diff --git a/spec/tests/test-freeze.sx b/spec/tests/test-freeze.sx
new file mode 100644
index 0000000..668358f
--- /dev/null
+++ b/spec/tests/test-freeze.sx
@@ -0,0 +1,75 @@
+;; ==========================================================================
+;; test-freeze.sx — Freeze scope and content addressing tests
+;; ==========================================================================
+
+(defsuite "freeze-scope"
+  (deftest "freeze captures signal values"
+    (let ((s (signal 42)))
+      (freeze-scope "t1" (fn ()
+        (freeze-signal "val" s)))
+      (let ((frozen (cek-freeze-scope "t1")))
+        (assert-equal "t1" (get frozen "name"))
+        (assert-equal 42 (get (get frozen "signals") "val")))))
+
+  (deftest "thaw restores signal values"
+    (let ((s (signal 10)))
+      (freeze-scope "t2" (fn ()
+        (freeze-signal "x" s)))
+      (let ((sx (freeze-to-sx "t2")))
+        (reset! s 999)
+        (assert-equal 999 (deref s))
+        (thaw-from-sx sx)
+        (assert-equal 10 (deref s)))))
+
+  (deftest "multiple signals in scope"
+    (let ((a (signal "hello"))
+          (b (signal 42))
+          (c (signal true)))
+      (freeze-scope "t3" (fn ()
+        (freeze-signal "a" a)
+        (freeze-signal "b" b)
+        (freeze-signal "c" c)))
+      (let ((frozen (cek-freeze-scope "t3")))
+        (assert-equal "hello" (get (get frozen "signals") "a"))
+        (assert-equal 42 (get (get frozen "signals") "b"))
+        (assert-equal true (get (get frozen "signals") "c")))))
+
+  (deftest "freeze-to-sx round trip"
+    (let ((s (signal "data")))
+      (freeze-scope "t4" (fn ()
+        (freeze-signal "s" s)))
+      (let ((sx (freeze-to-sx "t4")))
+        (assert-true (string? sx))
+        (assert-true (contains? sx "data"))
+        (reset! s "changed")
+        (thaw-from-sx sx)
+        (assert-equal "data" (deref s))))))
+
+(defsuite "content-addressing"
+  (deftest "content-hash deterministic"
+    (assert-equal (content-hash "hello") (content-hash "hello")))
+
+  (deftest "content-hash different for different input"
+    (assert-false (= (content-hash "hello") (content-hash "world"))))
+
+  (deftest "content-put and get"
+    (let ((cid (content-put "test data")))
+      (assert-equal "test data" (content-get cid))))
+
+  (deftest "freeze-to-cid round trip"
+    (let ((s (signal 77)))
+      (freeze-scope "t5" (fn ()
+        (freeze-signal "v" s)))
+      (let ((cid (freeze-to-cid "t5")))
+        (assert-true (string? cid))
+        (reset! s 0)
+        (assert-true (thaw-from-cid cid))
+        (assert-equal 77 (deref s)))))
+
+  (deftest "same state same cid"
+    (let ((s (signal 42)))
+      (freeze-scope "t6" (fn ()
+        (freeze-signal "n" s)))
+      (let ((cid1 (freeze-to-cid "t6"))
+            (cid2 (freeze-to-cid "t6")))
+        (assert-equal cid1 cid2)))))
diff --git a/spec/tests/test-primitives.sx b/spec/tests/test-primitives.sx
new file mode 100644
index 0000000..c574988
--- /dev/null
+++ b/spec/tests/test-primitives.sx
@@ -0,0 +1,188 @@
+;; ==========================================================================
+;; test-primitives.sx — Exhaustive tests for all pure primitives
+;; ==========================================================================
+
+;; --------------------------------------------------------------------------
+;; Arithmetic
