diff --git a/movie_editor/backend/pipeline_caps.py b/movie_editor/backend/pipeline_caps.py
new file mode 100644
index 00000000..98728749
--- /dev/null
+++ b/movie_editor/backend/pipeline_caps.py
@@ -0,0 +1,68 @@
+"""Which FunPack pipeline nodes are active for a project (Studio / Chain Sampler).
+
+UI and generation use these flags so Studio-only and Chain-only features stay off when
+the built-in pipeline is disabled or custom conditioning/sampler slots are selected.
+"""
+from __future__ import annotations
+
+from typing import Any, Optional
+
+from .timeline import Scene, source_type
+
+
+def _models_dict(models: Optional[dict]) -> dict:
+    return models if isinstance(models, dict) else {}
+
+
+def uses_funpack_studio(project: Any, models: Optional[dict] = None) -> bool:
+    if _models_dict(models).get("disable_core"):
+        return False
+    slot = getattr(project, "conditioning_slot", None) or "funpack"
+    return slot == "funpack"
+
+
+def uses_chain_sampler(project: Any, models: Optional[dict] = None) -> bool:
+    if _models_dict(models).get("disable_core"):
+        return False
+    slot = getattr(project, "sampler_slot", None) or "funpack"
+    return slot == "funpack"
+
+
+def capabilities(project: Any, models: Optional[dict] = None) -> dict[str, bool]:
+    m = _models_dict(models)
+    return {
+        "studio": uses_funpack_studio(project, m),
+        "chain_sampler": uses_chain_sampler(project, m),
+        "disable_core": bool(m.get("disable_core")),
+        "imported_workflow": bool(m.get("workflow_import")),
+    }
+
+
+# Source modes that only make sense with FunPack Chain Sampler in the graph.
+_CHAIN_ONLY_SOURCES = frozenset({"carry", "mixed", "generated_frame"})
+
+
+def effective_source_type(scene: Scene, chain_available: bool) -> str:
+    """Runtime source mode for generation/media prep.
+
+    Without Chain Sampler: fall back to t2v (empty) unless the scene has an explicit
+    image anchor. Stored carry/mixed/etc. values are preserved in the project file.
+    """
+    st = source_type(scene)
+    if chain_available:
+        return st
+    if st == "image" and scene.source and scene.source.media_ref:
+        return "image"
+    if st == "v2v" and scene.source and scene.source.media_ref:
+        return "v2v"
+    return "empty"
+
+
+def source_needs_anchor_media(scene: Scene, chain_available: bool) -> bool:
+    """True when generation expects a media-bin asset for this scene's source."""
+    st = effective_source_type(scene, chain_available)
+    return st in ("image", "mixed", "generated_frame", "v2v")
+
+
+def is_chain_only_source_type(st: str) -> bool:
+    return st in _CHAIN_ONLY_SOURCES or st == "v2v"
diff --git a/movie_editor/frontend/engine_settings.js b/movie_editor/frontend/engine_settings.js
index bdc92ff2..4770dc3e 100644
--- a/movie_editor/frontend/engine_settings.js
+++ b/movie_editor/frontend/engine_settings.js
@@ -430,20 +430,39 @@
       container.append(el("div", "pj-meta", "No project open."));
       return;
     }
-    const presetBar = el("div", "engine-preset-bar");
-    presetBar.append(el("span", "engine-preset-label", "Preset"));
-    Object.entries(S.ENGINE_PRESETS || {}).forEach(([key, p]) => {
-      const b = el("button", "btn ghost tiny", p.label || key);
-      b.onclick = () => S.applyEnginePreset(key);
-      presetBar.append(b);
-    });
-    container.append(presetBar);
+    const PC = window.PipelineCaps;
+    const studioOn = PC?.usesFunpackStudio(st);
+    const chainOn = PC?.usesChainSampler(st);
+    if (st.models?.disable_core) {
+      container.append(el("div", "insp-hint",
+        "Built-in FunPack pipeline is disabled — Studio and Chain Sampler settings are unavailable. Tune your workflow in Models."));
+      const foot = el("div", "insp-hint");
+      foot.append(el("span", null, "Workflow nodes: "));
+      const modelsLink = el("button", "btn ghost tiny", "Models & Pipeline…");
+      modelsLink.type = "button";
+      modelsLink.onclick = () => window.ModelsModal.open();
+      foot.append(modelsLink);
+      container.append(foot);
+      return;
+    }
+    if (!studioOn && !chainOn) {
+      container.append(el("div", "insp-hint",
+        "Neither FunPack Studio nor Chain Sampler is active — pick them under Pipeline nodes or use Models to wire custom nodes."));
+    }
+    if (studioOn || chainOn) {
+      const presetBar = el("div", "engine-preset-bar");
+      presetBar.append(el("span", "engine-preset-label", "Preset"));
+      Object.entries(S.ENGINE_PRESETS || {}).forEach(([key, p]) => {
+        const b = el("button", "btn ghost tiny", p.label || key);
+        b.onclick = () => S.applyEnginePreset(key);
+        presetBar.append(b);
+      });
+      container.append(presetBar);
+    }
     const p = st.project;
     const slots = (st.models?.slots || []);
 
