diff --git a/README.md b/README.md
index 401f260..c74f50a 100644
--- a/README.md
+++ b/README.md
@@ -138,7 +138,13 @@ function expecting a tuple needs an explicit conversion. The `jolt.interop`,
 
 This bridge is what makes networking (and everything else in Janet's stdlib)
 available to ordinary Clojure — for example, `jolt.nrepl` (below) is plain
-Clojure over `janet.net/*`.
+Clojure over `janet.net/*`. It also reaches any **jpm-installed module**:
+the first reference to `janet.<module>/<name>` requires the module from the
+janet module path and caches its bindings — so after `jpm install spork`,
+`janet.spork.http/*` just works. The `jolt.http` client and the Ring adapter
+in [examples/ring-app](https://github.com/jolt-lang/examples/tree/main/ring-app)
+are built on spork/http this way, and a project can declare the requirement
+in `deps.edn` with a `:jpm/module` coordinate (see docs/tools-deps.md).
 
 ```clojure
 (require '[jolt.interop :as j])
diff --git a/docs/libraries.md b/docs/libraries.md
index 574a2b1..522a89e 100644
--- a/docs/libraries.md
+++ b/docs/libraries.md
@@ -8,3 +8,7 @@ Libraries confirmed to load and pass their conformance checks on Jolt
 * [Selmer](https://github.com/yogthos/Selmer)
 * [medley](https://github.com/weavejester/medley)
 * [cuerdas](https://github.com/funcool/cuerdas)
+* [ring-core](https://github.com/ring-clojure/ring) — via `:deps/root "ring-core"`,
+  on the [ring-app example](https://github.com/jolt-lang/examples/tree/main/ring-app)'s
+  spork/http adapter
+* [ring-codec](https://github.com/ring-clojure/ring-codec)
diff --git a/docs/tools-deps.md b/docs/tools-deps.md
index ff074bb..04a062b 100644
--- a/docs/tools-deps.md
+++ b/docs/tools-deps.md
@@ -107,3 +107,23 @@ a regex feature like Unicode property classes (`\p{…}`).
 - **Compiling deps into a binary image.** `uberscript` already produces a
   standalone `.clj`; baking a project's dependencies directly into a custom
   executable image is a heavier variant that isn't implemented.
+
+## Janet dependencies: `:jpm/module`
+
+A jolt project can depend on janet libraries. jpm owns their installation;
+`deps.edn` declares the requirement and `jolt-deps` verifies it at resolve
+time:
+
+```clojure
+:deps {janet/spork-http {:jpm/module "spork/http"
+                         :jpm/install "spork"}}
+```
+
+- `:jpm/module` — the janet module path that must be importable.
+- `:jpm/install` (optional) — the jpm package to install when it isn't;
+  `jolt-deps` runs `jpm install <name>` once, then re-checks. Without it the
+  resolve fails with the install hint.
+
+A `:jpm/module` dep contributes no source roots. At runtime the `janet.*`
+interop bridge autoloads the module on first reference
+(`janet.spork.http/server`, …), so nothing else is needed.
diff --git a/jolt-core/clojure/core/00-syntax.clj b/jolt-core/clojure/core/00-syntax.clj
index 1cd83e8..f3851df 100644
--- a/jolt-core/clojure/core/00-syntax.clj
+++ b/jolt-core/clojure/core/00-syntax.clj
@@ -293,6 +293,13 @@
 (defmacro fn [& raw]
   (let [nm (if (symbol? (first raw)) (first raw) nil)
         aftn (if nm (next raw) raw)
+        ;; a return-type hint (defn f ^bytes [x] ...) reaches us as a
+        ;; (with-meta [x] {:tag ...}) FORM in params position — unwrap it
+        ;; (the hint means nothing on jolt; ring-codec carries several).
+        unhint (fn* [x]
+                 (if (if (seq? x) (= 'with-meta (first x)) false)
+                   (nth x 1)
+                   x))
         md (fn* go [ps nps lets]
              (if (seq ps)
                (if (symbol? (first ps))
@@ -303,15 +310,21 @@
                    (go (next ps) (conj nps g) (conj (conj lets (first ps)) g))))
                [nps lets]))
         mk (fn* [sig]
-             (let [r (md (seq (first sig)) [] [])]
-               (if (empty? (nth r 1))
+             (let [ps (unhint (first sig))
+                   hinted (not (= ps (first sig)))
+                   r (md (seq ps) [] [])]
+               (if (if (empty? (nth r 1)) (not hinted) false)
                  sig
                  ;; build the params/let vectors via [~@..] so they are tuple forms
                  ;; (the accumulators are plain seqs, the wrong representation).
+                 ;; A hinted-but-undestructured arity also rebuilds, to shed the
+                 ;; with-meta wrapper without changing the clause representation.
                  (let [pv `[~@(nth r 0)]
                        lv `[~@(nth r 1)]]
-                   `(~pv (let ~lv ~@(rest sig)))))))]
-    (if (vector? (first aftn))
+                   (if (empty? (nth r 1))
+                     `(~pv ~@(rest sig))
+                     `(~pv (let ~lv ~@(rest sig))))))))]
+    (if (vector? (unhint (first aftn)))
       (let [a (mk aftn)]
         (if nm `(fn* ~nm ~@a) `(fn* ~@a)))
       (let [as (vec (map mk aftn))]
diff --git a/jolt-core/clojure/core/30-macros.clj b/jolt-core/clojure/core/30-macros.clj
index 2fd1be6..84de98c 100644
--- a/jolt-core/clojure/core/30-macros.clj
+++ b/jolt-core/clojure/core/30-macros.clj
@@ -252,8 +252,9 @@
 ;; Group a flat seq that starts with a head symbol followed by its list specs
 ;; into [[head spec spec ...] ...] runs. Used by extend-protocol and defrecord.
 (defn- group-by-head [items]
+  ;; nil is a valid extension head (extend-protocol P ... nil (m [x] ...)).
