diff --git a/packages/adapters/codex-local/src/index.ts b/packages/adapters/codex-local/src/index.ts
index f09e50d9..da7a8d0b 100644
--- a/packages/adapters/codex-local/src/index.ts
+++ b/packages/adapters/codex-local/src/index.ts
@@ -24,7 +24,7 @@ Core fields:
 - cwd (string, optional): default absolute working directory fallback for the agent process (created if missing when possible)
 - instructionsFilePath (string, optional): absolute path to a markdown instructions file prepended to stdin prompt at runtime
 - model (string, optional): Codex model id
-- modelReasoningEffort (string, optional): reasoning effort override (minimal|low|medium|high) passed via -c model_reasoning_effort=...
+- modelReasoningEffort (string, optional): reasoning effort override (minimal|low|medium|high|xhigh) passed via -c model_reasoning_effort=...
 - promptTemplate (string, optional): run prompt template
 - search (boolean, optional): run codex with --search
 - dangerouslyBypassApprovalsAndSandbox (boolean, optional): run with bypass flag
diff --git a/packages/adapters/opencode-local/src/index.ts b/packages/adapters/opencode-local/src/index.ts
index 2688a0f2..5f5be605 100644
--- a/packages/adapters/opencode-local/src/index.ts
+++ b/packages/adapters/opencode-local/src/index.ts
@@ -4,6 +4,7 @@ export const DEFAULT_OPENCODE_LOCAL_MODEL = "openai/gpt-5.2-codex";
 
 export const models = [
   { id: DEFAULT_OPENCODE_LOCAL_MODEL, label: DEFAULT_OPENCODE_LOCAL_MODEL },
+  { id: "openai/gpt-5.4", label: "openai/gpt-5.4" },
   { id: "openai/gpt-5.2", label: "openai/gpt-5.2" },
   { id: "openai/gpt-5.1-codex-max", label: "openai/gpt-5.1-codex-max" },
   { id: "openai/gpt-5.1-codex-mini", label: "openai/gpt-5.1-codex-mini" },
@@ -27,7 +28,7 @@ Core fields:
 - cwd (string, optional): default absolute working directory fallback for the agent process (created if missing when possible)
 - instructionsFilePath (string, optional): absolute path to a markdown instructions file prepended to the run prompt
 - model (string, optional): OpenCode model id in provider/model format (for example openai/gpt-5.2-codex)
-- variant (string, optional): provider-specific reasoning/profile variant passed as --variant
+- variant (string, optional): provider-specific reasoning/profile variant passed as --variant (for example minimal|low|medium|high|xhigh|max)
 - promptTemplate (string, optional): run prompt template
 - command (string, optional): defaults to "opencode"
 - extraArgs (string[], optional): additional CLI args
diff --git a/server/src/__tests__/adapter-models.test.ts b/server/src/__tests__/adapter-models.test.ts
index b03166b6..1bd878b7 100644
--- a/server/src/__tests__/adapter-models.test.ts
+++ b/server/src/__tests__/adapter-models.test.ts
@@ -1,6 +1,7 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { models as codexFallbackModels } from "@paperclipai/adapter-codex-local";
 import { models as cursorFallbackModels } from "@paperclipai/adapter-cursor-local";
+import { models as opencodeFallbackModels } from "@paperclipai/adapter-opencode-local";
 import { listAdapterModels } from "../adapters/index.js";
 import { resetCodexModelsCacheForTests } from "../adapters/codex-models.js";
 import { resetCursorModelsCacheForTests, setCursorModelsRunnerForTests } from "../adapters/cursor-models.js";
@@ -72,6 +73,13 @@ describe("adapter model listing", () => {
     expect(models).toEqual(cursorFallbackModels);
   });
 
+  it("returns opencode fallback models including gpt-5.4", async () => {
+    const models = await listAdapterModels("opencode_local");
+
+    expect(models).toEqual(opencodeFallbackModels);
+    expect(models.some((model) => model.id === "openai/gpt-5.4")).toBe(true);
+  });
+
   it("loads cursor models dynamically and caches them", async () => {
     const runner = vi.fn(() => ({
       status: 0,
diff --git a/ui/src/components/AgentConfigForm.tsx b/ui/src/components/AgentConfigForm.tsx
index a99fb25b..b5a23db4 100644
--- a/ui/src/components/AgentConfigForm.tsx
+++ b/ui/src/components/AgentConfigForm.tsx
@@ -130,6 +130,7 @@ const codexThinkingEffortOptions = [
   { id: "low", label: "Low" },
   { id: "medium", label: "Medium" },
   { id: "high", label: "High" },
+  { id: "xhigh", label: "X-High" },
 ] as const;
 
 const opencodeVariantOptions = [
@@ -138,6 +139,7 @@ const opencodeVariantOptions = [
   { id: "low", label: "Low" },
   { id: "medium", label: "Medium" },
   { id: "high", label: "High" },
+  { id: "xhigh", label: "X-High" },
   { id: "max", label: "Max" },
 ] as const;
 
diff --git a/ui/src/components/NewIssueDialog.tsx b/ui/src/components/NewIssueDialog.tsx
index 1b07385f..1840c727 100644
--- a/ui/src/components/NewIssueDialog.tsx
+++ b/ui/src/components/NewIssueDialog.tsx
@@ -82,6 +82,7 @@ const ISSUE_THINKING_EFFORT_OPTIONS = {
     { value: "low", label: "Low" },
     { value: "medium", label: "Medium" },
     { value: "high", label: "High" },
+    { value: "xhigh", label: "X-High" },
   ],
   opencode_local: [
     { value: "", label: "Default" },
@@ -89,6 +90,7 @@ const ISSUE_THINKING_EFFORT_OPTIONS = {
     { value: "low", label: "Low" },
     { value: "medium", label: "Medium" },
     { value: "high", label: "High" },
+    { value: "xhigh", label: "X-High" },
     { value: "max", label: "Max" },
   ],
 } as const;