     const summary = el("div", "engine-modal-summary");
-    const studioOn = !p.conditioning_slot || p.conditioning_slot === "funpack";
-    const chainOn = !p.sampler_slot || p.sampler_slot === "funpack";
     const parts = [];
     parts.push(studioOn ? "FunPack Studio" : (slotLabelFor(st, p.conditioning_slot) || p.conditioning_slot));
     parts.push(chainOn ? "Chain Sampler" : (slotLabelFor(st, p.sampler_slot) || p.sampler_slot));
diff --git a/movie_editor/frontend/index.html b/movie_editor/frontend/index.html
index 6d9243d7..0e10d199 100644
--- a/movie_editor/frontend/index.html
+++ b/movie_editor/frontend/index.html
@@ -102,6 +102,7 @@
 
   <script src="api.js"></script>
   <script src="dom.js"></script>
+  <script src="pipeline_caps.js"></script>
   <script src="view_bus.js"></script>
   <script src="history.js"></script>
   <script src="media_picker.js"></script>
diff --git a/movie_editor/frontend/inspector.js b/movie_editor/frontend/inspector.js
index c7bca10b..73e5150e 100644
--- a/movie_editor/frontend/inspector.js
+++ b/movie_editor/frontend/inspector.js
@@ -143,6 +143,47 @@
     body.append(det);
     return inner;
   }
+  const PC = () => window.PipelineCaps;
+
+  function availableSourceOptions(st) {
+    if (PC()?.usesChainSampler(st)) return SRC;
+    return SRC.filter(([v]) => v === "empty" || v === "image");
+  }
+
+  function renderSourceField(st, root, scene) {
+    const chain = PC()?.usesChainSampler(st);
+    const stored = root.source?.type || (chain ? "carry" : "empty");
+    const opts = availableSourceOptions(st);
+    if (!opts.some(([v]) => v === stored) && PC()?.isChainOnlySource(stored)) {
+      const note = el("div", "insp-hint");
+      note.textContent = `Stored source “${PC().sourceLabel(stored)}” needs Chain Sampler — runs as text-to-video unless you pick an input image.`;
+      body.append(note);
+    }
+    const src = el("select");
+    opts.forEach(([v, label]) => {
+      const o = el("option", null, label);
+      o.value = v;
+      if (v === stored || (!opts.some(([vv]) => vv === stored) && v === "empty")) o.selected = true;
+      src.append(o);
+    });
+    if (stored && !opts.some(([v]) => v === stored)) {
+      const o = el("option", null, PC()?.sourceLabel(stored) + " (unavailable)");
+      o.value = stored;
+      o.selected = true;
+      src.append(o);
+    }
+    src.onchange = () => {
+      const prev = root.source?.type || (chain ? "carry" : "empty");
+      const next = src.value;
+      const patch = { source: { ...(root.source || {}), type: next } };
+      if (next === "image" || next === "empty") patch.guides = [];
+      else if (chain && (prev === "carry" || next === "carry" || prev === "mixed" || next === "mixed")) patch.guides = [];
+      S.patchScene(scene.id, patch);
+    };
+    body.append(field("Source", src));
+    const eff = PC()?.effectiveSourceType(root, st) || stored;
+    if (eff === "image") renderImageSource(st, root, body);
+  }
 
