host: blog persisted in durable SX store + materialised view, 158/158

Blog posts now live in the durable SX store (persist/durable-backend, on-disk
under $SX_PERSIST_DIR — already built: sx_persist_store.ml + lib/persist/
durable.sx). Publishing appends insert ops to the slug's content stream; posts
survive restarts (verified: seq/log stable across container restart, re-seed
idempotent).

Read path: http-listen handlers can't drive per-request perform/IO (sx_call
doesn't resolve the CEK IO suspension the way the main loop does), so posts are
materialised from the store into an in-memory view at boot (host/blog-load-all!
+ host/blog-seed!) and request handlers read the view — perform-free. Store is
source of truth; view is a boot-rebuilt cache.

Deploy: docker-compose.dev-sx-host.yml mounts /root/sx-host-persist (chowned to
appuser 10001) at /data/persist; SX_PERSIST_DIR set. blog.rose-ash.com/welcome/
live. Per-request-IO kernel fix tracked in the plan as the next task.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.dev-sx-host.yml

@@ -20,6 +20,8 @@ services:
       HOST_PORT: "8000"
       # Bind all interfaces so Caddy (on externalnet) can reach it.
       SX_HTTP_HOST: "0.0.0.0"
+      # Durable persist store root — on a named volume so data survives restarts.
+      SX_PERSIST_DIR: /data/persist
       OCAMLRUNPARAM: "b"
     volumes:
       # SX source (hot-reload on container restart)
@@ -27,6 +29,10 @@ services:
       - ./lib:/app/lib:ro
       # OCaml server binary — this worktree's build (has the SX_HTTP_HOST bind fix)
       - ./hosts/ocaml/_build/default/bin/sx_server.exe:/app/bin/sx_server:ro
+      # Durable persist store (the SX op-log/kv on disk) — survives restarts.
+      # Host dir, chowned to the image's appuser (uid 10001) so the non-root
+      # server can write: sudo mkdir -p /root/sx-host-persist && sudo chown 10001:10001 /root/sx-host-persist
+      - /root/sx-host-persist:/data/persist
     networks:
       - externalnet
       - default

lib/host/blog.sx

@@ -1,34 +1,72 @@
-;; lib/host/blog.sx — Blog domain on the host. Serves published posts as HTML at
+;; lib/host/blog.sx — Blog domain on the host. Posts are content-on-sx documents
-;; GET /<slug>/ — the original strangler target (Quart: blog/bp/post/routes.py,
+;; whose SOURCE OF TRUTH is the durable SX store (persist op-log on disk): a post
-;; handler post_detail). Published posts are world-visible, so this endpoint is
+;; is published by appending insert ops to its stream. Serving GET /<slug>/ renders
-;; ANONYMOUS — no auth, visibility is trivially "visible".
+;; the post to HTML via content/html. The original strangler target (Quart blog
+;; post_detail); published posts are world-visible, so this endpoint is ANONYMOUS.
 ;;
-;; A post is a content-on-sx document (CtDoc) rendered to HTML via the content
+;; READ PATH — materialised view, not per-request IO. The durable backend reads
-;; facade (content/html). Posts live in an in-memory registry keyed by slug: this
+;; via `perform` (kernel IO suspension), which is serviceable on the main thread
-;; is the "prove the machinery" step — swap host/blog-lookup for a persist-backed
+;; (boot) but NOT inside an http-listen request handler thread. So posts are
-;; content stream later without touching the handler or the route.
+;; materialised from the store into an in-memory view at boot (and on publish),
-;; Depends on lib/content/* (+ the Smalltalk + persist preloads its classes need)
+;; and request handlers read that view — fast, perform-free. The store stays the
-;; + lib/dream/* + lib/host/handler.sx.
+;; source of truth; the view is a cache rebuilt from it on startup.
+;; Depends on lib/content/* (+ Smalltalk + persist preloads) + lib/dream/* +
+;; lib/host/handler.sx.
 
-;; Register the content class table + render methods (idempotent). Must run before
+;; Register content classes + render methods (idempotent); called at load below.
-;; any CtDoc is built/rendered; called at module load below.
 (define host/blog-bootstrap!
   (fn () (begin (st-bootstrap-classes!) (content/bootstrap!))))
 
