cli: Use the correct build command during deploys.

docs/reference/config.md

@@ -305,7 +305,7 @@ Custom names are used in the deploy manifest and in wrangler binding sync for lo
 
 #### `inference.build`
 
-Override the build command. Useful for frameworks with their own CLIs (Nuxt, Astro) or custom build scripts. If omitted, the CLI uses the framework's default build command.
+Override the build command. Useful for frameworks with their own CLIs (Nuxt, Astro) or static apps with custom build scripts. If omitted, the CLI uses the detected default build command for the current app type.
 
 ```json
 { "inference": { "build": "nuxt build --preset cloudflare-module" } }

packages/void/src/cli/deploy.ts

@@ -204,6 +204,14 @@ export async function runDeploy(root: string, options?: RunDeployOptions): Promi
   const gitCommit = options?.skipBuild ? null : getGitCommit(root);
 
   if (preset) {
+    preset = {
+      ...preset,
+      buildCommand: resolveStaticBuildCommand(
+        preset,
+        voidConfig.inference?.build,
+        Boolean(options?.dir),
+      ),
+    };
     await runStaticDeploy(
       root,
       config,
@@ -220,6 +228,15 @@ export async function runDeploy(root: string, options?: RunDeployOptions): Promi
   }
 }
 
+export function resolveStaticBuildCommand(
+  preset: StaticPreset,
+  buildOverride?: string,
+  hasExplicitDir = false,
+): string | null {
+  if (hasExplicitDir) return null;
+  return buildOverride ?? preset.buildCommand;
+}
+
 async function streamDeploy(
   client: PlatformClient,
   projectId: string,

packages/void/src/cli/preset.ts

@@ -189,8 +189,9 @@ export function detectPreset(
 
   // 4. Vite/Vite+ in deps → static SPA
   if (pkg && hasViteLike(pkg)) {
+    const buildCommand = resolveProjectScriptCommand(root, "build");
     return {
-      buildCommand: resolveProjectCommand(root, "vite build"),
+      buildCommand: buildCommand ?? resolveProjectCommand(root, "vite build"),
       outputDir: resolve(root, "dist"),
       appType: "spa",
     };
@@ -247,6 +248,31 @@ function getAllDeps(pkg: Record<string, unknown>): Record<string, string> {
   };
 }
 
+function detectPackageManager(root: string): "pnpm" | "yarn" | "bun" | "npm" {
+  if (existsSync(join(root, "pnpm-lock.yaml"))) return "pnpm";
+  if (existsSync(join(root, "yarn.lock"))) return "yarn";
+  if (existsSync(join(root, "bun.lock")) || existsSync(join(root, "bun.lockb"))) return "bun";
+  return "npm";
+}
+
+function resolveProjectScriptCommand(root: string, scriptName: string): string | null {
+  const pkg = readPackageJson(root);
+  const script = pkg?.scripts;
+  if (!script || typeof script !== "object" || Array.isArray(script)) return null;
+  if (typeof (script as Record<string, unknown>)[scriptName] !== "string") return null;
+
+  switch (detectPackageManager(root)) {
+    case "pnpm":
+      return `pnpm ${scriptName}`;
+    case "yarn":
+      return `yarn ${scriptName}`;
+    case "bun":
+      return `bun run ${scriptName}`;
+    default:
+      return `npm run ${scriptName}`;
+  }
+}
+
 function hasViteLike(pkg: Record<string, unknown>): boolean {
   const deps = getAllDeps(pkg);
   return "vite" in deps || "vite-plus" in deps;

packages/void/test/unit/deploy-project.test.ts

@@ -2,7 +2,11 @@ import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { afterEach, describe, expect, it } from "vitest";
-import { resolveDistDir, resolveWorkerDirName } from "../../src/cli/deploy";
+import {
+  resolveDistDir,
+  resolveStaticBuildCommand,
+  resolveWorkerDirName,
+} from "../../src/cli/deploy";
 import { FRAMEWORK_PRESETS } from "../../src/cli/preset";
 import {
   getRequestedProjectSlug,
@@ -144,6 +148,35 @@ describe("resolveDistDir", () => {
   });
 });
 
+describe("resolveStaticBuildCommand", () => {
+  it("uses inference.build when provided", () => {
+    expect(
+      resolveStaticBuildCommand(
+        {
+          buildCommand: "vite build",
+          outputDir: "/tmp/dist",
+          appType: "static",
+        },
+        "pnpm build",
+      ),
+    ).toBe("pnpm build");
+  });
+
+  it("keeps explicit --dir deploys buildless even when inference.build is set", () => {
+    expect(
+      resolveStaticBuildCommand(
+        {
+          buildCommand: null,
+          outputDir: "/tmp/dist",
+          appType: "static",
+        },
+        "pnpm build",
+        true,
+      ),
+    ).toBeNull();
+  });
+});
+
 describe("resolveWorkerDirName", () => {
   afterEach(() => {
     while (tempDirs.length > 0) {

packages/void/test/unit/preset.test.ts

@@ -148,6 +148,22 @@ describe("detectPreset", () => {
     });
   });
 
+  it("prefers the project build script for plain Vite SPAs", () => {
+    const root = setupProject({
+      pkg: {
+        dependencies: { vite: "^6.0.0" },
+        scripts: { build: "vite build && node scripts/postbuild.js" },
+      },
+      files: { "pnpm-lock.yaml": "lockfileVersion: '9.0'\n" },
+    });
+    const result = detectPreset(root);
+    expect(result).toEqual({
+      buildCommand: "pnpm build",
+      outputDir: resolve(root, "dist"),
+      appType: "spa",
+    });
+  });
+
   it("detects Vite+ SPA (no backend files)", () => {
     const root = setupProject({
       pkg: { devDependencies: { "vite-plus": "^1.0.0" } },