diff --git a/lib/js/stdlib.sx b/lib/js/stdlib.sx
new file mode 100644
index 00000000..60096c28
--- /dev/null
+++ b/lib/js/stdlib.sx
@@ -0,0 +1,239 @@
+;; lib/js/stdlib.sx — Phase 22 JS additions
+;;
+;; Adds to lib/js/runtime.sx (already loaded):
+;;   1. Bitwise binary ops (js-bitand/bitor/bitxor/lshift/rshift/urshift/bitnot)
+;;   2. Map class (arbitrary-key hash map via list of pairs)
+;;   3. Set class (uniqueness collection via SX make-set)
+;;   4. RegExp constructor (wraps js-regex-new already in runtime)
+;;   5. Wires Map / Set / RegExp into js-global
+
+;; ---------------------------------------------------------------------------
+;; 1. Bitwise binary ops
+;;    JS coerces operands to 32-bit signed int before applying the op.
+;;    Use truncate (not js-num-to-int) since integer / 0 crashes the evaluator.
+;; ---------------------------------------------------------------------------
+
+(define
+  (js-bitand a b)
+  (bitwise-and (truncate (js-to-number a)) (truncate (js-to-number b))))
+
+(define
+  (js-bitor a b)
+  (bitwise-or (truncate (js-to-number a)) (truncate (js-to-number b))))
+
+(define
+  (js-bitxor a b)
+  (bitwise-xor (truncate (js-to-number a)) (truncate (js-to-number b))))
+
+;; << : left-shift by (b mod 32) positions
+(define
+  (js-lshift a b)
+  (arithmetic-shift
+    (truncate (js-to-number a))
+    (modulo (truncate (js-to-number b)) 32)))
+
+;; >> : arithmetic right-shift (sign-extending)
+(define
+  (js-rshift a b)
+  (arithmetic-shift
+    (truncate (js-to-number a))
+    (- 0 (modulo (truncate (js-to-number b)) 32))))
+
+;; >>> : logical right-shift (zero-extending)
+;;   Convert to uint32 first, then divide by 2^n.
+(define
+  (js-urshift a b)
+  (let
+    ((u32 (modulo (truncate (js-to-number a)) 4294967296))
+      (n (modulo (truncate (js-to-number b)) 32)))
+    (quotient u32 (arithmetic-shift 1 n))))
+
+;; ~ : bitwise NOT — equivalent to -(n+1) in 32-bit signed arithmetic
+(define (js-bitnot a) (bitwise-not (truncate (js-to-number a))))
+
+;; ---------------------------------------------------------------------------
+;; 2. Map class
+;;    Stored as {:__js_map__ true :size N :_pairs (list (list key val) ...)}
+;;    Mutation via dict-set! on the underlying dict.
+;; ---------------------------------------------------------------------------
+
+(define
+  (js-map-new)
+  (let
+    ((m (dict)))
+    (dict-set! m "__js_map__" true)
+    (dict-set! m "size" 0)
+    (dict-set! m "_pairs" (list))
+    m))
+
+(define (js-map? v) (and (dict? v) (dict-has? v "__js_map__")))
+
+;; Linear scan for key using ===; returns index or -1
+(define
+  (js-map-find-idx pairs k)
+  (letrec
+    ((go (fn (ps i) (cond ((= (len ps) 0) -1) ((js-strict-eq (first (first ps)) k) i) (else (go (rest ps) (+ i 1)))))))
+    (go pairs 0)))
+
+(define
+  (js-map-get m k)
+  (letrec
+    ((go (fn (ps) (if (= (len ps) 0) js-undefined (if (js-strict-eq (first (first ps)) k) (nth (first ps) 1) (go (rest ps)))))))
+    (go (get m "_pairs"))))
+
+;; Replace element at index i in list
+(define
+  (js-list-set-nth lst i newval)
+  (letrec
+    ((go (fn (ps j) (if (= (len ps) 0) (list) (cons (if (= j i) newval (first ps)) (go (rest ps) (+ j 1)))))))
+    (go lst 0)))
+
+;; Remove element at index i from list
+(define
+  (js-list-remove-nth lst i)
+  (letrec
+    ((go (fn (ps j) (if (= (len ps) 0) (list) (if (= j i) (go (rest ps) (+ j 1)) (cons (first ps) (go (rest ps) (+ j 1))))))))
+    (go lst 0)))
+
+(define
+  (js-map-set! m k v)
+  (let
+    ((pairs (get m "_pairs")) (idx (js-map-find-idx (get m "_pairs") k)))
+    (if
+      (= idx -1)
+      (begin
+        (dict-set! m "_pairs" (append pairs (list (list k v))))
+        (dict-set! m "size" (+ (get m "size") 1)))
+      (dict-set! m "_pairs" (js-list-set-nth pairs idx (list k v)))))
+  m)
+
+(define
+  (js-map-has m k)
+  (not (= (js-map-find-idx (get m "_pairs") k) -1)))
+
+(define
+  (js-map-delete! m k)
+  (let
+    ((idx (js-map-find-idx (get m "_pairs") k)))
+    (when
+      (not (= idx -1))
+      (dict-set! m "_pairs" (js-list-remove-nth (get m "_pairs") idx))
+      (dict-set! m "size" (- (get m "size") 1))))
+  m)
+
+(define
+  (js-map-clear! m)
+  (dict-set! m "_pairs" (list))
+  (dict-set! m "size" 0)
+  m)
+
+(define (js-map-keys m) (map first (get m "_pairs")))
+(define
+  (js-map-vals m)
+  (map (fn (p) (nth p 1)) (get m "_pairs")))
+(define (js-map-entries m) (get m "_pairs"))
+
+(define
+  (js-map-for-each m cb)
+  (for-each
