diff --git a/core-aam/acacia/blockquote.html b/core-aam/acacia/property-bag/blockquote.html
similarity index 100%
rename from core-aam/acacia/blockquote.html
rename to core-aam/acacia/property-bag/blockquote.html
diff --git a/core-aam/acacia/button.html b/core-aam/acacia/property-bag/button.html
similarity index 93%
rename from core-aam/acacia/button.html
rename to core-aam/acacia/property-bag/button.html
index 5dc231526f14c8..a1e42a5f12c9b3 100644
--- a/core-aam/acacia/button.html
+++ b/core-aam/acacia/property-bag/button.html
@@ -15,7 +15,7 @@
       const node = await test_driver.get_accessibility_api_node('test');
 
       if (node.API == 'atspi') {
-        assert_equals(node.role, 'push button', 'Atspi role');
+        assert_equals(node.role, 'button', 'Atspi role');
       }
       else if (node.API == 'axapi') {
         assert_equals(node.role, 'AXButton', 'AX API role');
diff --git a/core-aam/acacia/test-statements/aria-autocomplete.html b/core-aam/acacia/test-statements/aria-autocomplete.html
new file mode 100644
index 00000000000000..db8bd74acb0ace
--- /dev/null
+++ b/core-aam/acacia/test-statements/aria-autocomplete.html
@@ -0,0 +1,128 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>aria-braillelabel</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<input role='combobox' id='test1' aria-autocomplete='both'>
+<input role='combobox' id='test2' aria-autocomplete='inline'>
+<input role='combobox' id='test3' aria-autocomplete='list'>
+
+<script>
+  AAMUtils.verifyAPI(
+    'aria-autocomplete=both',
+    'test1',
+    {
+      "Atspi" : [
+        [
+          "property",
+          "objectAttributes",
+          "contains",
+          "autocomplete:both"
+        ],
+        [
+          "property",
+          "states",
+          "contains",
+          "STATE_SUPPORTS_AUTOCOMPLETION"
+        ]
+      ],
+      "IAccessible2" : [
+         [
+           "property",
+           "objectAttributes",
+           "contains",
+           "autocomplete:both"
+         ],
+         [
+           "property",
+           "states",
+           "contains",
+           "IA2_STATE_SUPPORTS_AUTOCOMPLETION"
+         ]
+      ]
+    }
+  );
+
+  AAMUtils.verifyAPI(
+    'aria-autocomplete=inline',
+    'test2',
+    {
+      "Atspi" : [
+        [
+          "property",
+          "objectAttributes",
+          "contains",
+          "autocomplete:inline"
+        ],
+        [
+          "property",
+          "states",
+          "contains",
+          "STATE_SUPPORTS_AUTOCOMPLETION"
+        ]
+      ],
+      "IAccessible2" : [
+         [
+           "property",
+           "objectAttributes",
+           "contains",
+           "autocomplete:inline"
+         ],
+         [
+           "property",
+           "states",
+           "contains",
+           "IA2_STATE_SUPPORTS_AUTOCOMPLETION"
+         ]
+      ]
+    }
+  );
+
+  AAMUtils.verifyAPI(
+    'aria-autocomplete=list',
+    'test3',
+    {
+      "Atspi" : [
+        [
+          "property",
+          "objectAttributes",
+          "contains",
+          "autocomplete:list"
+        ],
+        [
+          "property",
+          "states",
+          "contains",
+          "STATE_SUPPORTS_AUTOCOMPLETION"
+        ]
+      ],
+      "IAccessible2" : [
+         [
+           "property",
+           "objectAttributes",
+           "contains",
+           "autocomplete:list"
+         ],
+         [
+           "property",
+           "states",
+           "contains",
+           "IA2_STATE_SUPPORTS_AUTOCOMPLETION"
+         ]
+      ]
+    }
+  );
+
+</script>
+
+</body>
+</html>
diff --git a/core-aam/acacia/test-statements/aria-braillelabel.html b/core-aam/acacia/test-statements/aria-braillelabel.html
new file mode 100644
index 00000000000000..38662b73f4dc71
--- /dev/null
+++ b/core-aam/acacia/test-statements/aria-braillelabel.html
@@ -0,0 +1,59 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>aria-braillelabel</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<button id=test aria-braillelabel=foobar>
+
+<script>
+  AAMUtils.verifyAPI(
+    'aria-braillelabel',
+    'test',
+    {
+      "Atspi" : [
+        [
+          "property",
