feat: new types for directed identity, improved grant (#24)

* feat: new types for directed identity, improved grant

* chore: changeset

Author: BlairCurrey

.changeset/giant-dots-carry.md

@@ -0,0 +1,5 @@
+---
+'@interledger/open-payments': minor
+---
+
+New union client type to support directed identity. Exported grant type guards and added new, more explicit grant types.

open-payments-specifications

@@ -12,8 +12,12 @@ export {
   OutgoingPaymentGrantSpentAmounts,
   PendingGrant,
   Grant,
+  GrantWithAccessToken,
+  GrantWithSubject,
   isPendingGrant,
   isFinalizedGrant,
+  isFinalizedGrantWithAccessToken,
+  isFinalizedGrantWithSubject,
   JWK,
   JWKS,
   PaginationArgs,
@@ -22,7 +26,8 @@ export {
   AccessAction,
   AccessToken,
   AccessItem,
-  Subject
+  Subject,
+  Client
 } from './types'
 
 export {

packages/open-payments/src/index.ts

@@ -167,15 +167,31 @@ export interface components {
         };
         /**
          * client
-         * @description Wallet address of the client instance that is making this request.
+         * @description Client identification for grant requests.
          *
          *     When sending a non-continuation request to the AS, the client instance MUST identify itself by including the client field of the request and by signing the request.
          *
+         *     Can be either:
+         *     - A wallet address string (backwards compatible format)
+         *     - An object with either `jwk` (for directed identity) or `walletAddress` (mutually exclusive)
+         *
+         *     When using a wallet address string or the `walletAddress` property:
          *     A JSON Web Key Set document, including the public key that the client instance will use to protect this request and any continuation requests at the AS and any user-facing information about the client instance used in interactions, MUST be available at the wallet address + `/jwks.json` url.
          *
+         *     When using the `jwk` property (directed identity approach):
+         *     The client instance provides its public key directly in the request, eliminating the need for the AS to fetch it from a wallet address. This approach enhances privacy by not requiring the client to expose a persistent wallet address identifier. The `jwk` property can only be used for non-interactive grant requests (i.e.: incoming payments).
+         *
          *     If sending a grant initiation request that requires RO interaction, the wallet address MUST serve necessary client display information.
          */
-        client: string;
+        client: string | {
+            /**
+             * Format: uri
+             * @description Wallet address of the client instance that is making this request.
+             */
+            walletAddress: string;
+        } | {
+            jwk: components["schemas"]["json-web-key"];
+        };
         /**
          * continue
          * @description If the AS determines that the request can be continued with additional requests, it responds with the continue field.
@@ -307,6 +323,29 @@ export interface components {
                 format: "uri";
             }[];
         };
+        /**
+         * Ed25519 Public Key
+         * @description A JWK representation of an Ed25519 Public Key
+         */
+        "json-web-key": {
+            kid: string;
+            /**
+             * @description The cryptographic algorithm family used with the key. The only allowed value is `EdDSA`.
+             * @enum {string}
+             */
+            alg: "EdDSA";
+            /** @enum {string} */
+            use?: "sig";
+            /** @enum {string} */
+            kty: "OKP";
+            /**
+             * @description The cryptographic curve used with the key. This parameter identifies the elliptic curve (for EC keys) or the Edwards curve (for OKP keys). The only allowed value is `Ed25519`.
+             * @enum {string}
+             */
+            crv: "Ed25519";
+            /** @description The base64 url-encoded public key. */
+            x: string;
+        };
     };
     responses: never;
     parameters: never;

packages/open-payments/src/openapi/generated/auth-server-types.ts

@@ -894,8 +894,8 @@ export interface operations {
                 };
                 content: {
                     "application/json": {
-                        spentReceiveAmount?: components["schemas"]["amount"];
-                        spentDebitAmount?: components["schemas"]["amount"];
+                        spentReceiveAmount: components["schemas"]["amount"] | null;
+                        spentDebitAmount: components["schemas"]["amount"] | null;
                     };
                 };
             };

packages/open-payments/src/openapi/generated/resource-server-types.ts

@@ -85,14 +85,18 @@ export const getASPath = <P extends keyof ASPaths>(path: P): string =>
   path as string
 
 export type Subject = ASComponents['schemas']['subject']
+export type Client =
+  | string
+  | { walletAddress: string; jwk?: never }
+  | { jwk: JWK; walletAddress?: never }
 
 export type NonInteractiveGrantRequest = {
   access_token: ASOperations['post-request']['requestBody']['content']['application/json']['access_token']
-  client: ASOperations['post-request']['requestBody']['content']['application/json']['client']
+  client: Client
 }
 
 type BaseGrantRequest = {
-  client: ASOperations['post-request']['requestBody']['content']['application/json']['client']
+  client: Client
   interact?: ASOperations['post-request']['requestBody']['content']['application/json']['interact']
 }
 
@@ -113,6 +117,12 @@ export type Grant = {
   continue: ASComponents['schemas']['continue']
   subject?: Subject
 }
+export type GrantWithAccessToken = Grant & {
+  access_token: NonNullable<Grant['access_token']>
+}
+export type GrantWithSubject = Grant & {
+  subject: NonNullable<Grant['subject']>
+}
 export type GrantContinuation = {
   continue: ASComponents['schemas']['continue']
 }
@@ -145,12 +155,11 @@ export const isFinalizedGrant = (
 
 export const isFinalizedGrantWithAccessToken = (
   grant: GrantContinuation | Grant
-): grant is Grant & { access_token: ASComponents['schemas']['access_token'] } =>
-  !!(grant as Grant).access_token
+): grant is GrantWithAccessToken => !!(grant as Grant).access_token
 
 export const isFinalizedGrantWithSubject = (
   grant: GrantContinuation | Grant
-): grant is Grant & { subject: Subject } => !!(grant as Grant).subject
+): grant is GrantWithSubject => !!(grant as Grant).subject
 
 export type AccessIncomingActions =
   ASComponents['schemas']['access-incoming']['actions']