   function renderVideoSource(st, scene, parent, label) {
     parent = parent || body;
@@ -217,20 +258,11 @@
     const ta = el("textarea"); ta.rows = 4; ta.value = root.text || ""; ta.placeholder = "Describe this scene…"; ta.dataset.k = "sc-text";
     ta.oninput = () => S.patchSceneQuiet(scene.id, { text: ta.value });
     body.append(field("Prompt", ta));
-    const src = el("select");
-    SRC.forEach(([v, label]) => { const o = el("option", null, label); o.value = v; if ((root.source?.type) === v) o.selected = true; src.append(o); });
-    src.onchange = () => {
-      const prev = root.source?.type || "carry";
-      const next = src.value;
-      const patch = { source: { ...(root.source || {}), type: next } };
-      if (next === "image" || next === "empty" || next === "generated_frame") patch.guides = [];
-      else if (prev !== next && (prev === "carry" || next === "carry" || prev === "mixed" || next === "mixed")) patch.guides = [];
-      S.patchScene(scene.id, patch);
-    };
-    body.append(field("Source", src));
-    if ((root.source?.type) === "image" || (root.source?.type) === "mixed") renderImageSource(st, root, body);
-    if ((root.source?.type) === "generated_frame") renderGeneratedFrameSource(st, root);
-    if ((root.source?.type) === "v2v") renderVideoSource(st, root, body, "V2V source video");
+    renderSourceField(st, root, scene);
+    if (PC()?.usesChainSampler(st)) {
+      if ((root.source?.type) === "generated_frame") renderGeneratedFrameSource(st, root);
+      if ((root.source?.type) === "v2v") renderVideoSource(st, root, body, "V2V source video");
+    }
 
     const effFrames = effOf(scene, "frames"), effFps = effOf(scene, "fps") || 1;
     body.append(el("div", "insp-hint", `Duration ≈ ${(effFrames / effFps).toFixed(2)}s · trim on timeline · Convert to video on the timeline toolbar · generation splits: global prompt or Outgoing seam below`));
@@ -244,7 +276,7 @@
     body.append(actions);
 
     foldSection("More editing", false, (more) => {
-      renderSceneCharacters(st, scene, more);
+      if (PC()?.usesFunpackStudio(st)) renderSceneCharacters(st, scene, more);
 
       const fxTag = el("div", "insp-tag"); fxTag.textContent = "Video effects"; more.append(fxTag);
       const fx = scene.effects || {};
@@ -337,7 +369,7 @@
         more.append(reset);
       }
 
-      renderSceneGuides(st, scene, more);
+      if (PC()?.usesChainSampler(st)) renderSceneGuides(st, scene, more);
 
       const row = el("div", "insp-block");
       const chk = el("label", "chk"); const cb = el("input"); cb.type = "checkbox"; cb.checked = !!scene.excluded;
@@ -423,16 +455,28 @@
 
   function renderEngineStrip(st) {
     const p = st.project;
-    const studioOn = !p.conditioning_slot || p.conditioning_slot === "funpack";
-    const chainOn = !p.sampler_slot || p.sampler_slot === "funpack";
+    const strip = el("div", "insp-engine-strip");
+    const c = PC()?.caps(st) || {};
+    if (c.disable_core || c.imported_workflow) {
+      const name = st.models?.workflow_import?.name || "Custom workflow";
+      strip.append(el("span", "insp-engine-strip-txt", `Generating with imported workflow (${name})`));
+      const btn = el("button", "btn ghost tiny", "Models →");
+      btn.onclick = () => window.ModelsModal.open();
+      strip.append(btn);
+      body.append(strip);
+      return;
+    }
+    const studioOn = PC()?.usesFunpackStudio(st);
+    const chainOn = PC()?.usesChainSampler(st);
     const parts = [];
     parts.push(studioOn ? "FunPack Studio" : (slotLabelFor(st, p.conditioning_slot) || p.conditioning_slot));
     parts.push(chainOn ? "Chain Sampler" : (slotLabelFor(st, p.sampler_slot) || p.sampler_slot));
-    const strip = el("div", "insp-engine-strip");
     strip.append(el("span", "insp-engine-strip-txt", "Generating with " + parts.join(" + ")));
-    const btn = el("button", "btn ghost tiny", "Engine settings →");
-    btn.onclick = () => window.EngineSettingsModal.open();
-    strip.append(btn);
+    if (studioOn || chainOn) {
+      const btn = el("button", "btn ghost tiny", "Engine settings →");
+      btn.onclick = () => window.EngineSettingsModal.open();
+      strip.append(btn);
+    }
     body.append(strip);
   }
 