+          "objectAttributes",
+          "contains",
+          "braillelabel:foobar"
+        ]
+      ],
+      "AXAPI" : [
+        [
+          "property",
+          "AXBrailleLabel",
+          "is",
+          "foobar"
+        ]
+      ],
+      "IAccessible2" : [
+        [
+          "property",
+          "objectAttributes",
+          "contains",
+          "braillelabel:foobar"
+        ]
+      ],
+      "UIA" : [
+        [
+          "property",
+          "AriaProperties.braillelabel",
+          "is",
+          "foobar"
+        ]
+      ]
+    },
+  );
+</script>
+
+</body>
+</html>
diff --git a/core-aam/acacia/test-statements/aria-errormessage.html b/core-aam/acacia/test-statements/aria-errormessage.html
new file mode 100644
index 00000000000000..4886231d87546d
--- /dev/null
+++ b/core-aam/acacia/test-statements/aria-errormessage.html
@@ -0,0 +1,73 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>aria-flowto</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<div role='checkbox' id='test' aria-errormessage='error1 error2' aria-invalid='true'>content</div>
+<div id='error1'>hello</div>
+<div id='error2'>world</div>
+
+<script>
+  AAMUtils.verifyAPI(
+    'aria-flowto',
+    'test',
+    {
+      "Atspi" : [
+        [
+          "relation",
+          "RELATION_ERROR_MESSAGE",
+          "is",
+          ['error1', 'error2']
+        ],
+        [
+          "reverseRelation",
+          "RELATION_ERROR_FOR",
+          "is",
+          ['error1', 'error2']
+        ]
+      ],
+      "AXAPI" : [
+        [
+          "property",
+          "AXErrorMessageElements",
+          "is",
+          ['error1', 'error2']
+        ]
+      ],
+      "IAccessible2" : [
+        [
+          "relation",
+          "IA2_RELATION_ERROR",
+          "is",
+          ['error1', 'error2']
+        ],
+        [
+          "reverseRelation",
+          "IA2_RELATION_ERROR_FOR",
+          "is",
+          ['error1', 'error2']
+        ]
+      ],
+      "UIA" : [
+        [
+          "property",
+          "ControllerFor",
+          "is",
+          ['error1', 'error2']
+        ]
+      ]
+    }
+  );
+</script>
+
+</body>
+</html>
diff --git a/core-aam/acacia/test-statements/blockquote.html b/core-aam/acacia/test-statements/blockquote.html
new file mode 100644
index 00000000000000..80e3bc3893f81c
--- /dev/null
+++ b/core-aam/acacia/test-statements/blockquote.html
@@ -0,0 +1,77 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>role blockquote</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<div id=test role=blockquote>quote</div>
+
+<script>
+  AAMUtils.verifyAPI(
+    'role=blockquote',
+    'test',
+    {
+      "Atspi" : [
+         [
+            "property",
+            "role",
+            "is",
+            "block quote"
+         ]
+      ],
+      "AXAPI" : [
+         [
+            "property",
+            "AXRole",
+            "is",
+            "AXGroup"
+         ],
+         [
+            "property",
+            "AXSubrole",
+            "is",
+            "<nil>"
+         ]
+      ],
+      "IAccessible2" : [
+         [
+            "property",
+            "role",
+            "is",
+            "IA2_ROLE_BLOCK_QUOTE"
+         ],
+         [
+            "property",
+            "msaaRole",
+            "is",
+            "ROLE_SYSTEM_GROUPING"
+         ]
+      ],
+      "UIA" : [
+         [
+            "property",
+            "ControlType",
+            "is",
+            "Group"
+         ],
+         [
+            "property",
+            "LocalizedControlType",
+            "is",
+            "blockquote"
+         ]
+      ]
+    }
+  );
+</script>
+
+</body>
+</html>
diff --git a/core-aam/acacia/test-statements/button_with_default_values_for_aria-pressed_and_aria-haspopup.html b/core-aam/acacia/test-statements/button_with_default_values_for_aria-pressed_and_aria-haspopup.html
new file mode 100644
index 00000000000000..b3f0ac91c0289a
--- /dev/null
+++ b/core-aam/acacia/test-statements/button_with_default_values_for_aria-pressed_and_aria-haspopup.html
@@ -0,0 +1,71 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>role button with default values for aria-pressed and aria-hapopup</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<div id=test1 role=button>click me</div>
