diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..4e0c25b
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,57 @@
+/**
+ * Interface for lib/saml (Banno/node-saml).  It differs from the original
+ * designed for auth0/node-saml to include the enhancements for supporting
+ * a full SAML 2.0 Response in all signing modes.
+ */
+ declare module '@banno/saml' {
+    export interface SamlAttributes {
+        [key: string]: string;
+    }
+  
+    export interface KeyInfoProvider {
+        getKeyInfo(key: string, prefix: string): string;
+    }
+  
+    export interface SamlOpts {
+        authnContextClassRef?: string;
+        attributes?: SamlAttributes;
+        audiences?: string | string[];
+        cert: Buffer;
+        digestAlgorithm?: string;
+        encryptionAlgorithm?: string;
+        encryptionCert?: Buffer;
+        encryptionPublicKey?: Buffer;
+        holderOfKeyProofSecret?: string;
+        includeAttributeNameFormat?: boolean;
+        inResponseTo?: string;
+        issuer?: string;
+        key: Buffer;
+        keyEncryptionAlgorighm?: string; // sic https://github.com/auth0/node-xml-encryption/issues/17
+        keyInfoProvider?: KeyInfoProvider;
+        lifetimeInSeconds?: number;
+        nameIdentifier?: string;
+        nameIdentifierFormat?: string;
+        prefix?: string;
+        recipient?: string;
+        sessionIndex?: string;
+        signatureAlgorithm?: string;
+        signatureNamespacePrefix?: string;
+        subjectConfirmationMethod?: string;
+        typedAttributes?: boolean;
+        uid?: string;
+        responseUid?: string;
+        xpathToNodeBeforeSignature?: string;
+        createSignedSamlResponse?: boolean;
+        responseSigningLevel?: string;
+        destination?: string;
+    }
+  
+    export namespace Saml11 {
+        function create(opts: SamlOpts, cb?: (err: Error | null, result: any[], proofSecret: Buffer) => void): any;
+    }
+  
+    export namespace Saml20 {
+        function create(opts: SamlOpts, cb?: (err: Error | null, signed: string) => void): any;
+    }
+  }
+  
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