diff --git a/packages/adapters/codex-local/src/index.test.ts b/packages/adapters/codex-local/src/index.test.ts
index 213edf017e..9cb9589122 100644
--- a/packages/adapters/codex-local/src/index.test.ts
+++ b/packages/adapters/codex-local/src/index.test.ts
@@ -14,5 +14,6 @@ describe("codex local adapter metadata", () => {
     ]);
     expect(isCodexLocalFastModeSupported(DEFAULT_CODEX_LOCAL_MODEL)).toBe(true);
     expect(modelIds).not.toContain("gpt-5.3-codex");
+    expect(modelIds).not.toContain("gpt-5.3-codex-spark");
   });
 });
diff --git a/packages/adapters/codex-local/src/index.ts b/packages/adapters/codex-local/src/index.ts
index 709b2de09f..bddcc3dc7b 100644
--- a/packages/adapters/codex-local/src/index.ts
+++ b/packages/adapters/codex-local/src/index.ts
@@ -43,7 +43,6 @@ export const models = [
   { id: "gpt-5.6-luna", label: "gpt-5.6-luna" },
   { id: "gpt-5.4", label: "gpt-5.4" },
   { id: "gpt-5.4-mini", label: "gpt-5.4-mini" },
-  { id: "gpt-5.3-codex-spark", label: "gpt-5.3-codex-spark" },
   { id: "gpt-5", label: "gpt-5" },
   { id: "o3", label: "o3" },
   { id: "o4-mini", label: "o4-mini" },
@@ -57,12 +56,8 @@ export const modelProfiles: AdapterModelProfileDefinition[] = [
   {
     key: "cheap",
     label: "Cheap",
-    description: "Use the lowest-cost known Codex local model lane without changing the primary model.",
-    adapterConfig: {
-      model: "gpt-5.3-codex-spark",
-      // Spark is the cheap lane by model price; high effort keeps Codex coding behavior usable for delegated work.
-      modelReasoningEffort: "high",
-    },
+    description: "Use an explicitly configured lower-cost Codex model without changing the primary model.",
+    adapterConfig: {},
     source: "adapter_default",
   },
 ];
diff --git a/packages/adapters/codex-local/src/server/codex-args.test.ts b/packages/adapters/codex-local/src/server/codex-args.test.ts
index e0843ca2e6..0137372425 100644
--- a/packages/adapters/codex-local/src/server/codex-args.test.ts
+++ b/packages/adapters/codex-local/src/server/codex-args.test.ts
@@ -89,9 +89,9 @@ describe("buildCodexExecArgs", () => {
     ]);
   });
 
-  it("ignores fast mode for unsupported models", () => {
+  it("ignores fast mode for known unsupported models", () => {
     const result = buildCodexExecArgs({
-      model: "gpt-5.3-codex-spark",
+      model: "gpt-5",
       fastMode: true,
     });
 
@@ -104,7 +104,7 @@ describe("buildCodexExecArgs", () => {
       "exec",
       "--json",
       "--model",
-      "gpt-5.3-codex-spark",
+      "gpt-5",
       "-",
     ]);
   });
diff --git a/server/src/__tests__/adapter-models.test.ts b/server/src/__tests__/adapter-models.test.ts
index 2db24439dd..b3de0e6ecb 100644
--- a/server/src/__tests__/adapter-models.test.ts
+++ b/server/src/__tests__/adapter-models.test.ts
@@ -52,6 +52,7 @@ describe("adapter model listing", () => {
     expect(models.some((model) => model.id === "gpt-5.6-sol")).toBe(true);
     expect(models.some((model) => model.id === "gpt-5.6-terra")).toBe(true);
     expect(models.some((model) => model.id === "gpt-5.6-luna")).toBe(true);
+    expect(models.some((model) => model.id === "gpt-5.3-codex-spark")).toBe(false);
     expect(fetchSpy).not.toHaveBeenCalled();
   });
 
