diff --git a/packages/core/src/common/model-capabilities.ts b/packages/core/src/common/model-capabilities.ts
index 4835bfe3..1fac7028 100644
--- a/packages/core/src/common/model-capabilities.ts
+++ b/packages/core/src/common/model-capabilities.ts
@@ -1,8 +1,9 @@
-export const DEEPSEEK_V4_MODELS = new Set(["deepseek-v4-flash", "deepseek-v4-pro"]);
+export const DEEPSEEK_V4_MODELS = new Set(["deepseek-v4-flash", "deepseek-v4-pro", "deepseek-ai/deepseek-v4-pro"]);
 
 export const NON_MULTIMODAL_MODELS = new Set([
   "deepseek-v4-pro",
   "deepseek-v4-flash",
+  "deepseek-ai/deepseek-v4-pro",
   "deepseek-chat",
   "deepseek-reasoner",
 ]);
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index d389348c..e7d4c5d8 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -18,6 +18,8 @@ export {
   getDefaultAutoCompactWindow,
   DEFAULT_MODEL,
   DEFAULT_BASE_URL,
+  ATLASCLOUD_DEFAULT_MODEL,
+  ATLASCLOUD_BASE_URL,
 } from "./settings";
 export type {
   DeepcodingSettings,
diff --git a/packages/core/src/settings.ts b/packages/core/src/settings.ts
index da0e2d94..4c5b500f 100644
--- a/packages/core/src/settings.ts
+++ b/packages/core/src/settings.ts
@@ -518,6 +518,9 @@ export function resolveSettingsSources(
     ...projectEnv,
     ...systemEnv,
   };
+  const explicitApiKey = trimString(env.API_KEY);
+  const atlasCloudApiKey = trimString(processEnv.ATLASCLOUD_API_KEY);
+  const useAtlasCloudDefaults = !explicitApiKey && Boolean(atlasCloudApiKey);
 
   const model =
     trimString(systemEnv.MODEL) ||
@@ -525,6 +528,7 @@ export function resolveSettingsSources(
     trimString(projectEnv.MODEL) ||
     trimString(userSettings?.model) ||
     trimString(userEnv.MODEL) ||
+    (useAtlasCloudDefaults ? ATLASCLOUD_DEFAULT_MODEL : "") ||
     defaults.model;
 
   const contextWindow =
@@ -587,8 +591,8 @@ export function resolveSettingsSources(
 
   return {
     env,
-    apiKey: trimString(env.API_KEY) || undefined,
-    baseURL: trimString(env.BASE_URL) || defaults.baseURL,
+    apiKey: explicitApiKey || atlasCloudApiKey || undefined,
+    baseURL: trimString(env.BASE_URL) || (useAtlasCloudDefaults ? ATLASCLOUD_BASE_URL : defaults.baseURL),
     model,
     contextWindow,
     autoCompactWindow,
@@ -650,6 +654,8 @@ export function applyModelConfigSelection(
 
 export const DEFAULT_MODEL = "deepseek-v4-pro";
 export const DEFAULT_BASE_URL = "https://api.deepseek.com";
+export const ATLASCLOUD_DEFAULT_MODEL = "deepseek-ai/deepseek-v4-pro";
+export const ATLASCLOUD_BASE_URL = "https://api.atlascloud.ai/v1";
 
 // ---------------------------------------------------------------------------
 // Settings file I/O
diff --git a/packages/core/src/tests/settings-and-notify.test.ts b/packages/core/src/tests/settings-and-notify.test.ts
index 93e8dc29..57e3e090 100644
--- a/packages/core/src/tests/settings-and-notify.test.ts
+++ b/packages/core/src/tests/settings-and-notify.test.ts
@@ -62,6 +62,47 @@ test("resolveSettings gives top-level model priority over env MODEL", () => {
   assert.equal(resolved.model, "deepseek-v4-flash");
 });
 
+test("resolveSettings uses Atlas Cloud defaults with ATLASCLOUD_API_KEY", () => {
+  const resolved = resolveSettings(
+    {},
+    {
+      model: "default-model",
+      baseURL: "https://default.example.com",
+    },
+    {
+      ATLASCLOUD_API_KEY: "atlas-test-key",
+    }
+  );
+
+  assert.equal(resolved.apiKey, "atlas-test-key");
+  assert.equal(resolved.baseURL, "https://api.atlascloud.ai/v1");
+  assert.equal(resolved.model, "deepseek-ai/deepseek-v4-pro");
+  assert.equal(resolved.thinkingEnabled, true);
+});
+
+test("resolveSettings gives explicit API settings priority over Atlas Cloud defaults", () => {
+  const resolved = resolveSettings(
+    {
+      env: {
+        API_KEY: "explicit-key",
+        BASE_URL: "https://explicit.example.com/v1",
+        MODEL: "explicit-model",
+      },
+    },
+    {
+      model: "default-model",
+      baseURL: "https://default.example.com",
+    },
+    {
+      ATLASCLOUD_API_KEY: "atlas-test-key",
+    }
+  );
+
+  assert.equal(resolved.apiKey, "explicit-key");
+  assert.equal(resolved.baseURL, "https://explicit.example.com/v1");
+  assert.equal(resolved.model, "explicit-model");
+});
+
 test("resolveSettings derives model-specific context window defaults", () => {
   const regular = resolveSettings(
     {},