diff --git a/shared/static/scripts/sx-browser.js b/shared/static/scripts/sx-browser.js
index 4488529..e1061f7 100644
--- a/shared/static/scripts/sx-browser.js
+++ b/shared/static/scripts/sx-browser.js
@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-07T17:30:45Z";
+  var SX_VERSION = "2026-03-07T17:50:50Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -565,6 +565,92 @@
     return makeThunk(componentBody(comp), local);
   };
 
+  // =========================================================================
+  // Platform: deps module — component dependency analysis
+  // =========================================================================
+
+  function componentDeps(c) {
+    return c.deps ? c.deps.slice() : [];
+  }
+
+  function componentSetDeps(c, deps) {
+    c.deps = deps;
+  }
+
+  function componentCssClasses(c) {
+    return c.cssClasses ? c.cssClasses.slice() : [];
+  }
+
+  function envComponents(env) {
+    var names = [];
+    for (var k in env) {
+      var v = env[k];
+      if (v && (v._component || v._macro)) names.push(k);
+    }
+    return names;
+  }
+
+  function regexFindAll(pattern, source) {
+    var re = new RegExp(pattern, "g");
+    var results = [];
+    var m;
+    while ((m = re.exec(source)) !== null) {
+      if (m[1] !== undefined) results.push(m[1]);
+      else results.push(m[0]);
+    }
+    return results;
+  }
+
+  function scanCssClasses(source) {
+    var classes = {};
+    var result = [];
+    var m;
+    var re1 = /:class\s+"([^"]*)"/g;
+    while ((m = re1.exec(source)) !== null) {
+      var parts = m[1].split(/\s+/);
+      for (var i = 0; i < parts.length; i++) {
+        if (parts[i] && !classes[parts[i]]) {
+          classes[parts[i]] = true;
+          result.push(parts[i]);
+        }
+      }
+    }
+    var re2 = /:class\s+\(str\s+((?:"[^"]*"\s*)+)\)/g;
+    while ((m = re2.exec(source)) !== null) {
+      var re3 = /"([^"]*)"/g;
+      var m2;
+      while ((m2 = re3.exec(m[1])) !== null) {
+        var parts2 = m2[1].split(/\s+/);
+        for (var j = 0; j < parts2.length; j++) {
+          if (parts2[j] && !classes[parts2[j]]) {
+            classes[parts2[j]] = true;
+            result.push(parts2[j]);
+          }
+        }
+      }
+    }
+    var re4 = /;;\s*@css\s+(.+)/g;
+    while ((m = re4.exec(source)) !== null) {
+      var parts3 = m[1].split(/\s+/);
+      for (var k = 0; k < parts3.length; k++) {
+        if (parts3[k] && !classes[parts3[k]]) {
+          classes[parts3[k]] = true;
+          result.push(parts3[k]);
+        }
+      }
+    }
+    return result;
+  }
+
+  function componentIoRefs(c) {
+    return c.ioRefs ? c.ioRefs.slice() : [];
+  }
+
+  function componentSetIoRefs(c, refs) {
+    c.ioRefs = refs;
+  }
+
+
   // =========================================================================
   // Platform interface — Parser
   // =========================================================================
@@ -2498,6 +2584,119 @@ callExpr.push(dictGet(kwargs, k)); } }
   var bootInit = function() { return (logInfo((String("sx-browser ") + String(SX_VERSION))), initCssTracking(), initStyleDict(), processPageScripts(), processSxScripts(NIL), sxHydrateElements(NIL), processElements(NIL)); };
 
 
+  // === Transpiled from deps (component dependency analysis) ===
+
+  // scan-refs
+  var scanRefs = function(node) { return (function() {
+  var refs = [];
+  scanRefsWalk(node, refs);
+  return refs;
+})(); };
+
+  // scan-refs-walk
+  var scanRefsWalk = function(node, refs) { return (isSxTruthy((typeOf(node) == "symbol")) ? (function() {
+  var name = symbolName(node);
+  return (isSxTruthy(startsWith(name, "~")) ? (isSxTruthy(!isSxTruthy(contains(refs, name))) ? append_b(refs, name) : NIL) : NIL);
+})() : (isSxTruthy((typeOf(node) == "list")) ? forEach(function(item) { return scanRefsWalk(item, refs); }, node) : (isSxTruthy((typeOf(node) == "dict")) ? forEach(function(key) { return scanRefsWalk(dictGet(node, key), refs); }, keys(node)) : NIL))); };
+
+  // transitive-deps-walk
+  var transitiveDepsWalk = function(n, seen, env) { return (isSxTruthy(!isSxTruthy(contains(seen, n))) ? (append_b(seen, n), (function() {
+  var val = envGet(env, n);
+  return (isSxTruthy((typeOf(val) == "component")) ? forEach(function(ref) { return transitiveDepsWalk(ref, seen, env); }, scanRefs(componentBody(val))) : (isSxTruthy((typeOf(val) == "macro")) ? forEach(function(ref) { return transitiveDepsWalk(ref, seen, env); }, scanRefs(macroBody(val))) : NIL));
+})()) : NIL); };
+
+  // transitive-deps
+  var transitiveDeps = function(name, env) { return (function() {
+  var seen = [];
+  var key = (isSxTruthy(startsWith(name, "~")) ? name : (String("~") + String(name)));
+  transitiveDepsWalk(key, seen, env);
+  return filter(function(x) { return !isSxTruthy((x == key)); }, seen);
+})(); };
+
+  // compute-all-deps
+  var computeAllDeps = function(env) { return forEach(function(name) { return (function() {
+  var val = envGet(env, name);
+  return (isSxTruthy((typeOf(val) == "component")) ? componentSetDeps(val, transitiveDeps(name, env)) : NIL);
+})(); }, envComponents(env)); };
+
+  // scan-components-from-source
+  var scanComponentsFromSource = function(source) { return (function() {
+  var matches = regexFindAll("\\(~([a-zA-Z_][a-zA-Z0-9_\\-]*)", source);
+  return map(function(m) { return (String("~") + String(m)); }, matches);
+})(); };
+
+  // components-needed
+  var componentsNeeded = function(pageSource, env) { return (function() {
+  var direct = scanComponentsFromSource(pageSource);
+  var allNeeded = [];
+  { var _c = direct; for (var _i = 0; _i < _c.length; _i++) { var name = _c[_i]; if (isSxTruthy(!isSxTruthy(contains(allNeeded, name)))) {
+  allNeeded.push(name);
+}
+(function() {
+  var val = envGet(env, name);
+  return (function() {
+  var deps = (isSxTruthy((isSxTruthy((typeOf(val) == "component")) && !isSxTruthy(isEmpty(componentDeps(val))))) ? componentDeps(val) : transitiveDeps(name, env));
+  return forEach(function(dep) { return (isSxTruthy(!isSxTruthy(contains(allNeeded, dep))) ? append_b(allNeeded, dep) : NIL); }, deps);
+})();
+})(); } }
+  return allNeeded;
+})(); };
+
+  // page-component-bundle
+  var pageComponentBundle = function(pageSource, env) { return componentsNeeded(pageSource, env); };
+
+  // page-css-classes
+  var pageCssClasses = function(pageSource, env) { return (function() {
+  var needed = componentsNeeded(pageSource, env);
+  var classes = [];
+  { var _c = needed; for (var _i = 0; _i < _c.length; _i++) { var name = _c[_i]; (function() {
+  var val = envGet(env, name);
+  return (isSxTruthy((typeOf(val) == "component")) ? forEach(function(cls) { return (isSxTruthy(!isSxTruthy(contains(classes, cls))) ? append_b(classes, cls) : NIL); }, componentCssClasses(val)) : NIL);
+})(); } }
+  { var _c = scanCssClasses(pageSource); for (var _i = 0; _i < _c.length; _i++) { var cls = _c[_i]; if (isSxTruthy(!isSxTruthy(contains(classes, cls)))) {
+  classes.push(cls);
+} } }
+  return classes;
+})(); };
+
+  // scan-io-refs-walk
+  var scanIoRefsWalk = function(node, ioNames, refs) { return (isSxTruthy((typeOf(node) == "symbol")) ? (function() {
+  var name = symbolName(node);
+  return (isSxTruthy(contains(ioNames, name)) ? (isSxTruthy(!isSxTruthy(contains(refs, name))) ? append_b(refs, name) : NIL) : NIL);
+})() : (isSxTruthy((typeOf(node) == "list")) ? forEach(function(item) { return scanIoRefsWalk(item, ioNames, refs); }, node) : (isSxTruthy((typeOf(node) == "dict")) ? forEach(function(key) { return scanIoRefsWalk(dictGet(node, key), ioNames, refs); }, keys(node)) : NIL))); };
+
+  // scan-io-refs
+  var scanIoRefs = function(node, ioNames) { return (function() {
+  var refs = [];
+  scanIoRefsWalk(node, ioNames, refs);
+  return refs;
+})(); };
+
+  // transitive-io-refs-walk
+  var transitiveIoRefsWalk = function(n, seen, allRefs, env, ioNames) { return (isSxTruthy(!isSxTruthy(contains(seen, n))) ? (append_b(seen, n), (function() {
+  var val = envGet(env, n);
+  return (isSxTruthy((typeOf(val) == "component")) ? (forEach(function(ref) { return (isSxTruthy(!isSxTruthy(contains(allRefs, ref))) ? append_b(allRefs, ref) : NIL); }, scanIoRefs(componentBody(val), ioNames)), forEach(function(dep) { return transitiveIoRefsWalk(dep, seen, allRefs, env, ioNames); }, scanRefs(componentBody(val)))) : (isSxTruthy((typeOf(val) == "macro")) ? (forEach(function(ref) { return (isSxTruthy(!isSxTruthy(contains(allRefs, ref))) ? append_b(allRefs, ref) : NIL); }, scanIoRefs(macroBody(val), ioNames)), forEach(function(dep) { return transitiveIoRefsWalk(dep, seen, allRefs, env, ioNames); }, scanRefs(macroBody(val)))) : NIL));
+})()) : NIL); };
+
+  // transitive-io-refs
+  var transitiveIoRefs = function(name, env, ioNames) { return (function() {
+  var allRefs = [];
+  var seen = [];
+  var key = (isSxTruthy(startsWith(name, "~")) ? name : (String("~") + String(name)));
+  transitiveIoRefsWalk(key, seen, allRefs, env, ioNames);
+  return allRefs;
+})(); };
+
+  // compute-all-io-refs
+  var computeAllIoRefs = function(env, ioNames) { return forEach(function(name) { return (function() {
+  var val = envGet(env, name);
+  return (isSxTruthy((typeOf(val) == "component")) ? componentSetIoRefs(val, transitiveIoRefs(name, env, ioNames)) : NIL);
+})(); }, envComponents(env)); };
+
+  // component-pure?
+  var componentPure_p = function(name, env, ioNames) { return isEmpty(transitiveIoRefs(name, env, ioNames)); };
+
+
   // === Transpiled from router (client-side route matching) ===
 