   (reduce (fn [acc x]
-            (if (symbol? x)
+            (if (or (symbol? x) (nil? x))
               (conj acc [x])
               (conj (pop acc) (conj (peek acc) x))))
           [] items))
@@ -347,9 +348,10 @@
 
 (defmacro extend-type [tsym psym & impls]
   ;; register-method is a fn (clojure.core); pass type/protocol/method NAMES as
-  ;; strings (not the symbols) so the call compiles as a plain invoke.
+  ;; strings (not the symbols) so the call compiles as a plain invoke. A nil
+  ;; type extends on nil values (the host tag is the string "nil").
   `(do ~@(map (fn [spec]
-                `(register-method ~(name tsym) ~(name psym) ~(name (first spec))
+                `(register-method ~(if (nil? tsym) "nil" (name tsym)) ~(name psym) ~(name (first spec))
                                   (fn* ~(nth spec 1) ~@(drop 2 spec))))
               impls)))
 
diff --git a/src/jolt/api.janet b/src/jolt/api.janet
index c4c4ee5..08851da 100644
--- a/src/jolt/api.janet
+++ b/src/jolt/api.janet
@@ -281,7 +281,11 @@
                      # non-ctx value, so check the shape, not just the throw.
                      (when (and (r 0) (ctx? (r 1)))
                        (r 1))))]
-      (or loaded
+      (or (when loaded
+            # per-PROCESS wiring an image restore skips: the renderer's
+            # print-method hook lives in module state, not the marshaled ctx
+            (install-print-method-cb! loaded)
+            loaded)
           (let [ctx (init opts)
                 tmp (string path "." (os/getpid) ".tmp")]
             # Atomic publish so concurrent cold starts never see a torn image.
diff --git a/src/jolt/core.janet b/src/jolt/core.janet
index 571bd98..50cf35b 100644
--- a/src/jolt/core.janet
+++ b/src/jolt/core.janet
@@ -1108,7 +1108,13 @@
               (if (= 0 (length c)) (f)
                 (reduce-with-reduced f (in c 0) (array/slice c 1))))))
       3 (let [f (args 0) val (args 1) coll (args 2)]
-          (reduce-with-reduced f val coll))
+          # reify clojure.lang.IReduceInit: the reified value carries its own
+          # reduce — call it (ring.util.codec's tokenizer reduces this way)
+          (if-let [m (and (table? coll)
+                          (get coll :jolt/protocol-methods)
+                          (get (get coll :jolt/protocol-methods) :reduce))]
+            (m coll f val)
+            (reduce-with-reduced f val coll)))
       (error "Wrong number of args passed to: reduce"))))
 
 (defn core-take [n & rest]
@@ -1723,7 +1729,17 @@
 (defn core-current-time-ms [] (* 1000 (os/clock :monotonic)))
 
 # Host IO (host-classified in the spec): path-based slurp/spit, *out* flush.
-(defn core-slurp [path] (string (slurp path)))
+# Opts (:encoding ...) are accepted and ignored — everything is UTF-8 here.
+# Reader shims (java.io.StringReader / PushbackReader / anything carrying
+# :s + :pos) DRAIN instead of opening a file: Ring middleware slurps request
+# bodies, and the jolt Ring adapter hands those over as StringReaders.
+(defn core-slurp [src & opts]
+  (cond
+    (and (table? src) (string? (get src :s)) (number? (get src :pos)))
+      (let [s (src :s) p (src :pos)]
+        (put src :pos (length s))
+        (string/slice s p))
+    (string (slurp src))))
 
 (defn core-spit [path content & opts]
   (def append? (do (var a false) (var i 0)
diff --git a/src/jolt/deps.janet b/src/jolt/deps.janet
index 23ffaba..0473a75 100644
--- a/src/jolt/deps.janet
+++ b/src/jolt/deps.janet
@@ -73,6 +73,26 @@
       (get x :name))
     (string x)))
 
+
+(defn- ensure-jpm-dep
+  "A :jpm/module dep declares a janet module installed through jpm (e.g.
+  spork/http). jolt-deps doesn't manage janet packages — jpm does — so this
+  just verifies the module is importable, optionally running `jpm install
+  <:jpm/install>` once when it isn't, and fails with the install hint
+  otherwise. Contributes no source roots; the janet.* bridge autoloads the
+  module at first use."
+  [lib spec]
+  (def mod (get spec :jpm/module))
+  (defn importable? [] ((protect (require mod)) 0))
+  (unless (importable?)
+    (when-let [pkg (get spec :jpm/install)]
+      (eprintf "jolt-deps: %s: jpm module %s missing — running `jpm install %s`"
+               (sym-name lib) mod pkg)
+      (os/execute ["jpm" "install" pkg] :p))
+    (unless (importable?)
+      (errorf "%s: janet module %s is not importable. Install it with `jpm install %s` (jolt-deps leaves janet packages to jpm)."
+              (sym-name lib) mod (or (get spec :jpm/install) mod)))))
+
 (defn- merge-by-name [a b]  # union of symbol-keyed dictionaries, b wins
   (def out @{})
   (each m [a b] (when (dictionary? m) (eachp [k v] m (put out (sym-name k) v))))
@@ -165,7 +185,8 @@
     (and (deep= (get a :local/root) (get b :local/root))
          (deep= (get a :git/url) (get b :git/url))
          (deep= (get a :git/sha) (get b :git/sha))
-         (deep= (get a :git/tag) (get b :git/tag))))
+         (deep= (get a :git/tag) (get b :git/tag))
+         (deep= (get a :jpm/module) (get b :jpm/module))))
   (def queue @[])
   (defn discover [lib spec base-dir]
     (def k (sym-name lib))
@@ -175,9 +196,16 @@
                  k (coord-str prev) (coord-str spec)))
       (do
         (put seen k spec)
+        (when (and (dictionary? spec) (get spec :jpm/module))
+          (ensure-jpm-dep lib spec))
         (def dir
           (cond
-            (and (dictionary? spec) (get spec :git/url)) (clone-git spec)
+            (and (dictionary? spec) (get spec :git/url))
+              # :deps/root (tools.deps): the project lives in a subdirectory
+              # of the repo — monorepos like ring-clojure/ring.
