the practice loop),
+    //   - later (rig_builder, PR 3) deciding to learn simulated amps/effects and
+    //     dialing in a tone,
+    //   - and graduating to running a *real* rig alongside the game.
+    // If you add achievements here or in a sibling plugin, keep to that spirit:
+    // celebrate a skill or decision a working musician would recognize, so
+    // playing the game rewards learning the craft. Contributed to the
+    // achievements plugin via its cross-plugin API (career is a source,
+    // competency only).
+    const WELCOME_KEY = 'feedBack-career-welcomed';
+    const CAREER_ACHIEVEMENTS = [
+        { id: 'career_started', title: 'Hit the Road',
+          description: 'Start your career.', category: 'career', sourceId: 'career' },
+        { id: 'first_venue_gig', title: 'First Gig',
+          description: 'Play your first venue gig.', category: 'career', sourceId: 'career' },
+    ];
+
     let _state = null;
     let _pollTimer = 0;
     let _appliedManifestVenue = null;
@@ -47,6 +68,25 @@
 
     function $(id) { return document.getElementById(id); }
 
+    // Human-readable pack size for the download-consent disclosure. '' when
+    // unknown/absent so callers can omit the "(~X MB)" suffix entirely.
+    function formatBytes(n) {
+        if (!n || n <= 0) return '';
+        const mb = n / (1024 * 1024);
+        return mb >= 1024 ? `~${(mb / 1024).toFixed(1)} GB` : `~${Math.round(mb)} MB`;
+    }
+
+    // Run fn against the achievements API now if it's loaded, else queue it for
+    // the achievements plugin to drain when it comes up (documented contract in
+    // plugins/achievements/screen.js — the __feedBackAchievementsPending queue).
+    function withAchievements(fn) {
+        const api = window.feedBack && window.feedBack.achievements;
+        if (api) { try { fn(api); } catch (_) { /* optional */ } return; }
+        (window.__feedBackAchievementsPending =
+            window.__feedBackAchievementsPending || []).push(fn);
+    }
+    function grantAchievement(id) { withAchievements((api) => api.unlock(id)); }
+
     function esc(s) {
         return String(s == null ? '' : s).replace(/[&<>"']/g,
             (c) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c]));
@@ -121,7 +161,10 @@
         } else if (v.has_pack) {
             const err = dl.status === 'error'
                 ? `<div class="text-xs text-amber-400 mb-1">${esc(dl.error || 'Download failed')} — try again</div>` : '';
-            action = `${err}<button data-career-download="${esc(v.id)}" class="career-btn career-btn-primary">Download venue pack</button>`;
+            // Consent disclosure: this button starts a download — say its size.
+            const size = formatBytes(v.pack_bytes);
+            const label = size ? `Download venue pack (${size})` : 'Download venue pack';
+            action = `${err}<button data-career-download="${esc(v.id)}" class="career-btn career-btn-primary">${label}</button>`;
         } else {
             action = '<div class="text-xs text-gray-500">Venue pack coming soon — plays with the standard stage for now</div>';
         }
@@ -1309,6 +1352,7 @@
             });
             if (res.ok) gig = (await res.json()).gig;
         } catch (_) { /* summary still shows, unlogged */ }
+        if (gig) grantAchievement('first_venue_gig');  // idempotent; only 1st counts
         showGigSummary(run, gig);
         refreshPassports();
     }
@@ -1568,6 +1612,16 @@
         // announces the fresh mount points — same seam achievements uses.
         document.addEventListener('v3:profile-rendered', renderProfileWall);
         document.addEventListener('v3:dashboard-rendered', renderDashCard);
+        // Career achievements are contributed on every mount (register is
+        // idempotent) so they render greyed before they're earned.
+        withAchievements((api) => api.registerAll(CAREER_ACHIEVEMENTS));
+        // First visit IS "starting career" → the career_started milestone. The
+        // achievements plugin surfaces its own unlock toast, so career doesn't
+        // fire one here (would double up). WELCOME_KEY just avoids re-calling.
+        if (!lsGet(WELCOME_KEY)) {
+            lsSet(WELCOME_KEY, '1');
+            grantAchievement('career_started');
+        }
         refresh();
     }
 
@@ -1575,7 +1629,7 @@
     // the badge-diff logic; nothing here touches the DOM.
     window.__careerPassportTest = {
         ppKey, ppJitter, ppLabel, detectNewBadges, seenBadges, markBadgeSeen,
-        fmtHours, ppFillFraction, careerTotals, closestAskHTML,
+        fmtHours, ppFillFraction, careerTotals, closestAskHTML, formatBytes,
         onGigSongEnded, onGigSongStop,
         setGigRun(r) { _ppGigRun = r; },
         getGigRun() { return _ppGigRun; },
diff --git a/plugins/career/tests/passports.test.js b/plugins/career/tests/passports.test.js
index a106d5c8..ba839616 100644
--- a/plugins/career/tests/passports.test.js
+++ b/plugins/career/tests/passports.test.js
@@ -234,6 +234,44 @@ test('a gold slam marks the bronze moment seen too — never both ceremonies', (
     assert.equal(w2.notifications.length, 0);
 });
 