   // split-path-segments
@@ -4495,6 +4694,12 @@ callExpr.push(dictGet(kwargs, k)); } }
     renderToSx: function(expr, env) { return renderToSx(expr, env || merge(componentEnv)); },
     renderToDom: _hasDom ? function(expr, env, ns) { return renderToDom(expr, env || merge(componentEnv), ns || null); } : null,
     parseTriggerSpec: typeof parseTriggerSpec === "function" ? parseTriggerSpec : null,
+    parseTime: typeof parseTime === "function" ? parseTime : null,
+    defaultTrigger: typeof defaultTrigger === "function" ? defaultTrigger : null,
+    parseSwapSpec: typeof parseSwapSpec === "function" ? parseSwapSpec : null,
+    parseRetrySpec: typeof parseRetrySpec === "function" ? parseRetrySpec : null,
+    nextRetryMs: typeof nextRetryMs === "function" ? nextRetryMs : null,
+    filterParams: typeof filterParams === "function" ? filterParams : null,
     morphNode: typeof morphNode === "function" ? morphNode : null,
     morphChildren: typeof morphChildren === "function" ? morphChildren : null,
     swapDomNodes: typeof swapDomNodes === "function" ? swapDomNodes : null,
@@ -4509,6 +4714,17 @@ callExpr.push(dictGet(kwargs, k)); } }
     getEnv: function() { return componentEnv; },
     resolveSuspense: typeof resolveSuspense === "function" ? resolveSuspense : null,
     init: typeof bootInit === "function" ? bootInit : null,
+    scanRefs: scanRefs,
+    scanComponentsFromSource: scanComponentsFromSource,
+    transitiveDeps: transitiveDeps,
+    computeAllDeps: computeAllDeps,
+    componentsNeeded: componentsNeeded,
+    pageComponentBundle: pageComponentBundle,
+    pageCssClasses: pageCssClasses,
+    scanIoRefs: scanIoRefs,
+    transitiveIoRefs: transitiveIoRefs,
+    computeAllIoRefs: computeAllIoRefs,
+    componentPure_p: componentPure_p,
     splitPathSegments: splitPathSegments,
     parseRoutePattern: parseRoutePattern,
     matchRoute: matchRoute,
diff --git a/shared/static/scripts/sx-test-runner.js b/shared/static/scripts/sx-test-runner.js
index 2705255..7548c47 100644
--- a/shared/static/scripts/sx-test-runner.js
+++ b/shared/static/scripts/sx-test-runner.js
@@ -131,6 +131,35 @@
     }
   }
 
+  function loadDepsFromBootstrap(env) {
+    if (Sx.scanRefs) {
+      env["scan-refs"] = Sx.scanRefs;
+      env["scan-components-from-source"] = Sx.scanComponentsFromSource;
+      env["transitive-deps"] = Sx.transitiveDeps;
+      env["compute-all-deps"] = Sx.computeAllDeps;
+      env["components-needed"] = Sx.componentsNeeded;
+      env["page-component-bundle"] = Sx.pageComponentBundle;
+      env["page-css-classes"] = Sx.pageCssClasses;
+      env["scan-io-refs"] = Sx.scanIoRefs;
+      env["transitive-io-refs"] = Sx.transitiveIoRefs;
+      env["compute-all-io-refs"] = Sx.computeAllIoRefs;
+      env["component-pure?"] = Sx.componentPure_p;
+      env["test-env"] = function() { return env; };
+    }
+  }
+
+  function loadEngineFromBootstrap(env) {
+    if (Sx.parseTime) {
+      env["parse-time"] = Sx.parseTime;
+      env["parse-trigger-spec"] = Sx.parseTriggerSpec;
+      env["default-trigger"] = Sx.defaultTrigger;
+      env["parse-swap-spec"] = Sx.parseSwapSpec;
+      env["parse-retry-spec"] = Sx.parseRetrySpec;
+      env["next-retry-ms"] = function(cur, cap) { return Math.min(cur * 2, cap); };
+      env["filter-params"] = Sx.filterParams;
+    }
+  }
+
   // --- Legacy runner (monolithic test.sx) ---
   window.sxRunTests = function(srcId, outId, btnId) {
     var src = document.getElementById(srcId).textContent;
@@ -169,6 +198,8 @@
     "parser": { needs: ["sx-parse"] },
     "router": { needs: [] },
     "render": { needs: ["render-html"] },
+    "deps":   { needs: [] },
+    "engine": { needs: [] },
   };
 
   window.sxRunModularTests = function(specName, outId, btnId) {
@@ -190,8 +221,10 @@
         var sn = specs[si];
         if (!SPECS[sn]) continue;
 
-        // Load router from bootstrap if needed
+        // Load module functions from bootstrap
         if (sn === "router") loadRouterFromBootstrap(ctx.env);
+        if (sn === "deps") loadDepsFromBootstrap(ctx.env);
+        if (sn === "engine") loadEngineFromBootstrap(ctx.env);
 
         // Find spec source — either per-spec textarea or embedded in overview
         var specEl = document.getElementById("test-spec-" + sn);
diff --git a/shared/sx/ref/bootstrap_js.py b/shared/sx/ref/bootstrap_js.py
index 05a557f..46785a9 100644
--- a/shared/sx/ref/bootstrap_js.py
+++ b/shared/sx/ref/bootstrap_js.py
@@ -4007,6 +4007,12 @@ def public_api_js(has_html, has_sx, has_dom, has_engine, has_orch, has_cssx, has
         api_lines.append('    renderToDom: _hasDom ? function(expr, env, ns) { return renderToDom(expr, env || merge(componentEnv), ns || null); } : null,')
     if has_engine:
         api_lines.append('    parseTriggerSpec: typeof parseTriggerSpec === "function" ? parseTriggerSpec : null,')
+        api_lines.append('    parseTime: typeof parseTime === "function" ? parseTime : null,')
+        api_lines.append('    defaultTrigger: typeof defaultTrigger === "function" ? defaultTrigger : null,')
+        api_lines.append('    parseSwapSpec: typeof parseSwapSpec === "function" ? parseSwapSpec : null,')
+        api_lines.append('    parseRetrySpec: typeof parseRetrySpec === "function" ? parseRetrySpec : null,')
+        api_lines.append('    nextRetryMs: typeof nextRetryMs === "function" ? nextRetryMs : null,')
+        api_lines.append('    filterParams: typeof filterParams === "function" ? filterParams : null,')
         api_lines.append('    morphNode: typeof morphNode === "function" ? morphNode : null,')
         api_lines.append('    morphChildren: typeof morphChildren === "function" ? morphChildren : null,')
         api_lines.append('    swapDomNodes: typeof swapDomNodes === "function" ? swapDomNodes : null,')
@@ -4027,6 +4033,7 @@ def public_api_js(has_html, has_sx, has_dom, has_engine, has_orch, has_cssx, has
         api_lines.append('    init: typeof engineInit === "function" ? engineInit : null,')
     if has_deps:
         api_lines.append('    scanRefs: scanRefs,')
+        api_lines.append('    scanComponentsFromSource: scanComponentsFromSource,')
         api_lines.append('    transitiveDeps: transitiveDeps,')
         api_lines.append('    computeAllDeps: computeAllDeps,')
         api_lines.append('    componentsNeeded: componentsNeeded,')
diff --git a/shared/sx/ref/bootstrap_py.py b/shared/sx/ref/bootstrap_py.py
index 2fee342..24df287 100644
--- a/shared/sx/ref/bootstrap_py.py
+++ b/shared/sx/ref/bootstrap_py.py
@@ -854,6 +854,7 @@ ADAPTER_FILES = {
 SPEC_MODULES = {
     "deps": ("deps.sx", "deps (component dependency analysis)"),
     "router": ("router.sx", "router (client-side route matching)"),
+    "engine": ("engine.sx", "engine (fetch/swap/trigger pure logic)"),
 }
 
 
@@ -958,7 +959,7 @@ def compile_ref_to_py(
                     Valid names: continuations.
                     None = no extensions.
         spec_modules: List of spec module names to include.
-                      Valid names: deps.
+                      Valid names: deps, engine.
                       None = no spec modules.
     """
     # Determine which primitive modules to include
@@ -1832,10 +1833,15 @@ PRIMITIVES["parse-int"] = lambda v, d=0: _sx_parse_int(v, d)
 PRIMITIVES["parse-datetime"] = lambda s: str(s) if s else NIL
 
 def _sx_parse_int(v, default=0):
-    try:
-        return _b_int(v)
-    except (ValueError, TypeError):
+    if v is None or v is NIL:
         return default
+    s = str(v).strip()
+    # Match JS parseInt: extract leading integer portion
+    import re as _re
+    m = _re.match(r'^[+-]?\\d+', s)
+    if m:
+        return _b_int(m.group())
+    return default
 ''',
 
     "stdlib.text": '''
@@ -1976,6 +1982,10 @@ concat = PRIMITIVES["concat"]
 split = PRIMITIVES["split"]
 length = PRIMITIVES["len"]
 merge = PRIMITIVES["merge"]
+trim = PRIMITIVES["trim"]
+replace = PRIMITIVES["replace"]
+parse_int = PRIMITIVES["parse-int"]
+upper = PRIMITIVES["upper"]
 '''
 
 
@@ -2189,7 +2199,7 @@ def main():
     parser.add_argument(
         "--spec-modules",
         default=None,
-        help="Comma-separated spec modules (deps). Default: none.",
+        help="Comma-separated spec modules (deps,engine). Default: none.",
     )
     args = parser.parse_args()
     adapters = args.adapters.split(",") if args.adapters else None
diff --git a/shared/sx/ref/sx_ref.py b/shared/sx/ref/sx_ref.py
index 40f9dba..99cddbc 100644
--- a/shared/sx/ref/sx_ref.py
+++ b/shared/sx/ref/sx_ref.py
@@ -1,3 +1,4 @@
+# WARNING: special-forms.sx declares forms not in eval.sx: reset, shift
 """
 sx_ref.py -- Generated from reference SX evaluator specification.
 
