feat(studio): presets include load settings (#7347) (#7352)

* feat(studio): save load settings in chat presets

Presets previously stored only sampling params (temperature, top_p, etc.).
Extend them with an optional loadConfig blob that captures context length,
KV cache dtype, speculative decoding, and GPU layer knobs from the current
runtime when saving.

- Apply loadConfig when switching presets or hydrating on startup
- Show a short summary under the preset controls
- Prompt to reload when a model is already loaded

Fixes #7347

* fix(studio): persist preset loadConfig and capture GGUF context

Add ChatPresetLoadConfig to the chat settings API schema so presets with
load settings no longer 400 on save. Capture effective GGUF context from
ggufContextLength when customContextLength is cleared after auto-mode load.

* fix(studio): address Codex review on preset load settings

Coalesce default maxSeqLength/speculative/gpu knobs when capturing presets,
no-op apply for legacy presets without loadConfig, preserve GPU pin on apply,
and stop replaying stale loadConfig during settings hydration.

* Remove unused getOrderedPresets import

---------

Co-authored-by: Daniel Han <danielhanchen@gmail.com>

studio/backend/routes/chat_history.py

@@ -160,11 +160,26 @@ class ChatInferenceSettings(BaseModel):
     fastMode: Optional[bool] = None
 
 
+class ChatPresetLoadConfig(BaseModel):
+    model_config = ConfigDict(extra = "forbid")
+
+    customContextLength: Optional[int] = Field(default = None, gt = 0)
+    maxSeqLength: Optional[float] = None
+    kvCacheDtype: Optional[str] = None
+    speculativeType: Optional[str] = None
+    specDraftNMax: Optional[int] = Field(default = None, ge = 1, le = 16)
+    tensorParallel: Optional[bool] = None
+    gpuMemoryMode: Optional[Literal["manual"]] = None
+    gpuLayers: Optional[int] = None
+    nCpuMoe: Optional[int] = Field(default = None, ge = 0)
+
+
 class ChatPreset(BaseModel):
     model_config = ConfigDict(extra = "forbid")
 
     name: str
     params: ChatInferenceSettings
+    loadConfig: Optional[ChatPresetLoadConfig] = None
 
 
 class ChatSettingsPayload(BaseModel):

studio/backend/tests/test_chat_history_routes.py

@@ -91,6 +91,28 @@ def test_chat_settings_payload_accepts_fast_mode_presets():
     assert dumped["customPresets"][0]["params"]["fastMode"] is True
 
 
+def test_chat_settings_payload_accepts_preset_load_config():
+    payload = chat_history.ChatSettingsPayload.model_validate(
+        {
+            "customPresets": [
+                {
+                    "name": "GGUF preset",
+                    "params": {"temperature": 0.7, "maxTokens": 512},
+                    "loadConfig": {
+                        "customContextLength": 256,
+                        "kvCacheDtype": "q8_0",
+                        "tensorParallel": False,
+                    },
+                },
+            ],
+        }
+    )
+
+    dumped = payload.model_dump(exclude_unset = True)
+    assert dumped["customPresets"][0]["loadConfig"]["customContextLength"] == 256
+    assert dumped["customPresets"][0]["loadConfig"]["kvCacheDtype"] == "q8_0"
+
+
 def test_chat_settings_payload_accepts_nudge_tool_calls():
     # extra="forbid" 400s PUT /api/chat/settings on unknown keys, so the
     # frontend's persisted nudgeToolCalls needs a payload field (like

studio/frontend/src/features/chat/api/chat-settings-api.ts

@@ -13,6 +13,7 @@ export type PersistedInferenceParams = Partial<
 export interface PersistedChatPreset {
   name: string;
   params: PersistedInferenceParams;
+  loadConfig?: Record<string, unknown>;
 }
 
