Add swagger API definitions for addressDerivationPath.

specifications/api/swagger.yaml

@@ -895,8 +895,40 @@ x-addressIndex: &addressIndex
   # 2 ^ 32 - 1, whole range (soft and hard) for random addresses:
   maximum: 4294967295
   description: |
-    An optional address derivation index. Leave out to get an address
-    with a randomly generated index.
+    An address derivation index.
+
+x-relativeAddressIndex: &relativeAddressIndex
+  type: number
+  minimum: 0
+  # 2 ^ 31 - 1
+  maximum: 2147483647
+  description: |
+    A relative address derivation index.
+
+x-addressDerivationType: &addressDerivationType
+  type: string
+  description: |
+    The type of derivation used in an address derivation path.
+  enum:
+    - hardened
+    - soft
+
+x-addressDerivationSegment: &addressDerivationSegment
+  description: An individual segment within an address derivation path.
+  type: object
+  required:
+    derivation_index
+    derivation_type
+  properties:
+    derivation_index: *relativeAddressIndex
+    derivation_type: *addressDerivationType
+
+x-addressDerivationPath: &addressDerivationPath
+  description: A path for deriving an address.
+  type: array
+  minItems: 1
+  items:
+    type: addressDerivationSegment
 
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