diff --git a/sx/sx/layouts.sx b/sx/sx/layouts.sx
index 0cc5f2b..e2c6917 100644
--- a/sx/sx/layouts.sx
+++ b/sx/sx/layouts.sx
@@ -12,7 +12,7 @@
            (dict :label "Protocols" :href "/protocols/wire-format")
            (dict :label "Examples" :href "/examples/click-to-load")
            (dict :label "Essays" :href "/essays/sx-sucks")
-           (dict :label "Specs" :href "/specs/core"))))
+           (dict :label "Specs" :href "/specs/"))))
     (<> (map (lambda (item)
       (~nav-link
         :href (get item "href")
diff --git a/sx/sx/nav-data.sx b/sx/sx/nav-data.sx
index 162d746..0f61bd8 100644
--- a/sx/sx/nav-data.sx
+++ b/sx/sx/nav-data.sx
@@ -68,11 +68,17 @@
   (dict :label "The Reflexive Web" :href "/essays/reflexive-web")))
 
 (define specs-nav-items (list
+  (dict :label "Architecture" :href "/specs/")
   (dict :label "Core" :href "/specs/core")
   (dict :label "Parser" :href "/specs/parser")
   (dict :label "Evaluator" :href "/specs/evaluator")
   (dict :label "Primitives" :href "/specs/primitives")
-  (dict :label "Renderer" :href "/specs/renderer")))
+  (dict :label "Renderer" :href "/specs/renderer")
+  (dict :label "Adapters" :href "/specs/adapters")
+  (dict :label "DOM Adapter" :href "/specs/adapter-dom")
+  (dict :label "HTML Adapter" :href "/specs/adapter-html")
+  (dict :label "SX Wire Adapter" :href "/specs/adapter-sx")
+  (dict :label "SxEngine" :href "/specs/engine")))
 
 ;; Find the current nav label for a slug by matching href suffix.
 ;; Returns the label string or nil if no match.
diff --git a/sx/sx/specs.sx b/sx/sx/specs.sx
index 6e83467..4f8bb8b 100644
--- a/sx/sx/specs.sx
+++ b/sx/sx/specs.sx
@@ -1,9 +1,157 @@
 ;; Spec viewer components — display canonical SX specification source
 