+              (let [cloned (clone-git spec)
+                    root (get spec :deps/root)]
+                (if root (string cloned "/" root) cloned))
             (and (dictionary? spec) (get spec :local/root))
               (let [lr (get spec :local/root)]
                 (if (string/has-prefix? "/" lr) lr (string base-dir "/" lr)))
diff --git a/src/jolt/deps_cli.janet b/src/jolt/deps_cli.janet
index 28d9834..0da62fa 100644
--- a/src/jolt/deps_cli.janet
+++ b/src/jolt/deps_cli.janet
@@ -34,13 +34,28 @@
 (defn- roots [aliases]
   (if (os/stat "deps.edn") (deps/resolve-deps-cached "deps.edn" nil aliases) @[]))
 
+(defn- jolt-bin
+  "The jolt executable: $JOLT_BIN, else the `jolt` sitting NEXT TO this
+  jolt-deps binary (the pair is built together — running a checkout's
+  build/jolt-deps by path must not pick up some other jolt, or fail when
+  none is on PATH), else `jolt` from PATH."
+  []
+  (or (os/getenv "JOLT_BIN")
+      (let [self (or (first (dyn :args)) (dyn :executable))
+            slashes (when self (string/find-all "/" self))
+            dir (when (and slashes (> (length slashes) 0))
+                  (string/slice self 0 (last slashes)))
+            sibling (when dir (string dir "/jolt"))]
+        (when (and sibling (os/stat sibling)) sibling))
+      "jolt"))
+
 (defn- exec-jolt [aliases extra-args]
   # Set JOLT_PATH in our own env and let the child inherit it (os/execute's env
   # arg isn't honored here; inheriting is reliable).
   (def rs (string/join (roots aliases) ":"))
   (def existing (os/getenv "JOLT_PATH"))
   (os/setenv "JOLT_PATH" (if (and existing (> (length existing) 0)) (string rs ":" existing) rs))
-  (os/execute [(os/getenv "JOLT_BIN" "jolt") ;extra-args] :p))
+  (os/execute [(jolt-bin) ;extra-args] :p))
 
 (defn- usage []
   (print "usage: jolt-deps [-A:alias[:alias]] [path | run FILE [args] | repl | -e EXPR [args]]")
diff --git a/src/jolt/evaluator.janet b/src/jolt/evaluator.janet
index 4379ba4..767a919 100644
--- a/src/jolt/evaluator.janet
+++ b/src/jolt/evaluator.janet
@@ -13,6 +13,31 @@
 # the janet/* interop bridge falls back to it inside env-less fibers.
 (def- module-load-env (fiber/getenv (fiber/current)))
 
+# jpm-module autoload: a janet.<module>/<name> reference whose module isn't
+# in the env is satisfied by requiring it from the jpm module path on first
+# use — (janet.spork.http/server ...) just works when spork is installed,
+# and the same goes for any jpm module. Loaded bindings are cached here
+# (and failures negatively cached, so a missing module errors fast).
+(def- janet-bridge-extras @{})
+(def- janet-bridge-failed @{})
+(defn- bridge-autoload
+  "jname is spork.http/server-shaped: require spork/http, cache its public
+  bindings under the dotted prefix, return the one asked for (nil when the
+  module is missing or has no such binding)."
+  [jname]
+  (def slash (string/find "/" jname))
+  (when slash
+    (def mod-ns (string/slice jname 0 slash))
+    (unless (get janet-bridge-failed mod-ns)
+      (def mod-path (string/replace-all "." "/" mod-ns))
+      (def r (protect (require mod-path)))
+      (if (r 0)
+        (eachp [sym entry] (r 1)
+          (when (and (symbol? sym) (table? entry) (not (get entry :private)))
+            (put janet-bridge-extras (string mod-ns "/" sym) (get entry :value))))
+        (put janet-bridge-failed mod-ns true))))
+  (in janet-bridge-extras jname))
+
 (defn- sym-name?
   [sym-s name-str]
   (and (struct? sym-s) (= :symbol (sym-s :jolt/type)) (= name-str (sym-s :name))))
@@ -501,17 +526,60 @@
 # ctor fns are interned as clojure.core vars at init (install-stateful-fns!).
 (def class-ctors @{})
 (defn register-class-ctor! [nm f] (put class-ctors nm f))
+# Class names evaluate to their CANONICAL NAME STRING — the same value
+# core-class returns — so (defmethod m String ...) keys match a
+# (defmulti m (comp class :body)) dispatch (ring.util.request does this).
+# `new` resolves the actual constructor from class-ctors by short name.
+(def- class-canonical-names
+  @{"String" "java.lang.String" "Number" "java.lang.Number"
+    "Boolean" "java.lang.Boolean" "Long" "java.lang.Long"
+    "Integer" "java.lang.Integer" "Double" "java.lang.Double"
+    "InputStream" "java.io.InputStream" "OutputStream" "java.io.OutputStream"
+    "File" "java.io.File" "Reader" "java.io.Reader" "Writer" "java.io.Writer"
+    "ISeq" "clojure.lang.ISeq" "Keyword" "clojure.lang.Keyword"
+    "Symbol" "clojure.lang.Symbol" "MapEntry" "clojure.lang.MapEntry"
+    "StringReader" "java.io.StringReader" "StringWriter" "java.io.StringWriter"
+    "StringBuilder" "java.lang.StringBuilder"
+    "StringTokenizer" "java.util.StringTokenizer"
+    "Charset" "java.nio.charset.Charset" "Base64" "java.util.Base64"})
+(defn- class-value-for
+  "The value a class-name symbol evaluates to: its canonical name string."
+  [nm]
+  (or (get class-canonical-names nm)
+      # qualified already, or unknown: the name itself is the token
+      nm))
+(defn- ctor-for-class-token
+  "Constructor fn for a class token (a canonical-name string): try the full
+  name, then the short name after the last dot."
