diff --git a/infrastructure/web/api/routes/account.api.md b/infrastructure/web/api/routes/account.api.md
index 6d1214c..b46e730 100644
--- a/infrastructure/web/api/routes/account.api.md
+++ b/infrastructure/web/api/routes/account.api.md
@@ -7,13 +7,13 @@ Manage user accounts, forwarding emails, locked inboxes, and API tokens.
 
 ## Endpoints
 
-### GET `/api/account/`
+### GET `/api/v1/account/`
 Get account info and stats for the authenticated user.
 - **Auth:** Required
 - **Response:**
   - `userId`, `username`, `createdAt`, `lastLogin`, `verifiedEmails`, `lockedInboxes`, `apiToken`
 
-### POST `/api/account/verify-email`
+### POST `/api/v1/account/verify-email`
 Add a forwarding email (triggers verification).
 - **Auth:** Required
 - **Body:**
@@ -21,13 +21,13 @@ Add a forwarding email (triggers verification).
 - **Response:**
   - Success or error
 
-### DELETE `/api/account/verify-email/:id`
+### DELETE `/api/v1/account/verify-email/:id`
 Remove a forwarding email by ID.
 - **Auth:** Required
 - **Response:**
   - Success or error
 
-### POST `/api/account/change-password`
+### POST `/api/v1/account/change-password`
 Change account password.
 - **Auth:** Required
 - **Body:**
@@ -35,25 +35,25 @@ Change account password.
 - **Response:**
   - Success or error
 
-### DELETE `/api/account/`
+### DELETE `/api/v1/account/`
 Delete the user account.
 - **Auth:** Required
 - **Response:**
   - Success or error
 
-### GET `/api/account/token`
+### GET `/api/v1/account/token`
 Get API token info (not the token itself).
 - **Auth:** Required
 - **Response:**
   - `hasToken`, `createdAt`, `lastUsed`
 
-### POST `/api/account/token`
+### POST `/api/v1/account/token`
 Generate or regenerate API token.
 - **Auth:** Required
 - **Response:**
   - Success or error
 
-### DELETE `/api/account/token`
+### DELETE `/api/v1/account/token`
 Revoke API token.
 - **Auth:** Required
 - **Response:**
diff --git a/infrastructure/web/api/routes/auth.api.md b/infrastructure/web/api/routes/auth.api.md
index 5dbcf1a..88bdb7e 100644
--- a/infrastructure/web/api/routes/auth.api.md
+++ b/infrastructure/web/api/routes/auth.api.md
@@ -7,7 +7,7 @@ User registration, login, logout, and session management.
 
 ## Endpoints
 
-### POST `/api/auth/register`
+### POST `/api/v1/auth/register`
 Register a new user.
 - **Body:**
   - `username`: string (3-20 chars, alphanumeric/underscore)
@@ -17,7 +17,7 @@ Register a new user.
 - **Errors:**
   - `VALIDATION_ERROR`, `REGISTRATION_FAILED`, `AUTH_DISABLED`
 
-### POST `/api/auth/login`
+### POST `/api/v1/auth/login`
 Login user.
 - **Body:**
   - `username`, `password`
@@ -26,12 +26,12 @@ Login user.
 - **Errors:**
   - `VALIDATION_ERROR`, `AUTH_DISABLED`
 
-### POST `/api/auth/logout`
+### POST `/api/v1/auth/logout`
 Logout user.
 - **Response:**
   - Success or error
 
-### GET `/api/auth/session`
+### GET `/api/v1/auth/session`
 Get current session info.
 - **Response:**
   - `userId`, `username`, `isAuthenticated`, `createdAt`
diff --git a/infrastructure/web/api/routes/config.api.md b/infrastructure/web/api/routes/config.api.md
index 940b013..278443a 100644
--- a/infrastructure/web/api/routes/config.api.md
+++ b/infrastructure/web/api/routes/config.api.md
@@ -7,20 +7,20 @@ Public endpoints for configuration, domains, limits, and features.
 