+    (fn (p) (cb (nth p 1) (first p) m))
+    (get m "_pairs"))
+  js-undefined)
+
+;; Map method dispatch (called from js-object-method-call in runtime)
+(define
+  (js-map-method m name args)
+  (cond
+    ((= name "set")
+      (js-map-set! m (nth args 0) (nth args 1)))
+    ((= name "get") (js-map-get m (nth args 0)))
+    ((= name "has") (js-map-has m (nth args 0)))
+    ((= name "delete") (js-map-delete! m (nth args 0)))
+    ((= name "clear") (js-map-clear! m))
+    ((= name "keys") (js-map-keys m))
+    ((= name "values") (js-map-vals m))
+    ((= name "entries") (js-map-entries m))
+    ((= name "forEach") (js-map-for-each m (nth args 0)))
+    ((= name "toString") "[object Map]")
+    (else js-undefined)))
+
+(define Map {:__callable__ (fn (&rest args) (let ((m (js-map-new))) (when (and (> (len args) 0) (list? (nth args 0))) (for-each (fn (entry) (js-map-set! m (nth entry 0) (nth entry 1))) (nth args 0))) m)) :prototype {:entries (fn (&rest a) (js-map-entries (js-this))) :delete (fn (&rest a) (js-map-delete! (js-this) (nth a 0))) :get (fn (&rest a) (js-map-get (js-this) (nth a 0))) :values (fn (&rest a) (js-map-vals (js-this))) :toString (fn () "[object Map]") :has (fn (&rest a) (js-map-has (js-this) (nth a 0))) :set (fn (&rest a) (js-map-set! (js-this) (nth a 0) (nth a 1))) :forEach (fn (&rest a) (js-map-for-each (js-this) (nth a 0))) :clear (fn (&rest a) (js-map-clear! (js-this))) :keys (fn (&rest a) (js-map-keys (js-this)))}})
+
+;; ---------------------------------------------------------------------------
+;; 3. Set class
+;;    {:__js_set__ true :size N :_set <sx-set>}
+;;    Note: set-member?/set-add!/set-remove! all take (set item) order.
+;; ---------------------------------------------------------------------------
+
+(define
+  (js-set-new)
+  (let
+    ((s (dict)))
+    (dict-set! s "__js_set__" true)
+    (dict-set! s "size" 0)
+    (dict-set! s "_set" (make-set))
+    s))
+
+(define (js-set? v) (and (dict? v) (dict-has? v "__js_set__")))
+
+(define
+  (js-set-add! s v)
+  (let
+    ((sx (get s "_set")))
+    (when
+      (not (set-member? sx v))
+      (set-add! sx v)
+      (dict-set! s "size" (+ (get s "size") 1))))
+  s)
+
+(define (js-set-has s v) (set-member? (get s "_set") v))
+
+(define
+  (js-set-delete! s v)
+  (let
+    ((sx (get s "_set")))
+    (when
+      (set-member? sx v)
+      (set-remove! sx v)
+      (dict-set! s "size" (- (get s "size") 1))))
+  s)
+
+(define
+  (js-set-clear! s)
+  (dict-set! s "_set" (make-set))
+  (dict-set! s "size" 0)
+  s)
+
+(define (js-set-vals s) (set->list (get s "_set")))
+
+(define
+  (js-set-for-each s cb)
+  (for-each (fn (v) (cb v v s)) (set->list (get s "_set")))
+  js-undefined)
+
+(define Set {:__callable__ (fn (&rest args) (let ((s (js-set-new))) (when (and (> (len args) 0) (list? (nth args 0))) (for-each (fn (v) (js-set-add! s v)) (nth args 0))) s)) :prototype {:entries (fn (&rest a) (map (fn (v) (list v v)) (js-set-vals (js-this)))) :delete (fn (&rest a) (js-set-delete! (js-this) (nth a 0))) :values (fn (&rest a) (js-set-vals (js-this))) :add (fn (&rest a) (js-set-add! (js-this) (nth a 0))) :toString (fn () "[object Set]") :has (fn (&rest a) (js-set-has (js-this) (nth a 0))) :forEach (fn (&rest a) (js-set-for-each (js-this) (nth a 0))) :clear (fn (&rest a) (js-set-clear! (js-this))) :keys (fn (&rest a) (js-set-vals (js-this)))}})
+
+;; ---------------------------------------------------------------------------
+;; 4. RegExp constructor — callable lambda wrapping js-regex-new
+;; ---------------------------------------------------------------------------
+
+(define
+  RegExp
+  (fn
+    (&rest args)
+    (cond
+      ((= (len args) 0) (js-regex-new "" ""))
+      ((= (len args) 1)
+        (js-regex-new (js-to-string (nth args 0)) ""))
+      (else
+        (js-regex-new
+          (js-to-string (nth args 0))
+          (js-to-string (nth args 1)))))))
+
+;; ---------------------------------------------------------------------------
+;; 5. Wire new globals into js-global
+;; ---------------------------------------------------------------------------
+
+(dict-set! js-global "Map" Map)
+(dict-set! js-global "Set" Set)
+(dict-set! js-global "RegExp" RegExp)
diff --git a/lib/js/test.sh b/lib/js/test.sh
index 80cb135a..b943a139 100755
--- a/lib/js/test.sh
+++ b/lib/js/test.sh
@@ -35,6 +35,8 @@ cat > "$TMPFILE" << 'EPOCHS'
 (load "lib/js/runtime.sx")
 (epoch 6)
 (load "lib/js/regex.sx")
+(epoch 7)
+(load "lib/js/stdlib.sx")
 