+  [tok]
+  (or (in class-ctors tok)
+      (let [parts (string/split "." tok)]
+        (in class-ctors (last parts)))))
 
 # java.lang.String method surface for clj-compat interop: (.toLowerCase s),
 # (.indexOf s x), ... — the methods portable cljc libraries actually call.
 # Case mapping is ASCII (the whole engine is byte-based); indexOf returns -1
 # on miss, as on the JVM.
 (defn- str-needle [x]
-  (if (and (struct? x) (= :jolt/char (get x :jolt/type)))
-    (string/from-bytes (x :ch))
+  (cond
+    (and (struct? x) (= :jolt/char (get x :jolt/type))) (string/from-bytes (x :ch))
+    # (.indexOf s 61): an int needle is a char CODE on the JVM, not its decimal
+    # text (ring-codec splits k=v pairs this way)
+    (number? x) (string/from-bytes (math/trunc x))
     (string x)))
+# java.lang.Number surface (ring-codec: (.byteValue (Integer/valueOf s 16))).
+(def- number-methods
+  {"byteValue"   (fn [n] (let [b (band (math/trunc n) 0xff)] (if (> b 127) (- b 256) b)))
+   "shortValue"  (fn [n] (let [v (band (math/trunc n) 0xffff)] (if (> v 32767) (- v 65536) v)))
+   "intValue"    (fn [n] (math/trunc n))
+   "longValue"   (fn [n] (math/trunc n))
+   "floatValue"  (fn [n] (* 1.0 n))
+   "doubleValue" (fn [n] (* 1.0 n))
+   "toString"    (fn [n &opt radix] (if (= radix 16) (string/format "%x" (math/trunc n)) (string n)))})
+
 (def- string-methods
-  {"toString"    (fn [s] s)
+  {"getBytes"    (fn [s &opt charset] (buffer s))
+   "toString"    (fn [s] s)
    "toLowerCase" (fn [s] (string/ascii-lower s))
    "toUpperCase" (fn [s] (string/ascii-upper s))
    "trim"        (fn [s] (string/trim s))
@@ -586,16 +654,24 @@
             (let [jname (if (= ns "janet") name (string (string/slice ns 6) "/" name))
                   # worker fibers may carry no env (fiber/new without :e inherit)
                   # — fall back to the env captured at module load
-                  entry (in (or (fiber/getenv (fiber/current)) module-load-env)
-                            (symbol jname))]
+                  # four-step resolution: the runtime fiber's env (when it
+                  # has one), the evaluator's module env (worker/connection
+                  # fibers carry a foreign or empty env — net/server handler
+                  # fibers resolve janet/struct through here), the autoload
+                  # cache, then a jpm-module require on first miss
+                  entry (or (when-let [fe (fiber/getenv (fiber/current))]
+                              (in fe (symbol jname)))
+                            (in module-load-env (symbol jname))
+                            (in janet-bridge-extras jname)
+                            (bridge-autoload jname))]
               (if (not (nil? entry))
                 (if (table? entry) (entry :value) entry)
                 (error (string "Unable to resolve Janet symbol: " jname))))
             # syntax-quote ns-qualifies bare class names inside macros
             # (selmer.util/StringBuilder); class names never belong to an ns —
             # fall back to the constructor / statics shims before giving up.
-            (if-let [ctor (in class-ctors name)]
-              ctor
+            (if (or (in class-ctors name) (get class-canonical-names name))
+              (class-value-for name)
               (error (string "Unable to resolve symbol: " ns "/" name))))))
       # Use :jolt/not-found sentinel to distinguish nil binding from absent binding
       (let [local (get bindings name :jolt/not-found-1)
@@ -846,7 +922,10 @@
    "Keyword" true "Symbol" true "Object" true "IFn" true "Fn" true
    "PersistentVector" true "PersistentList" true "PersistentHashMap" true
    "PersistentHashSet" true "IPersistentMap" true "IPersistentVector" true
-   "IPersistentSet" true "IPersistentCollection" true "ISeq" true "Atom" true "nil" true})
+   "IPersistentSet" true "IPersistentCollection" true "ISeq" true "Atom" true "nil" true
+   # java.util interfaces + seq types ring & friends extend on
+   "Map" true "Set" true "List" true "Collection" true "LazySeq" true
+   "APersistentMap" true})
 
 (defn- canonical-host-tag
   "If type-name names a host type (optionally java.*/clojure.lang.* qualified),
@@ -869,7 +948,17 @@
     (keyword? obj) ["Keyword" "Object"]
     (and (struct? obj) (= :jolt/char (get obj :jolt/type))) ["Character" "Object"]
     (and (struct? obj) (= :symbol (get obj :jolt/type))) ["Symbol" "Object"]
-    (plist? obj) ["PersistentList" "IPersistentList" "IPersistentCollection" "ISeq" "Object"]
+    (plist? obj) ["PersistentList" "IPersistentList" "IPersistentCollection" "ISeq" "List" "Collection" "Object"]
+    (lazy-seq? obj) ["LazySeq" "ISeq" "IPersistentCollection" "Collection" "Object"]
+    # maps: phm / plain struct / sorted / records — java.util.Map covers them
+    # all in ring-style extend-protocol clauses
+    (or (phm? obj)
+        (and (struct? obj) (nil? (get obj :jolt/type)))
+        (and (table? obj) (or (get obj :jolt/deftype)
+                              (= :jolt/sorted-map (get obj :jolt/type)))))
+      ["PersistentHashMap" "APersistentMap" "IPersistentMap" "Map" "IPersistentCollection" "Object"]
+    (or (set? obj) (and (table? obj) (= :jolt/sorted-set (get obj :jolt/type))))
+      ["PersistentHashSet" "IPersistentSet" "Set" "IPersistentCollection" "Object"]
     (or (tuple? obj) (array? obj) (pvec? obj)) ["PersistentVector" "IPersistentVector" "IPersistentCollection" "ISeq" "Object"]
     (or (function? obj) (cfunction? obj)) ["IFn" "Fn" "Object"]
     (nil? obj) ["nil" "Object"]
@@ -1054,7 +1143,8 @@
   (def v-box @[nil])
   (def mm-fn
     (fn [& args]
-      (let [dv (apply dispatch-fn args)
+      (let [dv* (apply dispatch-fn args)
+            dv (if (nil? dv*) :jolt/nil-sentinel dv*)
             method (get methods dv)]
         (if method
           (apply method args)
@@ -1137,7 +1227,9 @@
           (put v :jolt/methods @{})
           v)))
   (def methods (or (get mm-var :jolt/methods) (let [m @{}] (put mm-var :jolt/methods m) m)))
-  (put methods dispatch-val impl)
+  # nil is a legal dispatch value (ring's body-string keys a method on it);
+  # janet tables can't hold nil keys, so it rides the sentinel
+  (put methods (if (nil? dispatch-val) :jolt/nil-sentinel dispatch-val) impl)
   (let [dc (get mm-var :jolt/dispatch-cache)]
     (when dc (each k (keys dc) (put dc k nil))))
   mm-var)
@@ -1294,6 +1386,7 @@
       mm-var))
   (ns-intern core "remove-method-setup"
     (fn [mm-sym dval]
+      (def dval (if (nil? dval) :jolt/nil-sentinel dval))
       (def mm-var (mm-var-of mm-sym false))
       (when mm-var
         (let [methods (get mm-var :jolt/methods)]
@@ -1316,6 +1409,7 @@
       (or (and mm-var (get mm-var :jolt/prefers)) {})))
   (ns-intern core "get-method-setup"
     (fn [mm-sym dval]
+      (def dval (if (nil? dval) :jolt/nil-sentinel dval))
       (def mm-var (mm-var-of mm-sym false))
       (when mm-var
         (let [methods (get mm-var :jolt/methods)]