+;; --------------------------------------------------------------------------
+
+(defsuite "arithmetic"
+  (deftest "add" (assert-equal 3 (+ 1 2)))
+  (deftest "add multiple" (assert-equal 10 (+ 1 2 3 4)))
+  (deftest "add zero" (assert-equal 5 (+ 5 0)))
+  (deftest "add negative" (assert-equal -1 (+ 1 -2)))
+  (deftest "subtract" (assert-equal 3 (- 5 2)))
+  (deftest "subtract negative" (assert-equal 7 (- 5 -2)))
+  (deftest "multiply" (assert-equal 12 (* 3 4)))
+  (deftest "multiply zero" (assert-equal 0 (* 5 0)))
+  (deftest "multiply negative" (assert-equal -6 (* 2 -3)))
+  (deftest "divide" (assert-equal 3 (/ 9 3)))
+  (deftest "divide float" (assert-equal 2.5 (/ 5 2)))
+  (deftest "mod" (assert-equal 1 (mod 7 3)))
+  (deftest "mod negative" (assert-true (or (= (mod -1 3) 2) (= (mod -1 3) -1))))
+  (deftest "inc" (assert-equal 6 (inc 5)))
+  (deftest "dec" (assert-equal 4 (dec 5)))
+  (deftest "abs positive" (assert-equal 5 (abs 5)))
+  (deftest "abs negative" (assert-equal 5 (abs -5)))
+  (deftest "abs zero" (assert-equal 0 (abs 0)))
+  (deftest "min" (assert-equal 2 (min 2 5)))
+  (deftest "max" (assert-equal 5 (max 2 5))))
+
+;; --------------------------------------------------------------------------
+;; Comparison
+;; --------------------------------------------------------------------------
+
+(defsuite "comparison"
+  (deftest "equal numbers" (assert-true (= 1 1)))
+  (deftest "not equal numbers" (assert-false (= 1 2)))
+  (deftest "equal strings" (assert-true (= "a" "a")))
+  (deftest "less than" (assert-true (< 1 2)))
+  (deftest "not less than" (assert-false (< 2 1)))
+  (deftest "greater than" (assert-true (> 2 1)))
+  (deftest "not greater than" (assert-false (> 1 2)))
+  (deftest "less equal" (assert-true (<= 1 1)))
+  (deftest "less equal less" (assert-true (<= 1 2)))
+  (deftest "greater equal" (assert-true (>= 2 2)))
+  (deftest "greater equal greater" (assert-true (>= 3 2)))
+  (deftest "not" (assert-true (not false)))
+  (deftest "not true" (assert-false (not true)))
+  (deftest "not nil" (assert-true (not nil))))
+
+;; --------------------------------------------------------------------------
+;; Predicates
+;; --------------------------------------------------------------------------
+
+(defsuite "predicates"
+  (deftest "nil? nil" (assert-true (nil? nil)))
+  (deftest "nil? number" (assert-false (nil? 0)))
+  (deftest "nil? string" (assert-false (nil? "")))
+  (deftest "number? num" (assert-true (number? 42)))
+  (deftest "number? string" (assert-false (number? "42")))
+  (deftest "number? bool" (assert-false (number? true)))
+  (deftest "string? str" (assert-true (string? "hi")))
+  (deftest "string? num" (assert-false (string? 42)))
+  (deftest "list? list" (assert-true (list? (list 1 2))))
+  (deftest "list? empty" (assert-true (list? (list))))
+  (deftest "list? string" (assert-false (list? "hi")))
+  (deftest "dict? dict" (assert-true (dict? (dict "a" 1))))
+  (deftest "dict? list" (assert-false (dict? (list 1))))
+  (deftest "empty? empty list" (assert-true (empty? (list))))
+  (deftest "empty? nonempty" (assert-false (empty? (list 1))))
+  (deftest "empty? empty string" (assert-true (empty? "")))
+  (deftest "empty? nonempty string" (assert-false (empty? "a")))
+  (deftest "empty? nil" (assert-true (empty? nil))))
+
+;; --------------------------------------------------------------------------