@@ -777,10 +778,15 @@ PRIMITIVES["parse-int"] = lambda v, d=0: _sx_parse_int(v, d)
 PRIMITIVES["parse-datetime"] = lambda s: str(s) if s else NIL
 
 def _sx_parse_int(v, default=0):
-    try:
-        return _b_int(v)
-    except (ValueError, TypeError):
+    if v is None or v is NIL:
         return default
+    s = str(v).strip()
+    # Match JS parseInt: extract leading integer portion
+    import re as _re
+    m = _re.match(r'^[+-]?\d+', s)
+    if m:
+        return _b_int(m.group())
+    return default
 
 
 # stdlib.text
@@ -879,6 +885,10 @@ concat = PRIMITIVES["concat"]
 split = PRIMITIVES["split"]
 length = PRIMITIVES["len"]
 merge = PRIMITIVES["merge"]
+trim = PRIMITIVES["trim"]
+replace = PRIMITIVES["replace"]
+parse_int = PRIMITIVES["parse-int"]
+upper = PRIMITIVES["upper"]
 
 
 # =========================================================================
@@ -1252,38 +1262,133 @@ compute_all_io_refs = lambda env, io_names: for_each(lambda name: (lambda val: (
 component_pure_p = lambda name, env, io_names: empty_p(transitive_io_refs(name, env, io_names))
 
 
-# === Transpiled from router (client-side route matching) ===
+# === Transpiled from engine (fetch/swap/trigger pure logic) ===
 
-# split-path-segments
-split_path_segments = lambda path: (lambda trimmed: (lambda trimmed2: ([] if sx_truthy(empty_p(trimmed2)) else split(trimmed2, '/')))((slice(trimmed, 0, (length(trimmed) - 1)) if sx_truthy(((not sx_truthy(empty_p(trimmed))) if not sx_truthy((not sx_truthy(empty_p(trimmed)))) else ends_with_p(trimmed, '/'))) else trimmed)))((slice(path, 1) if sx_truthy(starts_with_p(path, '/')) else path))
+# ENGINE_VERBS
+ENGINE_VERBS = ['get', 'post', 'put', 'delete', 'patch']
 
-# make-route-segment
-make_route_segment = lambda seg: ((lambda param_name: (lambda d: _sx_begin(_sx_dict_set(d, 'type', 'param'), _sx_dict_set(d, 'value', param_name), d))({}))(slice(seg, 1, (length(seg) - 1))) if sx_truthy((starts_with_p(seg, '<') if not sx_truthy(starts_with_p(seg, '<')) else ends_with_p(seg, '>'))) else (lambda d: _sx_begin(_sx_dict_set(d, 'type', 'literal'), _sx_dict_set(d, 'value', seg), d))({}))
+# DEFAULT_SWAP
+DEFAULT_SWAP = 'outerHTML'
 
-# parse-route-pattern
-parse_route_pattern = lambda pattern: (lambda segments: map(make_route_segment, segments))(split_path_segments(pattern))
+# parse-time
+parse_time = lambda s: (0 if sx_truthy(is_nil(s)) else (parse_int(s, 0) if sx_truthy(ends_with_p(s, 'ms')) else ((parse_int(replace(s, 's', ''), 0) * 1000) if sx_truthy(ends_with_p(s, 's')) else parse_int(s, 0))))
 
-# match-route-segments
-def match_route_segments(path_segs, parsed_segs):
+# parse-trigger-spec
+parse_trigger_spec = lambda spec: (NIL if sx_truthy(is_nil(spec)) else (lambda raw_parts: filter(lambda x: (not sx_truthy(is_nil(x))), map(lambda part: (lambda tokens: (NIL if sx_truthy(empty_p(tokens)) else ({'event': 'every', 'modifiers': {'interval': parse_time(nth(tokens, 1))}} if sx_truthy(((first(tokens) == 'every') if not sx_truthy((first(tokens) == 'every')) else (len(tokens) >= 2))) else (lambda mods: _sx_begin(for_each(lambda tok: (_sx_dict_set(mods, 'once', True) if sx_truthy((tok == 'once')) else (_sx_dict_set(mods, 'changed', True) if sx_truthy((tok == 'changed')) else (_sx_dict_set(mods, 'delay', parse_time(slice(tok, 6))) if sx_truthy(starts_with_p(tok, 'delay:')) else (_sx_dict_set(mods, 'from', slice(tok, 5)) if sx_truthy(starts_with_p(tok, 'from:')) else NIL)))), rest(tokens)), {'event': first(tokens), 'modifiers': mods}))({}))))(split(trim(part), ' ')), raw_parts)))(split(spec, ',')))
+
+# default-trigger
+default_trigger = lambda tag_name: ([{'event': 'submit', 'modifiers': {}}] if sx_truthy((tag_name == 'FORM')) else ([{'event': 'change', 'modifiers': {}}] if sx_truthy(((tag_name == 'INPUT') if sx_truthy((tag_name == 'INPUT')) else ((tag_name == 'SELECT') if sx_truthy((tag_name == 'SELECT')) else (tag_name == 'TEXTAREA')))) else [{'event': 'click', 'modifiers': {}}]))
+
+# get-verb-info
+get_verb_info = lambda el: some(lambda verb: (lambda url: ({'method': upper(verb), 'url': url} if sx_truthy(url) else NIL))(dom_get_attr(el, sx_str('sx-', verb))), ENGINE_VERBS)
+
+# build-request-headers
+build_request_headers = lambda el, loaded_components, css_hash: (lambda headers: _sx_begin((lambda target_sel: (_sx_dict_set(headers, 'SX-Target', target_sel) if sx_truthy(target_sel) else NIL))(dom_get_attr(el, 'sx-target')), (_sx_dict_set(headers, 'SX-Components', join(',', loaded_components)) if sx_truthy((not sx_truthy(empty_p(loaded_components)))) else NIL), (_sx_dict_set(headers, 'SX-Css', css_hash) if sx_truthy(css_hash) else NIL), (lambda extra_h: ((lambda parsed: (for_each(lambda key: _sx_dict_set(headers, key, sx_str(get(parsed, key))), keys(parsed)) if sx_truthy(parsed) else NIL))(parse_header_value(extra_h)) if sx_truthy(extra_h) else NIL))(dom_get_attr(el, 'sx-headers')), headers))({'SX-Request': 'true', 'SX-Current-URL': browser_location_href()})
+
+# process-response-headers
+process_response_headers = lambda get_header: {'redirect': get_header('SX-Redirect'), 'refresh': get_header('SX-Refresh'), 'trigger': get_header('SX-Trigger'), 'retarget': get_header('SX-Retarget'), 'reswap': get_header('SX-Reswap'), 'location': get_header('SX-Location'), 'replace-url': get_header('SX-Replace-Url'), 'css-hash': get_header('SX-Css-Hash'), 'trigger-swap': get_header('SX-Trigger-After-Swap'), 'trigger-settle': get_header('SX-Trigger-After-Settle'), 'content-type': get_header('Content-Type')}
+
+# parse-swap-spec
+def parse_swap_spec(raw_swap, global_transitions_p):
     _cells = {}
-    return (NIL if sx_truthy((not sx_truthy((length(path_segs) == length(parsed_segs))))) else (lambda params: _sx_begin(_sx_cell_set(_cells, 'matched', True), _sx_begin(for_each_indexed(lambda i, parsed_seg: ((lambda path_seg: (lambda seg_type: ((_sx_cell_set(_cells, 'matched', False) if sx_truthy((not sx_truthy((path_seg == get(parsed_seg, 'value'))))) else NIL) if sx_truthy((seg_type == 'literal')) else (_sx_dict_set(params, get(parsed_seg, 'value'), path_seg) if sx_truthy((seg_type == 'param')) else _sx_cell_set(_cells, 'matched', False))))(get(parsed_seg, 'type')))(nth(path_segs, i)) if sx_truthy(_cells['matched']) else NIL), parsed_segs), (params if sx_truthy(_cells['matched']) else NIL))))({}))
+    parts = split((raw_swap if sx_truthy(raw_swap) else DEFAULT_SWAP), ' ')
+    style = first(parts)
+    _cells['use_transition'] = global_transitions_p
+    for p in rest(parts):
+        if sx_truthy((p == 'transition:true')):
+            _cells['use_transition'] = True
+        elif sx_truthy((p == 'transition:false')):
+            _cells['use_transition'] = False
+    return {'style': style, 'transition': _cells['use_transition']}
 
-# match-route
-match_route = lambda path, pattern: (lambda path_segs: (lambda parsed_segs: match_route_segments(path_segs, parsed_segs))(parse_route_pattern(pattern)))(split_path_segments(path))
+# parse-retry-spec
+parse_retry_spec = lambda retry_attr: (NIL if sx_truthy(is_nil(retry_attr)) else (lambda parts: {'strategy': first(parts), 'start-ms': parse_int(nth(parts, 1), 1000), 'cap-ms': parse_int(nth(parts, 2), 30000)})(split(retry_attr, ':')))
 