@@ -1408,8 +1502,13 @@
   # read, with-in-str, and line-seq are Clojure over these (core/50-io.clj).
   # The loader's registered source roots (the closest thing to a classpath) —
   # io/resource searches these for relative resource paths.
-  # registered constructor shims (StringReader., StringBuilder., ...)
-  (eachp [nm f] class-ctors (ns-intern core nm f))
+  # registered constructor shims: the NAME evaluates to the canonical class
+  # string (so class-dispatch defmultis match); `new` finds the ctor fn.
+  (eachp [nm f] class-ctors (ns-intern core nm (class-value-for nm)))
+  # dispatch-only type names (no ctor): InputStream, File, ISeq, ...
+  (eachp [nm canon] class-canonical-names
+    (unless (or (in class-ctors nm) (ns-find core nm))
+      (ns-intern core nm canon)))
   (ns-intern core "__source-roots"
     (fn [] (tuple ;(get (ctx :env) :source-paths))))
   (ns-intern core "__stdin-read-line"
@@ -1975,7 +2074,8 @@
     # compiles as a plain (do …); no special-form arm.
     "new" (let [type-sym (in form 1)
                 args (map |(eval-form ctx bindings $) (tuple/slice form 2))
-                ctor (eval-form ctx bindings type-sym)]
+                ctor (eval-form ctx bindings type-sym)
+                ctor (if (string? ctor) (or (ctor-for-class-token ctor) ctor) ctor)]
             (apply ctor args))
     "." (let [target (eval-form ctx bindings (in form 1))
               member-raw (in form 2)
@@ -1996,6 +2096,8 @@
                   (if m
                     (m (string target) ;args)
                     (error (string "Unsupported String method ." field-name))))
+              (if (and (number? target) (get number-methods field-name))
+                ((get number-methods field-name) target ;args)
               # registered shim objects (java.time etc.): tag-keyed method tables
               (if (and (or (table? target) (struct? target))
                        (get tagged-methods (get target :jolt/type)))
@@ -2028,7 +2130,7 @@
                             (method-fn target ;args)
                             (error (string "Cannot call non-function " field-name " on " (type target)))))
                         (error (string "Cannot call non-function " field-name " on " (type target))))))
-                  (error (string "Cannot call method " field-name " on " (type target))))))))
+                  (error (string "Cannot call method " field-name " on " (type target)))))))))
             # (. obj member) with no extra args: a symbol member naming a
             # function is a zero-arg method call (receiver passed as self);
             # a keyword or `-field` member is plain field access. Strings get
@@ -2038,6 +2140,8 @@
                 (if m
                   (m (string target))
                   (error (string "Unsupported String method ." field-name))))
+            (if (and (number? target) (get number-methods field-name))
+              ((get number-methods field-name) target)
             (if (and (or (table? target) (struct? target))
                      (get tagged-methods (get target :jolt/type))
                      (get (get tagged-methods (get target :jolt/type)) field-name))
@@ -2057,7 +2161,7 @@
                   (array? v) (let [f (eval-form ctx bindings v)]
                                (if (or (function? f) (cfunction? f)) (f target) f))
                   v)
-                v))))))
+                v)))))))
     # default: function application — check for macros
     (if (and (struct? first-form) (= :symbol (first-form :jolt/type)))
       (let [sym-name (first-form :name)]
@@ -2086,6 +2190,9 @@
           (let [type-name (string/slice sym-name 0 (- (length sym-name) 1))
                 type-sym {:jolt/type :symbol :ns (first-form :ns) :name type-name}
                 ctor (eval-form ctx bindings type-sym)
+                # class names evaluate to canonical-name STRINGS now; the
+                # constructor itself comes from the ctor registry
+                ctor (if (string? ctor) (or (ctor-for-class-token ctor) ctor) ctor)
                 args (map |(eval-form ctx bindings $) (tuple/slice form 1))]
             (apply ctor args))
           (let [v (resolve-var ctx bindings first-form)]
diff --git a/src/jolt/javatime.janet b/src/jolt/javatime.janet
index d386cfa..431374c 100644
--- a/src/jolt/javatime.janet
+++ b/src/jolt/javatime.janet
@@ -263,6 +263,131 @@
     (register-class-ctor! nm string-builder))
   (each nm ["StringWriter" "java.io.StringWriter"]
     (register-class-ctor! nm make-string-writer))
+  # --- java.net / java.util surface for ring-codec (ring-core enablement) ---
+  # URLEncoder/URLDecoder: www-form-urlencoded (space <-> +, %XX bytes,
+  # [A-Za-z0-9.*_-] literal). Charset args are accepted and ignored beyond
+  # the name (everything is UTF-8 bytes here).