+<div id=test2 role=button aria-pressed>click me</div>
+<div id=test3 role=button aria-pressed aria-haspopup>click me</div>
+<div id=test4 role=button aria-haspopup>click me</div>
+<div id=test5 role=button aria-haspopup=false>click me</div>
+
+<script>
+  var test_statements = {
+    "Atspi" : [
+       [
+          "property",
+          "role",
+          "is",
+          "button"
+       ]
+    ],
+    "AXAPI" : [
+       [
+          "property",
+          "AXRole",
+          "is",
+          "AXButton"
+       ],
+       [
+          "property",
+          "AXSubrole",
+          "is",
+          "<nil>"
+       ]
+    ],
+    "IAccessible2" : [
+       [
+          "property",
+          "msaaRole",
+          "is",
+          "ROLE_SYSTEM_PUSHBUTTON"
+       ]
+    ],
+    "UIA" : [
+       [
+          "property",
+          "ControlType",
+          "is",
+          "Button"
+       ]
+    ]
+  };
+
+  AAMUtils.verifyAPI('role=button', 'test1', test_statements);
+  AAMUtils.verifyAPI('role=button aria-pressed', 'test2', test_statements);
+  AAMUtils.verifyAPI('role=button aria-pressed aria-haspopup', 'test3', test_statements);
+  AAMUtils.verifyAPI('role=button aria-haspopup', 'test4', test_statements);
+  AAMUtils.verifyAPI('role=button aria-haspopup=false', 'test5', test_statements);
+</script>
+
+</body>
+</html>
diff --git a/core-aam/acacia/test-statements/button_with_defined_value_for_aria-pressed.html b/core-aam/acacia/test-statements/button_with_defined_value_for_aria-pressed.html
new file mode 100644
index 00000000000000..fd84fec20d860b
--- /dev/null
+++ b/core-aam/acacia/test-statements/button_with_defined_value_for_aria-pressed.html
@@ -0,0 +1,70 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>role button with defined value for aria-pressed</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/role-map.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<div id=test1 role=button aria-pressed=true>press me</div>
+<div id=test2 role=button aria-pressed=false>press me</div>
+
+<script>
+  var test_statements = {
+    "Atspi" : [
+       [
+          "property",
+          "role",
+          "is",
+          "toggle button"
+       ]
+    ],
+    "AXAPI" : [
+       [
+          "property",
+          "AXRole",
+          "is",
+          "AXCheckBox"
+       ],
+       [
+          "property",
+          "AXSubrole",
+          "is",
+          "AXToggle"
+       ]
+    ],
+    "IAccessible2" : [
+       [
+          "property",
+          "role",
+          "is",
+          "IA2_ROLE_TOGGLE_BUTTON"
+       ],
+      [
+          "property",
+          "msaaRole",
+          "is",
+          "ROLE_SYSTEM_PUSHBUTTON"
+       ]
+    ],
+    "UIA" : [
+       [
+          "property",
+          "ControlType",
+          "is",
+          "Button"
+       ]
+    ]
+  };
+
+  AAMUtils.verifyAPI('role=button aria-pressed=true', 'test1', test_statements);
+  AAMUtils.verifyAPI('role=button aria-pressed=false','test2', test_statements);
+</script>
+</body>
diff --git a/core-aam/acacia/test-statements/button_with_non_false_value_for_aria-haspopup.html b/core-aam/acacia/test-statements/button_with_non_false_value_for_aria-haspopup.html
new file mode 100644
index 00000000000000..a6e5126352ea8c
--- /dev/null
+++ b/core-aam/acacia/test-statements/button_with_non_false_value_for_aria-haspopup.html
@@ -0,0 +1,109 @@
+<!doctype html>
+<meta charset=utf-8>
+<html>
+<head>
+  <title>role button with non false value for aria-pressed</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <script src="/resources/testdriver.js"></script>
+  <script src="/resources/testdriver-vendor.js"></script>
+  <script src="/resources/testdriver-actions.js"></script>
+  <script src="scripts/aam-utils.js"></script>
+</head>
+<body>
+
+<div id=test1 role=button aria-haspopup=true>click me</div>
+<div id=test2 role=button aria-haspopup=menu>click me</div>
+<div id=test3 role=button aria-haspopup=listbox>click me</div>
+<div id=test4 role=button aria-haspopup=tree>click me</div>
+<div id=test5 role=button aria-haspopup=grid>click me</div>