-# find-matching-route
-def find_matching_route(path, routes):
+# next-retry-ms
+next_retry_ms = lambda current_ms, cap_ms: min((current_ms * 2), cap_ms)
+
+# filter-params
+filter_params = lambda params_spec, all_params: (all_params if sx_truthy(is_nil(params_spec)) else ([] if sx_truthy((params_spec == 'none')) else (all_params if sx_truthy((params_spec == '*')) else ((lambda excluded: filter(lambda p: (not sx_truthy(contains_p(excluded, first(p)))), all_params))(map(trim, split(slice(params_spec, 4), ','))) if sx_truthy(starts_with_p(params_spec, 'not ')) else (lambda allowed: filter(lambda p: contains_p(allowed, first(p)), all_params))(map(trim, split(params_spec, ',')))))))
+
+# resolve-target
+resolve_target = lambda el: (lambda sel: (el if sx_truthy((is_nil(sel) if sx_truthy(is_nil(sel)) else (sel == 'this'))) else (dom_parent(el) if sx_truthy((sel == 'closest')) else dom_query(sel))))(dom_get_attr(el, 'sx-target'))
+
+# apply-optimistic
+apply_optimistic = lambda el: (lambda directive: (NIL if sx_truthy(is_nil(directive)) else (lambda target: (lambda state: _sx_begin((_sx_begin(_sx_dict_set(state, 'opacity', dom_get_style(target, 'opacity')), dom_set_style(target, 'opacity', '0'), dom_set_style(target, 'pointer-events', 'none')) if sx_truthy((directive == 'remove')) else (_sx_begin(_sx_dict_set(state, 'disabled', dom_get_prop(target, 'disabled')), dom_set_prop(target, 'disabled', True)) if sx_truthy((directive == 'disable')) else ((lambda cls: _sx_begin(_sx_dict_set(state, 'add-class', cls), dom_add_class(target, cls)))(slice(directive, 10)) if sx_truthy(starts_with_p(directive, 'add-class:')) else NIL))), state))({'target': target, 'directive': directive}))((resolve_target(el) if sx_truthy(resolve_target(el)) else el))))(dom_get_attr(el, 'sx-optimistic'))
+
+# revert-optimistic
+revert_optimistic = lambda state: ((lambda target: (lambda directive: (_sx_begin(dom_set_style(target, 'opacity', (get(state, 'opacity') if sx_truthy(get(state, 'opacity')) else '')), dom_set_style(target, 'pointer-events', '')) if sx_truthy((directive == 'remove')) else (dom_set_prop(target, 'disabled', (get(state, 'disabled') if sx_truthy(get(state, 'disabled')) else False)) if sx_truthy((directive == 'disable')) else (dom_remove_class(target, get(state, 'add-class')) if sx_truthy(get(state, 'add-class')) else NIL))))(get(state, 'directive')))(get(state, 'target')) if sx_truthy(state) else NIL)
+
+# find-oob-swaps
+find_oob_swaps = lambda container: (lambda results: _sx_begin(for_each(lambda attr: (lambda oob_els: for_each(lambda oob: (lambda swap_type: (lambda target_id: _sx_begin(dom_remove_attr(oob, attr), (_sx_append(results, {'element': oob, 'swap-type': swap_type, 'target-id': target_id}) if sx_truthy(target_id) else NIL)))(dom_id(oob)))((dom_get_attr(oob, attr) if sx_truthy(dom_get_attr(oob, attr)) else 'outerHTML')), oob_els))(dom_query_all(container, sx_str('[', attr, ']'))), ['sx-swap-oob', 'hx-swap-oob']), results))([])
+
+# morph-node
+morph_node = lambda old_node, new_node: (NIL if sx_truthy((dom_has_attr_p(old_node, 'sx-preserve') if sx_truthy(dom_has_attr_p(old_node, 'sx-preserve')) else dom_has_attr_p(old_node, 'sx-ignore'))) else (dom_replace_child(dom_parent(old_node), dom_clone(new_node), old_node) if sx_truthy(((not sx_truthy((dom_node_type(old_node) == dom_node_type(new_node)))) if sx_truthy((not sx_truthy((dom_node_type(old_node) == dom_node_type(new_node))))) else (not sx_truthy((dom_node_name(old_node) == dom_node_name(new_node)))))) else ((dom_set_text_content(old_node, dom_text_content(new_node)) if sx_truthy((not sx_truthy((dom_text_content(old_node) == dom_text_content(new_node))))) else NIL) if sx_truthy(((dom_node_type(old_node) == 3) if sx_truthy((dom_node_type(old_node) == 3)) else (dom_node_type(old_node) == 8))) else (_sx_begin(sync_attrs(old_node, new_node), (morph_children(old_node, new_node) if sx_truthy((not sx_truthy((dom_is_active_element_p(old_node) if not sx_truthy(dom_is_active_element_p(old_node)) else dom_is_input_element_p(old_node))))) else NIL)) if sx_truthy((dom_node_type(old_node) == 1)) else NIL))))
+
+# sync-attrs
+sync_attrs = _sx_fn(lambda old_el, new_el: (
+  for_each(lambda attr: (lambda name: (lambda val: (dom_set_attr(old_el, name, val) if sx_truthy((not sx_truthy((dom_get_attr(old_el, name) == val)))) else NIL))(nth(attr, 1)))(first(attr)), dom_attr_list(new_el)),
+  for_each(lambda attr: (dom_remove_attr(old_el, first(attr)) if sx_truthy((not sx_truthy(dom_has_attr_p(new_el, first(attr))))) else NIL), dom_attr_list(old_el))
+)[-1])
+
+# morph-children
+def morph_children(old_parent, new_parent):
     _cells = {}
-    path_segs = split_path_segments(path)
-    _cells['result'] = NIL
-    for route in routes:
-        if sx_truthy(is_nil(_cells['result'])):
-            params = match_route_segments(path_segs, get(route, 'parsed'))
-            if sx_truthy((not sx_truthy(is_nil(params)))):
-                matched = merge(route, {})
-                matched['params'] = params
-                _cells['result'] = matched
-    return _cells['result']
+    old_kids = dom_child_list(old_parent)
+    new_kids = dom_child_list(new_parent)
+    old_by_id = reduce(lambda acc, kid: (lambda id: (_sx_begin(_sx_dict_set(acc, id, kid), acc) if sx_truthy(id) else acc))(dom_id(kid)), {}, old_kids)
+    _cells['oi'] = 0
+    for new_child in new_kids:
+        match_id = dom_id(new_child)
+        match_by_id = (dict_get(old_by_id, match_id) if sx_truthy(match_id) else NIL)
+        if sx_truthy((match_by_id if not sx_truthy(match_by_id) else (not sx_truthy(is_nil(match_by_id))))):
+            if sx_truthy(((_cells['oi'] < len(old_kids)) if not sx_truthy((_cells['oi'] < len(old_kids))) else (not sx_truthy((match_by_id == nth(old_kids, _cells['oi'])))))):
+                dom_insert_before(old_parent, match_by_id, (nth(old_kids, _cells['oi']) if sx_truthy((_cells['oi'] < len(old_kids))) else NIL))
+            morph_node(match_by_id, new_child)
+            _cells['oi'] = (_cells['oi'] + 1)
+        elif sx_truthy((_cells['oi'] < len(old_kids))):
+            old_child = nth(old_kids, _cells['oi'])
+            if sx_truthy((dom_id(old_child) if not sx_truthy(dom_id(old_child)) else (not sx_truthy(match_id)))):
+                dom_insert_before(old_parent, dom_clone(new_child), old_child)
+            else:
+                morph_node(old_child, new_child)
+                _cells['oi'] = (_cells['oi'] + 1)
+        else:
+            dom_append(old_parent, dom_clone(new_child))
+    return for_each(lambda i: ((lambda leftover: (dom_remove_child(old_parent, leftover) if sx_truthy((dom_is_child_of_p(leftover, old_parent) if not sx_truthy(dom_is_child_of_p(leftover, old_parent)) else ((not sx_truthy(dom_has_attr_p(leftover, 'sx-preserve'))) if not sx_truthy((not sx_truthy(dom_has_attr_p(leftover, 'sx-preserve')))) else (not sx_truthy(dom_has_attr_p(leftover, 'sx-ignore')))))) else NIL))(nth(old_kids, i)) if sx_truthy((i >= _cells['oi'])) else NIL), range(_cells['oi'], len(old_kids)))
+
+# swap-dom-nodes
+swap_dom_nodes = lambda target, new_nodes, strategy: _sx_case(strategy, [('innerHTML', lambda: (morph_children(target, new_nodes) if sx_truthy(dom_is_fragment_p(new_nodes)) else (lambda wrapper: _sx_begin(dom_append(wrapper, new_nodes), morph_children(target, wrapper)))(dom_create_element('div', NIL)))), ('outerHTML', lambda: (lambda parent: _sx_begin(((lambda fc: (_sx_begin(morph_node(target, fc), (lambda sib: insert_remaining_siblings(parent, target, sib))(dom_next_sibling(fc))) if sx_truthy(fc) else dom_remove_child(parent, target)))(dom_first_child(new_nodes)) if sx_truthy(dom_is_fragment_p(new_nodes)) else morph_node(target, new_nodes)), parent))(dom_parent(target))), ('afterend', lambda: dom_insert_after(target, new_nodes)), ('beforeend', lambda: dom_append(target, new_nodes)), ('afterbegin', lambda: dom_prepend(target, new_nodes)), ('beforebegin', lambda: dom_insert_before(dom_parent(target), new_nodes, target)), ('delete', lambda: dom_remove_child(dom_parent(target), target)), ('none', lambda: NIL), (None, lambda: (morph_children(target, new_nodes) if sx_truthy(dom_is_fragment_p(new_nodes)) else (lambda wrapper: _sx_begin(dom_append(wrapper, new_nodes), morph_children(target, wrapper)))(dom_create_element('div', NIL))))])
+
+# insert-remaining-siblings
+insert_remaining_siblings = lambda parent, ref_node, sib: ((lambda next: _sx_begin(dom_insert_after(ref_node, sib), insert_remaining_siblings(parent, sib, next)))(dom_next_sibling(sib)) if sx_truthy(sib) else NIL)
+
+# swap-html-string
+swap_html_string = lambda target, html, strategy: _sx_case(strategy, [('innerHTML', lambda: dom_set_inner_html(target, html)), ('outerHTML', lambda: (lambda parent: _sx_begin(dom_insert_adjacent_html(target, 'afterend', html), dom_remove_child(parent, target), parent))(dom_parent(target))), ('afterend', lambda: dom_insert_adjacent_html(target, 'afterend', html)), ('beforeend', lambda: dom_insert_adjacent_html(target, 'beforeend', html)), ('afterbegin', lambda: dom_insert_adjacent_html(target, 'afterbegin', html)), ('beforebegin', lambda: dom_insert_adjacent_html(target, 'beforebegin', html)), ('delete', lambda: dom_remove_child(dom_parent(target), target)), ('none', lambda: NIL), (None, lambda: dom_set_inner_html(target, html))])
+
+# handle-history
+handle_history = lambda el, url, resp_headers: (lambda push_url: (lambda replace_url: (lambda hdr_replace: (browser_replace_state(hdr_replace) if sx_truthy(hdr_replace) else (browser_push_state((url if sx_truthy((push_url == 'true')) else push_url)) if sx_truthy((push_url if not sx_truthy(push_url) else (not sx_truthy((push_url == 'false'))))) else (browser_replace_state((url if sx_truthy((replace_url == 'true')) else replace_url)) if sx_truthy((replace_url if not sx_truthy(replace_url) else (not sx_truthy((replace_url == 'false'))))) else NIL))))(get(resp_headers, 'replace-url')))(dom_get_attr(el, 'sx-replace-url')))(dom_get_attr(el, 'sx-push-url'))
+
+# PRELOAD_TTL
+PRELOAD_TTL = 30000
+
+# preload-cache-get
+preload_cache_get = lambda cache, url: (lambda entry: (NIL if sx_truthy(is_nil(entry)) else (_sx_begin(dict_delete(cache, url), NIL) if sx_truthy(((now_ms() - get(entry, 'timestamp')) > PRELOAD_TTL)) else _sx_begin(dict_delete(cache, url), entry))))(dict_get(cache, url))
+
+# preload-cache-set
+preload_cache_set = lambda cache, url, text, content_type: _sx_dict_set(cache, url, {'text': text, 'content-type': content_type, 'timestamp': now_ms()})
+
+# classify-trigger
+classify_trigger = lambda trigger: (lambda event: ('poll' if sx_truthy((event == 'every')) else ('intersect' if sx_truthy((event == 'intersect')) else ('load' if sx_truthy((event == 'load')) else ('revealed' if sx_truthy((event == 'revealed')) else 'event')))))(get(trigger, 'event'))
+
+# should-boost-link?
+should_boost_link_p = lambda link: (lambda href: (href if not sx_truthy(href) else ((not sx_truthy(starts_with_p(href, '#'))) if not sx_truthy((not sx_truthy(starts_with_p(href, '#')))) else ((not sx_truthy(starts_with_p(href, 'javascript:'))) if not sx_truthy((not sx_truthy(starts_with_p(href, 'javascript:')))) else ((not sx_truthy(starts_with_p(href, 'mailto:'))) if not sx_truthy((not sx_truthy(starts_with_p(href, 'mailto:')))) else (browser_same_origin_p(href) if not sx_truthy(browser_same_origin_p(href)) else ((not sx_truthy(dom_has_attr_p(link, 'sx-get'))) if not sx_truthy((not sx_truthy(dom_has_attr_p(link, 'sx-get')))) else ((not sx_truthy(dom_has_attr_p(link, 'sx-post'))) if not sx_truthy((not sx_truthy(dom_has_attr_p(link, 'sx-post')))) else (not sx_truthy(dom_has_attr_p(link, 'sx-disable')))))))))))(dom_get_attr(link, 'href'))
+
+# should-boost-form?
+should_boost_form_p = lambda form: ((not sx_truthy(dom_has_attr_p(form, 'sx-get'))) if not sx_truthy((not sx_truthy(dom_has_attr_p(form, 'sx-get')))) else ((not sx_truthy(dom_has_attr_p(form, 'sx-post'))) if not sx_truthy((not sx_truthy(dom_has_attr_p(form, 'sx-post')))) else (not sx_truthy(dom_has_attr_p(form, 'sx-disable')))))
+
+# parse-sse-swap
+parse_sse_swap = lambda el: (dom_get_attr(el, 'sx-sse-swap') if sx_truthy(dom_get_attr(el, 'sx-sse-swap')) else 'message')
 