-(defcomp ~spec-core-content (&key spec-files)
-  (~doc-page :title "SX Core Specification"
+;; ---------------------------------------------------------------------------
+;; Architecture intro page
+;; ---------------------------------------------------------------------------
+
+(defcomp ~spec-architecture-content ()
+  (~doc-page :title "Spec Architecture"
+    (div :class "space-y-8"
+
+      (div :class "space-y-4"
+        (p :class "text-lg text-stone-600"
+          "SX is defined in SX. The canonical specification is a set of s-expression files that are both documentation and executable definition. Bootstrap compilers read these files to generate native implementations in JavaScript, Python, Rust, or any other target.")
+        (p :class "text-stone-600"
+          "The spec is split into two layers: a "
+          (strong "core") " that defines the language itself, and "
+          (strong "adapters") " that connect it to specific environments."))
+
+      (div :class "space-y-3"
+        (h2 :class "text-2xl font-semibold text-stone-800" "Core")
+        (p :class "text-stone-600"
+          "The core is platform-independent. It defines how SX source is parsed, how expressions are evaluated, what primitives exist, and what shared rendering definitions all adapters use. These four files are the language.")
+        (div :class "overflow-x-auto rounded border border-stone-200"
+          (table :class "w-full text-left text-sm"
+            (thead (tr :class "border-b border-stone-200 bg-stone-100"
+              (th :class "px-3 py-2 font-medium text-stone-600" "File")
+              (th :class "px-3 py-2 font-medium text-stone-600" "Role")))
+            (tbody
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/parser" :class "hover:underline"
+                     :sx-get "/specs/parser" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "parser.sx"))
+                (td :class "px-3 py-2 text-stone-700" "Tokenization and parsing of SX source text into AST"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/evaluator" :class "hover:underline"
+                     :sx-get "/specs/evaluator" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "eval.sx"))
+                (td :class "px-3 py-2 text-stone-700" "Tree-walking evaluation of SX expressions"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/primitives" :class "hover:underline"
+                     :sx-get "/specs/primitives" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "primitives.sx"))
+                (td :class "px-3 py-2 text-stone-700" "All built-in pure functions and their signatures"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/renderer" :class "hover:underline"
+                     :sx-get "/specs/renderer" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "render.sx"))
+                (td :class "px-3 py-2 text-stone-700" "Shared rendering registries and utilities used by all adapters"))))))
+
+      (div :class "space-y-3"
+        (h2 :class "text-2xl font-semibold text-stone-800" "Adapters")
+        (p :class "text-stone-600"
+          "Adapters are selectable rendering backends. Each one takes the same evaluated expression tree and produces output for a specific environment. You only need the adapters relevant to your target.")
+        (div :class "overflow-x-auto rounded border border-stone-200"
+          (table :class "w-full text-left text-sm"
+            (thead (tr :class "border-b border-stone-200 bg-stone-100"
+              (th :class "px-3 py-2 font-medium text-stone-600" "File")
+              (th :class "px-3 py-2 font-medium text-stone-600" "Output")
+              (th :class "px-3 py-2 font-medium text-stone-600" "Environment")))
+            (tbody
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/adapter-dom" :class "hover:underline"
+                     :sx-get "/specs/adapter-dom" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "adapter-dom.sx"))
+                (td :class "px-3 py-2 text-stone-700" "Live DOM nodes")
+                (td :class "px-3 py-2 text-stone-500" "Browser"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/adapter-html" :class "hover:underline"
+                     :sx-get "/specs/adapter-html" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "adapter-html.sx"))
+                (td :class "px-3 py-2 text-stone-700" "HTML strings")
+                (td :class "px-3 py-2 text-stone-500" "Server"))
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/adapter-sx" :class "hover:underline"
+                     :sx-get "/specs/adapter-sx" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "adapter-sx.sx"))
+                (td :class "px-3 py-2 text-stone-700" "SX wire format")
+                (td :class "px-3 py-2 text-stone-500" "Server to client"))))))
+
+      (div :class "space-y-3"
+        (h2 :class "text-2xl font-semibold text-stone-800" "Engine")
+        (p :class "text-stone-600"
+          "The engine is the browser-side fetch/swap/history system. It processes "
+          (code :class "text-violet-700 text-sm" "sx-*")
+          " attributes on elements to make HTTP requests, swap content, manage browser history, and handle events. It depends on the core evaluator and the DOM adapter.")
+        (div :class "overflow-x-auto rounded border border-stone-200"
+          (table :class "w-full text-left text-sm"
+            (thead (tr :class "border-b border-stone-200 bg-stone-100"
+              (th :class "px-3 py-2 font-medium text-stone-600" "File")
+              (th :class "px-3 py-2 font-medium text-stone-600" "Role")))
+            (tbody
+              (tr :class "border-b border-stone-100"
+                (td :class "px-3 py-2 font-mono text-sm text-violet-700"
+                  (a :href "/specs/engine" :class "hover:underline"
+                     :sx-get "/specs/engine" :sx-target "#main-panel" :sx-select "#main-panel"
+                     :sx-swap "outerHTML" :sx-push-url "true"
+                     "engine.sx"))
+                (td :class "px-3 py-2 text-stone-700" "SxEngine — fetch, swap, history, SSE, triggers, indicators"))))))
+
+      (div :class "space-y-3"
+        (h2 :class "text-2xl font-semibold text-stone-800" "Dependency graph")
+        (div :class "bg-stone-100 rounded-lg p-5 mx-auto max-w-3xl"
+          (pre :class "text-sm leading-relaxed whitespace-pre-wrap break-words font-mono text-stone-700"
+"parser.sx          (standalone — no dependencies)
+primitives.sx       (standalone — declarative registry)
+eval.sx             depends on: parser, primitives
+render.sx           (standalone — shared registries)
+
+adapter-dom.sx      depends on: render, eval
+adapter-html.sx     depends on: render, eval
+adapter-sx.sx       depends on: render, eval
+
+engine.sx           depends on: eval, adapter-dom")))
+
+      (div :class "space-y-3"
+        (h2 :class "text-2xl font-semibold text-stone-800" "Self-hosting")
+        (p :class "text-stone-600"
+          "Every spec file is written in the same restricted subset of SX that the evaluator itself defines. A bootstrap compiler for a new target only needs to understand this subset — roughly 20 special forms and 80 primitives — to generate a fully native implementation. The spec files are the single source of truth; implementations are derived artifacts.")
+        (p :class "text-stone-600"
+          "This is not a theoretical exercise. The JavaScript implementation ("
+          (code :class "text-violet-700 text-sm" "sx.js")
+          ") and the Python implementation ("
+          (code :class "text-violet-700 text-sm" "shared/sx/")
+          ") are both generated from these spec files via "
+          (code :class "text-violet-700 text-sm" "bootstrap_js.py")
+          " and its Python counterpart.")))))
+
+;; ---------------------------------------------------------------------------
+;; Overview pages (Core / Adapters) — show truncated previews of each file
+;; ---------------------------------------------------------------------------
+
+(defcomp ~spec-overview-content (&key spec-files)
+  (~doc-page :title (or spec-title "Specs")
     (p :class "text-stone-600 mb-6"
-      "SX is defined in SX. These four files constitute the canonical, self-hosting specification of the language. Each file is both documentation and executable definition — bootstrap compilers read them to generate native implementations.")
+      (case spec-title
+        "Core Language"
+          "The core specification defines the language itself — parsing, evaluation, primitives, and shared rendering definitions. These four files are platform-independent and sufficient to implement SX on any target."
+        "Adapters & Engine"
+          "Adapters connect the core language to specific environments. Each adapter takes evaluated expression trees and produces output for its target. The engine adds browser-side fetch/swap behaviour."
+        :else ""))
     (div :class "space-y-8"
       (map (fn (spec)
         (div :class "space-y-3"
@@ -21,6 +169,10 @@
               (code (highlight (get spec "source") "sx"))))))
         spec-files))))
 
