diff --git a/backend/openapi/components/parameters/x-signature.yaml b/backend/openapi/components/parameters/x-signature.yaml
new file mode 100644
index 0000000..7c1f4ec
--- /dev/null
+++ b/backend/openapi/components/parameters/x-signature.yaml
@@ -0,0 +1,6 @@
+name: X-Signature
+in: header
+description: HMAC signature for webhook verification
+example: 1234567890abcdef
+schema:
+    type: string
diff --git a/backend/openapi/components/parameters/x-timestamp.yaml b/backend/openapi/components/parameters/x-timestamp.yaml
new file mode 100644
index 0000000..37668fd
--- /dev/null
+++ b/backend/openapi/components/parameters/x-timestamp.yaml
@@ -0,0 +1,6 @@
+name: X-Timestamp
+in: header
+description: Timestamp of the webhook event (in Unix Epoch seconds)
+example: 1678901234
+schema:
+    type: string