diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3d7f15f..9e24466 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,6 +21,7 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: "22"
+          registry-url: https://registry.npmjs.org
           cache: npm
 
       - name: Install dependencies
diff --git a/package-lock.json b/package-lock.json
index ce39a1d..182f6dc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@carboncode/cli",
-  "version": "0.1.2",
+  "version": "0.1.5",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@carboncode/cli",
-      "version": "0.1.2",
+      "version": "0.1.5",
       "license": "MIT",
       "dependencies": {
         "cli-highlight": "^2.1.11",
@@ -2225,7 +2225,7 @@
     },
     "node_modules/@types/ws": {
       "version": "8.18.1",
-      "resolved": "https://registry.npmmirror.com/@types/ws/-/ws-8.18.1.tgz",
+      "resolved": "https://registry.npmjs.org/@types/ws/-/ws-8.18.1.tgz",
       "integrity": "sha512-ThVF6DCVhA8kUGy+aazFQ4kXQ7E1Ty7A3ypFOe0IcJV8O/M511G99AW24irKrW56Wt44yG9+ij8FaqoBGkuBXg==",
       "dev": true,
       "license": "MIT",
@@ -6891,7 +6891,7 @@
     },
     "node_modules/ws": {
       "version": "8.20.1",
-      "resolved": "https://registry.npmmirror.com/ws/-/ws-8.20.1.tgz",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-8.20.1.tgz",
       "integrity": "sha512-It4dO0K5v//JtTXuPkfEOaI3uUN87iYPnqo/ZzqCoG3g8uhA66QUMs/SrM0YK7/NAu+r4LMh/9dq2A7k+rHs+w==",
       "license": "MIT",
       "engines": {
diff --git a/package.json b/package.json
index 4aeaec7..7be76a3 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@carboncode/cli",
-  "version": "0.1.2",
+  "version": "0.1.5",
   "description": "Chinese-first DeepSeek-powered terminal coding agent for personal developer workflows.",
   "type": "module",
   "bin": {
diff --git a/src/cli/index.ts b/src/cli/index.ts
index 92b72a3..7403643 100644
--- a/src/cli/index.ts
+++ b/src/cli/index.ts
@@ -90,23 +90,25 @@ function resolveDashboardPort(
     : undefined;
 }
 
-/** Resolution order: flag → REASONIX_DASHBOARD_HOST env → config.dashboard.host → undefined (server defaults to 127.0.0.1). */
+/** Resolution order: flag → CARBONCODE_DASHBOARD_HOST env → legacy REASONIX_DASHBOARD_HOST env → config.dashboard.host → undefined (server defaults to 127.0.0.1). */
 function resolveDashboardHost(
   flagValue: string | undefined,
   noConfig: boolean,
 ): string | undefined {
   const fromFlag = flagValue?.trim();
   if (fromFlag) return fromFlag;
-  const fromEnv = process.env.REASONIX_DASHBOARD_HOST?.trim();
+  const fromEnv =
+    process.env.CARBONCODE_DASHBOARD_HOST?.trim() ?? process.env.REASONIX_DASHBOARD_HOST?.trim();
   if (fromEnv) return fromEnv;
   if (noConfig) return undefined;
   const fromCfg = readConfig().dashboard?.host;
   return typeof fromCfg === "string" && fromCfg.trim() ? fromCfg.trim() : undefined;
 }
 
-/** Resolution order: REASONIX_DASHBOARD_TOKEN env → config.dashboard.token → undefined (server mints a fresh per-boot token). Min 16 chars; shorter values are dropped with a warning to avoid trivially-guessable tokens. */
+/** Resolution order: CARBONCODE_DASHBOARD_TOKEN env → legacy REASONIX_DASHBOARD_TOKEN env → config.dashboard.token → undefined (server mints a fresh per-boot token). Min 16 chars; shorter values are dropped with a warning to avoid trivially-guessable tokens. */
 function resolveDashboardToken(noConfig: boolean): string | undefined {
-  const fromEnv = process.env.REASONIX_DASHBOARD_TOKEN?.trim();
+  const fromEnv =
+    process.env.CARBONCODE_DASHBOARD_TOKEN?.trim() ?? process.env.REASONIX_DASHBOARD_TOKEN?.trim();
   const fromCfg = noConfig ? undefined : readConfig().dashboard?.token?.trim();
   const candidate = fromEnv || fromCfg;
   if (!candidate) return undefined;
diff --git a/src/cli/startup-profile.ts b/src/cli/startup-profile.ts
index df3d0c4..31cd070 100644
--- a/src/cli/startup-profile.ts
+++ b/src/cli/startup-profile.ts
@@ -9,7 +9,7 @@ const marks: PhaseMark[] = [];
 let dumped = false;
 