 export interface PersistedChatSettings {

studio/frontend/src/features/chat/chat-settings-sheet.tsx

@@ -75,6 +75,12 @@ import {
   isSamePresetConfig,
   toPresetParams,
 } from "./presets/preset-policy";
+import {
+  applyPresetLoadConfig,
+  capturePresetLoadConfig,
+  formatPresetLoadConfigSummary,
+  isSamePresetLoadConfig,
+} from "./presets/preset-load-config";
 import {
   type ProviderCapabilities,
   getExternalMaxOutputTokens,
@@ -385,6 +391,12 @@ export function ChatSettingsPanel({
     (s) => s.ggufMaxContextLength,
   );
   const customContextLength = useChatRuntimeStore((s) => s.customContextLength);
+  const kvCacheDtype = useChatRuntimeStore((s) => s.kvCacheDtype);
+  const gpuMemoryMode = useChatRuntimeStore((s) => s.gpuMemoryMode);
+  const gpuLayers = useChatRuntimeStore((s) => s.gpuLayers);
+  const nCpuMoe = useChatRuntimeStore((s) => s.nCpuMoe);
+  const tensorParallel = useChatRuntimeStore((s) => s.tensorParallel);
+  const specDraftNMax = useChatRuntimeStore((s) => s.specDraftNMax);
   const speculativeType = useChatRuntimeStore((s) => s.speculativeType);
   const specFallbackReason = useChatRuntimeStore((s) => s.specFallbackReason);
   const mtpUpdatable =
@@ -469,11 +481,50 @@ export function ChatSettingsPanel({
       if (activePresetDefinition == null) {
         return false;
       }
-      if (activePresetDefinition.name === "Default") {
-        return activePresetSource === "modified";
-      }
-      return !isSamePresetConfig(activePresetDefinition.params, params);
-  }, [activePresetDefinition, activePresetSource, params]);
+      const samplingChanged =
+        activePresetDefinition.name === "Default"
+          ? activePresetSource === "modified"
+          : !isSamePresetConfig(activePresetDefinition.params, params);
+      const currentLoadConfig = capturePresetLoadConfig();
+      const loadChanged = !isSamePresetLoadConfig(
+        activePresetDefinition.loadConfig,
+        currentLoadConfig,
+      );
+      return samplingChanged || loadChanged;
+  }, [
+    activePresetDefinition,
+    activePresetSource,
+    params,
+    customContextLength,
+    ggufContextLength,
+    kvCacheDtype,
+    gpuMemoryMode,
+    gpuLayers,
+    nCpuMoe,
+    tensorParallel,
+    speculativeType,
+    specDraftNMax,
+    params.maxSeqLength,
+  ]);
+  const activePresetLoadSummary = useMemo(
+    () => formatPresetLoadConfigSummary(activePresetDefinition?.loadConfig),
+    [activePresetDefinition],
+  );
+  const currentLoadSummary = useMemo(
+    () => formatPresetLoadConfigSummary(capturePresetLoadConfig()),
+    [
+      customContextLength,
+      ggufContextLength,
+      kvCacheDtype,
+      gpuMemoryMode,
+      gpuLayers,
+      nCpuMoe,
+      tensorParallel,
+      speculativeType,
+      specDraftNMax,
+      params.maxSeqLength,
+    ],
+  );
   const presetSaveState = useMemo(
     () =>
       getPresetSaveState({
@@ -549,8 +600,14 @@ export function ChatSettingsPanel({
       onParamsChange({
         ...applyPresetParams(params, p.params),
       });
+      if (p.loadConfig) {
+        applyPresetLoadConfig(p.loadConfig);
+      }
       setActivePreset(name);
       setActivePresetSource(getPresetSource(name));
+      if (p.loadConfig && params.checkpoint) {
+        toast.info("Reload the model to apply load settings from this preset.");
+      }
     }
   }
 
@@ -571,9 +628,14 @@ export function ChatSettingsPanel({
       ? getBuiltinVariantName(trimmed, usedNames)
       : trimmed;
     const next = customPresets.filter((p) => p.name !== saveName);
+    const loadConfig = capturePresetLoadConfig();
     const merged = [
       ...next,
-      { name: saveName, params: toPresetParams(params) },
+      {
+        name: saveName,
+        params: toPresetParams(params),
+        ...(loadConfig ? { loadConfig } : {}),
+      },
     ];
     setCustomPresets(merged);
     setActivePreset(saveName);
@@ -598,8 +660,11 @@ export function ChatSettingsPanel({
     if (activePreset === name) {
       if (fallbackPreset) {
         onParamsChange({
-          ...applyPresetParams(params, fallbackPreset.params),
+          ...        applyPresetParams(params, fallbackPreset.params),
         });
+        if (fallbackPreset.loadConfig) {
+          applyPresetLoadConfig(fallbackPreset.loadConfig);
+        }
         setActivePreset(fallbackPreset.name);
         setActivePresetSource("builtin-default");
       }
@@ -901,6 +966,23 @@ export function ChatSettingsPanel({
                 Delete
               </Button>
             </div>
+            <p className="text-[11px] leading-relaxed text-muted-foreground">
+              Saving a preset also stores current load settings (context length,
+              KV cache dtype, speculative decoding, GPU layers).
+              {currentLoadSummary ? (
+                <>
+                  {" "}
+                  Active now: {currentLoadSummary}.
+                </>
+              ) : null}
+              {activePresetLoadSummary &&
+              activePresetLoadSummary !== currentLoadSummary ? (
+                <>
+                  {" "}
+                  Saved in preset: {activePresetLoadSummary}.
+                </>
+              ) : null}
+            </p>
           </div>
         </CollapsibleSection>
 