+<div id=test6 role=button aria-haspopup=dialog>click me</div>
+
+<script>
+  var test_statements =  {
+     "Atspi" : [
+        [
+           "property",
+           "role",
+           "is",
+           "button"
+        ]
+     ],
+     "AXAPI" : [
+        [
+           "property",
+           "AXRole",
+           "is",
+           "AXPopUpButton"
+        ],
+        [
+           "property",
+           "AXSubrole",
+           "is",
+           "<nil>"
+        ],
+        [
+           "property",
+           "actions",
+           "contains",
+           "AXShowMenu"
+        ]
+     ],
+     "IAccessible2" : [
+        [
+           "property",
+           "msaaRole",
+           "is",
+           "ROLE_SYSTEM_PUSHBUTTON"
+        ]
+     ],
+     "UIA" : [
+        [
+           "property",
+           "ControlType",
+           "is",
+           "Button"
+        ]
+     ]
+  };
+
+
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=true',
+    'test1',
+    test_statements
+  );
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=menu',
+    'test2',
+    test_statements
+  );
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=listbox',
+    'test3',
+    test_statements
+  );
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=tree',
+    'test4',
+    test_statements
+  );
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=grid',
+    'test5',
+    test_statements
+  );
+
+  AAMUtils.verifyAPI(
+    'role=button aria-haspopup=dialog',
+    'test6',
+    test_statements
+  );
+
+</script>
+</body>
diff --git a/core-aam/acacia/test-statements/scripts/aam-utils.js b/core-aam/acacia/test-statements/scripts/aam-utils.js
new file mode 100644
index 00000000000000..3bc0008b23bd20
--- /dev/null
+++ b/core-aam/acacia/test-statements/scripts/aam-utils.js
@@ -0,0 +1,53 @@
+/*
+  Utility files for platform specific accessibility API tests for the
+  Accessibility API Mappings (AAM) standards: Core-AAM and HTML-aam
+*/
+
+const AAMUtils = {
+  APIS: ['Atspi', 'AXAPI', 'IAccessible2', 'UIA'],
+
+  runAssertions: function(test_statements, results) {
+    // If the test was not run, the API doesn't apply to backend OS,
+    // pass with no asserts.
+    if (!results) {
+      return;
+    }
+
+    if (results.length !== test_statements.length)
+      assert_unreached(`Recieved a different number of results than test statements: ${results}`)
+
+    for (i = 0; i < results.length; i++) {
+      assert_equals(results[i], "Pass", `${test_statements[i].join(' ')}`)
+    }
+  },
+
+
+  /*
+    Creates a subtest for each API. Runs no asserts for APIs not found.
+
+    id:     id of element to test the accessibility node of
+    map:    entry in role-map.js, or similar
+    name:   name of the test
+  */
+
+  verifyAPI: function(test_name, id, map) {
+    if (!map) {
+      throw "Error: missing accessibility API test map";
+    }
+
+    for (const api of this.APIS) {
+      if (map[api] && map[api].length) {
+        promise_test(async t => {
+          let results = await test_driver.test_accessibility_api(
+            id,
+            map,
+            api
+          );
+
+          this.runAssertions(map[api], results);
+
+        }, `api: ${api}, ${test_name}`);
+      }
+    }
+  }
+}
diff --git a/resources/testdriver.js b/resources/testdriver.js
index ac3ed65bd039f3..668c3b94ccceaf 100644
--- a/resources/testdriver.js
+++ b/resources/testdriver.js
@@ -1080,6 +1080,21 @@
                 .then((jsonresult) => {
                   return JSON.parse(jsonresult);
                 });
+        },
+
+        /**
+         * Test properties of API's accessibility node.
+         *
+         * @param {id}         id of element
+         * @param {test}       an object of tests
+         * @param {api}        string indicating the API to test
+         * @returns {Promise}  The string "match" when the test succeeds,
+         *                     a failure message otherwise
+         */
+        test_accessibility_api: async function(dom_id, test, api) {
+            return window.test_driver_internal.test_accessibility_api(
+              dom_id, test, api, location.href
+            );
         }
     };
 