 function envFlag(): boolean {
-  const v = process.env.REASONIX_PROFILE_STARTUP;
+  const v = process.env.CARBONCODE_PROFILE_STARTUP ?? process.env.REASONIX_PROFILE_STARTUP;
   return v === "1" || v === "true" || v === "yes";
 }
 
@@ -36,7 +36,7 @@ export function dumpStartupProfile(stream: NodeJS.WriteStream = process.stderr):
     prev = m.t;
   }
   lines.push(
-    `─── ${Math.round(totalMs)}ms total · last phase ${marks[marks.length - 1]!.name} · set REASONIX_PROFILE_STARTUP=0 to silence`,
+    `─── ${Math.round(totalMs)}ms total · last phase ${marks[marks.length - 1]!.name} · set CARBONCODE_PROFILE_STARTUP=0 to silence`,
   );
   stream.write(`${lines.join("\n")}\n`);
 }
diff --git a/src/cli/ui/App.tsx b/src/cli/ui/App.tsx
index 4261884..6f5cb7e 100644
--- a/src/cli/ui/App.tsx
+++ b/src/cli/ui/App.tsx
@@ -294,10 +294,10 @@ export interface AppProps {
  * Throttle interval in ms. 50ms —20Hz —slow enough that cursor-up
  * repaints on winpty/MINTTY/ConEmu/tmux don't leave half-drawn frames,
  * fast enough that streaming text still reads as continuous. Override
- * via `REASONIX_FLUSH_MS` if you want 60Hz on a terminal you trust.
+ * via `CARBONCODE_FLUSH_MS` if you want 60Hz on a terminal you trust.
  */
 const FLUSH_INTERVAL_MS = (() => {
-  const raw = process.env.REASONIX_FLUSH_MS;
+  const raw = process.env.CARBONCODE_FLUSH_MS ?? process.env.REASONIX_FLUSH_MS;
   if (!raw) return 50;
   const parsed = Number(raw);
   if (!Number.isFinite(parsed) || parsed < 16 || parsed > 1000) return 50;
@@ -393,7 +393,7 @@ export function App(props: AppProps): React.ReactElement {
     [props.session],
   );
   const [themeName, setThemeName] = React.useState<ThemeName>(() =>
-    resolveThemePreference(loadTheme(), process.env.REASONIX_THEME),
+    resolveThemePreference(loadTheme(), process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME),
   );
   const statusBar = React.useMemo((): StatusBarConfig => {
     const cfg = readConfig().statusBar ?? {};
@@ -2535,7 +2535,10 @@ function AppInner({
   const handleQQThemePick = useCallback(
     (target: ThemeChoice): string => {
       saveTheme(target);
-      const active = resolveThemePreference(target, process.env.REASONIX_THEME);
+      const active = resolveThemePreference(
+        target,
+        process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
+      );
       setThemeName(active);
       return `theme saved: ${target}\nactive now: ${active}`;
     },
@@ -4282,7 +4285,7 @@ function AppInner({
                       saveTheme(outcome.value);
                       const active = resolveThemePreference(
                         outcome.value,
-                        process.env.REASONIX_THEME,
+                        process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
                       );
                       setThemeName(active);
                       log.pushInfo(`theme saved: ${outcome.value}\n  active now: ${active}`);
diff --git a/src/cli/ui/Wizard.tsx b/src/cli/ui/Wizard.tsx
index 9706f8b..459c163 100644
--- a/src/cli/ui/Wizard.tsx
+++ b/src/cli/ui/Wizard.tsx
@@ -94,13 +94,19 @@ export function Wizard({
   useEffect(() => onLanguageChange(() => setLanguageVersion((v) => v + 1)), []);
 
   const [previewTheme, setPreviewTheme] = useState<ThemeName>(() =>
-    resolveThemePreference(initial?.theme ?? loadTheme(), process.env.REASONIX_THEME),
+    resolveThemePreference(
+      initial?.theme ?? loadTheme(),
+      process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
+    ),
   );
 