studio/frontend/src/features/chat/presets/preset-load-config.ts

@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+// Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import {
+  applyPerModelConfigToRuntime,
+  currentRuntimePerModelConfig,
+  perModelConfigsEqual,
+} from "@/features/model-picker";
+import {
+  CONTEXT_LENGTH_MIN,
+  DEFAULT_PER_MODEL_CONFIG,
+  DEFAULT_MAX_SEQ_LENGTH,
+  KV_CACHE_DTYPES,
+  MTP_SPECULATIVE_TYPES,
+  SPECULATIVE_TYPES,
+  normalizeMaxSeqLength,
+  type PerModelConfig,
+} from "@/features/model-picker/model-config/per-model-config";
+import {
+  GPU_LAYERS_AUTO,
+  useChatRuntimeStore,
+  normalizeSpeculativeType,
+} from "../stores/chat-runtime-store";
+
+/** Load/runtime knobs saved in a chat preset (excludes per-model-only blobs). */
+export type PresetLoadConfig = Pick<
+  PerModelConfig,
+  | "customContextLength"
+  | "maxSeqLength"
+  | "kvCacheDtype"
+  | "speculativeType"
+  | "specDraftNMax"
+  | "tensorParallel"
+  | "gpuMemoryMode"
+  | "gpuLayers"
+  | "nCpuMoe"
+>;
+
+const VALID_KV_CACHE_DTYPES = new Set<string>(KV_CACHE_DTYPES);
+const VALID_SPECULATIVE_TYPES = new Set<string>(SPECULATIVE_TYPES);
+
+export const EMPTY_PRESET_LOAD_CONFIG: PresetLoadConfig = {
+  customContextLength: null,
+  maxSeqLength: null,
+  kvCacheDtype: null,
+  speculativeType: null,
+  specDraftNMax: null,
+  tensorParallel: false,
+};
+
+function toComparablePerModelConfig(
+  config: PresetLoadConfig,
+): PerModelConfig {
+  return {
+    ...DEFAULT_PER_MODEL_CONFIG,
+    ...config,
+    chatTemplateOverride: null,
+    selectedGpuIds: null,
+  };
+}
+
+export function normalizePresetLoadConfig(
+  raw: unknown,
+): PresetLoadConfig | undefined {
+  if (raw == null || typeof raw !== "object" || Array.isArray(raw)) {
+    return undefined;
+  }
+  const partial = raw as Record<string, unknown>;
+  const rawSpecType =
+    typeof partial.speculativeType === "string"
+      ? normalizeSpeculativeType(partial.speculativeType)
+      : null;
+  const speculativeType = rawSpecType ?? null;
+  const specDraftNMax =
+    speculativeType != null &&
+    MTP_SPECULATIVE_TYPES.has(speculativeType) &&
+    typeof partial.specDraftNMax === "number" &&
+    Number.isFinite(partial.specDraftNMax)
+      ? Math.max(1, Math.min(16, Math.round(partial.specDraftNMax)))
+      : null;
+  const gpuMemoryMode =
+    partial.gpuMemoryMode === "manual" ? ("manual" as const) : undefined;
+  let gpuLayers: number | undefined;
+  if (typeof partial.gpuLayers === "number" && Number.isFinite(partial.gpuLayers)) {
+    gpuLayers = partial.gpuLayers < 0 ? GPU_LAYERS_AUTO : Math.floor(partial.gpuLayers);
+  }
+  let nCpuMoe: number | undefined;
+  if (typeof partial.nCpuMoe === "number" && Number.isFinite(partial.nCpuMoe)) {
+    nCpuMoe = Math.max(0, Math.floor(partial.nCpuMoe));
+  }
+
+  const normalized: PresetLoadConfig = {
+    customContextLength:
+      typeof partial.customContextLength === "number" &&
+      Number.isFinite(partial.customContextLength) &&
+      partial.customContextLength > 0
+        ? Math.max(CONTEXT_LENGTH_MIN, Math.floor(partial.customContextLength))
+        : null,
+    maxSeqLength: normalizeMaxSeqLength(partial.maxSeqLength as number | null),
+    kvCacheDtype:
+      typeof partial.kvCacheDtype === "string" &&
+      VALID_KV_CACHE_DTYPES.has(partial.kvCacheDtype)
+        ? partial.kvCacheDtype
+        : null,
+    speculativeType:
+      speculativeType && VALID_SPECULATIVE_TYPES.has(speculativeType)
+        ? speculativeType
+        : null,
+    specDraftNMax,
+    tensorParallel:
+      typeof partial.tensorParallel === "boolean"
+        ? partial.tensorParallel
+        : false,
+    ...(gpuMemoryMode ? { gpuMemoryMode } : {}),
+    ...(gpuLayers !== undefined ? { gpuLayers } : {}),
+    ...(nCpuMoe !== undefined ? { nCpuMoe } : {}),
+  };
+
+  return hasPresetLoadConfig(normalized) ? normalized : undefined;
+}
+
+export function hasPresetLoadConfig(
+  config?: PresetLoadConfig | null,
+): boolean {
+  return !isSamePresetLoadConfig(config, EMPTY_PRESET_LOAD_CONFIG);
