diff --git a/http/static.md b/http/static.md
index 19a3e1a..ee42bc2 100644
--- a/http/static.md
+++ b/http/static.md
@@ -1,10 +1,11 @@
 # HTTP — Serving static content
 
-The `static` HTTP middleware serves static content using RoadRunner on the main HTTP plugin endpoint. Using this middleware
-can slow down the overall performance by up to `~10%`, because RoadRunner has to check the path for each file request.
+The `static` HTTP middleware serves static content using RoadRunner on the main HTTP plugin endpoint.
+
+To avoid a filesystem lookup on every request, the middleware caches file metadata and misses in memory with a short TTL (`10s` by default). A repeated request for the same path is then answered without touching the filesystem, so the overhead of enabling the middleware stays small. The cache trades a few seconds of staleness for that speed: a file added, changed, or removed on disk is picked up within one TTL. Set the TTLs to `0s` to check the filesystem on every request, or run `rr reset static` to flush the cache at once (for example, after a deploy).
 
 {% hint style="info" %}
-If there is no file to serve, RR will redirect the request back to the PHP worker.
+If there is no file to serve, RR forwards the request back to the PHP worker. Only `GET` and `HEAD` requests are served; every other method goes to the worker.
 {% endhint %}
 
 ## Enable HTTP middleware
@@ -26,6 +27,15 @@ http:
     calculate_etag: false
     weak: false
     allow: [ ".txt", ".php" ]
+    # Serve only request paths that start with one of these prefixes.
+    # Empty (the default) considers every request.
+    prefixes: [ "/assets/", "/build/" ]
+    # File metadata cache TTL. "0s" disables it. Default: 10s.
+    cache_ttl: 10s
+    # Miss cache TTL. "0s" disables it. Default: 10s.
+    cache_miss_ttl: 10s
+    # Maximum entries kept in each cache map. Default: 16384.
+    cache_max_entries: 16384
     request:
       input: "custom-header"
     response:
@@ -40,8 +50,12 @@ Where:
 2. `forbid`: file extensions that should not be served.
 3. `allow`: extensions that should be served (empty = serve all except forbidden). If an extension is present in both lists (allow and forbid), it is treated as forbidden.
 4. `calculate_etag`: enable etag calculation for the static file.
-5. `weak`: use a weak generator (/W); it uses only the filename to generate a CRC32 sum. If false, the entire file content is used to generate the CRC32 sum.
-6. `request/response`: custom headers for the static files.
+5. `weak`: use a weak generator (`W/`). The weak etag is derived from the file size and modification time. If false, the whole file content is used to produce a strong CRC32 etag.
+6. `prefixes`: restrict serving to request paths that start with one of these prefixes. When empty (the default), every path is considered. A path that matches no prefix goes to the worker without a filesystem lookup. The match is a plain prefix, so include the trailing slash (`/assets/`) to scope it to a directory.
+7. `cache_ttl`: TTL for the file metadata cache (etag, content type, size, modification time). Active only when `calculate_etag` is enabled. `0s` disables it. Default: `10s`.
+8. `cache_miss_ttl`: TTL for the miss cache. A request whose path does not resolve to a file records a miss and skips the filesystem check for this duration, which removes the per-request lookup on dynamic routes that share the URL space with static files. `0s` disables it. Default: `10s`.
+9. `cache_max_entries`: upper bound on the number of entries in each cache map (metadata and miss). When a map is full, expired entries are evicted; if none can be freed, the middleware checks the filesystem instead. Default: `16384`.
+10. `request/response`: custom headers for the static files.
 
 To combine static content with other middleware, use the following sequence (static last, then headers and gzip):
 
@@ -81,9 +95,7 @@ http:
 ## Fileserver plugin
 
 The Fileserver plugin serves static files. It works similarly to the `static` HTTP middleware and has extended functionality.
-Static HTTP middleware slows down request processing by `~10%` because RR has to check each request for the
-corresponding file.
-The file server plugin uses a different port and serves only static files.
+The `static` middleware runs on the main HTTP endpoint, while the file server plugin uses a different port and serves only static files.
 
 ## File server configuration