   const [step, setStep] = useState<Step>("language");
   const [data, setData] = useState<WizardData>(() => ({
     language: getLanguage(),
-    theme: resolveThemePreference(initial?.theme ?? loadTheme(), process.env.REASONIX_THEME),
+    theme: resolveThemePreference(
+      initial?.theme ?? loadTheme(),
+      process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
+    ),
     apiKey: existingApiKey ?? "",
     preset: initial?.preset ?? "auto",
     selectedCatalog: deriveInitialCatalog(initial?.mcp ?? []),
diff --git a/src/cli/ui/open-url.ts b/src/cli/ui/open-url.ts
index 6185624..9e4d7e3 100644
--- a/src/cli/ui/open-url.ts
+++ b/src/cli/ui/open-url.ts
@@ -1,4 +1,4 @@
-/** Cross-platform URL opener; no-op under CI / when REASONIX_NO_OPEN is set. */
+/** Cross-platform URL opener; no-op under CI / when CARBONCODE_NO_OPEN or legacy REASONIX_NO_OPEN is set. */
 
 import { spawn } from "node:child_process";
 import { platform } from "node:os";
@@ -10,7 +10,9 @@ export interface OpenUrlResult {
 
 export function openUrl(url: string): OpenUrlResult {
   if (process.env.CI) return { opened: false, reason: "ci" };
-  if (process.env.REASONIX_NO_OPEN) return { opened: false, reason: "disabled" };
+  if (process.env.CARBONCODE_NO_OPEN ?? process.env.REASONIX_NO_OPEN) {
+    return { opened: false, reason: "disabled" };
+  }
 
   const os = platform();
   let cmd: string;
diff --git a/src/cli/ui/slash/handlers/observability.ts b/src/cli/ui/slash/handlers/observability.ts
index c28cb0f..3b26ac3 100644
--- a/src/cli/ui/slash/handlers/observability.ts
+++ b/src/cli/ui/slash/handlers/observability.ts
@@ -230,7 +230,10 @@ function estimateCost(userText: string, loop: import("@/loop.js").CacheFirstLoop
 }
 
 const feedback: SlashHandler = (_args, loop, ctx) => {
-  const themeName = resolveThemePreference(loadTheme(), process.env.REASONIX_THEME);
+  const themeName = resolveThemePreference(
+    loadTheme(),
+    process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
+  );
   const diagnostic = buildFeedbackDiagnostic({
     version: VERSION,
     latestVersion: ctx.latestVersion ?? undefined,
diff --git a/src/cli/ui/slash/handlers/theme.ts b/src/cli/ui/slash/handlers/theme.ts
index ed519af..a81402c 100644
--- a/src/cli/ui/slash/handlers/theme.ts
+++ b/src/cli/ui/slash/handlers/theme.ts
@@ -17,7 +17,10 @@ const theme: SlashHandler = (args) => {
   }
 
   saveTheme(next);
-  const active = resolveThemePreference(next, process.env.REASONIX_THEME);
+  const active = resolveThemePreference(
+    next,
+    process.env.CARBONCODE_THEME ?? process.env.REASONIX_THEME,
+  );
   return { info: `theme saved: ${next}\nactive on next launch: ${active}` };
 };
 