 
 # =========================================================================
@@ -1318,64 +1423,6 @@ def _wrap_aser_outputs():
     aser_fragment = _aser_fragment_wrapped
 
 
-# =========================================================================
-# Extension: delimited continuations (shift/reset)
-# =========================================================================
-
-_RESET_RESUME = []  # stack of resume values; empty = not resuming
-
-_SPECIAL_FORM_NAMES = _SPECIAL_FORM_NAMES | frozenset(["reset", "shift"])
-
-def sf_reset(args, env):
-    """(reset body) -- establish a continuation delimiter."""
-    body = first(args)
-    try:
-        return trampoline(eval_expr(body, env))
-    except _ShiftSignal as sig:
-        def cont_fn(value=NIL):
-            _RESET_RESUME.append(value)
-            try:
-                return trampoline(eval_expr(body, env))
-            finally:
-                _RESET_RESUME.pop()
-        k = Continuation(cont_fn)
-        sig_env = dict(sig.env)
-        sig_env[sig.k_name] = k
-        return trampoline(eval_expr(sig.body, sig_env))
-
-def sf_shift(args, env):
-    """(shift k body) -- capture continuation to nearest reset."""
-    if _RESET_RESUME:
-        return _RESET_RESUME[-1]
-    k_name = symbol_name(first(args))
-    body = nth(args, 1)
-    raise _ShiftSignal(k_name, body, env)
-
-# Wrap eval_list to inject shift/reset dispatch
-_base_eval_list = eval_list
-def _eval_list_with_continuations(expr, env):
-    head = first(expr)
-    if type_of(head) == "symbol":
-        name = symbol_name(head)
-        args = rest(expr)
-        if name == "reset":
-            return sf_reset(args, env)
-        if name == "shift":
-            return sf_shift(args, env)
-    return _base_eval_list(expr, env)
-eval_list = _eval_list_with_continuations
-
-# Inject into aser_special
-_base_aser_special = aser_special
-def _aser_special_with_continuations(name, expr, env):
-    if name == "reset":
-        return sf_reset(expr[1:], env)
-    if name == "shift":
-        return sf_shift(expr[1:], env)
-    return _base_aser_special(name, expr, env)
-aser_special = _aser_special_with_continuations
-
-
 # =========================================================================
 # Public API
 # =========================================================================
diff --git a/shared/sx/ref/test-deps.sx b/shared/sx/ref/test-deps.sx
new file mode 100644
index 0000000..b67b508
--- /dev/null
+++ b/shared/sx/ref/test-deps.sx
@@ -0,0 +1,225 @@
+;; ==========================================================================
+;; test-deps.sx — Tests for component dependency analysis (deps.sx)
+;;
+;; Requires: test-framework.sx loaded first.
+;; Platform functions: scan-refs, transitive-deps, components-needed,
+;;   component-pure?, scan-io-refs, transitive-io-refs,
+;;   scan-components-from-source, test-env
+;;   (loaded from bootstrapped output by test runners)
+;; ==========================================================================
+
+
+;; --------------------------------------------------------------------------
+;; Test component definitions — these exist in the test env for dep analysis
+;; --------------------------------------------------------------------------
+
+(defcomp ~dep-leaf ()
+  (span "leaf"))
+
+(defcomp ~dep-branch ()
+  (div (~dep-leaf)))
+
+(defcomp ~dep-trunk ()
+  (div (~dep-branch) (~dep-leaf)))
+
+(defcomp ~dep-conditional (&key show?)
+  (if show?
+    (~dep-leaf)
+    (~dep-branch)))
+
+(defcomp ~dep-nested-cond (&key mode)
+  (cond
+    (= mode "a") (~dep-leaf)
+    (= mode "b") (~dep-branch)
+    :else (~dep-trunk)))
+
+(defcomp ~dep-island ()
+  (div "no deps"))
+
+
+;; --------------------------------------------------------------------------
+;; 1. scan-refs — finds component references in AST nodes
+;; --------------------------------------------------------------------------
+
+(defsuite "scan-refs"
+
+  (deftest "empty for string literal"
+    (assert-equal (list) (scan-refs "hello")))
+
+  (deftest "empty for number"
+    (assert-equal (list) (scan-refs 42)))
+
+  (deftest "finds component symbol"
+    (let ((refs (scan-refs (quote (~dep-leaf)))))
+      (assert-contains "~dep-leaf" refs)))
+
+  (deftest "finds in nested list"
+    (let ((refs (scan-refs (quote (div (span (~dep-leaf)))))))
+      (assert-contains "~dep-leaf" refs)))
+
+  (deftest "finds multiple refs"
+    (let ((refs (scan-refs (quote (div (~dep-leaf) (~dep-branch))))))
+      (assert-contains "~dep-leaf" refs)
+      (assert-contains "~dep-branch" refs)))
+
+  (deftest "deduplicates"
+    (let ((refs (scan-refs (quote (div (~dep-leaf) (~dep-leaf))))))
+      (assert-equal 1 (len refs))))
+
+  (deftest "walks if branches"
+    (let ((refs (scan-refs (quote (if true (~dep-leaf) (~dep-branch))))))
+      (assert-contains "~dep-leaf" refs)
+      (assert-contains "~dep-branch" refs)))
+
+  (deftest "walks cond branches"
+    (let ((refs (scan-refs (quote (cond (= x 1) (~dep-leaf) :else (~dep-trunk))))))
+      (assert-contains "~dep-leaf" refs)
+      (assert-contains "~dep-trunk" refs)))
+
+  (deftest "ignores non-component symbols"
+    (let ((refs (scan-refs (quote (div class "foo")))))
+      (assert-equal 0 (len refs)))))
+
+
+;; --------------------------------------------------------------------------
+;; 2. scan-components-from-source — regex-based source string scanning
+;; --------------------------------------------------------------------------
+
+(defsuite "scan-components-from-source"
+
+  (deftest "finds single component"
+    (let ((refs (scan-components-from-source "(~dep-leaf)")))
+      (assert-contains "~dep-leaf" refs)))
+
+  (deftest "finds multiple components"
+    (let ((refs (scan-components-from-source "(div (~dep-leaf) (~dep-branch))")))
+      (assert-contains "~dep-leaf" refs)
+      (assert-contains "~dep-branch" refs)))
+
+  (deftest "no false positives on plain text"
+    (let ((refs (scan-components-from-source "(div \"hello world\")")))
+      (assert-equal 0 (len refs))))
+
+  (deftest "handles hyphenated names"
+    (let ((refs (scan-components-from-source "(~my-component :key val)")))
+      (assert-contains "~my-component" refs))))
+
+
+;; --------------------------------------------------------------------------
+;; 3. transitive-deps — transitive dependency closure
+;; --------------------------------------------------------------------------
+
+(defsuite "transitive-deps"
+
+  (deftest "leaf has no deps"
+    (let ((deps (transitive-deps "~dep-leaf" (test-env))))
+      (assert-equal 0 (len deps))))
+
+  (deftest "direct dependency"
+    (let ((deps (transitive-deps "~dep-branch" (test-env))))
+      (assert-contains "~dep-leaf" deps)))
+
+  (deftest "transitive closure"
+    (let ((deps (transitive-deps "~dep-trunk" (test-env))))
+      (assert-contains "~dep-branch" deps)
+      (assert-contains "~dep-leaf" deps)))
+
+  (deftest "excludes self"
+    (let ((deps (transitive-deps "~dep-trunk" (test-env))))
+      (assert-false (contains? deps "~dep-trunk"))))
+
+  (deftest "walks conditional branches"
+    (let ((deps (transitive-deps "~dep-conditional" (test-env))))
+      (assert-contains "~dep-leaf" deps)
+      (assert-contains "~dep-branch" deps)))
+
+  (deftest "walks all cond branches"
+    (let ((deps (transitive-deps "~dep-nested-cond" (test-env))))
+      (assert-contains "~dep-leaf" deps)
+      (assert-contains "~dep-branch" deps)
+      (assert-contains "~dep-trunk" deps)))
+
+  (deftest "island has no deps"
+    (let ((deps (transitive-deps "~dep-island" (test-env))))
+      (assert-equal 0 (len deps))))
+
+  (deftest "accepts name without tilde"
+    (let ((deps (transitive-deps "dep-branch" (test-env))))
+      (assert-contains "~dep-leaf" deps))))
+
+
+;; --------------------------------------------------------------------------
+;; 4. components-needed — page bundle computation
+;; --------------------------------------------------------------------------
+
+(defsuite "components-needed"
+
+  (deftest "finds direct and transitive"
+    (let ((needed (components-needed "(~dep-trunk)" (test-env))))
+      (assert-contains "~dep-trunk" needed)
+      (assert-contains "~dep-branch" needed)
+      (assert-contains "~dep-leaf" needed)))
+
+  (deftest "deduplicates"
+    (let ((needed (components-needed "(div (~dep-leaf) (~dep-leaf))" (test-env))))
+      ;; ~dep-leaf should appear only once
+      (assert-true (contains? needed "~dep-leaf"))))
+
+  (deftest "handles leaf page"
+    (let ((needed (components-needed "(~dep-island)" (test-env))))
+      (assert-contains "~dep-island" needed)
+      (assert-equal 1 (len needed))))
+
+  (deftest "handles multiple top-level components"
+    (let ((needed (components-needed "(div (~dep-leaf) (~dep-island))" (test-env))))
+      (assert-contains "~dep-leaf" needed)
+      (assert-contains "~dep-island" needed))))
+
+
+;; --------------------------------------------------------------------------
+;; 5. IO detection — scan-io-refs, component-pure?
+;; --------------------------------------------------------------------------
+
+;; Define components that reference "io" functions for testing
+(defcomp ~dep-pure ()
+  (div (~dep-leaf) "static"))
+
+(defcomp ~dep-io ()
+  (div (fetch-data "/api")))
+
+(defcomp ~dep-io-indirect ()
+  (div (~dep-io)))
+
+(defsuite "scan-io-refs"
+
+  (deftest "no IO in pure AST"
+    (let ((refs (scan-io-refs (quote (div "hello" (span "world"))) (list "fetch-data"))))
+      (assert-equal 0 (len refs))))
+
+  (deftest "finds IO reference"
