diff --git a/DigitalData.Auth.Claims/DigitalData.Auth.Claims.csproj b/DigitalData.Auth.Claims/DigitalData.Auth.Claims.csproj
new file mode 100644
index 0000000..327398d
--- /dev/null
+++ b/DigitalData.Auth.Claims/DigitalData.Auth.Claims.csproj
@@ -0,0 +1,29 @@
+
+
+
+ net8.0
+ enable
+ enable
+
+
+ DigitalData.Auth.Claims
+ Digital Data GmbH
+ Digital Data GmbH
+ DigitalData.Auth.Claims
+
+ Provides strongly-typed JWT claim name constants for the DigitalData.Auth ecosystem.
+ Includes domain-specific claim definitions (e.g. envelope and receiver claims)
+ to be shared across API, client, and consumer projects.
+
+ Copyright 2026 Digital Data GmbH
+ https://git.dd/AppStd/DigitalData.Auth
+ digital data auth claims jwt constants
+ false
+ 1.0.0
+ 1.0.0
+ 1.0.0
+ false
+
+
+
+
diff --git a/DigitalData.Auth.Claims/EnvelopeClaimNames.cs b/DigitalData.Auth.Claims/EnvelopeClaimNames.cs
new file mode 100644
index 0000000..c30619a
--- /dev/null
+++ b/DigitalData.Auth.Claims/EnvelopeClaimNames.cs
@@ -0,0 +1,34 @@
+namespace DigitalData.Auth.Claims
+{
+ ///
+ /// Defines the custom JWT claim names used for envelope receiver tokens.
+ /// These claims are domain-specific and have no equivalent in .
+ ///
+ public static class EnvelopeClaimNames
+ {
+ ///
+ /// The database primary key of the envelope.
+ /// Claim name: envelope_id
+ ///
+ public const string EnvelopeId = "envelope_id";
+
+ ///
+ /// The unique identifier (UUID) of the envelope.
+ /// Claim name: envelope_uuid
+ ///
+ public const string EnvelopeUuid = "envelope_uuid";
+
+ ///
+ /// The database primary key of the envelope receiver.
+ /// Claim name: receiver_id
+ ///
+ public const string ReceiverId = "receiver_id";
+
+ ///
+ /// The cryptographic signature of the envelope receiver.
+ /// Together with , it forms the unique envelope key via ToEnvelopeKey().
+ /// Claim name: receiver_sig
+ ///
+ public const string ReceiverSignature = "receiver_sig";
+ }
+}