+;; ---------------------------------------------------------------------------
+;; Detail page — full source of a single spec file
+;; ---------------------------------------------------------------------------
+
 (defcomp ~spec-detail-content (&key spec-title spec-desc spec-filename spec-source)
   (~doc-page :title spec-title
     (div :class "flex items-baseline gap-3 mb-4"
@@ -30,6 +182,10 @@
       (pre :class "text-sm leading-relaxed whitespace-pre-wrap break-words"
         (code (highlight spec-source "sx"))))))
 
+;; ---------------------------------------------------------------------------
+;; Not found
+;; ---------------------------------------------------------------------------
+
 (defcomp ~spec-not-found (&key slug)
   (~doc-page :title "Spec Not Found"
     (p :class "text-stone-600"
diff --git a/sx/sxc/pages/docs.sx b/sx/sxc/pages/docs.sx
index 6f46692..9041617 100644
--- a/sx/sxc/pages/docs.sx
+++ b/sx/sxc/pages/docs.sx
@@ -253,11 +253,10 @@
   :layout (:sx-section
     :section "Specs"
     :sub-label "Specs"
-    :sub-href "/specs/core"
-    :sub-nav (~section-nav :items specs-nav-items :current "Core")
-    :selected "Core")
-  :data (spec-data "core")
-  :content (~spec-core-content :spec-files spec-files))
+    :sub-href "/specs/"
+    :sub-nav (~section-nav :items specs-nav-items :current "Architecture")
+    :selected "Architecture")
+  :content (~spec-architecture-content))
 