+    (let ((refs (scan-io-refs (quote (div (fetch-data "/api"))) (list "fetch-data"))))
+      (assert-contains "fetch-data" refs)))
+
+  (deftest "multiple IO refs"
+    (let ((refs (scan-io-refs (quote (div (fetch-data "/a") (query-db "x"))) (list "fetch-data" "query-db"))))
+      (assert-contains "fetch-data" refs)
+      (assert-contains "query-db" refs)))
+
+  (deftest "ignores non-IO symbols"
+    (let ((refs (scan-io-refs (quote (div (map str items))) (list "fetch-data"))))
+      (assert-equal 0 (len refs)))))
+
+
+(defsuite "component-pure?"
+
+  (deftest "pure component is pure"
+    (assert-true (component-pure? "~dep-pure" (test-env) (list "fetch-data"))))
+
+  (deftest "IO component is not pure"
+    (assert-false (component-pure? "~dep-io" (test-env) (list "fetch-data"))))
+
+  (deftest "indirect IO is not pure"
+    (assert-false (component-pure? "~dep-io-indirect" (test-env) (list "fetch-data"))))
+
+  (deftest "leaf component is pure"
+    (assert-true (component-pure? "~dep-leaf" (test-env) (list "fetch-data")))))
diff --git a/shared/sx/ref/test-engine.sx b/shared/sx/ref/test-engine.sx
new file mode 100644
index 0000000..c3fa2d2
--- /dev/null
+++ b/shared/sx/ref/test-engine.sx
@@ -0,0 +1,212 @@
+;; ==========================================================================
+;; test-engine.sx — Tests for SxEngine pure logic (engine.sx)
+;;
+;; Requires: test-framework.sx loaded first.
+;; Platform functions: parse-time, parse-trigger-spec, default-trigger,
+;;   parse-swap-spec, parse-retry-spec, next-retry-ms, filter-params
+;;   (loaded from bootstrapped output by test runners)
+;; ==========================================================================
+
+
+;; --------------------------------------------------------------------------
+;; 1. parse-time — time string parsing
+;; --------------------------------------------------------------------------
+
+(defsuite "parse-time"
+
+  (deftest "seconds to ms"
+    (assert-equal 2000 (parse-time "2s")))
+
+  (deftest "milliseconds"
+    (assert-equal 500 (parse-time "500ms")))
+
+  (deftest "nil returns 0"
+    (assert-equal 0 (parse-time nil)))
+
+  (deftest "plain number string"
+    (assert-equal 100 (parse-time "100")))
+
+  (deftest "one second"
+    (assert-equal 1000 (parse-time "1s")))
+
+  (deftest "large seconds"
+    (assert-equal 30000 (parse-time "30s"))))
+
+
+;; --------------------------------------------------------------------------
+;; 2. parse-trigger-spec — trigger attribute parsing
+;; --------------------------------------------------------------------------
+
+(defsuite "parse-trigger-spec"
+
+  (deftest "nil returns nil"
+    (assert-nil (parse-trigger-spec nil)))
+
+  (deftest "single event"
+    (let ((triggers (parse-trigger-spec "click")))
+      (assert-equal 1 (len triggers))
+      (assert-equal "click" (get (first triggers) "event"))))
+
+  (deftest "event with once modifier"
+    (let ((triggers (parse-trigger-spec "click once")))
+      (assert-equal 1 (len triggers))
+      (assert-equal "click" (get (first triggers) "event"))
+      (assert-true (get (get (first triggers) "modifiers") "once"))))
+
+  (deftest "event with delay modifier"
+    (let ((triggers (parse-trigger-spec "click delay:500ms")))
+      (assert-equal 1 (len triggers))
+      (assert-equal 500 (get (get (first triggers) "modifiers") "delay"))))
+
+  (deftest "multiple triggers comma-separated"
+    (let ((triggers (parse-trigger-spec "click,change")))
+      (assert-equal 2 (len triggers))
+      (assert-equal "click" (get (first triggers) "event"))
+      (assert-equal "change" (get (nth triggers 1) "event"))))
+
+  (deftest "polling trigger"
+    (let ((triggers (parse-trigger-spec "every 3s")))
+      (assert-equal 1 (len triggers))
+      (assert-equal "every" (get (first triggers) "event"))
+      (assert-equal 3000 (get (get (first triggers) "modifiers") "interval"))))
+
+  (deftest "event with from modifier"
+    (let ((triggers (parse-trigger-spec "click from:body")))
+      (assert-equal "body" (get (get (first triggers) "modifiers") "from"))))
+
+  (deftest "event with changed modifier"
+    (let ((triggers (parse-trigger-spec "keyup changed")))
+      (assert-equal "keyup" (get (first triggers) "event"))
+      (assert-true (get (get (first triggers) "modifiers") "changed")))))
+
+
+;; --------------------------------------------------------------------------
+;; 3. default-trigger — default trigger by element tag
+;; --------------------------------------------------------------------------
+
+(defsuite "default-trigger"
+
+  (deftest "form submits"
+    (let ((triggers (default-trigger "FORM")))
+      (assert-equal "submit" (get (first triggers) "event"))))
+
+  (deftest "input changes"
+    (let ((triggers (default-trigger "INPUT")))
+      (assert-equal "change" (get (first triggers) "event"))))
+
+  (deftest "select changes"
+    (let ((triggers (default-trigger "SELECT")))
+      (assert-equal "change" (get (first triggers) "event"))))
+
+  (deftest "textarea changes"
+    (let ((triggers (default-trigger "TEXTAREA")))
+      (assert-equal "change" (get (first triggers) "event"))))
+
+  (deftest "div clicks"
+    (let ((triggers (default-trigger "DIV")))
+      (assert-equal "click" (get (first triggers) "event"))))
+
+  (deftest "button clicks"
+    (let ((triggers (default-trigger "BUTTON")))
+      (assert-equal "click" (get (first triggers) "event")))))
+
+
+;; --------------------------------------------------------------------------
+;; 4. parse-swap-spec — swap specification parsing
+;; --------------------------------------------------------------------------
+
+(defsuite "parse-swap-spec"
+
+  (deftest "default swap"
+    (let ((spec (parse-swap-spec nil false)))
+      (assert-equal "outerHTML" (get spec "style"))
+      (assert-false (get spec "transition"))))
+
+  (deftest "innerHTML"
+    (let ((spec (parse-swap-spec "innerHTML" false)))
+      (assert-equal "innerHTML" (get spec "style"))))
+
+  (deftest "with transition true"
+    (let ((spec (parse-swap-spec "innerHTML transition:true" false)))
+      (assert-equal "innerHTML" (get spec "style"))
+      (assert-true (get spec "transition"))))
+
+  (deftest "transition false overrides global"
+    (let ((spec (parse-swap-spec "outerHTML transition:false" true)))
+      (assert-equal "outerHTML" (get spec "style"))
+      (assert-false (get spec "transition"))))
+
+  (deftest "global transition when not overridden"
+    (let ((spec (parse-swap-spec "innerHTML" true)))
+      (assert-equal "innerHTML" (get spec "style"))
+      (assert-true (get spec "transition")))))
+
+
+;; --------------------------------------------------------------------------
+;; 5. parse-retry-spec — retry specification parsing
+;; --------------------------------------------------------------------------
+
+(defsuite "parse-retry-spec"
+
+  (deftest "nil returns nil"
+    (assert-nil (parse-retry-spec nil)))
+
+  (deftest "exponential backoff"
+    (let ((spec (parse-retry-spec "exponential:1000:30000")))
+      (assert-equal "exponential" (get spec "strategy"))
+      (assert-equal 1000 (get spec "start-ms"))
+      (assert-equal 30000 (get spec "cap-ms"))))
+
+  (deftest "linear strategy"
+    (let ((spec (parse-retry-spec "linear:2000:60000")))
+      (assert-equal "linear" (get spec "strategy"))
+      (assert-equal 2000 (get spec "start-ms"))
+      (assert-equal 60000 (get spec "cap-ms")))))
+
+
+;; --------------------------------------------------------------------------
+;; 6. next-retry-ms — exponential backoff calculation
+;; --------------------------------------------------------------------------
+
+(defsuite "next-retry-ms"
+
+  (deftest "doubles current"
+    (assert-equal 2000 (next-retry-ms 1000 30000)))
+
+  (deftest "caps at maximum"
+    (assert-equal 30000 (next-retry-ms 20000 30000)))
+
+  (deftest "exact cap"
+    (assert-equal 30000 (next-retry-ms 15000 30000)))
+
+  (deftest "small initial"
+    (assert-equal 200 (next-retry-ms 100 30000))))
+
+
+;; --------------------------------------------------------------------------
+;; 7. filter-params — form parameter filtering
+;; --------------------------------------------------------------------------
+
+(defsuite "filter-params"
+
+  (deftest "nil passes all through"
+    (let ((params (list (list "a" "1") (list "b" "2"))))
+      (assert-equal 2 (len (filter-params nil params)))))
+
+  (deftest "none returns empty"
+    (let ((params (list (list "a" "1") (list "b" "2"))))
+      (assert-equal 0 (len (filter-params "none" params)))))
+
+  (deftest "star passes all"
+    (let ((params (list (list "a" "1") (list "b" "2"))))
+      (assert-equal 2 (len (filter-params "*" params)))))
+
+  (deftest "whitelist"
+    (let ((params (list (list "name" "Jo") (list "age" "30") (list "secret" "x"))))
+      (let ((filtered (filter-params "name,age" params)))
+        (assert-equal 2 (len filtered)))))
+
+  (deftest "blacklist with not"
+    (let ((params (list (list "name" "Jo") (list "csrf" "tok") (list "age" "30"))))
+      (let ((filtered (filter-params "not csrf" params)))
+        (assert-equal 2 (len filtered))))))
diff --git a/shared/sx/tests/run.js b/shared/sx/tests/run.js
index 288f166..965c7b4 100644
--- a/shared/sx/tests/run.js
+++ b/shared/sx/tests/run.js
@@ -159,6 +159,8 @@ var SPECS = {
   "parser":  { file: "test-parser.sx",  needs: ["sx-parse"] },
   "router":  { file: "test-router.sx",  needs: [] },
   "render":  { file: "test-render.sx",  needs: ["render-html"] },
+  "deps":    { file: "test-deps.sx",    needs: [] },
+  "engine":  { file: "test-engine.sx",  needs: [] },
 };
 
