diff --git a/custom.css b/custom.css
index 3a0922b..2d1049b 100644
--- a/custom.css
+++ b/custom.css
@@ -130,19 +130,6 @@ div.nav-tabs :not(a[data-active="true"]) {
   border-radius: 8px;
 }
 
-/* ── Buttons (primary) ─────────────────────────────────────────────────────── */
-button[class*='primary'],
-a[class*='button'][class*='primary'] {
-  background-color: var(--df-primary);
-  color: #fff;
-  border-radius: 6px;
-}
-
-button[class*='primary']:hover,
-a[class*='button'][class*='primary']:hover {
-  background-color: var(--df-navy);
-}
-
 /* ── Tables ────────────────────────────────────────────────────────────────── */
 thead {
   background-color: var(--df-sidebar);
diff --git a/index.mdx b/index.mdx
index 65cfbfd..c751930 100644
--- a/index.mdx
+++ b/index.mdx
@@ -73,7 +73,7 @@ Each API uses a different subdomain pattern:
 | Category Merchandising | `https://{zone}-category-merchandising.doofinder.com` |
 
 <Note>
-  Your search zone is shown in the [Doofinder Admin Panel](https://admin.doofinder.com). All Search API keys are zone-prefixed (e.g. `eu1-ab46030x...`).
+  Your search zone is shown in the [Doofinder Admin Panel](https://admin.doofinder.com). The zone prefix on API keys (e.g. `eu1-ab46030x...`) is optional — the zone is determined by the hostname you call.
 </Note>
 
 ## Authentication at a Glance
diff --git a/introduction/authentication.mdx b/introduction/authentication.mdx
index a70190b..96607e9 100644
--- a/introduction/authentication.mdx
+++ b/introduction/authentication.mdx
@@ -13,27 +13,16 @@ Generate an API key in the [Doofinder Admin Panel](https://admin.doofinder.com/a
   Only the API key of the **account owner** is valid for API operations. Keys generated by team members will not work.
 </Warning>
 
-### Search API: zone-prefixed format
+### Key format
 
-When calling the Search API, prepend your zone to the key:
+The same key works across all APIs. You may see it written with a zone prefix (e.g. `eu1-ab46030x...`) — this prefix is optional and ignored by the API. Both formats are valid:
 
 ```
-eu1-ab46030xza33960aac71a10248489b6c26172f07
+eu1-ab46030xza33960aac71a10248489b6c26172f07   ← zone prefix included (optional)
+ab46030xza33960aac71a10248489b6c26172f07        ← no prefix (also valid)
 ```
 
-The prefix (`eu1`, `us1`, `ap1`) routes the request to the correct datacenter.
-
-<Warning>
-  Always use the prefix that matches your search engine's zone. Using a mismatched zone prefix will result in authentication errors.
-</Warning>
-
-### Management & Stats API: unprefixed format
-
-When calling the Management or Stats API, use the key without a zone prefix:
-
-```
-ab46030xza33960aac71a10248489b6c26172f07
-```
+The zone that serves your request is determined by the **hostname** you call, not by the key.
 
 ---
 
diff --git a/introduction/errors.mdx b/introduction/errors.mdx
index 66bb936..ce7636d 100644
--- a/introduction/errors.mdx
+++ b/introduction/errors.mdx
@@ -56,7 +56,7 @@ The request is missing an `Authorization` header, or the provided API key is inv
 **Common causes:**
 - No `Authorization` header sent
 - API key has been revoked or does not exist
-- Wrong key format (e.g. missing the zone prefix for the Search API, or including it for the Management API)
+- Wrong key format (e.g. using a JWT token where a plain token is expected)
 
 ---
 
diff --git a/search-api/overview.mdx b/search-api/overview.mdx
index f10de9a..8d2a881 100644
--- a/search-api/overview.mdx
+++ b/search-api/overview.mdx
@@ -21,7 +21,7 @@ Replace `{search_zone}` with your zone (`eu1`, `us1`, `ap1`).
 
 ## Authentication
 
-The Search API uses zone-prefixed API keys:
+The Search API uses the standard Doofinder API key. The zone prefix is optional:
 
 ```http
 Authorization: Token eu1-ab46030xza33960aac71a10248489b6c26172f07