@@ -483,6 +527,7 @@
 
   function renderSceneGuides(st, scene, parent) {
     parent = parent || body;
+    if (!PC()?.usesChainSampler(st)) return;
     if (!normGuideSettings(st.project).stack_enabled) return;
     const sceneNo = st.project.scenes.indexOf(scene) + 1;
     const tag = el("div", "insp-tag"); tag.textContent = "i2v guides"; parent.append(tag);
@@ -585,7 +630,10 @@
       const why = val.anchors_changed_since_last_queue && !val.text_changed_since_last_queue
         ? "Anchor or source mode changed since last generate"
         : "Prompt or anchors changed since last generate";
-      w.append(el("span", null, `${why} — next run rebuilds guides and clears stale action/detail repairs; Studio training history is kept.`));
+      const studioNote = PC()?.usesFunpackStudio(st)
+        ? " — next run rebuilds guides and clears stale action/detail repairs; Studio training history is kept."
+        : ".";
+      w.append(el("span", null, why + studioNote));
       box.append(w);
     }
     if (pv.parse_error) { const w = el("div", "pv-warn"); w.append(el("span", null, "▲")); w.append(el("span", null, "ComfyUI offline — preview paused")); box.append(w); }
diff --git a/movie_editor/frontend/menubar.js b/movie_editor/frontend/menubar.js
index 647cf119..180a0bd0 100644
--- a/movie_editor/frontend/menubar.js
+++ b/movie_editor/frontend/menubar.js
@@ -53,6 +53,10 @@
 
   function menuSpec() {
     const st = S.get();
+    const PC = window.PipelineCaps;
+    const studioOn = PC?.usesFunpackStudio(st);
+    const chainOn = PC?.usesChainSampler(st);
+    const customPipe = !!(st.models?.disable_core);
     const recent = (st.projects || []).slice(0, 8).map((p) => ({
       label: p.name, hint: `${p.scene_count}▦`, action: () => S.loadProject(p.id),
     }));
@@ -88,21 +92,24 @@
         { label: "Reset Layout", action: () => { const r = document.documentElement; r.style.removeProperty("--media-w"); r.style.removeProperty("--timeline-h"); } },
       ],
       Settings: [
-        { label: "Engine settings…", disabled: !hasProject(), action: () => window.EngineSettingsModal.open() },
+        { label: "Engine settings…", disabled: !hasProject() || (!studioOn && !chainOn),
+          action: () => window.EngineSettingsModal.open() },
         { sep: true },
         { label: "Models…", action: () => window.ModelsModal.open() },
         { label: "Import ComfyUI Workflow…", disabled: !hasProject(),
           action: () => window.WorkflowImportWizard?.open() },
         { label: "Refresh model list", hint: "R", action: async () => { try { await window.MovieEditorAPI.refreshModels(); } catch (_) {} } },
         { sep: true },
-        { label: `Conditioning: ${_roleLabel(st.project?.conditioning_slot, "FunPack Studio")}`, disabled: !hasProject(),
+        { label: `Conditioning: ${_roleLabel(st.project?.conditioning_slot, "FunPack Studio")}`,
+          disabled: !hasProject() || customPipe,
           action: () => _pickRole("conditioning_slot", "Conditioning node", st) },
-        { label: `Sampler: ${_roleLabel(st.project?.sampler_slot, "FunPack Chain Sampler")}`, disabled: !hasProject(),
+        { label: `Sampler: ${_roleLabel(st.project?.sampler_slot, "FunPack Chain Sampler")}`,
+          disabled: !hasProject() || customPipe,
           action: () => _pickRole("sampler_slot", "Sampler node", st) },
       ],
       FunPack: [
         { label: st.resetSessionArmed ? "Reset Studio session ✓ armed — click to cancel" : "Reset Studio session",
-          disabled: !hasProject(), action: () => S.resetStudioSession() },
+          disabled: !hasProject() || !studioOn, action: () => S.resetStudioSession() },
         { sep: true },
         { menulabel: "Libraries (in ComfyUI Studio)" },
         { label: "Open ComfyUI", hint: "↗", action: () => window.open("/", "_blank") },
diff --git a/movie_editor/frontend/models.js b/movie_editor/frontend/models.js
index ef615bb2..61c53d79 100644
--- a/movie_editor/frontend/models.js
+++ b/movie_editor/frontend/models.js
@@ -543,6 +543,12 @@
 