@@ -1272,6 +1287,11 @@
 
         async get_accessibility_api_node(dom_id, url) {
             throw new Error("get_accessibility_api_node() is not available.");
+        },
+
+        async test_accessibility_api(dom_id, test, api, url) {
+            throw new Error("test_accessibility_api() is not available.");
         }
+
     };
 })();
diff --git a/tools/wptrunner/wptrunner/executors/actions.py b/tools/wptrunner/wptrunner/executors/actions.py
index 41c56585c70ce7..0ca0bc82f0efb3 100644
--- a/tools/wptrunner/wptrunner/executors/actions.py
+++ b/tools/wptrunner/wptrunner/executors/actions.py
@@ -476,6 +476,20 @@ def __call__(self, payload):
         url = payload["url"]
         return self.protocol.platform_accessibility.get_accessibility_api_node(dom_id, url)
 
+class TestAccessibilityAPIAction:
+    name = "test_accessibility_api"
+
+    def __init__(self, logger, protocol):
+        self.logger = logger
+        self.protocol = protocol
+
+    def __call__(self, payload):
+        dom_id = payload["dom_id"]
+        test = payload["test"]
+        api = payload["api"]
+        url = payload["url"]
+        return self.protocol.platform_accessibility.test_accessibility_api(dom_id, test, api, url)
+
 
 actions = [ClickAction,
            DeleteAllCookiesAction,
@@ -513,4 +527,5 @@ def __call__(self, payload):
            GetVirtualSensorInformationAction,
            SetDevicePostureAction,
            ClearDevicePostureAction,
-           GetAccessibilityAPINodeAction]
+           GetAccessibilityAPINodeAction,
+           TestAccessibilityAPIAction]
diff --git a/tools/wptrunner/wptrunner/executors/executoratspi.py b/tools/wptrunner/wptrunner/executors/executoratspi.py
index c71caecb128d0f..21868934ab3e29 100644
--- a/tools/wptrunner/wptrunner/executors/executoratspi.py
+++ b/tools/wptrunner/wptrunner/executors/executoratspi.py
@@ -55,15 +55,15 @@ def is_ready(tab, product, url):
         return True
     return False
 
-
-def serialize_node(node):
-    node_dictionary = {}
-    node_dictionary["API"] = "atspi"
-    node_dictionary["role"] = Atspi.Accessible.get_role_name(node)
-    node_dictionary["name"] = Atspi.Accessible.get_name(node)
-    node_dictionary["description"] = Atspi.Accessible.get_description(node)
-
-    return node_dictionary
+def find_browser(name):
+    desktop = Atspi.get_desktop(0)
+    child_count = Atspi.Accessible.get_child_count(desktop)
+    for i in range(child_count):
+        app = Atspi.Accessible.get_child_at_index(desktop, i)
+        full_app_name = Atspi.Accessible.get_name(app)
+        if name in full_app_name.lower():
+            return (app, full_app_name)
+    return (None, None)
 
 
 def find_node(root, dom_id):
@@ -73,7 +73,7 @@ def find_node(root, dom_id):
 
         attributes = Atspi.Accessible.get_attributes(node)
         if "id" in attributes and attributes["id"] == dom_id:
-            return node
+            return TestNode(root, dom_id, node)
 
         for i in range(Atspi.Accessible.get_child_count(node)):
             child = Atspi.Accessible.get_child_at_index(node, i)
@@ -82,17 +82,6 @@ def find_node(root, dom_id):
     return None
 
 
-def find_browser(name):
-    desktop = Atspi.get_desktop(0)
-    child_count = Atspi.Accessible.get_child_count(desktop)
-    for i in range(child_count):
-        app = Atspi.Accessible.get_child_at_index(desktop, i)
-        full_app_name = Atspi.Accessible.get_name(app)
-        if name in full_app_name.lower():
-            return (app, full_app_name)
-    return (None, None)
-
-
 class AtspiExecutorImpl:
     def setup(self, product_name, logger):
         self.logger = logger
@@ -108,8 +97,7 @@ def setup(self, product_name, logger):
                 f"Couldn't find browser {self.product_name} in accessibility API ATSPI. Accessibility API queries will not succeeded."
             )
 
-
-    def get_accessibility_api_node(self, dom_id, url):
+    def __poll_for_tab_if_necessary(self, url):
         if not self.root:
             raise Exception(
                 f"Couldn't find browser {self.product_name} in accessibility API ATSPI. Did you turn on accessibility?"
@@ -119,10 +107,168 @@ def get_accessibility_api_node(self, dom_id, url):
             self.test_url = url
             self.document = poll_for_tab(self.root, self.product_name, url)
 