+test('formatBytes renders the download-size disclosure (MB/GB, empty when unknown)', () => {
+    const f = load().__careerPassportTest.formatBytes;
+    assert.equal(f(351284599), '~335 MB');   // arena
+    assert.equal(f(359899852), '~343 MB');   // club
+    assert.equal(f(2 * 1024 * 1024 * 1024), '~2.0 GB');
+    assert.equal(f(0), '');                    // nothing to download
+    assert.equal(f(null), '');
+    assert.equal(f(undefined), '');
+});
+
+test('boot registers career achievements and unlocks career_started on first visit', () => {
+    // No achievements API in the bare-vm harness, so career's contributions
+    // land in the __feedBackAchievementsPending queue (the documented drain
+    // contract). Draining against a fake API must registerAll + unlock.
+    const w = load();   // fresh window → WELCOME_KEY unset → first visit
+    const pending = w.__feedBackAchievementsPending || [];
+    assert.ok(pending.length >= 2, 'register + career_started unlock should be queued');
+
+    const registered = [];
+    const unlocked = [];
+    const api = {
+        register: () => {},
+        registerAll: (defs) => defs.forEach((d) => registered.push(d.id)),
+        unlock: (id) => unlocked.push(id),
+    };
+    pending.forEach((fn) => fn(api));
+    assert.deepEqual(registered, ['career_started', 'first_venue_gig']);
+    assert.deepEqual(unlocked, ['career_started']);
+
+    // Second boot (welcomed flag now set) must NOT re-unlock career_started.
+    const store = { 'feedBack-career-welcomed': '1' };
+    const w2 = load(store);
+    const pending2 = w2.__feedBackAchievementsPending || [];
+    const unlocked2 = [];
+    pending2.forEach((fn) => fn({ register() {}, registerAll() {}, unlock: (id) => unlocked2.push(id) }));
+    assert.deepEqual(unlocked2, []);
+});
+
 test('careerTotals counts gold badges on the wall', () => {
     const t = load().__careerPassportTest;
     t.setView({
diff --git a/tests/plugins/career/test_routes.py b/tests/plugins/career/test_routes.py
index dcb844cc..3d3f7da3 100644
--- a/tests/plugins/career/test_routes.py
+++ b/tests/plugins/career/test_routes.py
@@ -226,6 +226,46 @@ def test_content_packs_rejects_files_the_downloader_would_refuse(tmp_path):
         raise AssertionError("build_pack accepted a .DS_Store the downloader rejects")
 
 
+def test_unlocked_venue_survives_media_being_unbundled(client, meta_db, monkeypatch, tmp_path):
+    # Upgrade / no-progress-loss: a player who already unlocked arena upgrades
+    # into the slim build where arena media is no longer bundled. The venue must
+    # stay UNLOCKED and become DOWNLOADABLE — never locked or broken — and a
+    # download must restore it. (Star state lives in meta.db, untouched by the
+    # bundle change; `unlocked` is computed from stars, not pack presence.)
+    empty = tmp_path / "no-bundled-media"
+    empty.mkdir()
+    # Simulate the slim build: nothing bundled under venue-packs/.
+    monkeypatch.setattr(career_routes, "_bundled_venue_dir", lambda vid: empty / vid)
+    # Earn 150 stars (50 songs x 3 stars) → arena (threshold 150) unlocked.
+    for i in range(50):
+        meta_db.add(f"song{i}.feedpak", "guitar", 0.99)
+
+    arena = {v["id"]: v for v in client.get("/api/plugins/career/state").json()["venues"]}["arena"]
+    assert arena["unlocked"] is True          # progress preserved
+    assert arena["bundled"] is False          # media stripped from the build
+    assert arena["installed"] is False         # nothing to play yet
+    assert arena["has_pack"] is True           # but it's downloadable
+    assert arena["pack_bytes"] and arena["pack_bytes"] > 0   # size known for the disclosure
+
+    # And a real download restores it (mirror the file:// worker path).
+    src = tmp_path / "src"
+    src.mkdir()
+    for s in career_routes.REQUIRED_LOOPS:
+        (src / f"{s}.mp4").write_bytes(b"v-" + s.encode())
+    (src / "manifest.json").write_text(json.dumps(
+        {"venue": "arena", "version": 1,
+         "loops": {s: f"{s}.mp4" for s in career_routes.REQUIRED_LOOPS}}))
+    zip_path = tmp_path / "arena.zip"
+    with zipfile.ZipFile(zip_path, "w") as zf:
+        for p in src.iterdir():
+            zf.write(p, p.name)
+    sha = hashlib.sha256(zip_path.read_bytes()).hexdigest()
+    progress = {"status": "running", "bytes_done": 0, "bytes_total": 0, "error": None}
+    career_routes._download_pack("arena", {"url": zip_path.as_uri(), "sha256": sha}, progress)
+    assert progress["status"] == "done", progress["error"]
+    assert career_routes._installed("arena") is True
+
+
 def test_double_download_409s(client, monkeypatch):
     bar = career_routes._venue("bar")
     monkeypatch.setitem(bar, "pack", {"url": "http://x/pack.zip", "sha256": "0" * 64, "bytes": 123})