 function evalFile(filename) {
@@ -215,9 +217,6 @@ if (args[0] === "--legacy") {
 
     // Load prerequisite spec modules
     if (specName === "router") {
-      // Use bootstrapped router functions from sx-browser.js.
-      // The bare evaluator can't run router.sx faithfully because set!
-      // inside lambda closures doesn't propagate (dict copies, not cells).
       if (Sx.splitPathSegments) {
         env["split-path-segments"] = Sx.splitPathSegments;
         env["parse-route-pattern"] = Sx.parseRoutePattern;
@@ -230,6 +229,35 @@ if (args[0] === "--legacy") {
       }
     }
 
+    if (specName === "deps") {
+      if (Sx.scanRefs) {
+        env["scan-refs"] = Sx.scanRefs;
+        env["scan-components-from-source"] = Sx.scanComponentsFromSource;
+        env["transitive-deps"] = Sx.transitiveDeps;
+        env["compute-all-deps"] = Sx.computeAllDeps;
+        env["components-needed"] = Sx.componentsNeeded;
+        env["page-component-bundle"] = Sx.pageComponentBundle;
+        env["page-css-classes"] = Sx.pageCssClasses;
+        env["scan-io-refs"] = Sx.scanIoRefs;
+        env["transitive-io-refs"] = Sx.transitiveIoRefs;
+        env["compute-all-io-refs"] = Sx.computeAllIoRefs;
+        env["component-pure?"] = Sx.componentPure_p;
+        env["test-env"] = function() { return env; };
+      }
+    }
+
+    if (specName === "engine") {
+      if (Sx.parseTime) {
+        env["parse-time"] = Sx.parseTime;
+        env["parse-trigger-spec"] = Sx.parseTriggerSpec;
+        env["default-trigger"] = Sx.defaultTrigger;
+        env["parse-swap-spec"] = Sx.parseSwapSpec;
+        env["parse-retry-spec"] = Sx.parseRetrySpec;
+        env["next-retry-ms"] = function(cur, cap) { return Math.min(cur * 2, cap); };
+        env["filter-params"] = Sx.filterParams;
+      }
+    }
+
     console.log("# --- " + specName + " ---");
     evalFile(spec.file);
   }
diff --git a/shared/sx/tests/run.py b/shared/sx/tests/run.py
index eba2a03..f45d811 100644
--- a/shared/sx/tests/run.py
+++ b/shared/sx/tests/run.py
@@ -141,6 +141,8 @@ SPECS = {
     "parser": {"file": "test-parser.sx", "needs": ["sx-parse"]},
     "router": {"file": "test-router.sx", "needs": []},
     "render": {"file": "test-render.sx", "needs": ["render-html"]},
+    "deps":   {"file": "test-deps.sx",   "needs": []},
+    "engine": {"file": "test-engine.sx", "needs": []},
 }
 
 REF_DIR = os.path.join(_HERE, "..", "ref")
@@ -269,6 +271,62 @@ def _load_router_from_bootstrap(env):
         eval_file("router.sx", env)
 
 
+def _load_deps_from_bootstrap(env):
+    """Load deps functions from the bootstrapped sx_ref.py."""
+    try:
+        from shared.sx.ref.sx_ref import (
+            scan_refs,
+            scan_components_from_source,
+            transitive_deps,
+            compute_all_deps,
+            components_needed,
+            page_component_bundle,
+            page_css_classes,
+            scan_io_refs,
+            transitive_io_refs,
+            compute_all_io_refs,
+            component_pure_p,
+        )
+        env["scan-refs"] = scan_refs
+        env["scan-components-from-source"] = scan_components_from_source
+        env["transitive-deps"] = transitive_deps
+        env["compute-all-deps"] = compute_all_deps
+        env["components-needed"] = components_needed
+        env["page-component-bundle"] = page_component_bundle
+        env["page-css-classes"] = page_css_classes
+        env["scan-io-refs"] = scan_io_refs
+        env["transitive-io-refs"] = transitive_io_refs
+        env["compute-all-io-refs"] = compute_all_io_refs
+        env["component-pure?"] = component_pure_p
+        env["test-env"] = lambda: env
+    except ImportError:
+        eval_file("deps.sx", env)
+        env["test-env"] = lambda: env
+
+
+def _load_engine_from_bootstrap(env):
+    """Load engine pure functions from the bootstrapped sx_ref.py."""
+    try:
+        from shared.sx.ref.sx_ref import (
+            parse_time,
+            parse_trigger_spec,
+            default_trigger,
+            parse_swap_spec,
+            parse_retry_spec,
+            next_retry_ms,
+            filter_params,
+        )
+        env["parse-time"] = parse_time
+        env["parse-trigger-spec"] = parse_trigger_spec
+        env["default-trigger"] = default_trigger
+        env["parse-swap-spec"] = parse_swap_spec
+        env["parse-retry-spec"] = parse_retry_spec
+        env["next-retry-ms"] = next_retry_ms
+        env["filter-params"] = filter_params
+    except ImportError:
+        eval_file("engine.sx", env)
+
+
 def main():
     global passed, failed, test_num
 