diff --git a/server/src/__tests__/adapter-registry.test.ts b/server/src/__tests__/adapter-registry.test.ts
index 23455f282e..eb95aa673e 100644
--- a/server/src/__tests__/adapter-registry.test.ts
+++ b/server/src/__tests__/adapter-registry.test.ts
@@ -268,7 +268,7 @@ describe("server adapter registry", () => {
     await expect(listAdapterModelProfiles("codex_local")).resolves.toEqual([
       expect.objectContaining({
         key: "cheap",
-        adapterConfig: expect.objectContaining({ model: "gpt-5.3-codex-spark" }),
+        adapterConfig: {},
         source: "adapter_default",
       }),
     ]);
diff --git a/server/src/__tests__/agent-permissions-routes.test.ts b/server/src/__tests__/agent-permissions-routes.test.ts
index 83bcaeadd2..0f45292f1e 100644
--- a/server/src/__tests__/agent-permissions-routes.test.ts
+++ b/server/src/__tests__/agent-permissions-routes.test.ts
@@ -972,7 +972,7 @@ describe.sequential("agent permission routes", () => {
       .send({
         name: "Builder",
         role: "engineer",
-        adapterType: "process",
+        adapterType: "codex_local",
         adapterConfig: {},
         runtimeConfig: {
           heartbeat: {
@@ -991,11 +991,79 @@ describe.sequential("agent permission routes", () => {
             intervalSec: 3600,
             maxConcurrentRuns: 20,
           },
+          modelProfiles: {
+            cheap: { enabled: false },
+          },
         },
       }),
     );
   });
 
+  it("creates agents when optional adapter model profile discovery fails", async () => {
+    const { registerServerAdapter, unregisterServerAdapter } = await import("../adapters/index.js");
+    registerServerAdapter({
+      type: "failing_profile_discovery",
+      execute: async () => ({ exitCode: 0, signal: null, timedOut: false }),
+      testEnvironment: async () => ({
+        adapterType: "failing_profile_discovery",
+        status: "pass",
+        checks: [],
+        testedAt: new Date(0).toISOString(),
+      }),
+      listModelProfiles: async () => {
+        throw new Error("profile discovery unavailable");
+      },
+    });
+
+    try {
+      const app = await createApp({
+        type: "board",
+        userId: "board-user",
+        source: "local_implicit",
+        isInstanceAdmin: true,
+        companyIds: [companyId],
+      });
+
+      const res = await requestApp(app, (baseUrl) => request(baseUrl)
+        .post(`/api/companies/${companyId}/agents`)
+        .send({
+          name: "Builder",
+          role: "engineer",
+          adapterType: "failing_profile_discovery",
+          adapterConfig: {},
+          runtimeConfig: {
+            modelProfiles: {
+              cheap: {
+                enabled: true,
+                adapterConfig: {},
+              },
+            },
+          },
+        }));
+
+      expect(res.status, JSON.stringify(res.body)).toBe(201);
+      expect(mockAgentService.create).toHaveBeenCalledWith(
+        companyId,
+        expect.objectContaining({
+          runtimeConfig: {
+            heartbeat: {
+              enabled: false,
+              maxConcurrentRuns: 20,
+            },
+            modelProfiles: {
+              cheap: {
+                enabled: true,
+                adapterConfig: {},
+              },
+            },
+          },
+        }),
+      );
+    } finally {
+      unregisterServerAdapter("failing_profile_discovery");
+    }
+  });
+
   it("seeds opencode agent creation with the static default model without live discovery", async () => {
     mockEnsureOpenCodeModelConfiguredAndAvailable.mockRejectedValue(
       new Error("`opencode models` should not be called during creation"),
@@ -1082,7 +1150,7 @@ describe.sequential("agent permission routes", () => {
       .send({
         name: "Builder",
         role: "engineer",
-        adapterType: "process",
+        adapterType: "codex_local",
         adapterConfig: {},
         runtimeConfig: {
           heartbeat: {
@@ -1101,6 +1169,9 @@ describe.sequential("agent permission routes", () => {
             intervalSec: 3600,
             maxConcurrentRuns: 20,
           },
+          modelProfiles: {
+            cheap: { enabled: false },
+          },
         },
       }),
     );
diff --git a/server/src/__tests__/heartbeat-model-profile.test.ts b/server/src/__tests__/heartbeat-model-profile.test.ts
index 80a973c5ff..2ed42a4bfa 100644
--- a/server/src/__tests__/heartbeat-model-profile.test.ts
+++ b/server/src/__tests__/heartbeat-model-profile.test.ts
@@ -21,7 +21,7 @@ const cheapProfile: AdapterModelProfileDefinition = {
 };
 