   function requirementsPanel() {
     const sec = el("div", "req-panel");
+    if (config.disable_core) {
+      sec.append(el("div", "req-title", "Custom workflow"));
+      sec.append(el("div", "req-empty",
+        "Built-in FunPack pipeline is off. Wire your workflow nodes below; FunPack loader requirements do not apply."));
+      return sec;
+    }
     sec.append(el("div", "req-title", "Pipeline requirements"));
 
     if (!requirements.length) {
diff --git a/movie_editor/frontend/pipeline_caps.js b/movie_editor/frontend/pipeline_caps.js
new file mode 100644
index 00000000..27e4b7d9
--- /dev/null
+++ b/movie_editor/frontend/pipeline_caps.js
@@ -0,0 +1,68 @@
+// Shared FunPack pipeline capability flags (Studio / Chain Sampler availability).
+(function () {
+  const CHAIN_ONLY = new Set(["carry", "mixed", "generated_frame", "v2v"]);
+
+  function models(st) {
+    return (st && st.models) || {};
+  }
+
+  function usesFunpackStudio(st) {
+    if (models(st).disable_core) return false;
+    const slot = (st && st.project && st.project.conditioning_slot) || "funpack";
+    return slot === "funpack";
+  }
+
+  function usesChainSampler(st) {
+    if (models(st).disable_core) return false;
+    const slot = (st && st.project && st.project.sampler_slot) || "funpack";
+    return slot === "funpack";
+  }
+
+  function caps(st) {
+    const m = models(st);
+    return {
+      studio: usesFunpackStudio(st),
+      chain_sampler: usesChainSampler(st),
+      disable_core: !!m.disable_core,
+      imported_workflow: !!m.workflow_import,
+    };
+  }
+
+  function effectiveSourceType(scene, st) {
+    const t = (scene && scene.source && scene.source.type) || "carry";
+    if (usesChainSampler(st)) return t;
+    if (t === "image" && scene.source && scene.source.media_ref) return "image";
+    if (t === "v2v" && scene.source && scene.source.media_ref) return "v2v";
+    return "empty";
+  }
+
+  function isChainOnlySource(type) {
+    return CHAIN_ONLY.has(type);
+  }
+
+  function defaultSceneSourceType(st) {
+    return usesChainSampler(st) ? "carry" : "empty";
+  }
+
+  function sourceLabel(type) {
+    const map = {
+      empty: "Empty · text-to-video",
+      image: "Image · i2v anchor",
+      generated_frame: "From generated frame",
+      v2v: "Video · v2v source",
+      carry: "Carry i2v guide · continue previous",
+      mixed: "Mixed · Img2Video anchor + prior guides",
+    };
+    return map[type] || type;
+  }
+
+  window.PipelineCaps = {
+    usesFunpackStudio,
+    usesChainSampler,
+    caps,
+    effectiveSourceType,
+    isChainOnlySource,
+    defaultSceneSourceType,
+    sourceLabel,
+  };
+})();
diff --git a/movie_editor/frontend/store.js b/movie_editor/frontend/store.js
index 60d3f114..c0782240 100644
--- a/movie_editor/frontend/store.js
+++ b/movie_editor/frontend/store.js
@@ -233,7 +233,7 @@
       gen_unit_id: id,
       text: ps.text || "",
       transition_to_next: "",
-      source: { type: "carry" },
+      source: { type: window.PipelineCaps?.defaultSceneSourceType(state) || "carry" },
       excluded: false,
     };
   }
@@ -246,7 +246,7 @@
       gen_unit_id: id,
       text: text || ghost.text || "",
       transition_to_next: "",
-      source: { type: "carry" },
+      source: { type: window.PipelineCaps?.defaultSceneSourceType(state) || "carry" },