 ## Endpoints
 
-### GET `/api/config/domains`
+### GET `/api/v1/config/domains`
 Get allowed email domains.
 - **Response:**
   - `domains`: array of strings
 
-### GET `/api/config/limits`
+### GET `/api/v1/config/limits`
 Get rate limits and constraints.
 - **Response:**
   - `api.rateLimit`, `email.purgeTime`, `email.purgeUnit`, `email.maxForwardedPerRequest`, `user.maxVerifiedEmails`, `user.maxLockedInboxes`, `user.lockReleaseHours`
 
-### GET `/api/config/features`
+### GET `/api/v1/config/features`
 Get enabled features.
 - **Response:**
-  - `authentication`, `forwarding`, `statistics`, `inboxLocking`
+  - `authentication`, `forwarding`, `statistics`
 
 ---
 
diff --git a/infrastructure/web/api/routes/inbox.api.md b/infrastructure/web/api/routes/inbox.api.md
index 0cf5e1e..0063c9f 100644
--- a/infrastructure/web/api/routes/inbox.api.md
+++ b/infrastructure/web/api/routes/inbox.api.md
@@ -7,13 +7,13 @@ Endpoints for listing emails, retrieving full/raw emails, and downloading attach
 
 ## Endpoints
 
-### GET `/api/inbox/:address`
+### GET `/api/v1/inbox/:address`
 List mail summaries for an inbox.
 - **Auth:** Optional
 - **Response:**
   - Array of mail summary objects
 
-### GET `/api/inbox/:address/:uid`
+### GET `/api/v1/inbox/:address/:uid`
 Get full email by UID.
 - **Auth:** Optional
 - **Response:**
@@ -21,7 +21,7 @@ Get full email by UID.
 - **Errors:**
   - `VALIDATION_ERROR`, `NOT_FOUND`
 
-### GET `/api/inbox/:address/:uid/raw`
+### GET `/api/v1/inbox/:address/:uid/raw`
 Get raw email source.
 - **Auth:** Optional
 - **Response:**
@@ -29,7 +29,7 @@ Get raw email source.
 - **Errors:**
   - `VALIDATION_ERROR`, `NOT_FOUND`
 
-### GET `/api/inbox/:address/:uid/attachment/:checksum`
+### GET `/api/v1/inbox/:address/:uid/attachment/:checksum`
 Download attachment by checksum.
 - **Auth:** Optional
 - **Response:**
diff --git a/infrastructure/web/api/routes/locks.api.md b/infrastructure/web/api/routes/locks.api.md
index 12c7ef8..904c243 100644
--- a/infrastructure/web/api/routes/locks.api.md
+++ b/infrastructure/web/api/routes/locks.api.md
@@ -7,7 +7,7 @@ APIs for managing locked inboxes for users. All responses include a `templateCon
 
 ## Endpoints
 
-### GET `/api/locks/`
+### GET `/api/v1/locks/`
 List all inboxes locked by the authenticated user.
 - **Auth:** Required
 - **Response:**
@@ -15,7 +15,7 @@ List all inboxes locked by the authenticated user.
   - `data`: array of locked inboxes
   - `templateContext`: `{ userId, config: { maxLockedInboxes } }`
 
-### POST `/api/locks/`
+### POST `/api/v1/locks/`
 Lock an inbox for the authenticated user.
 - **Auth:** Required
 - **Body:**
@@ -32,7 +32,7 @@ Lock an inbox for the authenticated user.
   - Locked by other: `LOCKED_BY_OTHER`
   - All errors include `templateContext`
 
-### DELETE `/api/locks/:address`
+### DELETE `/api/v1/locks/:address`
 Unlock/release a locked inbox.
 - **Auth:** Required
 - **Response:**
@@ -42,7 +42,7 @@ Unlock/release a locked inbox.
 - **Errors:**
   - Not found/unauthorized: `NOT_FOUND` (includes `templateContext`)
 