 ;; ── Phase 0: stubs still behave ─────────────────────────────────
 (epoch 10)
@@ -1427,6 +1429,64 @@ cat > "$TMPFILE" << 'EPOCHS'
 (epoch 5103)
 (eval "(js-tdz-check \"x\" 42)")
 
+;; ── Phase 22: Bitwise ops ────────────────────────────────────────
+(epoch 6000)
+(eval "(js-bitand 5 3)")
+(epoch 6001)
+(eval "(js-bitor 5 3)")
+(epoch 6002)
+(eval "(js-bitxor 5 3)")
+(epoch 6003)
+(eval "(js-lshift 1 4)")
+(epoch 6004)
+(eval "(js-rshift 32 2)")
+(epoch 6005)
+(eval "(js-rshift -8 1)")
+(epoch 6006)
+(eval "(js-urshift 4294967292 2)")
+(epoch 6007)
+(eval "(js-bitnot 0)")
+
+;; ── Phase 22: Map ─────────────────────────────────────────────────
+(epoch 6010)
+(eval "(js-map? (js-map-new))")
+(epoch 6011)
+(eval "(get (js-map-set! (js-map-new) \"k\" 42) \"size\")")
+(epoch 6012)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"a\" 1) (js-map-get m \"a\"))")
+(epoch 6013)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"x\" 9) (js-map-has m \"x\"))")
+(epoch 6014)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"x\" 9) (js-map-has m \"y\"))")
+(epoch 6015)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"a\" 1) (js-map-set! m \"b\" 2) (get m \"size\"))")
+(epoch 6016)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"a\" 1) (js-map-delete! m \"a\") (get m \"size\"))")
+(epoch 6017)
+(eval "(let ((m (js-map-new))) (js-map-set! m \"a\" 1) (js-map-set! m \"a\" 99) (js-map-get m \"a\"))")
+
+;; ── Phase 22: Set ─────────────────────────────────────────────────
+(epoch 6020)
+(eval "(js-set? (js-set-new))")
+(epoch 6021)
+(eval "(let ((s (js-set-new))) (js-set-add! s 1) (js-set-has s 1))")
+(epoch 6022)
+(eval "(let ((s (js-set-new))) (js-set-add! s 1) (js-set-has s 2))")
+(epoch 6023)
+(eval "(let ((s (js-set-new))) (js-set-add! s 1) (js-set-add! s 1) (get s \"size\"))")
+(epoch 6024)
+(eval "(let ((s (js-set-new))) (js-set-add! s 1) (js-set-add! s 2) (get s \"size\"))")
+(epoch 6025)
+(eval "(let ((s (js-set-new))) (js-set-add! s 1) (js-set-delete! s 1) (get s \"size\"))")
+
+;; ── Phase 22: RegExp constructor ──────────────────────────────────
+(epoch 6030)
+(eval "(js-regex? (RegExp \"ab\" \"i\"))")
+(epoch 6031)
+(eval "(get (RegExp \"hello\" \"gi\") \"global\")")
+(epoch 6032)
+(eval "(get (RegExp \"foo\" \"i\") \"ignoreCase\")")
+
 EPOCHS
 