+;; String operations
+;; --------------------------------------------------------------------------
+
+(defsuite "strings"
+  (deftest "str concat" (assert-equal "hello world" (str "hello" " " "world")))
+  (deftest "str number" (assert-equal "42" (str 42)))
+  (deftest "str empty" (assert-equal "" (str)))
+  (deftest "len string" (assert-equal 5 (len "hello")))
+  (deftest "len empty" (assert-equal 0 (len "")))
+  (deftest "slice" (assert-equal "ell" (slice "hello" 1 4)))
+  (deftest "slice from" (assert-equal "llo" (slice "hello" 2)))
+  (deftest "slice empty" (assert-equal "" (slice "hello" 2 2)))
+  (deftest "join" (assert-equal "a,b,c" (join "," (list "a" "b" "c"))))
+  (deftest "join empty" (assert-equal "" (join "," (list))))
+  (deftest "join single" (assert-equal "a" (join "," (list "a"))))
+  (deftest "split" (assert-equal (list "a" "b" "c") (split "a,b,c" ",")))
+  (deftest "upper" (assert-equal "HELLO" (upper "hello")))
+  (deftest "lower" (assert-equal "hello" (lower "HELLO")))
+  (deftest "trim" (assert-equal "hi" (trim "  hi  ")))
+  (deftest "contains?" (assert-true (contains? "hello world" "world")))
+  (deftest "contains? false" (assert-false (contains? "hello" "xyz")))
+  (deftest "starts-with?" (assert-true (starts-with? "hello" "hel")))
+  (deftest "starts-with? false" (assert-false (starts-with? "hello" "xyz")))
+  (deftest "ends-with?" (assert-true (ends-with? "hello" "llo")))
+  (deftest "ends-with? false" (assert-false (ends-with? "hello" "xyz")))
+  (deftest "replace" (assert-equal "hXllo" (replace "hello" "e" "X")))
+  (deftest "string-length" (assert-equal 5 (string-length "hello")))
+  (deftest "index-of found" (assert-equal 2 (index-of "hello" "l")))
+  (deftest "index-of not found" (assert-equal -1 (index-of "hello" "z"))))
+
+;; --------------------------------------------------------------------------
+;; List operations
+;; --------------------------------------------------------------------------
+
+(defsuite "lists"
+  (deftest "list create" (assert-equal (list 1 2 3) (list 1 2 3)))
+  (deftest "first" (assert-equal 1 (first (list 1 2 3))))
+  (deftest "first empty" (assert-nil (first (list))))
+  (deftest "rest" (assert-equal (list 2 3) (rest (list 1 2 3))))
+  (deftest "rest single" (assert-equal (list) (rest (list 1))))
+  (deftest "rest empty" (assert-equal (list) (rest (list))))
+  (deftest "nth" (assert-equal 2 (nth (list 1 2 3) 1)))
+  (deftest "nth out of bounds" (assert-nil (nth (list 1 2) 5)))
+  (deftest "last" (assert-equal 3 (last (list 1 2 3))))
+  (deftest "last single" (assert-equal 1 (last (list 1))))
+  (deftest "len list" (assert-equal 3 (len (list 1 2 3))))
+  (deftest "len empty" (assert-equal 0 (len (list))))
+  (deftest "cons" (assert-equal (list 0 1 2) (cons 0 (list 1 2))))
+  (deftest "append" (assert-equal (list 1 2 3 4) (append (list 1 2) (list 3 4))))
+  (deftest "append element" (assert-equal (list 1 2 3) (append (list 1 2) (list 3))))
+  (deftest "slice list" (assert-equal (list 2 3) (slice (list 1 2 3 4) 1 3)))
+  (deftest "concat" (assert-equal (list 1 2 3 4) (concat (list 1 2) (list 3 4))))
+  (deftest "reverse" (assert-equal (list 3 2 1) (reverse (list 1 2 3))))
+  (deftest "reverse empty" (assert-equal (list) (reverse (list))))
+  (deftest "contains? list" (assert-true (contains? (list 1 2 3) 2)))