 describe("heartbeat model profile application", () => {
-  it("uses the Codex local adapter cheap default when the agent has no runtime override", async () => {
+  it("keeps Codex on its primary model when cheap has no explicit model override", async () => {
     const modelProfile = resolveModelProfileApplication({
       adapterModelProfiles: await listAdapterModelProfiles("codex_local"),
       agentRuntimeConfig: {},
@@ -29,17 +29,21 @@ describe("heartbeat model profile application", () => {
       contextSnapshot: {},
     });
 
+    const merged = mergeModelProfileAdapterConfig({
+      baseConfig: { model: "primary" },
+      modelProfile,
+      issueAdapterConfig: null,
+    });
+
     expect(modelProfile).toMatchObject({
       requested: "cheap",
       requestedBy: "issue_override",
       applied: "cheap",
       configSource: "adapter_default",
       fallbackReason: null,
-      adapterConfig: {
-        model: "gpt-5.3-codex-spark",
-        modelReasoningEffort: "high",
-      },
+      adapterConfig: {},
     });
+    expect(merged).toEqual({ model: "primary" });
   });
 
   it("applies cheap profile patches before explicit issue adapter config overrides", () => {
diff --git a/server/src/routes/agents.ts b/server/src/routes/agents.ts
index 32fbf97476..b484275e2e 100644
--- a/server/src/routes/agents.ts
+++ b/server/src/routes/agents.ts
@@ -67,6 +67,7 @@ import type { AdapterExecutionTarget } from "@paperclipai/adapter-utils/executio
 import type {
   AdapterEnvironmentCheck,
   AdapterEnvironmentTestResult,
+  AdapterModelProfileDefinition,
 } from "@paperclipai/adapter-utils";
 import { skillVersionSelectionMap } from "../services/runtime-skill-selections.js";
 import { secretService } from "../services/secrets.js";
@@ -104,6 +105,7 @@ import { recoveryService } from "../services/recovery/service.js";
 import { resolveCoreTrustPreset } from "../services/trust-preset-resolver.js";
 import { readObject } from "../lib/objects.js";
 import { listInvalidOrgChainDescendantIds } from "../services/agent-invokability.js";
+import { logger } from "../middleware/logger.js";
 import {
   AGENT_PROFILE_CHANGE_CONSENT_FIELDS,
   agentInstructionsChangeTargetKey,
@@ -1107,7 +1109,24 @@ export function agentRoutes(
     };
   }
 
-  function normalizeNewAgentRuntimeConfig(runtimeConfig: unknown): Record<string, unknown> {
+  async function listNewAgentAdapterModelProfiles(
+    adapterType: string,
+  ): Promise<AdapterModelProfileDefinition[]> {
+    try {
+      return await listAdapterModelProfiles(adapterType);
+    } catch (error) {
+      logger.warn(
+        { err: error, adapterType },
+        "Failed to discover adapter model profiles while normalizing a new agent; continuing without profile defaults",
+      );
+      return [];
+    }
+  }
+
+  async function normalizeNewAgentRuntimeConfig(
+    adapterType: string,
+    runtimeConfig: unknown,
+  ): Promise<Record<string, unknown>> {
     const parsedRuntimeConfig = asRecord(runtimeConfig);
     const normalizedRuntimeConfig = parsedRuntimeConfig ? { ...parsedRuntimeConfig } : {};
     const parsedHeartbeat = asRecord(normalizedRuntimeConfig.heartbeat);
@@ -1121,6 +1140,19 @@ export function agentRoutes(
     }
 
     normalizedRuntimeConfig.heartbeat = heartbeat;
+
+    const parsedModelProfiles = asRecord(normalizedRuntimeConfig.modelProfiles);
+    const modelProfiles = parsedModelProfiles ? { ...parsedModelProfiles } : {};
+    if (!Object.prototype.hasOwnProperty.call(modelProfiles, "cheap")) {
+      const adapterModelProfiles = await listNewAgentAdapterModelProfiles(adapterType);
+      if (adapterModelProfiles.some((profile) => profile.key === "cheap")) {
+        modelProfiles.cheap = { enabled: false };
+      }
+    }
+    if (Object.keys(modelProfiles).length > 0) {
+      normalizedRuntimeConfig.modelProfiles = modelProfiles;
+    }
+
     return normalizedRuntimeConfig;
   }
 