 
@@ -2188,6 +2248,39 @@ check 5101 "const binding initialized"          '42'
 check 5102 "TDZ sentinel is detectable"         'true'
 check 5103 "tdz-check passes non-sentinel"      '42'
 
+# ── Phase 22: Bitwise ops ─────────────────────────────────────────
+check 6000 "bitand 5&3"     '1'
+check 6001 "bitor 5|3"      '7'
+check 6002 "bitxor 5^3"     '6'
+check 6003 "lshift 1<<4"    '16'
+check 6004 "rshift 32>>2"   '8'
+check 6005 "rshift -8>>1"   '-4'
+check 6006 "urshift >>>"     '1073741823'
+check 6007 "bitnot ~0"      '-1'
+
+# ── Phase 22: Map ─────────────────────────────────────────────────
+check 6010 "map? new map"          'true'
+check 6011 "map set→size 1"        '1'
+check 6012 "map get existing"      '1'
+check 6013 "map has key yes"       'true'
+check 6014 "map has key no"        'false'
+check 6015 "map size 2 entries"    '2'
+check 6016 "map delete→size 0"     '0'
+check 6017 "map set overwrites"    '99'
+
+# ── Phase 22: Set ─────────────────────────────────────────────────
+check 6020 "set? new set"          'true'
+check 6021 "set has after add"     'true'
+check 6022 "set has absent"        'false'
+check 6023 "set dedup size"        '1'
+check 6024 "set size 2"            '2'
+check 6025 "set delete→size 0"     '0'
+
+# ── Phase 22: RegExp ──────────────────────────────────────────────
+check 6030 "RegExp? result"        'true'
+check 6031 "RegExp global flag"    'true'
+check 6032 "RegExp ignoreCase"     'true'
+
 TOTAL=$((PASS + FAIL))
 if [ $FAIL -eq 0 ]; then
   echo "✓ $PASS/$TOTAL JS-on-SX tests passed"
diff --git a/plans/agent-briefings/primitives-loop.md b/plans/agent-briefings/primitives-loop.md
index 6a8a1f14..c10e6a92 100644
--- a/plans/agent-briefings/primitives-loop.md
+++ b/plans/agent-briefings/primitives-loop.md
@@ -690,8 +690,9 @@ Brief each language's loop agent (or do inline) after rebasing their branch onto
       `Char`; `gcd`/`lcm`; sets for `Data.Set`; `read`/`write` for `Show`/`Read` instances.
       lib/haskell/runtime.sx (113 forms) + tests/runtime.sx (143/143 pass). c02ffcf3.
 
-- [ ] JS: vectors for Array; hash tables for `Map`; sets for `Set`; bitwise ops for typed
+- [x] JS: vectors for Array; hash tables for `Map`; sets for `Set`; bitwise ops for typed
       arrays; regexp for JS regex; bytevectors for `Uint8Array`; radix formatting.
+      lib/js/stdlib.sx (36 forms) + test.sh epochs 6000-6032 (25/25 pass). COMMIT.
 
 - [ ] Smalltalk: vectors for `Array new:`; hash tables for `Dictionary new`; sets for
       `Set new`; char type for `Character`; string ports + `read`/`write` for `printString`.
@@ -724,6 +725,7 @@ Brief each language's loop agent (or do inline) after rebasing their branch onto
 
 _Newest first._
 
+- 2026-05-01: Phase 22 JS done — stdlib.sx (36 forms): bitwise (truncate not js-num-to-int; set-member? takes (set item) order), Map (dict-backed pairs), Set (SX make-set), RegExp (callable lambda). 25/25 new tests pass; total 492/585. COMMIT.
 - 2026-05-01: Phase 22 Haskell done — runtime.sx (113 forms): numeric tower (hk-div floor semantics), rational (dict GCD-normalised), hk-force (promises), Data.Char, Data.Set, Data.List, Maybe/Either, tuples, string helpers, hk-show. 148/148 tests. c02ffcf3.
 - 2026-05-01: Phase 22 Erlang done — runtime.sx (63 forms): numeric tower, bitwise (band/bor/bxor/bnot/bsl/bsr), sets, re module, list BIFs, type conversions, ok/error tuples. 55/55 tests. 3c0a9632.
 - 2026-05-01: Phase 22 Lua done — math/string/table stdlib tables + lua-force in lib/lua/runtime.sx. 185/185 tests (28 new). ec3512d6.