+}
+
+export function isSamePresetLoadConfig(
+  a?: PresetLoadConfig | null,
+  b?: PresetLoadConfig | null,
+): boolean {
+  return perModelConfigsEqual(
+    toComparablePerModelConfig({ ...EMPTY_PRESET_LOAD_CONFIG, ...a }),
+    toComparablePerModelConfig({ ...EMPTY_PRESET_LOAD_CONFIG, ...b }),
+  );
+}
+
+export function capturePresetLoadConfig(): PresetLoadConfig | undefined {
+  const snapshot = currentRuntimePerModelConfig({ includeMaxSeqLength: true });
+  const store = useChatRuntimeStore.getState();
+  const isGguf =
+    store.activeGgufVariant != null ||
+    store.ggufContextLength != null ||
+    (store.params.checkpoint?.toLowerCase().endsWith(".gguf") ?? false);
+  const effectiveContextLength =
+    snapshot.customContextLength ??
+    (isGguf ? store.ggufContextLength : null);
+  const captured: PresetLoadConfig = {
+    customContextLength: effectiveContextLength ?? null,
+    maxSeqLength: normalizeMaxSeqLength(snapshot.maxSeqLength),
+    kvCacheDtype: snapshot.kvCacheDtype ?? null,
+    speculativeType: normalizeSpeculativeType(snapshot.speculativeType),
+    specDraftNMax: snapshot.specDraftNMax ?? null,
+    tensorParallel: snapshot.tensorParallel ?? false,
+    ...(snapshot.gpuMemoryMode === "manual"
+      ? { gpuMemoryMode: "manual" as const }
+      : {}),
+    ...(snapshot.gpuLayers != null && snapshot.gpuLayers >= 0
+      ? { gpuLayers: snapshot.gpuLayers }
+      : snapshot.gpuMemoryMode === "manual"
+        ? { gpuLayers: GPU_LAYERS_AUTO }
+        : {}),
+    ...(snapshot.nCpuMoe != null && snapshot.nCpuMoe > 0
+      ? { nCpuMoe: snapshot.nCpuMoe }
+      : {}),
+  };
+  return hasPresetLoadConfig(coalesceDefaultLoadKnobs(captured))
+    ? coalesceDefaultLoadKnobs(captured)
+    : undefined;
+}
+
+function coalesceDefaultLoadKnobs(
+  captured: PresetLoadConfig,
+): PresetLoadConfig {
+  const result: PresetLoadConfig = { ...captured };
+  if (normalizeMaxSeqLength(result.maxSeqLength) === DEFAULT_MAX_SEQ_LENGTH) {
+    result.maxSeqLength = null;
+  }
+  const speculativeType = normalizeSpeculativeType(result.speculativeType);
+  if (speculativeType == null || speculativeType === "auto") {
+    result.speculativeType = null;
+  }
+  if (
+    (result.gpuLayers == null || result.gpuLayers < 0) &&
+    result.gpuMemoryMode !== "manual"
+  ) {
+    delete result.gpuLayers;
+  }
+  if ((result.nCpuMoe ?? 0) === 0) {
+    delete result.nCpuMoe;
+  }
+  return result;
+}
+
+export function applyPresetLoadConfig(
+  config?: PresetLoadConfig | null,
+): void {
+  if (config == null) {
+    return;
+  }
+  const store = useChatRuntimeStore.getState();
+  applyPerModelConfigToRuntime({
+    ...DEFAULT_PER_MODEL_CONFIG,
+    maxSeqLength: normalizeMaxSeqLength(config.maxSeqLength) ?? DEFAULT_MAX_SEQ_LENGTH,
+    customContextLength: config.customContextLength ?? null,
+    kvCacheDtype: config.kvCacheDtype ?? null,
+    speculativeType: config.speculativeType ?? null,
+    specDraftNMax: config.specDraftNMax ?? null,
+    tensorParallel: config.tensorParallel ?? false,
+    chatTemplateOverride: null,
+    gpuMemoryMode: config.gpuMemoryMode,
+    gpuLayers: config.gpuLayers,
+    nCpuMoe: config.nCpuMoe,
+    selectedGpuIds: store.selectedGpuIds,
+  });
+}
+
+export function formatPresetLoadConfigSummary(
+  config?: PresetLoadConfig | null,
+): string | null {
+  if (!config || !hasPresetLoadConfig(config)) {
+    return null;
+  }
+  const parts: string[] = [];
+  if (config.customContextLength != null) {
+    parts.push(`Ctx ${config.customContextLength.toLocaleString()}`);
+  }
+  if (config.kvCacheDtype) {
+    parts.push(`KV ${config.kvCacheDtype}`);
+  }
+  if (config.speculativeType && config.speculativeType !== "auto") {
+    parts.push(`Spec ${config.speculativeType}`);
+  }
+  if (config.gpuMemoryMode === "manual") {
+    parts.push("GPU manual");
+  }
+  if (config.gpuLayers != null && config.gpuLayers >= 0) {
+    parts.push(`${config.gpuLayers} layers`);
+  }
+  if (config.tensorParallel) {
+    parts.push("TP");
+  }
+  return parts.length > 0 ? parts.join(" · ") : null;
+}