-        node = find_node(self.document, dom_id)
-        if not node:
+    def get_accessibility_api_node(self, dom_id, url):
+        self.__poll_for_tab_if_necessary(url)
+
+        test_node = find_node(self.document, dom_id)
+        if not test_node:
             raise Exception(
                 f"Couldn't find node with id={dom_id} in accessibility API ATSPI."
             )
 
-        return json.dumps(serialize_node(node))
+        return json.dumps(test_node.serialize())
+
+    def test_accessibility_api(self, dom_id, test, api, url):
+        self.__poll_for_tab_if_necessary(url)
+
+        test_node = find_node(self.document, dom_id)
+
+        results = []
+        for test_statement in test['Atspi']:
+            results.append(test_node.run_test_statement(TestStatement(test_statement)));
+
+        return results
+
+
+class TestNode():
+    """Wrapper around an Atspi Node for testing purposes"""
+    def __init__(self, root, dom_id, node):
+        self.root = root
+        self.dom_id = dom_id
+        self.node = node
+
+    def serialize(self):
+        node_dictionary = {}
+        node_dictionary["API"] = "atspi"
+        node_dictionary["role"] = Atspi.Accessible.get_role_name(self.node)
+        node_dictionary["name"] = Atspi.Accessible.get_name(self.node)
+        node_dictionary["description"] = Atspi.Accessible.get_description(self.node)
+        node_dictionary["states"] = self.get_state_list()
+        node_dictionary["objectAttributes"] = Atspi.Accessible.get_attributes_as_array(self.node)
+        node_dictionary["relations"] = self.get_relations_dictionary()
+
+        return node_dictionary
+
+    # 'statement' is a TestStatement object
+    def run_test_statement(self, statement):
+        if statement.type == 'property':
+            return self.run_property_test(statement)
+
+        if statement.type == 'relation':
+            return self.run_relation_test(statement)
+
+        if statement.type == 'reverseRelation':
+            return self.run_reverse_relation_test(statement)
+            return "not implemented reverse relations"
+
+        return "Error: not implemented ({statement.type})"
+
+    # 'statement' is a TestStatement object
+    def run_property_test(self, statement):
+        if statement.key == 'role':
+            role = Atspi.Accessible.get_role_name(self.node)
+            return statement.value_compare_with(role)
+
+        if statement.key == 'objectAttributes':
+            attributes = Atspi.Accessible.get_attributes_as_array(self.node)
+            return statement.value_contained_or_not_contained_in(attributes)
+
+        if statement.key == 'states':
+            states = self.get_state_list()
+            return statement.value_contained_or_not_contained_in(states)
+
+        return f"Error: not implemented ({statement.key})"
+
+    # 'statement' is a TestStatement object
+    def run_relation_test(self, statement):
+        expected_relation = statement.key
+        expected_ids = statement.value
+        relations_dict = self.get_relations_dictionary()
+        if expected_relation not in relations_dict:
+            return f"Fail: relation not in list: {list(relations_dict.keys())}"
+        id_str = ','.join(relations_dict[expected_relation])
+        expected_ids.sort()
+        expected_id_str = ','.join(expected_ids)
+        if (id_str != expected_id_str):
+            return f"Fail: {expected_relation}={relations_dict[expected_relation]}"
+        return "Pass"
+
+    # 'statement' is a TestStatement object
+    def run_reverse_relation_test(self, statement):
+        expected_relation = statement.key
+        # statement.value is a list of dom_ids representing the nodes that should have
+        # a reverse relation back to this node.
+        expected_elements = statement.value
+
+        for element in expected_elements:
+            test_node = find_node(self.root, element)
+            relations_dict = test_node.get_relations_dictionary()
+
+            if expected_relation not in relations_dict:
+                return f"Fail: element '{element}' does not have reverse relation, has relations: {list(relations_dict.keys())}"
+
+            if self.dom_id not in relations_dict[expected_relation]:
+                return f"Fail: element '{element}' {expected_relation}={relations_dict[expected_relation]}"
+
+        return "Pass"
+
+    # are a sorted list of dom IDs.
+    def get_relations_dictionary(self):
+        relations_dict = {}
+        relations = Atspi.Accessible.get_relation_set(self.node)
+        for relation in relations:
+            name = relation.get_relation_type().value_name.removeprefix('ATSPI_')
+            relations_dict[name] = []
+            num_targets = relation.get_n_targets()
+
+            for i in range(num_targets):
+                target = relation.get_target(i)
+                attributes = Atspi.Accessible.get_attributes(target)
+                if "id" in attributes:
+                    relations_dict[name].append(attributes["id"])
+                else:
+                    relations_dict[name].append("[unknown id]")
+        return relations_dict
+
+    def get_state_list(self):
+        state_list =  Atspi.Accessible.get_state_set(self.node).get_states()
+        state_string_list = []
+        for state in state_list:
+            state_string_list.append(state.value_name.replace('ATSPI_',''))
+        return state_string_list
+
+
+class TestStatement:
+    def __init__(self, test_statement_arr):
+        self.test_statement_arr = test_statement_arr
+
+        self.type = test_statement_arr[0];
+        self.key = test_statement_arr[1];
+        self.assertion = test_statement_arr[2];
+        self.value = test_statement_arr[3];
+
+    # Returns error or undefined
+    def value_compare_with(self, value):
+        if self.assertion == 'is':
+            if self.value != value:
+                return f"Fail: {self.key} is {value}"
+        elif self.assertion == 'isNot':
+            if self.value == value:
+                return f"Fail: {self.key} is {value}"
+        else:
+            return f"Error: Test statement malformed, '{self.assertion}' must be 'is' or 'isNot'."
+
+        return "Pass"
+
+    # returns error undefined
+    def value_contained_or_not_contained_in(self, array):
+        if self.assertion == 'contains':
+            if self.value not in array:
+                return f"Fail: {array} does not contain {self.value}"
+        elif self.assertion == 'doesNotContain':
+            if self.value in array:
+                return f"Fail: {array} contains {self.value}"
+        else:
+            return f"Error: Test statement malformed, '{self.assertion}' must be 'contains' or 'doesNotContain'."
+
+        return "Pass"
diff --git a/tools/wptrunner/wptrunner/executors/executorplatformaccessibility.py b/tools/wptrunner/wptrunner/executors/executorplatformaccessibility.py
index f7868dc4c16a92..7a3cd2eba1dc9b 100644
--- a/tools/wptrunner/wptrunner/executors/executorplatformaccessibility.py
+++ b/tools/wptrunner/wptrunner/executors/executorplatformaccessibility.py
@@ -16,6 +16,15 @@
     windows = True
     from .executorwindowsaccessibility import WindowsAccessibilityExecutorImpl
 