-### GET `/api/locks/:address/status`
+### GET `/api/v1/locks/:address/status`
 Check if an inbox is locked and if owned by the user.
 - **Auth:** Optional
 - **Response:**
diff --git a/infrastructure/web/api/routes/mail.api.md b/infrastructure/web/api/routes/mail.api.md
index fa20c2c..2c35919 100644
--- a/infrastructure/web/api/routes/mail.api.md
+++ b/infrastructure/web/api/routes/mail.api.md
@@ -7,7 +7,7 @@ Endpoints for deleting emails and forwarding mail.
 
 ## Endpoints
 
-### DELETE `/api/mail/inbox/:address/:uid`
+### DELETE `/api/v1/mail/inbox/:address/:uid`
 Delete a single email by UID.
 - **Auth:** Optional
 - **Response:**
@@ -15,7 +15,7 @@ Delete a single email by UID.
 - **Errors:**
   - `VALIDATION_ERROR`, `NOT_FOUND`
 
-### DELETE `/api/mail/inbox/:address`
+### DELETE `/api/v1/mail/inbox/:address`
 Delete all emails in an inbox (requires `?confirm=true`).
 - **Auth:** Optional
 - **Response:**
@@ -23,7 +23,7 @@ Delete all emails in an inbox (requires `?confirm=true`).
 - **Errors:**
   - `CONFIRMATION_REQUIRED`, `NOT_FOUND`
 
-### POST `/api/mail/forward`
+### POST `/api/v1/mail/forward`
 Forward a single email.
 - **Auth:** Required
 - **Body:**
@@ -33,7 +33,7 @@ Forward a single email.
 - **Errors:**
   - `VALIDATION_ERROR`, `NOT_FOUND`, `FORWARD_FAILED`
 
-### POST `/api/mail/forward-all`
+### POST `/api/v1/mail/forward-all`
 Forward all emails in an inbox.
 - **Auth:** Required
 - **Body:**
diff --git a/infrastructure/web/api/routes/stats.api.md b/infrastructure/web/api/routes/stats.api.md
index 07481ed..d01d51c 100644
--- a/infrastructure/web/api/routes/stats.api.md
+++ b/infrastructure/web/api/routes/stats.api.md
@@ -7,12 +7,12 @@ Endpoints for retrieving statistics and historical data.
 
 ## Endpoints
 
-### GET `/api/stats/`
+### GET `/api/v1/stats/`
 Get lightweight statistics (no historical analysis).
 - **Response:**
   - `currentCount`, `allTimeTotal`, `last24Hours` (object with `receives`, `deletes`, `forwards`, `timeline`)
 
-### GET `/api/stats/enhanced`
+### GET `/api/v1/stats/enhanced`
 Get full statistics with historical data and predictions.
 - **Response:**
   - `currentCount`, `allTimeTotal`, `last24Hours`, `historical`, `prediction`, `enhanced`
diff --git a/infrastructure/web/web.js b/infrastructure/web/web.js
index 7785676..559be3a 100644
--- a/infrastructure/web/web.js
+++ b/infrastructure/web/web.js
@@ -153,6 +153,18 @@ app.use((req, res, next) => {
     next()
 })
 
+// Redirect /api/* to /api/v1/* if version is missing
+app.use((req, res, next) => {
+    // Only match /api/ (not /api/v1/ or /api/v2/ etc.)
+    const apiMatch = req.path.match(/^\/api\/(?!v\d+\/)([^/?#]+)(.*)/)
+    if (apiMatch) {
+        // Redirect to latest stable version (v1)
+        const rest = apiMatch[1] + (apiMatch[2] || '')
+        return res.redirect(307, `/api/v1/${rest}`)
+    }
+    next()
+})
+
 // Mount API router (v1)
 app.use('/api/v1', (req, res, next) => {
     const apiTokenRepository = req.app.get('apiTokenRepository')