diff --git a/src/i18n/EN.ts b/src/i18n/EN.ts
index 0ac9539..4fb77d0 100644
--- a/src/i18n/EN.ts
+++ b/src/i18n/EN.ts
@@ -487,7 +487,7 @@ export const EN: TranslationSchema = {
     footer: "↑↓ pick · ⏎ confirm · esc cancel",
     currentPref: "current preference",
     activeNow: "active now",
-    autoDesc: "use REASONIX_THEME or default",
+    autoDesc: "use CARBONCODE_THEME or default",
   },
   planFlow: {
     approveCardTitle: "Approve plan",
diff --git a/src/i18n/zh-CN.ts b/src/i18n/zh-CN.ts
index 7afc2e3..a38f6f5 100644
--- a/src/i18n/zh-CN.ts
+++ b/src/i18n/zh-CN.ts
@@ -473,7 +473,7 @@ export const zhCN: TranslationSchema = {
     footer: "↑↓ 选择 · ⏎ 确认 · Esc 取消",
     currentPref: "当前偏好",
     activeNow: "当前生效",
-    autoDesc: "使用 REASONIX_THEME 或默认主题",
+    autoDesc: "使用 CARBONCODE_THEME 或默认主题",
   },
   planFlow: {
     approveCardTitle: "确认计划",
diff --git a/src/server/api/health.ts b/src/server/api/health.ts
index 6583d11..d43fcea 100644
--- a/src/server/api/health.ts
+++ b/src/server/api/health.ts
@@ -1,9 +1,7 @@
 import { existsSync, readdirSync, statSync } from "node:fs";
-import { homedir } from "node:os";
 import { join } from "node:path";
-import { listSessions } from "../../memory/session.js";
 import { VERSION } from "../../version.js";
-import type { DashboardContext } from "../context.js";
+import { type DashboardContext, resolveCarboncodeHome } from "../context.js";
 import type { ApiResult } from "../router.js";
 
 interface DirStat {
@@ -56,6 +54,17 @@ function dirSize(path: string): DirStat {
   return { path, exists: true, fileCount, totalBytes };
 }
 
+function countSessionFiles(path: string): number {
+  if (!existsSync(path)) return 0;
+  try {
+    return readdirSync(path).filter(
+      (file) => file.endsWith(".jsonl") && !file.endsWith(".events.jsonl"),
+    ).length;
+  } catch {
+    return 0;
+  }
+}
+
 export async function handleHealth(
   method: string,
   _rest: string[],
@@ -65,8 +74,7 @@ export async function handleHealth(
   if (method !== "GET") {
     return { status: 405, body: { error: "GET only" } };
   }
-  const home = homedir();
-  const carboncodeHome = join(home, ".carboncode");
+  const carboncodeHome = resolveCarboncodeHome(ctx.configPath);
 
   const sessionsStat = dirSize(join(carboncodeHome, "sessions"));
   const memoryStat = dirSize(join(carboncodeHome, "memory"));
@@ -81,8 +89,6 @@ export async function handleHealth(
     }
   }
 
-  const sessions = listSessions();
-
   return {
     status: 200,
     body: {
@@ -91,7 +97,7 @@ export async function handleHealth(
       carboncodeHome,
       sessions: {
         path: sessionsStat.path,
-        count: sessions.length,
+        count: countSessionFiles(sessionsStat.path),
         totalBytes: sessionsStat.totalBytes,
       },
       memory: {
diff --git a/src/server/api/memory.ts b/src/server/api/memory.ts
index e244ce5..28871d0 100644
--- a/src/server/api/memory.ts
+++ b/src/server/api/memory.ts
@@ -10,26 +10,25 @@ import {
   unlinkSync,
   writeFileSync,
 } from "node:fs";
-import { homedir } from "node:os";
 import { basename, dirname, join, resolve as resolvePath } from "node:path";
 import {
   PROJECT_MEMORY_FILE,
   findProjectMemoryPath,
   resolveProjectMemoryWritePath,
 } from "../../memory/project.js";
-import type { DashboardContext } from "../context.js";
+import { type DashboardContext, resolveCarboncodeHome } from "../context.js";
 import type { ApiResult } from "../router.js";
 
 function projectHash(rootDir: string): string {
   return createHash("sha1").update(resolvePath(rootDir)).digest("hex").slice(0, 16);
 }
 
-function globalMemoryDir(): string {
-  return join(homedir(), ".carboncode", "memory", "global");
+function globalMemoryDir(carboncodeHome: string): string {
+  return join(carboncodeHome, "memory", "global");
 }
 
-function projectMemoryDir(rootDir: string): string {
-  return join(homedir(), ".carboncode", "memory", projectHash(rootDir));
+function projectMemoryDir(carboncodeHome: string, rootDir: string): string {
+  return join(carboncodeHome, "memory", projectHash(rootDir));
 }
 
 interface WriteBody {
@@ -74,8 +73,9 @@ export async function handleMemory(
   ctx: DashboardContext,
 ): Promise<ApiResult> {
   const cwd = ctx.getCurrentCwd?.();
-  const globalDir = globalMemoryDir();
-  const projectMemDir = cwd ? projectMemoryDir(cwd) : "";
+  const carboncodeHome = resolveCarboncodeHome(ctx.configPath);
+  const globalDir = globalMemoryDir(carboncodeHome);
+  const projectMemDir = cwd ? projectMemoryDir(carboncodeHome, cwd) : "";
 