       excluded: false,
       frames: ghost.frames,
       frames_mode: ghost.frames_mode,
@@ -973,9 +973,8 @@
   function addScene() {
     if (!state.project) return;
     _historyRecord();
-    // Default to "carry": a new scene continues the previous one (overlap) unless the
-    // user picks an anchor/empty. Scene 1 carrying just starts a fresh run.
-    const s = { text: "", transition_to_next: "", source: { type: "carry" }, excluded: false };
+    const srcType = window.PipelineCaps?.defaultSceneSourceType(state) || "carry";
+    const s = { text: "", transition_to_next: "", source: { type: srcType }, excluded: false };
     state.project.scenes.push(s);
     window.Timeline?.requestAutoFit?.();
     notify(); scheduleSave(); // server assigns id; reselect after commit
@@ -1771,6 +1770,9 @@
   }
   function _runs() {
     const active = state.project.scenes.filter((s) => !s.excluded && isGenerativeScene(s));
+    if (window.PipelineCaps && !window.PipelineCaps.usesChainSampler(state)) {
+      return active.length ? [active.map((s) => s.id)] : [];
+    }
     const runs = [];
     for (const s of active) {
       const t = (s.source && s.source.type) || "empty";
@@ -2578,6 +2580,10 @@
   // ── pluggable models / exposed controls ──────────────────────────────────────
   async function loadModels() {
     try { state.models = await API.getModels(state.project?.id); } catch (_) { state.models = { slots: [] }; }
+    if (window.PipelineCaps && !window.PipelineCaps.usesFunpackStudio(state)) {
+      _resetSessionPending = false;
+      state.resetSessionArmed = false;
+    }
     notify();
     loadImageTargets();
   }
@@ -2779,6 +2785,7 @@
   }
   // True when this scene continues the current chain run (not a new run anchor).
   function _continuesChainRun(s) {
+    if (window.PipelineCaps && !window.PipelineCaps.usesChainSampler(state)) return false;
     const active = state.project.scenes.filter((sc) => !sc.excluded);
     const idx = active.findIndex((sc) => sc.id === s.id);
     if (idx <= 0) return false;
diff --git a/movie_editor/frontend/timeline.js b/movie_editor/frontend/timeline.js
index e0691d43..b8ac784f 100644
--- a/movie_editor/frontend/timeline.js
+++ b/movie_editor/frontend/timeline.js
@@ -1151,10 +1151,10 @@
   // ── toolbar ─────────────────────────────────────────────────────────────────────
   function toolbarRatingBlock(st, p) {
     const wrap = el("div", "tl-rating-block");
-    const studioCond = !st.project.conditioning_slot || st.project.conditioning_slot === "funpack";
+    const studioOn = window.PipelineCaps?.usesFunpackStudio(st);
     const hasSel = !!st.selectedSceneId;
     const Picker = window.MovieRatingPicker;
-    if (!studioCond || !hasSel || !hasRender(st, st.selectedSceneId) || !Picker) return wrap;
+    if (!studioOn || !hasSel || !hasRender(st, st.selectedSceneId) || !Picker) return wrap;
     const sc = S.scene(st.selectedSceneId);
     if (!sc || !S.isGenerativeScene(sc)) return wrap;
     const sceneNo = p.scenes.indexOf(sc) + 1;
diff --git a/movie_editor/server.py b/movie_editor/server.py
index 2788adde..b9a4cd55 100644
--- a/movie_editor/server.py
+++ b/movie_editor/server.py
@@ -19,7 +19,7 @@ except Exception:  # pragma: no cover - only available inside ComfyUI
     web = None
     PromptServer = None
 