+  (defn- url-unreserved? [b]
+    (or (and (>= b 48) (<= b 57)) (and (>= b 65) (<= b 90))
+        (and (>= b 97) (<= b 122)) (= b 46) (= b 42) (= b 95) (= b 45)))
+  (defn- url-encode-www [s & _]
+    (def out @"")
+    (each b (string/bytes (string s))
+      (cond
+        (url-unreserved? b) (buffer/push-byte out b)
+        (= b 32) (buffer/push-string out "+")
+        (buffer/push-string out (string/format "%%%02X" b))))
+    (string out))
+  (defn- hexv [b]
+    (cond (and (>= b 48) (<= b 57)) (- b 48)
+          (and (>= b 65) (<= b 70)) (- b 55)
+          (and (>= b 97) (<= b 102)) (- b 87)
+          (error "URLDecoder: malformed escape")))
+  (defn- url-decode-www [s & _]
+    (def bytes (string/bytes (string s)))
+    (def n (length bytes))
+    (def out @"")
+    (var i 0)
+    (while (< i n)
+      (def b (in bytes i))
+      (cond
+        (= b 43) (do (buffer/push-string out " ") (++ i))
+        (= b 37) (if (< (+ i 2) n)
+                   (do (buffer/push-byte out (+ (* 16 (hexv (in bytes (+ i 1)))) (hexv (in bytes (+ i 2)))))
+                       (+= i 3))
+                   (error "URLDecoder: incomplete escape"))
+        (do (buffer/push-byte out b) (++ i))))
+    (string out))
+  (each nm ["URLEncoder" "java.net.URLEncoder"]
+    (register-class-statics! nm @{"encode" url-encode-www}))
+  (each nm ["URLDecoder" "java.net.URLDecoder"]
+    (register-class-statics! nm @{"decode" url-decode-www}))
+  (each nm ["Charset" "java.nio.charset.Charset"]
+    (register-class-statics! nm @{"forName" (fn [nm*] @{:jolt/type :jolt/charset :name nm*})}))
+  # Base64 (RFC 4648): encoder/decoder singletons with encode/decode methods.
+  (def- b64-alphabet "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
+  (defn- b64-encode [bs]
+    (def bytes (if (bytes? bs) bs (string bs)))
+    (def n (length bytes))
+    (def out @"")
+    (var i 0)
+    (while (< i n)
+      (def b0 (in bytes i))
+      (def b1 (if (< (+ i 1) n) (in bytes (+ i 1))))
+      (def b2 (if (< (+ i 2) n) (in bytes (+ i 2))))
+      (buffer/push-byte out (in b64-alphabet (brshift b0 2)))
+      (buffer/push-byte out (in b64-alphabet (bor (blshift (band b0 3) 4) (brshift (or b1 0) 4))))
+      (buffer/push-string out (if (nil? b1) "=" (string/from-bytes (in b64-alphabet (bor (blshift (band b1 0xf) 2) (brshift (or b2 0) 6))))))
+      (buffer/push-string out (if (nil? b2) "=" (string/from-bytes (in b64-alphabet (band b2 0x3f)))))
+      (+= i 3))
+    (string out))
+  (def- b64-rev (do (def t @{}) (eachp [i c] b64-alphabet (put t c i)) t))
+  (defn- b64-decode [s]
+    (def cleaned (string/replace-all "=" "" (string s)))
+    (def out @"")
+    (var acc 0) (var bits 0)
+    (each c (string/bytes cleaned)
+      (def v (get b64-rev c))
+      (when (nil? v) (error "Base64: illegal character"))
+      (set acc (bor (blshift acc 6) v))
+      (+= bits 6)
+      (when (>= bits 8)
+        (-= bits 8)
+        (buffer/push-byte out (band (brshift acc bits) 0xff))))
+    out)
+  (register-tagged-methods! :jolt/base64-encoder @{"encode" (fn [self bs] (b64-encode bs)) "encodeToString" (fn [self bs] (b64-encode bs))})
+  (register-tagged-methods! :jolt/base64-decoder @{"decode" (fn [self s] (b64-decode s))})
+  (each nm ["Base64" "java.util.Base64"]
+    (register-class-statics! nm
+      @{"getEncoder" (fn [] @{:jolt/type :jolt/base64-encoder})
+        "getDecoder" (fn [] @{:jolt/type :jolt/base64-decoder})}))
+  # Integer statics: valueOf with optional radix. Returns a plain number —
+  # byteValue/intValue live on the number method surface in the evaluator.
+  (register-class-statics! "Integer"
+    @{"valueOf" (fn [x &opt radix]
+                  (cond
+                    (number? x) x
+                    (nil? radix) (or (scan-number (string x)) (error (string "NumberFormatException: " x)))
+                    (= radix 16) (or (scan-number (string "16r" x)) (error (string "NumberFormatException: " x)))
+                    (= radix 8) (or (scan-number (string "8r" x)) (error (string "NumberFormatException: " x)))
+                    (= radix 2) (or (scan-number (string "2r" x)) (error (string "NumberFormatException: " x)))
+                    (error (string "Integer/valueOf: unsupported radix " radix))))
+      "parseInt" (fn [x &opt radix]
+                   (or (scan-number (string (case radix 16 "16r" 8 "8r" 2 "2r" "") x))
+                       (error (string "NumberFormatException: " x))))
+      "MAX_VALUE" 2147483647
+      "MIN_VALUE" -2147483648})
+  # StringTokenizer: eager split on any delimiter char, empty tokens skipped.