+def valid_api_for_platform(api):
+    if (linux and api == "Atspi"):
+        return True
+    if (mac and api == "AXAPI"):
+        return True
+    if (windows and (api == "UIA" or api == "IAccessible2")):
+        return True
+    return False
+
 class PlatformAccessibilityProtocolPart(ProtocolPart):
     """Protocol part for platform accessibility introspection"""
     name = "platform_accessibility"
@@ -35,3 +44,12 @@ def setup(self):
 
     def get_accessibility_api_node(self, dom_id, url):
         return self.impl.get_accessibility_api_node(dom_id, url)
+
+    def test_accessibility_api(self, dom_id, test, api, url):
+        # TODO: this is a bit of a hack, it will cause the test to
+        # "pass" with no assertions ran. We will use this until WPT supports
+        # some kind of "not applicable" test result.
+        if not valid_api_for_platform(api):
+          return ""
+
+        return self.impl.test_accessibility_api(dom_id, test, api, url)
diff --git a/tools/wptrunner/wptrunner/testdriver-extra.js b/tools/wptrunner/wptrunner/testdriver-extra.js
index 9a5880b17a4713..e97f5d42fec37f 100644
--- a/tools/wptrunner/wptrunner/testdriver-extra.js
+++ b/tools/wptrunner/wptrunner/testdriver-extra.js
@@ -339,4 +339,9 @@
     window.test_driver_internal.get_accessibility_api_node = function(dom_id, url) {
         return create_action("get_accessibility_api_node", {dom_id, url});
     };
+
+    window.test_driver_internal.test_accessibility_api = function(dom_id, test, api, url) {
+        return create_action("test_accessibility_api", {dom_id, test, api, url});
+    };
+
 })();