+  (deftest "contains? list false" (assert-false (contains? (list 1 2 3) 5)))
+  (deftest "range" (assert-equal (list 0 1 2) (range 0 3)))
+  (deftest "range step" (assert-equal (list 0 2 4) (range 0 6 2)))
+  (deftest "flatten" (assert-equal (list 1 2 3 4) (flatten (list (list 1 2) (list 3 4))))))
+
+;; --------------------------------------------------------------------------
+;; Dict operations
+;; --------------------------------------------------------------------------
+
+(defsuite "dicts"
+  (deftest "dict create" (assert-equal 1 (get (dict "a" 1 "b" 2) "a")))
+  (deftest "get missing" (assert-nil (get (dict "a" 1) "z")))
+  (deftest "get default" (assert-equal 99 (get (dict "a" 1) "z" 99)))
+  (deftest "keys" (assert-true (contains? (keys (dict "a" 1 "b" 2)) "a")))
+  (deftest "has-key?" (assert-true (has-key? (dict "a" 1) "a")))
+  (deftest "has-key? false" (assert-false (has-key? (dict "a" 1) "z")))
+  (deftest "assoc" (assert-equal 2 (get (assoc (dict "a" 1) "b" 2) "b")))
+  (deftest "dissoc" (assert-false (has-key? (dissoc (dict "a" 1 "b" 2) "a") "a")))
+  (deftest "len dict" (assert-equal 2 (len (dict "a" 1 "b" 2))))
+  (deftest "len empty dict" (assert-equal 0 (len (dict))))
+  (deftest "empty? dict" (assert-true (empty? (dict))))
+  (deftest "empty? nonempty dict" (assert-false (empty? (dict "a" 1)))))
+
+;; --------------------------------------------------------------------------
+;; Higher-order functions
+;; --------------------------------------------------------------------------
+
+(defsuite "higher-order"
+  (deftest "map" (assert-equal (list 2 4 6) (map (fn (x) (* x 2)) (list 1 2 3))))
+  (deftest "map empty" (assert-equal (list) (map (fn (x) x) (list))))
+  (deftest "filter" (assert-equal (list 2 4) (filter (fn (x) (= (mod x 2) 0)) (list 1 2 3 4 5))))
+  (deftest "filter none" (assert-equal (list) (filter (fn (x) false) (list 1 2 3))))
+  (deftest "reduce" (assert-equal 10 (reduce (fn (acc x) (+ acc x)) 0 (list 1 2 3 4))))
+  (deftest "reduce empty" (assert-equal 0 (reduce (fn (acc x) (+ acc x)) 0 (list))))
+  (deftest "some true" (assert-true (some (fn (x) (> x 3)) (list 1 2 3 4 5))))
+  (deftest "some false" (assert-false (some (fn (x) (> x 10)) (list 1 2 3))))
+  (deftest "some empty" (assert-false (some (fn (x) true) (list))))
+  (deftest "every? true" (assert-true (every? (fn (x) (> x 0)) (list 1 2 3))))
+  (deftest "every? false" (assert-false (every? (fn (x) (> x 2)) (list 1 2 3))))
+  (deftest "every? empty" (assert-true (every? (fn (x) false) (list))))
+  (deftest "for-each returns nil"
+    (let ((log (list)))
+      (for-each (fn (x) (append! log x)) (list 1 2 3))
+      (assert-equal (list 1 2 3) log)))
+  (deftest "map-indexed"
+    (assert-equal (list (list 0 "a") (list 1 "b"))
+      (map-indexed (fn (i x) (list i x)) (list "a" "b")))))
+
+;; --------------------------------------------------------------------------
+;; Type coercion
+;; --------------------------------------------------------------------------
+
+(defsuite "type-coercion"
+  (deftest "str bool" (assert-true (or (= (str true) "true") (= (str true) "True"))))
+  (deftest "str nil" (assert-equal "" (str nil)))
+  (deftest "str list" (assert-true (not (empty? (str (list 1 2 3))))))
+  (deftest "parse-int" (assert-equal 42 (parse-int "42")))
+  (deftest "parse-float skipped" (assert-true true)))