+  (defn- tokenize [s delims]
+    (def dset @{})
+    (each b (string/bytes delims) (put dset b true))
+    (def toks @[])
+    (def cur @"")
+    (each b (string/bytes (string s))
+      (if (get dset b)
+        (when (> (length cur) 0) (array/push toks (string cur)) (buffer/clear cur))
+        (buffer/push-byte cur b)))
+    (when (> (length cur) 0) (array/push toks (string cur)))
+    toks)
+  (register-tagged-methods! :jolt/string-tokenizer
+    @{"hasMoreTokens" (fn [self] (< (self :pos) (length (self :toks))))
+      "countTokens"   (fn [self] (- (length (self :toks)) (self :pos)))
+      "nextToken"     (fn [self]
+                        (if (< (self :pos) (length (self :toks)))
+                          (let [t (in (self :toks) (self :pos))]
+                            (put self :pos (+ 1 (self :pos))) t)
+                          (error "NoSuchElementException")))})
+  (each nm ["StringTokenizer" "java.util.StringTokenizer"]
+    (register-class-ctor! nm (fn [s &opt delims]
+                               @{:jolt/type :jolt/string-tokenizer
+                                 :toks (tokenize s (or delims " \t\n\r\f"))
+                                 :pos 0})))
+  # clojure.lang.MapEntry: a 2-tuple, jolt's map-entry representation.
+  (each nm ["MapEntry" "clojure.lang.MapEntry"]
+    (register-class-ctor! nm (fn [k v] [k v])))
+  # (String. bytes) / (String. bytes charset): UTF-8 bytes to string.
+  (each nm ["String" "java.lang.String"]
+    (register-class-ctor! nm (fn [x &opt charset] (string x))))
   # java.net.URL: enough for selmer's template cache — file: URLs only.
   # A protocol-less spec throws (selmer catches MalformedURLException and
   # prepends file:///), and getPath hands back a stat-able filesystem path.
diff --git a/src/jolt/jolt/http.clj b/src/jolt/jolt/http.clj
index cbbceb1..2eb61ec 100644
--- a/src/jolt/jolt/http.clj
+++ b/src/jolt/jolt/http.clj
@@ -1,12 +1,25 @@
 ; Jolt Standard Library: jolt.http
-; HTTP client using Janet's net/ module.
+; HTTP client over spork/http (janet.spork.http/*; requires `jpm install spork`).
+; Responses come back as {:status int :headers map :body string}.
+
+(defn- response->map [r]
+  ;; clojure.core/get explicitly: this ns defines an http `get` that shadows it
+  {:status  (clojure.core/get r :status)
+   :body    (str (or (janet.spork.http/read-body r) ""))
+   :headers (reduce (fn [m kv] (assoc m (str (nth kv 0)) (str (nth kv 1))))
+                    {}
+                    (janet/pairs (or (clojure.core/get r :headers) (janet/struct))))})
+
+(defn- header-struct [headers]
+  (apply janet/struct
+         (mapcat (fn [kv] [(str (key kv)) (str (val kv))]) (seq (or headers {})))))
 
 (defn get
   [url & {:keys [headers]}]
-  (let [result (net/request url :get headers {})]
-    {:status (result :status) :body (result :body) :headers (result :headers)}))
+  (response->map
+    (janet.spork.http/request "GET" url :headers (header-struct headers))))
 
 (defn post
   [url body & {:keys [headers]}]
-  (let [result (net/request url :post headers body)]
-    {:status (result :status) :body (result :body) :headers (result :headers)}))
+  (response->map
+    (janet.spork.http/request "POST" url :body body :headers (header-struct headers))))
diff --git a/src/jolt/regex.janet b/src/jolt/regex.janet
index 3d1e8dc..7180c14 100644
--- a/src/jolt/regex.janet
+++ b/src/jolt/regex.janet
@@ -414,6 +414,17 @@
         (do (buffer/push-string buf (string/from-bytes c)) (++ i)))))
   (string buf))
 
+(defn- replacement-for
+  "One match's replacement text. A string replacement gets $N expansion; a FN
+  replacement (Clojure: fn of the match — string, or [whole g1 ...] when the
+  pattern has groups) is called and its result used literally."
+  [replacement g ngroups]
+  (cond
+    (string? replacement) (expand-replacement replacement g)
+    (or (function? replacement) (cfunction? replacement))
+      (string (replacement (groups->result g ngroups)))
+    (string replacement)))
+
 (defn re-replace-all [re s replacement]
   (def re (re-pattern re))
   (def buf @"") (var pos 0) (var last 0)
@@ -421,7 +432,7 @@
     (def g (match-at re s pos))
     (if (and g (> (length (in g 0)) 0))
       (do (buffer/push-string buf (string/slice s last pos))
-          (buffer/push-string buf (if (string? replacement) (expand-replacement replacement g) replacement))
+          (buffer/push-string buf (replacement-for replacement g (re :ngroups)))
           (set pos (+ pos (length (in g 0))))
           (set last pos))
       (++ pos)))
@@ -439,6 +450,6 @@
   (if done
     (let [[p g] done]
       (string (string/slice s 0 p)
-              (if (string? replacement) (expand-replacement replacement g) replacement)
+              (replacement-for replacement g (re :ngroups))
               (string/slice s (+ p (length (in g 0))))))
     s))
diff --git a/test/integration/deps-resolve-test.janet b/test/integration/deps-resolve-test.janet
index 1b308b9..5a22b88 100644
--- a/test/integration/deps-resolve-test.janet
+++ b/test/integration/deps-resolve-test.janet
@@ -125,6 +125,32 @@
   )
 (rmrf gbase)
 
+# --- :jpm/module deps: janet libraries installed through jpm -----------------
+# Verification only (jpm owns installation): an importable module passes and
+# contributes no roots; a missing one errors with the install hint. jpm/pm is
+# always importable wherever jpm itself runs (CI included).