   if (method === "GET" && rest.length === 0) {
     const existingProjectMemory = cwd ? findProjectMemoryPath(cwd) : null;
diff --git a/src/server/context.ts b/src/server/context.ts
index 83fa7c8..50faefa 100644
--- a/src/server/context.ts
+++ b/src/server/context.ts
@@ -1,11 +1,20 @@
 /** Callbacks (not refs) so endpoints read live loop state per request, not a frozen closure. */
 
+import { homedir } from "node:os";
+import { basename, dirname, join } from "node:path";
 import type { McpServerSummary } from "../cli/ui/slash/types.js";
 import type { EditMode } from "../config.js";
 import type { CacheFirstLoop } from "../loop.js";
 import type { ToolRegistry } from "../tools.js";
 import type { JobRegistry } from "../tools/jobs.js";
 
+export function resolveCarboncodeHome(configPath: string): string {
+  if (!configPath.trim()) return join(homedir(), ".carboncode");
+  const configDir = dirname(configPath);
+  if (basename(configDir).toLowerCase() === ".carboncode") return configDir;
+  return join(configDir, ".carboncode");
+}
+
 export interface DashboardContext {
   /** Caller resolves via `defaultConfigPath()`; module deliberately avoids `homedir()` so tests can redirect. */
   configPath: string;
diff --git a/tests/cli-bare-routing.test.ts b/tests/cli-bare-routing.test.ts
index 8c99a98..9556d7f 100644
--- a/tests/cli-bare-routing.test.ts
+++ b/tests/cli-bare-routing.test.ts
@@ -6,6 +6,7 @@ import { join } from "node:path";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { writeConfig } from "../src/config.js";
 
+const HEAP_REEXEC_ENV = "REASONIX_HEAP_REEXEC";
 const codeCommand = vi.fn(async () => {});
 const chatCommand = vi.fn(async () => {});
 const setupCommand = vi.fn(async () => {});
@@ -25,6 +26,7 @@ describe("bare CLI routing", () => {
   let cwd: string;
   const origHome = process.env.HOME;
   const origUserProfile = process.env.USERPROFILE;
+  const origHeapReexec = process.env[HEAP_REEXEC_ENV];
   const origArgv = process.argv;
   const origCwd = process.cwd();
   let stderr: ReturnType<typeof vi.spyOn>;
@@ -38,6 +40,7 @@ describe("bare CLI routing", () => {
     cwd = realpathSync(mkdtempSync(join(tmpdir(), "carboncode-cli-cwd-")));
     process.env.HOME = home;
     process.env.USERPROFILE = home;
+    process.env[HEAP_REEXEC_ENV] = "1";
     process.chdir(cwd);
     codeCommand.mockClear();
     chatCommand.mockClear();
@@ -63,6 +66,11 @@ describe("bare CLI routing", () => {
     } else {
       process.env.USERPROFILE = origUserProfile;
     }
+    if (origHeapReexec === undefined) {
+      delete process.env[HEAP_REEXEC_ENV];
+    } else {
+      process.env[HEAP_REEXEC_ENV] = origHeapReexec;
+    }
   });
 