-;; ── in-memory post registry (slug -> CtDoc) ─────────────────────────
+;; ── store (durable source of truth) + view (in-memory serving cache) ─
-(define host/blog-posts {})
+(define host/blog-store (persist/open))
-(define host/blog-register!
+(define host/blog-view {})
-  (fn (slug doc) (set! host/blog-posts (assoc host/blog-posts slug doc))))
+(define host/blog-use-store!
-(define host/blog-lookup (fn (slug) (get host/blog-posts slug)))
+  (fn (b) (begin (set! host/blog-store b) (set! host/blog-view {}))))
-(define host/blog-reset! (fn () (set! host/blog-posts {})))
 
-;; Build a simple post doc (title heading + body paragraph). Convenience for
+;; content streams are keyed "content:<slug>"; recover the slug.
-;; seeding and tests; real posts arrive from the content store.
+(define host/blog--stream-slug
-(define host/blog-make
+  (fn (stream)
-  (fn (slug title body)
+    (if (starts-with? stream "content:") (substr stream 8) nil)))
-    (doc-append
+
-      (doc-append (doc-empty slug) (mk-heading (str slug "-h") 1 title))
+;; ── publish + lookup ────────────────────────────────────────────────
-      (mk-text (str slug "-body") body))))
+;; Publish a simple post (title heading + body paragraph): append its insert ops
+;; to the durable store, then refresh the in-memory view. `at` is a logical ts.
+(define host/blog-publish!
+  (fn (slug title body at)
+    (let ((hid (str slug "-h")) (tid (str slug "-body")))
+      (content/commit-all! host/blog-store slug
+        (list
+          (op-insert (mk-heading hid 1 title) nil)
+          (op-insert (mk-text tid body) hid))
+        at)
+      (set! host/blog-view
+        (assoc host/blog-view slug (content/head host/blog-store slug))))))
+
+;; Materialise every persisted post from the store into the view. Run at boot on
+;; the main thread (content/head performs IO, fine here, not in a request).
+(define host/blog-load-all!
+  (fn ()
+    (for-each
+      (fn (stream)
+        (let ((slug (host/blog--stream-slug stream)))
+          (when slug
+            (let ((doc (content/head host/blog-store slug)))
+              (when (> (content/count doc) 0)
+                (set! host/blog-view (assoc host/blog-view slug doc)))))))
+      (persist/backend-streams host/blog-store))))
+
+;; Idempotent seed: if the slug isn't already materialised, recover it from the
+;; store (prior run) or publish it fresh. No duplicate ops on restart.
+(define host/blog-seed!
+  (fn (slug title body at)
+    (when (nil? (get host/blog-view slug))
+      (let ((existing (content/head host/blog-store slug)))
+        (if (> (content/count existing) 0)
+          (set! host/blog-view (assoc host/blog-view slug existing))
+          (host/blog-publish! slug title body at))))))
+
+;; Lookup is pure in-memory (no perform) — safe inside a request handler.
+(define host/blog-lookup (fn (slug) (get host/blog-view slug)))
 
 ;; ── handler: GET /<slug>/ -> rendered HTML (200) or 404 ─────────────
 (define host/blog-post

lib/host/conformance.sh

@@ -70,6 +70,8 @@ MODULES=(
   "lib/content/doc.sx"
   "lib/content/render.sx"
   "lib/content/api.sx"
+  "lib/content/store.sx"
+  "lib/persist/durable.sx"
   "lib/dream/types.sx"
   "lib/dream/json.sx"
   "lib/dream/auth.sx"