-from .backend import bridge, builder, config, media, nodes, projects, workflow_import
+from .backend import bridge, builder, config, media, nodes, pipeline_caps, projects, workflow_import
 from .backend.nle_effects import zoompan_z_expr
 from .backend.timeline import (
     Project,
@@ -184,7 +184,7 @@ def _copy_scene_media(ref: str, indir: str) -> Optional[str]:
     return fn
 
 
-def _prepare_media(proj: Project, extra_refs: Optional[list] = None) -> Optional[dict]:
+def _prepare_media(proj: Project, extra_refs: Optional[list] = None, *, chain_available: bool = True) -> Optional[dict]:
     """Copy scene image assets into ComfyUI's input folder.
 
     Returns {"primary": {filename, target}, "by_scene": {scene_id: {filename, media_ref, target}}}
@@ -223,7 +223,7 @@ def _prepare_media(proj: Project, extra_refs: Optional[list] = None) -> Optional
         src = sc.source
         ref = getattr(src, "media_ref", None)
         tgt = getattr(src, "target", None)
-        stype = getattr(src, "type", "") if src else ""
+        stype = pipeline_caps.effective_source_type(sc, chain_available)
         if stype not in ("image", "generated_frame", "mixed") or not ref:
             continue
         _add_ref(ref, tgt, sc.id, set_primary=True)
@@ -297,7 +297,13 @@ def _solo(p: Project, only_scene: Optional[str]) -> Project:
     return collapse_generative_units(_segment(p, ids))
 
 
-def _run_studio_inputs(target: Project, active_scenes: list, *, prompt_changed: bool = False) -> dict:
+def _run_studio_inputs(
+    target: Project,
+    active_scenes: list,
+    *,
+    prompt_changed: bool = False,
+    models: Optional[dict] = None,
+) -> dict:
     """Studio widget overrides for this run, incl. the RLHF rating of the run's last
     render (Studio refines from it).
 
@@ -311,7 +317,7 @@ def _run_studio_inputs(target: Project, active_scenes: list, *, prompt_changed:
     When the generation prompt changed since the last queue, send
     MOVIE_EDITOR_FRESH_PROMPT_RATING instead — clears stale repairs only, keeps training.
     refine_v2 uses Initial discovery when there is no previous run to refine from."""
-    if target.conditioning_slot != "funpack":
+    if not pipeline_caps.uses_funpack_studio(target, models):
         return {}
     si = dict(target.studio_inputs or {})
     try:
@@ -363,13 +369,19 @@ def _resolve_run_seed(target: Project) -> int:
     return random.randint(1, 0xFFFFFFFFFFFFFFFF)
 
 
-def _run_sampler_inputs(target: Project, scene_count: int, full: Optional[Project] = None) -> dict:
+def _run_sampler_inputs(
+    target: Project,
+    scene_count: int,
+    full: Optional[Project] = None,
+    *,
+    models: Optional[dict] = None,
+) -> dict:
     """Sampler widget overrides for one generation run.
 
     Auto continuity (project.continuity_settings) builds guides and sampler knobs per run
     for carry, mixed, image, and empty sources. Manual guide_settings.stack_enabled wins.
     """
-    if target.sampler_slot != "funpack":
+    if not pipeline_caps.uses_chain_sampler(target, models):
         return {}
     import json
     from .backend.timeline import (
@@ -434,8 +446,10 @@ def _missing_continuity_media(full: Project, target: Project) -> list[str]:
     return missing
 
 
-def _missing_scene_anchor_media(target: Project) -> list[str]:
+def _missing_scene_anchor_media(target: Project, *, chain_available: bool = True) -> list[str]:
     """i2v anchor images referenced on scenes but missing from the media bin."""
+    if not chain_available:
+        return []
     from .backend.timeline import scene_anchor_media_refs
 