   it("routes bare carboncode to code mode rooted at cwd", async () => {
diff --git a/tests/helpers/codex-parity-harness.ts b/tests/helpers/codex-parity-harness.ts
index 67e127c..2bb03c6 100644
--- a/tests/helpers/codex-parity-harness.ts
+++ b/tests/helpers/codex-parity-harness.ts
@@ -139,6 +139,7 @@ function runCommand(
     const child = spawn(command, [...args], {
       cwd,
       env: { ...process.env, CI: "1" },
+      shell: process.platform === "win32",
       stdio: ["ignore", "pipe", "pipe"],
     });
     const chunks: Buffer[] = [];
diff --git a/tests/open-url.test.ts b/tests/open-url.test.ts
new file mode 100644
index 0000000..4182e9b
--- /dev/null
+++ b/tests/open-url.test.ts
@@ -0,0 +1,40 @@
+import { afterEach, describe, expect, it } from "vitest";
+import { openUrl } from "../src/cli/ui/open-url.js";
+
+describe("openUrl", () => {
+  const originalCi = process.env.CI;
+  const originalCarbonNoOpen = process.env.CARBONCODE_NO_OPEN;
+  const originalReasonixNoOpen = process.env.REASONIX_NO_OPEN;
+
+  afterEach(() => {
+    if (originalCi === undefined) Reflect.deleteProperty(process.env, "CI");
+    else process.env.CI = originalCi;
+    if (originalCarbonNoOpen === undefined)
+      Reflect.deleteProperty(process.env, "CARBONCODE_NO_OPEN");
+    else process.env.CARBONCODE_NO_OPEN = originalCarbonNoOpen;
+    if (originalReasonixNoOpen === undefined)
+      Reflect.deleteProperty(process.env, "REASONIX_NO_OPEN");
+    else process.env.REASONIX_NO_OPEN = originalReasonixNoOpen;
+  });
+
+  it("does not open URLs in CI", () => {
+    process.env.CI = "1";
+
+    expect(openUrl("https://example.com")).toEqual({ opened: false, reason: "ci" });
+  });
+
+  it("respects CARBONCODE_NO_OPEN", () => {
+    Reflect.deleteProperty(process.env, "CI");
+    process.env.CARBONCODE_NO_OPEN = "1";
+
+    expect(openUrl("https://example.com")).toEqual({ opened: false, reason: "disabled" });
+  });
+
+  it("keeps legacy REASONIX_NO_OPEN compatibility", () => {
+    Reflect.deleteProperty(process.env, "CI");
+    Reflect.deleteProperty(process.env, "CARBONCODE_NO_OPEN");
+    process.env.REASONIX_NO_OPEN = "1";
+
+    expect(openUrl("https://example.com")).toEqual({ opened: false, reason: "disabled" });
+  });
+});
diff --git a/tests/slash.test.ts b/tests/slash.test.ts
index 135865b..4b45045 100644
--- a/tests/slash.test.ts
+++ b/tests/slash.test.ts
@@ -1231,21 +1231,29 @@ describe("handleSlash", () => {
     let tempHome: string;
     let originalHome: string | undefined;
     let originalUserProfile: string | undefined;
+    let originalCarbonTheme: string | undefined;
     let originalTheme: string | undefined;
 
     beforeEach(() => {
       tempHome = mkdtempSync(join(tmpdir(), "reasonix-theme-slash-"));
       originalHome = process.env.HOME;
       originalUserProfile = process.env.USERPROFILE;
+      originalCarbonTheme = process.env.CARBONCODE_THEME;
       originalTheme = process.env.REASONIX_THEME;
       process.env.HOME = tempHome;
       process.env.USERPROFILE = tempHome;
+      process.env.CARBONCODE_THEME = "github-dark";
       process.env.REASONIX_THEME = "github-dark";
     });
 
     afterEach(() => {
       process.env.HOME = originalHome;
       process.env.USERPROFILE = originalUserProfile;
+      if (originalCarbonTheme === undefined) {
+        process.env.CARBONCODE_THEME = undefined;
+      } else {
+        process.env.CARBONCODE_THEME = originalCarbonTheme;
+      }
       if (originalTheme === undefined) {
         process.env.REASONIX_THEME = undefined;
       } else {
@@ -1273,6 +1281,16 @@ describe("handleSlash", () => {
       expect(loadTheme()).toBe("auto");
     });
 
+    it("prefers CARBONCODE_THEME over legacy REASONIX_THEME", () => {
+      process.env.CARBONCODE_THEME = "tokyo-night";
+      process.env.REASONIX_THEME = "github-light";
+
+      const r = handleSlash("theme", ["auto"], makeLoop());
+
+      expect(r.info).toMatch(/active on next launch: tokyo-night/);
+      expect(loadTheme()).toBe("auto");
+    });
+
     it("rejects unknown theme names", () => {
       const r = handleSlash("theme", ["solarized"], makeLoop());
       expect(r.info).toMatch(/unknown theme: solarized/);
diff --git a/tests/startup-profile.test.ts b/tests/startup-profile.test.ts
index e78c17e..82ea12c 100644
--- a/tests/startup-profile.test.ts
+++ b/tests/startup-profile.test.ts
@@ -19,19 +19,25 @@ function makeSink(): { stream: NodeJS.WriteStream; output: () => string } {
 }
 