studio/frontend/src/features/chat/presets/preset-policy.ts

@@ -5,12 +5,15 @@ import {
   DEFAULT_INFERENCE_PARAMS,
   type InferenceParams,
 } from "../types/runtime";
+import type { PresetLoadConfig } from "./preset-load-config";
 
 export const defaultInferenceParams = DEFAULT_INFERENCE_PARAMS;
 
 export interface Preset {
   name: string;
   params: InferenceParams;
+  /** Optional GGUF/load knobs captured with the preset. */
+  loadConfig?: PresetLoadConfig;
 }
 
 export type PresetOwnedParams = Pick<
@@ -85,6 +88,7 @@ export function normalizeCustomPresets(presets: Preset[]): Preset[] {
       return {
         name,
         params: preset.params,
+        ...(preset.loadConfig ? { loadConfig: preset.loadConfig } : {}),
       };
     })
     .filter((preset): preset is Preset => preset !== null);

studio/frontend/src/features/chat/stores/chat-runtime-store.ts

@@ -11,6 +11,7 @@ import {
   type Preset,
   getPresetSource,
 } from "../presets/preset-policy";
+import { normalizePresetLoadConfig } from "../presets/preset-load-config";
 import { getExternalMaxOutputTokens } from "../provider-capabilities";
 import {
   type ChatLoraSummary,
@@ -1159,13 +1160,17 @@ function getHydratedCustomPresets(
   state: ChatRuntimeStore,
 ): Preset[] {
   return (
-    settings.customPresets?.map((preset) => ({
-      name: preset.name,
-      params: {
-        ...DEFAULT_INFERENCE_PARAMS,
-        ...preset.params,
-      },
-    })) ?? state.customPresets
+    settings.customPresets?.map((preset) => {
+      const loadConfig = normalizePresetLoadConfig(preset.loadConfig);
+      return {
+        name: preset.name,
+        params: {
+          ...DEFAULT_INFERENCE_PARAMS,
+          ...preset.params,
+        },
+        ...(loadConfig ? { loadConfig } : {}),
+      };
+    }) ?? state.customPresets
   );
 }
 