     missing: list[str] = []
@@ -1169,6 +1183,10 @@ if web is not None and PromptServer is not None:
             oi = await bridge.object_info()
         except Exception as e:  # noqa: BLE001
             return web.json_response({"detail": f"Node registry unavailable: {e}"}, status=502)
+        models_cfg = _project_models(p)
+        caps = pipeline_caps.capabilities(p, models_cfg)
+        if not caps["studio"]:
+            reset_session = False
         bridge.reset_progress()
         bridge.current_progress()  # ensure the sampler step-progress hook is installed
         active_scenes = [s for s in target.scenes if not s.excluded and not is_video_clip(s)]
@@ -1178,14 +1196,14 @@ if web is not None and PromptServer is not None:
                 {"detail": "Nothing to generate — all clips are video-only or excluded."},
                 status=400,
             )
-        missing_media = _missing_continuity_media(p, target)
+        missing_media = _missing_continuity_media(p, target) if caps["chain_sampler"] else []
         if missing_media:
             ids = ", ".join(missing_media)
             return web.json_response(
                 {"detail": f"Missing media for continuity or guide stack ({ids}). Re-upload or clear the reference in Engine settings / Scene inspector."},
                 status=400,
             )
-        missing_anchors = _missing_scene_anchor_media(target)
+        missing_anchors = _missing_scene_anchor_media(target, chain_available=caps["chain_sampler"])
         if missing_anchors:
             ids = ", ".join(missing_anchors)
             return web.json_response(
@@ -1207,17 +1225,24 @@ if web is not None and PromptServer is not None:
             else target.num_frames_per_scene
         )
         try:
-            media_pack = _prepare_media(target, continuity_media_refs(p, target))
-            sampler_inputs = _run_sampler_inputs(target, active_scene_count, full=p)
-            _attach_scene_anchors(sampler_inputs, media_pack, target)
-            graph, report = builder.build(oi, _project_models(target), {
+            media_pack = _prepare_media(
+                target,
+                continuity_media_refs(p, target) if caps["chain_sampler"] else [],
+                chain_available=caps["chain_sampler"],
+            )
+            sampler_inputs = _run_sampler_inputs(target, active_scene_count, full=p, models=models_cfg)
+            if caps["chain_sampler"]:
+                _attach_scene_anchors(sampler_inputs, media_pack, target)
+            graph, report = builder.build(oi, models_cfg, {
                 "prompt": prompt, "seed": _resolve_run_seed(target),
                 "num_frames_per_scene": effective_frames,
                 "frame_rate": target.frame_rate,
                 "width": target.width, "height": target.height,
                 "negative_prompt": effective_negative_prompt(target) or None,
                 "max_scenes": active_scene_count,
-                "studio_inputs": _run_studio_inputs(target, active_scenes, prompt_changed=prompt_changed),
+                "studio_inputs": _run_studio_inputs(
+                    target, active_scenes, prompt_changed=prompt_changed, models=models_cfg,
+                ),
                 "sampler_inputs": sampler_inputs,
                 "reset_session": reset_session,
             }, media=(media_pack or {}).get("primary") if media_pack else None)
@@ -1573,6 +1598,11 @@ if web is not None and PromptServer is not None:
     # Per-project pipeline config (slots + links). Falls back to the global default
     # when the project has none yet; saving also updates the global default so the
     # next NEW project inherits your latest loaders.
+    @routes.get(UI_PREFIX + "/api/projects/{pid}/pipeline-caps")
+    async def _pipeline_caps(req):
+        p = _project_or_404(req.match_info["pid"])
+        return web.json_response(pipeline_caps.capabilities(p, _project_models(p)))
+
     @routes.get(UI_PREFIX + "/api/projects/{pid}/models")
     async def _project_models_get(req):
         return web.json_response(_project_models(_project_or_404(req.match_info["pid"])))
diff --git a/movie_editor/tests/test_pipeline_caps.py b/movie_editor/tests/test_pipeline_caps.py
new file mode 100644
index 00000000..d96eb113
--- /dev/null
+++ b/movie_editor/tests/test_pipeline_caps.py
@@ -0,0 +1,47 @@
+"""Tests for pipeline capability flags (Studio / Chain Sampler availability)."""
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+
+ROOT = Path(__file__).resolve().parents[2]
+sys.path.insert(0, str(ROOT))
+
+from movie_editor.backend import pipeline_caps  # noqa: E402
+from movie_editor.backend.timeline import Project, Scene, SceneSource  # noqa: E402
+
+
+def _scene(stype: str, ref: str | None = None) -> Scene:
+    return Scene(
+        id="s1",
+        text="x",
+        source=SceneSource(type=stype, media_ref=ref),
+    )
+
+
+def test_disable_core_turns_off_studio_and_chain():
+    p = Project(name="t")
+    m = {"disable_core": True, "workflow_import": {"name": "W"}}
+    c = pipeline_caps.capabilities(p, m)
+    assert c["studio"] is False
+    assert c["chain_sampler"] is False
+
+
+def test_custom_slots_without_disable_core():
+    p = Project(name="t", conditioning_slot="custom1", sampler_slot="custom2")
+    c = pipeline_caps.capabilities(p, {"slots": []})
+    assert c["studio"] is False
+    assert c["chain_sampler"] is False
+
+
+def test_effective_source_fallback_without_chain():
+    sc = _scene("carry")
+    assert pipeline_caps.effective_source_type(sc, False) == "empty"
+    sc2 = _scene("mixed", "img1")
+    assert pipeline_caps.effective_source_type(sc2, False) == "empty"
+    sc3 = _scene("image", "img1")
+    assert pipeline_caps.effective_source_type(sc3, False) == "image"
+
+
+def test_effective_source_unchanged_with_chain():
+    sc = _scene("carry")
+    assert pipeline_caps.effective_source_type(sc, True) == "carry"