 describe("startup-profile", () => {
-  const original = process.env.REASONIX_PROFILE_STARTUP;
+  const originalCarbon = process.env.CARBONCODE_PROFILE_STARTUP;
+  const originalReasonix = process.env.REASONIX_PROFILE_STARTUP;
 
   beforeEach(() => {
     _resetForTests();
   });
 
   afterEach(() => {
-    if (original === undefined) Reflect.deleteProperty(process.env, "REASONIX_PROFILE_STARTUP");
-    else process.env.REASONIX_PROFILE_STARTUP = original;
+    if (originalCarbon === undefined)
+      Reflect.deleteProperty(process.env, "CARBONCODE_PROFILE_STARTUP");
+    else process.env.CARBONCODE_PROFILE_STARTUP = originalCarbon;
+    if (originalReasonix === undefined)
+      Reflect.deleteProperty(process.env, "REASONIX_PROFILE_STARTUP");
+    else process.env.REASONIX_PROFILE_STARTUP = originalReasonix;
     _resetForTests();
   });
 
   it("is disabled by default — markPhase + dumpStartupProfile are no-ops", () => {
+    Reflect.deleteProperty(process.env, "CARBONCODE_PROFILE_STARTUP");
     Reflect.deleteProperty(process.env, "REASONIX_PROFILE_STARTUP");
     expect(isStartupProfileEnabled()).toBe(false);
     markPhase("a");
@@ -43,15 +49,24 @@ describe("startup-profile", () => {
 
   it("recognizes 1 / true / yes as enable values", () => {
     for (const v of ["1", "true", "yes"]) {
-      process.env.REASONIX_PROFILE_STARTUP = v;
+      process.env.CARBONCODE_PROFILE_STARTUP = v;
       expect(isStartupProfileEnabled()).toBe(true);
     }
-    process.env.REASONIX_PROFILE_STARTUP = "0";
+    process.env.CARBONCODE_PROFILE_STARTUP = "0";
     expect(isStartupProfileEnabled()).toBe(false);
   });
 
-  it("emits a formatted profile when enabled, with cumulative + delta per phase", () => {
+  it("prefers CARBONCODE_PROFILE_STARTUP over legacy REASONIX_PROFILE_STARTUP", () => {
+    process.env.CARBONCODE_PROFILE_STARTUP = "0";
     process.env.REASONIX_PROFILE_STARTUP = "1";
+    expect(isStartupProfileEnabled()).toBe(false);
+
+    Reflect.deleteProperty(process.env, "CARBONCODE_PROFILE_STARTUP");
+    expect(isStartupProfileEnabled()).toBe(true);
+  });
+
+  it("emits a formatted profile when enabled, with cumulative + delta per phase", () => {
+    process.env.CARBONCODE_PROFILE_STARTUP = "1";
     markPhase("first");
     markPhase("second");
     markPhase("third");
@@ -64,10 +79,11 @@ describe("startup-profile", () => {
     expect(out).toContain("third");
     expect(out).toMatch(/total/);
     expect(out).toMatch(/last phase third/);
+    expect(out).toContain("CARBONCODE_PROFILE_STARTUP=0");
   });
 
   it("dumpStartupProfile is idempotent — second call is silent", () => {
-    process.env.REASONIX_PROFILE_STARTUP = "1";
+    process.env.CARBONCODE_PROFILE_STARTUP = "1";
     markPhase("only");
     const sink1 = makeSink();
     dumpStartupProfile(sink1.stream);
@@ -80,14 +96,14 @@ describe("startup-profile", () => {
   });
 
   it("emits nothing when enabled but no phases were marked", () => {
-    process.env.REASONIX_PROFILE_STARTUP = "1";
+    process.env.CARBONCODE_PROFILE_STARTUP = "1";
     const sink = makeSink();
     dumpStartupProfile(sink.stream);
     expect(sink.output()).toBe("");
   });
 
   it("each line shows ms + phase name + (+delta) suffix", () => {
-    process.env.REASONIX_PROFILE_STARTUP = "1";
+    process.env.CARBONCODE_PROFILE_STARTUP = "1";
     markPhase("alpha");
     markPhase("beta");
     const sink = makeSink();