studio/frontend/src/features/chat/utils/chat-settings-storage.ts

@@ -8,6 +8,7 @@ import {
   type PersistedChatSettings,
   type PersistedInferenceParams,
 } from "../api/chat-settings-api";
+import { normalizePresetLoadConfig } from "../presets/preset-load-config";
 import {
   BUILTIN_PRESETS,
   defaultInferenceParams,
@@ -152,6 +153,7 @@ function sanitizeInferenceParams(
 }
 
 function toFullPreset(preset: PersistedChatPreset): Preset {
+  const loadConfig = normalizePresetLoadConfig(preset.loadConfig);
   return {
     name: preset.name,
     params: {
@@ -159,6 +161,7 @@ function toFullPreset(preset: PersistedChatPreset): Preset {
       ...preset.params,
       checkpoint: defaultInferenceParams.checkpoint,
     },
+    ...(loadConfig ? { loadConfig } : {}),
   };
 }
 
@@ -174,7 +177,12 @@ function sanitizeCustomPresets(
       const name = item.name.trim();
       if (!name) return null;
       const params = sanitizeInferenceParams(item.params);
-      return { name, params: params ?? {} };
+      const loadConfig = normalizePresetLoadConfig(item.loadConfig);
+      return {
+        name,
+        params: params ?? {},
+        ...(loadConfig ? { loadConfig } : {}),
+      };
     })
     .filter((preset): preset is PersistedChatPreset => preset !== null);
 
@@ -183,6 +191,7 @@ function sanitizeCustomPresets(
     (preset, index) => ({
       name: preset.name,
       params: presets[index]?.params ?? {},
+      ...(preset.loadConfig ? { loadConfig: preset.loadConfig } : {}),
     }),
   );
 }

tests/studio/test_chat_preset_load_config.py

@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+"""Contract coverage for preset load settings (#7347)."""
+
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def _read(relative: str) -> str:
+    path = ROOT / relative
+    if not path.exists():
+        path = ROOT / "unsloth_repo" / relative
+    return path.read_text(encoding = "utf-8")
+
+
+def test_preset_interface_includes_load_config():
+    policy = _read("studio/frontend/src/features/chat/presets/preset-policy.ts")
+    assert "loadConfig?: PresetLoadConfig" in policy
+
+
+def test_preset_save_captures_load_config():
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "capturePresetLoadConfig()" in sheet
+    assert "applyPresetLoadConfig" in sheet
+
+
+def test_preset_apply_restores_load_config():
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "if (p.loadConfig)" in sheet
+    assert "applyPresetLoadConfig(p.loadConfig)" in sheet
+
+
+def test_persisted_preset_serializes_load_config():
+    storage = _read("studio/frontend/src/features/chat/utils/chat-settings-storage.ts")
+    assert "normalizePresetLoadConfig(item.loadConfig)" in storage
+    api = _read("studio/frontend/src/features/chat/api/chat-settings-api.ts")
+    assert "loadConfig?: Record<string, unknown>" in api
+
+
+def test_capture_reads_gguf_loaded_context():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "store.ggufContextLength" in source
+    assert "effectiveContextLength" in source
+
+
+def test_apply_skips_missing_load_config():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "if (config == null)" in source
+    assert "selectedGpuIds: store.selectedGpuIds" in source
+    sheet = _read("studio/frontend/src/features/chat/chat-settings-sheet.tsx")
+    assert "if (p.loadConfig)" in sheet
+
+
+def test_hydration_does_not_replay_preset_load_config():
+    store = _read("studio/frontend/src/features/chat/stores/chat-runtime-store.ts")
+    assert "applyPresetLoadConfig(activeDefinition.loadConfig)" not in store
+
+
+def test_capture_coalesces_default_load_knobs():
+    source = _read("studio/frontend/src/features/chat/presets/preset-load-config.ts")
+    assert "coalesceDefaultLoadKnobs" in source
+    assert "DEFAULT_MAX_SEQ_LENGTH" in source
+
+
+def test_backend_chat_preset_accepts_load_config():
+    routes = _read("studio/backend/routes/chat_history.py")
+    assert "class ChatPresetLoadConfig" in routes
+    assert "loadConfig: Optional[ChatPresetLoadConfig]" in routes