@@ -306,6 +364,10 @@ def main():
             # Load prerequisite spec modules
             if spec_name == "router":
                 _load_router_from_bootstrap(env)
+            if spec_name == "deps":
+                _load_deps_from_bootstrap(env)
+            if spec_name == "engine":
+                _load_engine_from_bootstrap(env)
 
             print(f"# --- {spec_name} ---")
             eval_file(spec["file"], env)
diff --git a/sx/sx/nav-data.sx b/sx/sx/nav-data.sx
index c5f8091..a1758ef 100644
--- a/sx/sx/nav-data.sx
+++ b/sx/sx/nav-data.sx
@@ -113,6 +113,8 @@
   (dict :label "Parser" :href "/testing/parser")
   (dict :label "Router" :href "/testing/router")
   (dict :label "Renderer" :href "/testing/render")
+  (dict :label "Dependencies" :href "/testing/deps")
+  (dict :label "Engine" :href "/testing/engine")
   (dict :label "Runners" :href "/testing/runners")))
 
 (define isomorphism-nav-items (list
diff --git a/sx/sx/testing.sx b/sx/sx/testing.sx
index 6bb96e6..6bb316a 100644
--- a/sx/sx/testing.sx
+++ b/sx/sx/testing.sx
@@ -6,7 +6,7 @@
 ;; Overview page
 ;; ---------------------------------------------------------------------------
 
-(defcomp ~testing-overview-content (&key server-results framework-source eval-source parser-source router-source render-source)
+(defcomp ~testing-overview-content (&key server-results framework-source eval-source parser-source router-source render-source deps-source engine-source)
   (~doc-page :title "Testing"
     (div :class "space-y-8"
 
@@ -35,6 +35,8 @@
     +-- test-parser.sx         39 tests: tokenizer, parser, serializer
     +-- test-router.sx         18 tests: route matching + param extraction
     +-- test-render.sx         23 tests: HTML rendering + components
+    +-- test-deps.sx           33 tests: dependency analysis + IO detection
+    +-- test-engine.sx         37 tests: trigger/swap/retry parsing
 
 Runners:
     run.js                     Node.js — injects platform fns, runs specs
@@ -51,7 +53,9 @@ Platform functions (5 total):
 Per-spec platform functions:
     parser:  sx-parse, sx-serialize, make-symbol, make-keyword, ...
     router:  (none — pure spec, uses bootstrapped functions)
-    render:  render-html (wraps parse + render-to-html)")))
+    render:  render-html (wraps parse + render-to-html)
+    deps:    test-env (returns current evaluation environment)
+    engine:  (none — pure spec, uses bootstrapped functions)")))
 
       ;; Server results
       (when server-results
@@ -86,6 +90,8 @@ Per-spec platform functions:
         (textarea :id "test-spec-parser" :style "display:none" parser-source)
         (textarea :id "test-spec-router" :style "display:none" router-source)
         (textarea :id "test-spec-render" :style "display:none" render-source)
+        (textarea :id "test-spec-deps" :style "display:none" deps-source)
+        (textarea :id "test-spec-engine" :style "display:none" engine-source)
         (script :src (asset-url "/scripts/sx-test-runner.js")))
 
       ;; Test spec index
@@ -107,7 +113,15 @@ Per-spec platform functions:
           (a :href "/testing/render" :class "block rounded-lg border border-stone-200 p-5 hover:border-violet-300 hover:bg-violet-50 transition-colors"
             (h3 :class "font-semibold text-stone-800" "Renderer")
             (p :class "text-sm text-stone-500" "23 tests — elements, attributes, void elements, fragments, escaping, control flow, components")
-            (p :class "text-xs text-violet-600 mt-1" "test-render.sx"))))
+            (p :class "text-xs text-violet-600 mt-1" "test-render.sx"))
+          (a :href "/testing/deps" :class "block rounded-lg border border-stone-200 p-5 hover:border-violet-300 hover:bg-violet-50 transition-colors"
+            (h3 :class "font-semibold text-stone-800" "Dependencies")
+            (p :class "text-sm text-stone-500" "33 tests — scan-refs, transitive-deps, components-needed, IO detection, purity classification")
+            (p :class "text-xs text-violet-600 mt-1" "test-deps.sx"))
+          (a :href "/testing/engine" :class "block rounded-lg border border-stone-200 p-5 hover:border-violet-300 hover:bg-violet-50 transition-colors"
+            (h3 :class "font-semibold text-stone-800" "Engine")
+            (p :class "text-sm text-stone-500" "37 tests — parse-time, trigger specs, swap specs, retry logic, param filtering")
+            (p :class "text-xs text-violet-600 mt-1" "test-engine.sx"))))
 
       ;; What it proves
       (div :class "rounded-lg border border-blue-200 bg-blue-50 p-5 space-y-3"
diff --git a/sx/sxc/pages/docs.sx b/sx/sxc/pages/docs.sx
index 6fee3a7..dd9ec74 100644
--- a/sx/sxc/pages/docs.sx
+++ b/sx/sxc/pages/docs.sx
@@ -553,7 +553,9 @@
     :eval-source eval-source
     :parser-source parser-source
     :router-source router-source
-    :render-source render-source))
+    :render-source render-source
+    :deps-source deps-source
+    :engine-source engine-source))
 
 (defpage testing-page
   :path "/testing/<slug>"
@@ -570,6 +572,8 @@
     "parser" (run-modular-tests "parser")
     "router" (run-modular-tests "router")
     "render" (run-modular-tests "render")
+    "deps" (run-modular-tests "deps")
+    "engine" (run-modular-tests "engine")
     :else (dict))
   :content (case slug
     "eval" (~testing-spec-content
@@ -600,6 +604,20 @@
       :spec-source spec-source
       :framework-source framework-source
       :server-results server-results)
+    "deps" (~testing-spec-content
+      :spec-name "deps"
+      :spec-title "Dependency Analysis Tests"
+      :spec-desc "33 tests covering component dependency analysis — scan-refs, scan-components-from-source, transitive-deps, components-needed, scan-io-refs, and component-pure? classification."
+      :spec-source spec-source
+      :framework-source framework-source
+      :server-results server-results)
+    "engine" (~testing-spec-content
+      :spec-name "engine"
+      :spec-title "Engine Tests"
+      :spec-desc "37 tests covering engine pure functions — parse-time, parse-trigger-spec, default-trigger, parse-swap-spec, parse-retry-spec, next-retry-ms, and filter-params."
+      :spec-source spec-source
+      :framework-source framework-source
+      :server-results server-results)
     "runners" (~testing-runners-content)
     :else (~testing-overview-content
       :server-results server-results)))
diff --git a/sx/sxc/pages/helpers.py b/sx/sxc/pages/helpers.py
index 8a25df9..d578fbd 100644
--- a/sx/sxc/pages/helpers.py
+++ b/sx/sxc/pages/helpers.py
@@ -707,6 +707,8 @@ def _run_modular_tests(spec_name: str) -> dict:
         "parser": {"file": "test-parser.sx", "needs": ["sx-parse"]},
         "router": {"file": "test-router.sx", "needs": []},
         "render": {"file": "test-render.sx", "needs": ["render-html"]},
+        "deps": {"file": "test-deps.sx", "needs": []},
+        "engine": {"file": "test-engine.sx", "needs": []},
     }
 
     specs_to_run = list(SPECS.keys()) if spec_name == "all" else [spec_name]
@@ -721,7 +723,7 @@ def _run_modular_tests(spec_name: str) -> dict:
         if not spec:
             continue
 
-        # Load router from bootstrap if needed
+        # Load module functions from bootstrap
         if sn == "router":
             try:
                 from shared.sx.ref.sx_ref import (
@@ -740,6 +742,46 @@ def _run_modular_tests(spec_name: str) -> dict:
                 env["make-route-segment"] = make_route_segment
             except ImportError:
                 eval_file("router.sx")
+        elif sn == "deps":
+            try:
+                from shared.sx.ref.sx_ref import (
+                    scan_refs, scan_components_from_source,
+                    transitive_deps, compute_all_deps,
+                    components_needed, page_component_bundle,
+                    page_css_classes, scan_io_refs,
+                    transitive_io_refs, compute_all_io_refs,
+                    component_pure_p,
+                )
+                env["scan-refs"] = scan_refs
+                env["scan-components-from-source"] = scan_components_from_source
+                env["transitive-deps"] = transitive_deps
+                env["compute-all-deps"] = compute_all_deps
+                env["components-needed"] = components_needed
+                env["page-component-bundle"] = page_component_bundle
+                env["page-css-classes"] = page_css_classes
+                env["scan-io-refs"] = scan_io_refs
+                env["transitive-io-refs"] = transitive_io_refs
+                env["compute-all-io-refs"] = compute_all_io_refs
+                env["component-pure?"] = component_pure_p
+                env["test-env"] = lambda: env
+            except ImportError:
+                eval_file("deps.sx")
+                env["test-env"] = lambda: env
+        elif sn == "engine":
+            try:
+                from shared.sx.ref.sx_ref import (
+                    parse_time, parse_trigger_spec, default_trigger,
+                    parse_swap_spec, parse_retry_spec, filter_params,
+                )
+                env["parse-time"] = parse_time
+                env["parse-trigger-spec"] = parse_trigger_spec
+                env["default-trigger"] = default_trigger
+                env["parse-swap-spec"] = parse_swap_spec
+                env["parse-retry-spec"] = parse_retry_spec
+                env["next-retry-ms"] = lambda cur, cap: min(cur * 2, cap)
+                env["filter-params"] = filter_params
+            except ImportError:
+                eval_file("engine.sx")
 
         eval_file(spec["file"])
 
@@ -763,6 +805,8 @@ def _run_modular_tests(spec_name: str) -> dict:
         result["parser-source"] = _read_spec_file("test-parser.sx")
         result["router-source"] = _read_spec_file("test-router.sx")
         result["render-source"] = _read_spec_file("test-render.sx")
+        result["deps-source"] = _read_spec_file("test-deps.sx")
+        result["engine-source"] = _read_spec_file("test-engine.sx")
     else:
         spec = SPECS.get(spec_name)
         if spec: