mitchmac · mitchmac · Apr 23, 2026 · Apr 23, 2026 · May 6, 2026 · May 8, 2026
diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
@@ -14,4 +14,7 @@ jobs:
         working-directory: ./test
 
       - run: ./run-s3-test.sh
+        working-directory: ./test
+
+      - run: ./run-blob-test.sh
         working-directory: ./test
diff --git a/api/index.js b/api/index.js
@@ -7,89 +7,85 @@ const sandbox = require('../util/sandbox.js');
 const readOnly = require('../util/readOnly.js');
 
 const pathToWP = '/tmp/wp';
-let initSqliteS3 = false;
+const wpContentPath = pathToWP + '/wp-content';
+const sqlitePluginPath = wpContentPath + '/plugins/sqlite-database-integration';
 
-// Move the /wp directory to /tmp/wp so that it is writeable.
-setup();
-
-// This is where all requests to WordPress are routed through.
-// See vercel.json or netlify.toml for the redirection rules.
-exports.handler = async function (event, context, callback) {
-    if ((process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']) && !initSqliteS3) {
-        let wpContentPath = pathToWP + '/wp-content';
-        let sqlitePluginPath = wpContentPath + '/plugins/sqlite-database-integration';
-        await sqliteS3.prepPlugin(wpContentPath, sqlitePluginPath);
-
-        let branchSlug = '';
-        let bucketFallback = '';
-
-        // Vercel
-        if (process.env['VERCEL']) {
-            const branch = sqliteS3.branchNameToS3file(process.env['VERCEL_GIT_COMMIT_REF']);
-            branchSlug = branch ? '-' + branch : '';
-            bucketFallback = process.env['VERCEL_PROJECT_ID'];
-        }
+const hasSqliteS3 = !!(process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']);
+const readOnlyActive = !!process.env['SERVERLESSWP_READ_ONLY_MODE']
+    && !['false', '0', 'no'].includes(process.env['SERVERLESSWP_READ_ONLY_MODE'].toLowerCase());
 
-        // Configure the sqliteS3 plugin.
-        let sqliteS3Config = {
-            bucket: process.env['SQLITE_S3_BUCKET'] || bucketFallback,
-            file:`wp-sqlite-s3${branchSlug}.sqlite`,
-            S3Client: {
-                credentials: {
-                    "accessKeyId": process.env['SQLITE_S3_API_KEY'] || process.env['VERCEL_PROJECT_ID'],
-                    "secretAccessKey": process.env['SQLITE_S3_API_SECRET'] || process.env['SERVERLESSWP_DATA_SECRET']
-                },
-                region: process.env['SQLITE_S3_REGION'],
-            }
-        };
+let sqliteSelection = null;
+let initDone = false;
 
-        if (process.env['SQLITE_S3_ENDPOINT']) {
-            sqliteS3Config.S3Client.endpoint = process.env['SQLITE_S3_ENDPOINT'];
+function buildSqliteS3Config(overrides = {}) {
+    const config = {
+        bucket: overrides.bucket || process.env['SQLITE_S3_BUCKET'],
+        file: overrides.file || 'wp-sqlite-s3.sqlite',
+        S3Client: {
+            credentials: {
+                accessKeyId: overrides.accessKeyId || process.env['SQLITE_S3_API_KEY'],
+                secretAccessKey: process.env['SQLITE_S3_API_SECRET'] || process.env['SERVERLESSWP_DATA_SECRET'],
+            },
+            region: process.env['SQLITE_S3_REGION'],
         }
+    };
 
-        if (process.env['SQLITE_S3_FORCE_PATH_STYLE'] || process.env['SERVERLESSWP_DATA_SECRET']) {
-            sqliteS3Config.S3Client.forcePathStyle = true;
-        }
-
-        if (process.env['SERVERLESSWP_DATA_SECRET']) {
-            sqliteS3Config.S3Client.endpoint = 'https://data.serverlesswp.com';
-            sqliteS3Config.onAuthError = () => sandbox.register(
-                sqliteS3Config.bucket,
-                process.env['SERVERLESSWP_DATA_SECRET']
-            );
-        }
-
-        sqliteS3.config(sqliteS3Config);
-        initSqliteS3 = true;
+    if (process.env['SQLITE_S3_ENDPOINT']) {
+        config.S3Client.endpoint = process.env['SQLITE_S3_ENDPOINT'];
     }
 
-    // Send the request (event object) to the serverlesswp library.
-    // It includes the PHP server that allows WordPress to handle the request.
-    let response = await serverlesswp({docRoot: pathToWP, event: event});
-
-    // Check to see if the database environment variables are in place.
-    let checkInstall = validate(response);
-
-    if (checkInstall) {
-        return checkInstall;
+    if (process.env['SQLITE_S3_FORCE_PATH_STYLE'] || process.env['SERVERLESSWP_DATA_SECRET']) {
+        config.S3Client.forcePathStyle = true;
     }
-    else {
-        // Return the response for serving.
-        return response;
+
+    if (process.env['SERVERLESSWP_DATA_SECRET']) {
+        config.S3Client.endpoint = 'https://data.serverlesswp.com';
+        config.onAuthError = () => sandbox.register(config.bucket, process.env['SERVERLESSWP_DATA_SECRET']);
     }
-}
 
-if (process.env['SERVERLESSWP_READ_ONLY_MODE'] && !['false', '0', 'no'].includes(process.env['SERVERLESSWP_READ_ONLY_MODE'].toLowerCase())) {
-    // Register before sqliteS3 so blocked requests force a response before the S3 fetch.
-    serverlesswp.registerPlugin(readOnly);
+    return config;
 }
 
-if (process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']) {
-    // Register the sqlite serverlesswp plugin.
-    serverlesswp.registerPlugin(sqliteS3);
+// Platform entry points (api/vercel.js) may call this before the first request
+// to override which sqlite plugin gets used or pass a platform-tuned config.
+function useSqlitePlugin(plugin, config) {
+    sqliteSelection = { plugin, config };
 }
 
-if (process.env['SERVERLESSWP_DATA_SECRET']) {
-    // Register the sandbox widget plugin.
-    serverlesswp.registerPlugin(sandbox);
+exports.useSqlitePlugin = useSqlitePlugin;
+exports.buildSqliteS3Config = buildSqliteS3Config;
+
+// Default: use sqliteS3 when its env vars are present.
+if (hasSqliteS3) {
+    useSqlitePlugin(sqliteS3, buildSqliteS3Config());
 }
+
+// Move the /wp directory to /tmp/wp so that it is writeable.
+setup();
+
+// This is where all requests to WordPress are routed through.
+// See netlify.toml or serverless.yml for the redirection rules.
+// On Vercel, requests come through api/vercel.js which then calls this handler.
+exports.handler = async function (event, context, callback) {
+    if (!initDone) {
+        // Register readOnly first so blocked mutations short-circuit before the
+        // sqlite plugin tries to hit storage.
+        if (readOnlyActive) {
+            serverlesswp.registerPlugin(readOnly);
+        }
+        if (sqliteSelection) {
+            const { plugin, config } = sqliteSelection;
+            await plugin.prepPlugin(wpContentPath, sqlitePluginPath);
+            plugin.config(config);
+            serverlesswp.registerPlugin(plugin);
+        }
+        if (process.env['SERVERLESSWP_DATA_SECRET']) {
+            serverlesswp.registerPlugin(sandbox);
+        }
+        initDone = true;
+    }
+
+    const response = await serverlesswp({ docRoot: pathToWP, event: event });
+    const checkInstall = validate(response);
+    return checkInstall || response;
+};
diff --git a/api/vercel.js b/api/vercel.js
@@ -1,98 +1,37 @@
-const serverlesswp = require('serverlesswp');
+// Vercel-specific entry point. Adds Vercel Blob as a storage option and
+// layers VERCEL_* env var fallbacks onto the SQLite + S3 config, then delegates
+// to the core handler in api/index.js.
 
-const { validate } = require('../util/install.js');
-const { setup } = require('../util/directory.js');
+const core = require('./index.js');
 const sqliteS3 = require('../util/sqliteS3.js');
-const sandbox = require('../util/sandbox.js');
-const readOnly = require('../util/readOnly.js');
+const sqliteVercelBlob = require('../util/sqliteVercelBlob.js');
 
-const pathToWP = '/tmp/wp';
-let initSqliteS3 = false;
+const hasSqliteS3 = !!(process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']);
+const useVercelBlob = !!process.env['BLOB_READ_WRITE_TOKEN'] && !hasSqliteS3;
 
-// Move the /wp directory to /tmp/wp so that it is writeable.
-setup();
-
-// This is where all requests to WordPress are routed through.
-// See vercel.json or netlify.toml for the redirection rules.
-async function handler(event, context, callback) {
-    if ((process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']) && !initSqliteS3) {
-        let wpContentPath = pathToWP + '/wp-content';
-        let sqlitePluginPath = wpContentPath + '/plugins/sqlite-database-integration';
-        await sqliteS3.prepPlugin(wpContentPath, sqlitePluginPath);
-
-        let branchSlug = '';
-        let bucketFallback = '';
-
-        // Vercel
-        if (process.env['VERCEL']) {
-            const branch = sqliteS3.branchNameToS3file(process.env['VERCEL_GIT_COMMIT_REF']);
-            branchSlug = branch ? '-' + branch : '';
-            bucketFallback = process.env['VERCEL_PROJECT_ID'];
-        }
-
-        // Configure the sqliteS3 plugin.
-        let sqliteS3Config = {
-            bucket: process.env['SQLITE_S3_BUCKET'] || bucketFallback,
-            file:`wp-sqlite-s3${branchSlug}.sqlite`,
-            S3Client: {
-                credentials: {
-                    "accessKeyId": process.env['SQLITE_S3_API_KEY'] || process.env['VERCEL_PROJECT_ID'],
-                    "secretAccessKey": process.env['SQLITE_S3_API_SECRET'] || process.env['SERVERLESSWP_DATA_SECRET']
-                },
-                region: process.env['SQLITE_S3_REGION'],
-            }
-        };
-
-        if (process.env['SQLITE_S3_ENDPOINT']) {
-            sqliteS3Config.S3Client.endpoint = process.env['SQLITE_S3_ENDPOINT'];
-        }
-
-        if (process.env['SQLITE_S3_FORCE_PATH_STYLE'] || process.env['SERVERLESSWP_DATA_SECRET']) {
-            sqliteS3Config.S3Client.forcePathStyle = true;
-        }
-
-        if (process.env['SERVERLESSWP_DATA_SECRET']) {
-            sqliteS3Config.S3Client.endpoint = 'https://data.serverlesswp.com';
-            sqliteS3Config.onAuthError = () => sandbox.register(
-                sqliteS3Config.bucket,
-                process.env['SERVERLESSWP_DATA_SECRET']
-            );
-        }
-
-        sqliteS3.config(sqliteS3Config);
-        initSqliteS3 = true;
+// Encode the current Vercel git branch so each branch gets its own database.
+function branchSlug() {
+    if (process.env['VERCEL_GIT_COMMIT_REF']) {
+        const branch = encodeURIComponent(process.env['VERCEL_GIT_COMMIT_REF']);
+        return branch ? '-' + branch : '';
     }
-
-    // Send the request (event object) to the serverlesswp library.
-    // It includes the PHP server that allows WordPress to handle the request.
-    let response = await serverlesswp({docRoot: pathToWP, event: event});
-
-    // Check to see if the database environment variables are in place.
-    let checkInstall = validate(response);
-
-    if (checkInstall) {
-        return checkInstall;
-    }
-    else {
-        // Return the response for serving.
-        return response;
-    }
-}
-
-if (process.env['SERVERLESSWP_READ_ONLY_MODE'] && !['false', '0', 'no'].includes(process.env['SERVERLESSWP_READ_ONLY_MODE'].toLowerCase())) {
-    // Register before sqliteS3 so blocked requests force a response before the S3 fetch.
-    serverlesswp.registerPlugin(readOnly);
-}
-
-if (process.env['SQLITE_S3_BUCKET'] || process.env['SERVERLESSWP_DATA_SECRET']) {
-    // Register the sqlite serverlesswp plugin.
-    serverlesswp.registerPlugin(sqliteS3);
+    return '';
 }
 
-if (process.env['SERVERLESSWP_DATA_SECRET']) {
-    // Register the sandbox widget plugin.
-    serverlesswp.registerPlugin(sandbox);
+if (hasSqliteS3) {
+    // Re-configure the S3 plugin with Vercel-aware overrides: the sandbox flow
+    // uses VERCEL_PROJECT_ID as the bucket name and the API key fallback, and
+    // branch-aware filenames keep preview deploys isolated.
+    core.useSqlitePlugin(sqliteS3, core.buildSqliteS3Config({
+        bucket: process.env['SQLITE_S3_BUCKET'] || process.env['VERCEL_PROJECT_ID'],
+        file: `wp-sqlite-s3${branchSlug()}.sqlite`,
+        accessKeyId: process.env['SQLITE_S3_API_KEY'] || process.env['VERCEL_PROJECT_ID'],
+    }));
+} else if (useVercelBlob) {
+    core.useSqlitePlugin(sqliteVercelBlob, {
+        pathname: `wp-sqlite${branchSlug()}.sqlite`,
+    });
 }
 
-module.exports = handler;
-module.exports.handler = handler;
+module.exports = core.handler;
+module.exports.handler = core.handler;
diff --git a/package.json b/package.json
@@ -5,6 +5,7 @@
   "license": "MIT",
   "dependencies": {
     "@aws-sdk/client-s3": "^3.772.0",
+    "@vercel/blob": "^2.3.3",
     "serverlesswp": "^0.5.1",
     "sqlite3": "^5.1.7"
   },

diff --git a/test/Dockerfile-blob b/test/Dockerfile-blob
@@ -0,0 +1,13 @@
+FROM public.ecr.aws/lambda/nodejs:22
+
+COPY package.json ${LAMBDA_TASK_ROOT}/
+RUN npm install --omit=optional --omit=dev
+
+COPY api/ ${LAMBDA_TASK_ROOT}/api/
+COPY util/ ${LAMBDA_TASK_ROOT}/util/
+COPY wp/ ${LAMBDA_TASK_ROOT}/wp/
+COPY test/installer.php ${LAMBDA_TASK_ROOT}/wp/
+COPY test/vercel-blob-emulator/undici-patch.js ${LAMBDA_TASK_ROOT}/blob-test/undici-patch.js
+COPY test/vercel-blob-emulator/handler.js ${LAMBDA_TASK_ROOT}/blob-test/handler.js
+
+CMD [ "blob-test/handler.handler" ]