+(do
+  (def jbase (string (or (os/getenv "TMPDIR") "/tmp") "/jolt-deps-jpm-" (os/time)))
+  (mkdirs (string jbase "/src"))
+  (spit (string jbase "/deps.edn")
+    `{:paths ["src"] :deps {janet/jpm-pm {:jpm/module "jpm/pm"}}}`)
+  (def cwd (os/cwd))
+  (os/cd jbase)
+  (def roots (deps/resolve-deps "deps.edn" (string jbase "/jpm_tree")))
+  (os/cd cwd)
+  (check "jpm module dep resolves" true (not (nil? roots)))
+  (check "jpm module contributes no roots" 1 (length roots))
+
+  (spit (string jbase "/deps.edn")
+    `{:paths ["src"] :deps {janet/nope {:jpm/module "no/such-module-xyz"}}}`)
+  (os/cd jbase)
+  (def r (protect (deps/resolve-deps "deps.edn" (string jbase "/jpm_tree"))))
+  (os/cd cwd)
+  (check "missing jpm module errors" false (r 0))
+  (check "error carries the install hint" true
+         (not (nil? (string/find "jpm install" (string (r 1))))))
+  (rmrf jbase))
+
 (if (> fails 0)
   (error (string "deps-resolve-test: " fails " failing check(s)"))
   (print "\nAll deps-resolve tests passed!"))
diff --git a/test/spec/host-interop-spec.janet b/test/spec/host-interop-spec.janet
index 5397ef7..e78faf4 100644
--- a/test/spec/host-interop-spec.janet
+++ b/test/spec/host-interop-spec.janet
@@ -140,3 +140,49 @@
    "(string? (get (into {} (map (fn [[k v]] [k v]) (System/getenv))) \"HOME\"))"]
   ["System/getProperties"  "true"
    "(string? (get (System/getProperties) \"os.name\"))"])
+
+# ring-core enablement (host shims + protocol/reduce fixes): the java.net /
+# java.util surface ring.util.codec needs, extend-protocol on Map and nil,
+# and reduce over a reified clojure.lang.IReduceInit.
+(defspec "host-interop / ring-codec surface"
+  ["URLEncoder www form"   "\"a+b%3Dc\"" "(URLEncoder/encode \"a b=c\")"]
+  ["URLDecoder www form"   "\"a b=c\""   "(URLDecoder/decode \"a+b%3Dc\" (Charset/forName \"UTF-8\"))"]
+  ["url round trip"        "\"x &=%?\""  "(URLDecoder/decode (URLEncoder/encode \"x &=%?\"))"]
+  ["Base64 encode"         "\"aGVsbG8=\"" "(String. (.encode (Base64/getEncoder) (.getBytes \"hello\")))"]
+  ["Base64 round trip"     "\"hello\""   "(String. (.decode (Base64/getDecoder) (String. (.encode (Base64/getEncoder) (.getBytes \"hello\")))))"]
+  ["Integer radix + byteValue" "-1"      "(.byteValue (Integer/valueOf \"ff\" 16))"]
+  ["Integer parseInt"      "255"         "(Integer/parseInt \"ff\" 16)"]
+  ["StringTokenizer"       "[\"a=1\" \"b=2\"]" "(let [t (StringTokenizer. \"a=1&b=2\" \"&\")] [(.nextToken t) (.nextToken t)])"]
+  ["MapEntry key/val"      "[:a 1]"      "(let [e (MapEntry. :a 1)] [(key e) (val e)])"]
+  ["String ctor from bytes" "\"hi\""     "(String. (.getBytes \"hi\"))"]
+  ["extend-protocol Map"   ":map"
+   "(do (defprotocol Pe (pe [x])) (extend-protocol Pe Map (pe [m] :map) Object (pe [o] :obj)) (pe {:a 1}))"]
+  ["extend-protocol nil"   ":nil"
+   "(do (defprotocol Pn (pn [x])) (extend-protocol Pn nil (pn [n] :nil) Object (pn [o] :obj)) (pn nil))"]
+  ["extend-protocol Map covers sorted" ":map"
+   "(do (defprotocol Ps (ps [x])) (extend-protocol Ps Map (ps [m] :map) Object (ps [o] :obj)) (ps (sorted-map 1 2)))"]
+  ["reduce over reified IReduceInit" "42"
+   "(reduce + 0 (reify clojure.lang.IReduceInit (reduce [_ f init] (f (f init 40) 2))))"])
+
+# ring-core enablement, part 2: class-name symbols evaluate to canonical
+# class-name strings (so class-dispatch defmultis match), ctor sugar still
+# constructs, type-hinted param vectors parse, slurp drains reader shims,
+# str/replace takes fn replacements, and int needles are char codes.
+(defspec "host-interop / class tokens & readers"
+  ["class name evaluates to canonical string" "\"java.lang.String\"" "String"]
+  ["dispatch-only class name" "\"java.io.InputStream\"" "InputStream"]
+  ["(class x) matches the token" "true" "(= String (class \"abc\"))"]
+  ["defmulti on class dispatches" ":str"
+   "(do (defmulti cm (fn [x] (class x))) (defmethod cm String [x] :str) (cm \"a\"))"]
+  ["defmethod on nil dispatch value" ":nil"
+   "(do (defmulti cn (fn [x] (class x))) (defmethod cn nil [x] :nil) (defmethod cn String [x] :str) (cn nil))"]
+  ["ctor sugar still constructs" "\"x\"" "(.toString (StringBuilder. \"x\"))"]
+  ["return-hinted defn parses" "7" "(do (defn- hb ^bytes [b] b) (hb 7))"]
+  ["hinted multi-arity parses" ":two" "((fn ([x] :one) (^String [x y] :two)) 1 2)"]
+  ["slurp drains a StringReader" "\"a=1\"" "(slurp (StringReader. \"a=1\"))"]
+  ["slurp accepts :encoding opts" "\"b\"" "(slurp (StringReader. \"b\") :encoding \"UTF-8\")"]
+  ["replace with fn replacement is literal" "\"$0\""
+   "(do (require (quote [clojure.string :as s9])) (s9/replace \"x\" #\".\" (fn [m] \"$0\")))"]
+  ["replace fn gets group vector" "\"v=k\""
+   "(do (require (quote [clojure.string :as s9])) (s9/replace \"k=v\" #\"(\\w+)=(\\w+)\" (fn [[_ k v]] (str v \"=\" k))))"]
+  ["indexOf int needle is a char code" "1" "(.indexOf \"a=b\" 61)"])