 (defpage specs-page
   :path "/specs/<slug>"
@@ -265,7 +264,7 @@
   :layout (:sx-section
     :section "Specs"
     :sub-label "Specs"
-    :sub-href "/specs/core"
+    :sub-href "/specs/"
     :sub-nav (~section-nav :items specs-nav-items
                :current (find-current specs-nav-items slug))
     :selected (or (find-current specs-nav-items slug) ""))
@@ -273,7 +272,8 @@
   :content (if spec-not-found
     (~spec-not-found :slug slug)
     (case slug
-      "core" (~spec-core-content :spec-files spec-files)
+      "core" (~spec-overview-content :spec-files spec-files)
+      "adapters" (~spec-overview-content :spec-files spec-files)
       :else (~spec-detail-content
         :spec-title spec-title
         :spec-desc spec-desc
diff --git a/sx/sxc/pages/helpers.py b/sx/sxc/pages/helpers.py
index f7ce796..1d0bec5 100644
--- a/sx/sxc/pages/helpers.py
+++ b/sx/sxc/pages/helpers.py
@@ -104,21 +104,28 @@ def _reference_data(slug: str) -> dict:
     }
 
 
-_SPEC_FILES = {
+_CORE_SPECS = {
     "parser": ("parser.sx", "Parser", "Tokenization and parsing of SX source text into AST."),
     "evaluator": ("eval.sx", "Evaluator", "Tree-walking evaluation of SX expressions."),
     "primitives": ("primitives.sx", "Primitives", "All built-in pure functions and their signatures."),
-    "renderer": ("render.sx", "Renderer", "Rendering evaluated expressions to DOM, HTML, or SX wire format."),
+    "renderer": ("render.sx", "Renderer", "Shared rendering registries and utilities used by all adapters."),
 }
 
+_ADAPTER_SPECS = {
+    "adapter-dom": ("adapter-dom.sx", "DOM Adapter", "Renders SX expressions to live DOM nodes. Browser-only."),
+    "adapter-html": ("adapter-html.sx", "HTML Adapter", "Renders SX expressions to HTML strings. Server-side."),
+    "adapter-sx": ("adapter-sx.sx", "SX Wire Adapter", "Serializes SX for client-side rendering. Component calls stay unexpanded."),
+    "engine": ("engine.sx", "SxEngine", "Fetch/swap/history engine for browser-side SX. Like HTMX but native to SX."),
+}
+
+_ALL_SPECS = {**_CORE_SPECS, **_ADAPTER_SPECS}
+
 
 def _spec_data(slug: str) -> dict:
-    """Return spec file source and highlighted version for display."""
+    """Return spec file source and metadata for display."""
     import os
-    from content.highlight import highlight as _highlight
 
     ref_dir = os.path.join(os.path.dirname(__file__), "..", "..", "shared", "sx", "ref")
-    # Normalise — inside container shared is at /app/shared
     if not os.path.isdir(ref_dir):
         ref_dir = "/app/shared/sx/ref"
 
@@ -128,19 +135,28 @@ def _spec_data(slug: str) -> dict:
     if slug == "core":
         specs = []
         for key in ("parser", "evaluator", "primitives", "renderer"):
-            filename, title, desc = _SPEC_FILES[key]
+            filename, title, desc = _CORE_SPECS[key]
             filepath = os.path.join(ref_dir, filename)
             source = _read_spec(filepath)
             specs.append({
-                "title": title,
-                "desc": desc,
-                "filename": filename,
-                "source": source,
-                "href": f"/specs/{key}",
+                "title": title, "desc": desc, "filename": filename,
+                "source": source, "href": f"/specs/{key}",
             })
-        return {**base, "spec-title": "SX Core Specification", "spec-files": specs}
+        return {**base, "spec-title": "Core Language", "spec-files": specs}
 
-    info = _SPEC_FILES.get(slug)
+    if slug == "adapters":
+        specs = []
+        for key in ("adapter-dom", "adapter-html", "adapter-sx", "engine"):
+            filename, title, desc = _ADAPTER_SPECS[key]
+            filepath = os.path.join(ref_dir, filename)
+            source = _read_spec(filepath)
+            specs.append({
+                "title": title, "desc": desc, "filename": filename,
+                "source": source, "href": f"/specs/{key}",
+            })
+        return {**base, "spec-title": "Adapters & Engine", "spec-files": specs}
+
+    info = _ALL_SPECS.get(slug)
     if not info:
         return {**base, "spec-not-found": True}