diff --git a/actionbody.go b/actionbody.go
new file mode 100644
index 0000000..c211bb8
--- /dev/null
+++ b/actionbody.go
@@ -0,0 +1,45 @@
+package frameproto
+
+import (
+	"sourcecode.social/reiver/go-opt"
+)
+
+// ActionBody represents the data sent to a Frame-Protocol's (i.e., Farcaster Frame's) application when it is POSTed to.
+//
+// Example usage:
+//
+//	p, err := io.ReadAll(request.Body)
+//	if nil != err {
+//		return err
+//	}
+//	
+//	var actionBody frameproto.ActionBody
+//	
+//	err := json.Unmarshal(p, &actionBody)
+//	if nil != err {
+//		return err
+//	}
+type ActionBody struct {
+	UntrustedData ActionBodyUntrustedData `json:"untrustedData"`
+	TrustedData   ActionBodyTrustedData   `json:"trustedData"`
+}
+
+type ActionBodyUntrustedData struct {
+	FID         opt.Optional[uint64] `json:"fid"`
+	URL         opt.Optional[string] `json:"url"`
+	MessageHash opt.Optional[string] `json:"messageHash"`
+	Timestamp   opt.Optional[int64]  `json:"timestamp"`
+	Network     opt.Optional[uint64] `json:"network"`
+	ButtonIndex opt.Optional[uint64] `json:"buttonIndex"`
+	InputText   opt.Optional[string] `json:"inputText"`
+	CastID      ActionBodyCastID     `json:"castId"`
+}
+
+type ActionBodyTrustedData struct {
+	MessageBytes opt.Optional[string]
+}
+
+type ActionBodyCastID struct {
+		FID  opt.Optional[uint64] `json:"fid"`
+		Hash opt.Optional[string] `json:"hash"`
+}
diff --git a/actionbody_test.go b/actionbody_test.go
new file mode 100644
index 0000000..8286ed4
--- /dev/null
+++ b/actionbody_test.go
@@ -0,0 +1,87 @@
+package frameproto
+
+import (
+	"testing"
+
+	"encoding/json"
+
+	"sourcecode.social/reiver/go-opt"
+)
+
+func TestActionBody(t *testing.T) {
+
+	tests := []struct{
+		JSON string
+		Expected ActionBody
+	}{
+		{
+			JSON:
+`
+{
+  "untrustedData": {
+    "fid": 2,
+    "url": "https://fcpolls.com/polls/1",
+    "messageHash": "0xd2b1ddc6c88e865a33cb1a565e0058d757042974",
+    "timestamp": 1706243218,
+    "network": 1,
+    "buttonIndex": 2,
+    "inputText": "hello world",
+    "castId": {
+      "fid": 226,
+      "hash": "0xa48dd46161d8e57725f5e26e34ec19c13ff7f3b9"
+    }
+  },
+  "trustedData": {
+    "messageBytes": "d2b1ddc6c88e865a33cb1a565e0058d757042974..."
+  }
+}
+`,
+			Expected: ActionBody{
+				ActionBodyUntrustedData{
+					FID: opt.Something(uint64(2)),
+					URL: opt.Something("https://fcpolls.com/polls/1"),
+					MessageHash: opt.Something("0xd2b1ddc6c88e865a33cb1a565e0058d757042974"),
+					Timestamp: opt.Something(int64(1706243218)),
+					Network: opt.Something(uint64(1)),
+					ButtonIndex: opt.Something(uint64(2)),
+					InputText: opt.Something("hello world"),
+					CastID: ActionBodyCastID{
+						FID: opt.Something(uint64(226)),
+						Hash: opt.Something("0xa48dd46161d8e57725f5e26e34ec19c13ff7f3b9"),
+					},
+				},
+				ActionBodyTrustedData{
+					MessageBytes: opt.Something("d2b1ddc6c88e865a33cb1a565e0058d757042974..."),
+				},
+			},
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		var p []byte = []byte(test.JSON)
+
+		var actual ActionBody
+
+		err := json.Unmarshal(p, &actual)
+
+		if nil != err {
+			t.Errorf("For test #%d, did not expect to get an error but actually got one.", testNumber)
+			t.Logf("ERROR: (%T) %s", err, err)
+			t.Logf("JSON:\n%s", test.JSON)
+			continue
+		}
+
+		{
+			expected := test.Expected
+
+			if expected != actual {
+				t.Errorf("For test #%d, the actual value is not what wa expected.", testNumber)
+				t.Logf("EXPECTED: %#v", expected)
+				t.Logf("ACTUAL:   %#v", actual)
+				t.Logf("JSON:\n%s", test.JSON)
+				continue
+			}
+		}
+	}
+}