lib/host/serve.sh

@@ -75,6 +75,8 @@ MODULES=(
   "lib/content/doc.sx"
   "lib/content/render.sx"
   "lib/content/api.sx"
+  "lib/content/store.sx"
+  "lib/persist/durable.sx"
   "lib/dream/types.sx"
   "lib/dream/json.sx"
   "lib/dream/auth.sx"
@@ -95,10 +97,20 @@ EPOCH=1
   for M in "${MODULES[@]}"; do
     echo "(epoch $EPOCH)"; echo "(load \"$M\")"; EPOCH=$((EPOCH+1))
   done
-  # Seed a welcome post so blog.rose-ash.com/welcome/ renders live (until posts
+  # Point the blog at the DURABLE file backend (persists under $SX_PERSIST_DIR),
-  # arrive from a persist-backed content store).
+  # then idempotently seed a welcome post — re-seeding is a no-op if it already
+  # exists on disk, so restarts don't duplicate blocks.
   echo "(epoch $EPOCH)"
-  echo "(eval \"(host/blog-register! \\\"welcome\\\" (host/blog-make \\\"welcome\\\" \\\"Welcome to the SX host\\\" \\\"This page is rendered by lib/host on the SX runtime — no Quart.\\\"))\")"
+  echo "(eval \"(host/blog-use-store! (persist/durable-backend))\")"
+  EPOCH=$((EPOCH+1))
+  echo "(epoch $EPOCH)"
+  # Materialise any persisted posts into the in-memory view, then ensure the
+  # welcome post exists (idempotent). Both run on the main thread (IO is fine
+  # here; request handlers only read the view).
+  echo "(eval \"(host/blog-load-all!)\")"
+  EPOCH=$((EPOCH+1))
+  echo "(epoch $EPOCH)"
+  echo "(eval \"(host/blog-seed! \\\"welcome\\\" \\\"Welcome to the SX host\\\" \\\"This page is rendered by lib/host on the SX runtime, persisted in the SX store — no Quart.\\\" 1)\")"
   EPOCH=$((EPOCH+1))
   echo "(epoch $EPOCH)"
   # Anonymous read endpoints: feed timeline + relations container reads + blog

lib/host/tests/blog.sx

@@ -22,9 +22,9 @@
 (define host-bl-app
   (host/make-app (list host/feed-routes host/blog-routes)))
 
-;; ── render a registered post ────────────────────────────────────────
+;; ── publish a post to a fresh in-memory store (hermetic) ────────────
-(host/blog-reset!)
+(host/blog-use-store! (persist/open))
-(host/blog-register! "welcome" (host/blog-make "welcome" "Hello SX" "Served by lib/host."))
+(host/blog-publish! "welcome" "Hello SX" "Served by lib/host." 1)
 
 (host-bl-test
   "post 200"
@@ -48,11 +48,17 @@
   (dream-status (host-bl-app (host-bl-req "/welcome")))
   200)
 
-;; golden: endpoint body == content facade render of the same doc
+;; golden: endpoint body == the exact rendered HTML of the published post
 (host-bl-test
-  "golden = content/html"
+  "golden render"
   (dream-resp-body (host-bl-app (host-bl-req "/welcome/")))
-  (content/html (host/blog-make "welcome" "Hello SX" "Served by lib/host.")))
+  "<h1>Hello SX</h1><p>Served by lib/host.</p>")
+
+;; persistence: a post materialises from the op-log (replay), and re-seeding is
+;; idempotent (no duplicate blocks appended).
+(host-bl-test "lookup materialises 2 blocks" (content/count (host/blog-lookup "welcome")) 2)
+(host/blog-seed! "welcome" "Hello SX" "Served by lib/host." 2)
+(host-bl-test "re-seed is idempotent" (content/count (host/blog-lookup "welcome")) 2)
 
 ;; ── unknown slug -> 404 ─────────────────────────────────────────────
 (host-bl-test

plans/host-on-sx.md

@@ -36,8 +36,18 @@ host — no `ocaml-on-sx` dependency.
 
 ## Status (rolling)
 
-`bash lib/host/conformance.sh` → **156/156** (9 suites: handler, middleware, sxtp,
+`bash lib/host/conformance.sh` → **158/158** (9 suites: handler, middleware, sxtp,
-router, feed, relations, blog, server, ledger). Phases 1 & 2 DONE; Phase 3 cut-over
+router, feed, relations, blog, server, ledger). Blog posts now persist in the
+durable SX store (`persist/durable-backend`, on-disk under `$SX_PERSIST_DIR`),
+materialised into an in-memory view at boot and served from there.
+
+> **Per-request IO gap (kernel):** `http-listen` handlers run via
+> `Sx_runtime.sx_call`, which does NOT drive `perform`/IO to completion the way
+> the main eval loop does (`Sx_types._cek_io_resolver` is global but the handler
+> path returns the suspension). Proven: a handler doing a durable `persist/read`
+> returns an empty/broken response. Workaround for blog reads = materialise at
+> boot. REAL FIX (next): make the http-listen handler invocation resolve IO like
+> the main loop — then handlers can read/write the store per request. Phases 1 & 2 DONE; Phase 3 cut-over
 landed (50% off Quart). **The host now serves live HTTP** — `lib/host/server.sx`
 bridges the native `http-listen` server to the Dream app and `lib/host/serve.sh`
 boots it (verified: GET /health, /feed, /feed?actor=, relations get-children/