@@ -1191,7 +1223,7 @@ export function agentRoutes(
   ): Promise<Record<string, unknown>> {
     const entries = listRuntimeModelProfileAdapterConfigs(runtimeConfig);
     if (entries.length === 0) return runtimeConfig;
-    const adapterModelProfiles = await listAdapterModelProfiles(adapterType);
+    const adapterModelProfiles = await listNewAgentAdapterModelProfiles(adapterType);
 
     const normalizedRuntimeConfig = { ...runtimeConfig };
     const modelProfiles = asRecord(runtimeConfig.modelProfiles) ?? {};
@@ -2391,7 +2423,7 @@ export function agentRoutes(
     const normalizedRuntimeConfig = await normalizeRuntimeConfigAdapterConfigsForPersistence(
       companyId,
       hireInput.adapterType,
-      normalizeNewAgentRuntimeConfig(hireInput.runtimeConfig),
+      await normalizeNewAgentRuntimeConfig(hireInput.adapterType, hireInput.runtimeConfig),
       normalizedAdapterConfig,
     );
     const normalizedHireInput = {
@@ -2586,7 +2618,7 @@ export function agentRoutes(
     const normalizedRuntimeConfig = await normalizeRuntimeConfigAdapterConfigsForPersistence(
       companyId,
       createInput.adapterType,
-      normalizeNewAgentRuntimeConfig(createInput.runtimeConfig),
+      await normalizeNewAgentRuntimeConfig(createInput.adapterType, createInput.runtimeConfig),
       normalizedAdapterConfig,
     );
     await assertAgentEnvironmentSelection(companyId, createInput.adapterType, createInput.defaultEnvironmentId);
diff --git a/ui/src/lib/new-agent-runtime-config.test.ts b/ui/src/lib/new-agent-runtime-config.test.ts
index bbac8c6eb2..af33566268 100644
--- a/ui/src/lib/new-agent-runtime-config.test.ts
+++ b/ui/src/lib/new-agent-runtime-config.test.ts
@@ -58,6 +58,18 @@ describe("buildNewAgentRuntimeConfig", () => {
     expect(config.modelProfiles).toBeUndefined();
   });
 
+  it("persists explicit cheap-profile opt-in when using the adapter default", () => {
+    const config = buildNewAgentRuntimeConfig({
+      cheapModelEnabled: true,
+    });
+    expect(config.modelProfiles).toEqual({
+      cheap: {
+        enabled: true,
+        adapterConfig: {},
+      },
+    });
+  });
+
   it("omits modelProfiles when cheap model is set but explicitly disabled", () => {
     const config = buildNewAgentRuntimeConfig({
       cheapModel: "claude-sonnet-4-6",
diff --git a/ui/src/lib/new-agent-runtime-config.ts b/ui/src/lib/new-agent-runtime-config.ts
index 206a7797f8..c1376d81ad 100644
--- a/ui/src/lib/new-agent-runtime-config.ts
+++ b/ui/src/lib/new-agent-runtime-config.ts
@@ -20,11 +20,11 @@ export function buildNewAgentRuntimeConfig(input?: {
 
   const cheapModel = input?.cheapModel?.trim() ?? "";
   const cheapEnabled = input?.cheapModelEnabled ?? false;
-  if (cheapModel && cheapEnabled) {
+  if (cheapEnabled) {
     config.modelProfiles = {
       cheap: {
         enabled: true,
-        adapterConfig: { model: cheapModel },
+        adapterConfig: cheapModel ? { model: cheapModel } : {},
       },
     };
   }