feat: pass siwe params in channel body (#201)

## Motivation

Simplify SIWF QR codes by passing SIWE parameters in the channel body.

## Change Summary

Add `signatureParams` to channel body and `/status` response.

## Merge Checklist

_Choose all relevant options below by adding an `x` now or at any time
before submitting for review_

- [x] PR title adheres to the [conventional
commits](https://www.conventionalcommits.org/en/v1.0.0/) standard
- [x] PR has a changeset
- [x] PR has been tagged with a change label(s) (i.e. documentation,
feature, bugfix, or chore)
- [ ] PR includes documentation if necessary
- [x] All commits have been signed

.changeset/fifty-experts-love.md

@@ -0,0 +1,6 @@
+---
+"@farcaster/auth-client": patch
+"@farcaster/auth-relay": patch
+---
+
+feat: add SIWE params to channel body

apps/relay/src/handlers.ts

@@ -37,6 +37,7 @@ export type RelaySession = {
   pfpUrl?: string;
   verifications?: string[];
   custody?: Hex;
+  signatureParams: CreateChannelRequest;
 };
 
 const constructUrl = (channelToken: string, nonce: string, extraParams: CreateChannelRequest): string => {
@@ -57,6 +58,7 @@ export async function createChannel(request: FastifyRequest<{ Body: CreateChanne
       nonce,
       url,
       connectUri: url,
+      signatureParams: request.body,
     });
     if (update.isOk()) {
       return reply.code(201).send({ channelToken, url, connectUri: url, nonce });

apps/relay/src/server.test.ts

@@ -372,7 +372,12 @@ describe("relay server", () => {
       const { state, nonce, ...rest } = response.data;
       expect(state).toBe("pending");
       expect(nonce).toMatch(/[a-zA-Z0-9]{16}/);
-      expect(rest).toStrictEqual({});
+      expect(rest).toStrictEqual({
+        signatureParams: {
+          domain: "example.com",
+          siweUri: "https://example.com",
+        },
+      });
     });
 
     test("GET with invalid token", async () => {

packages/auth-client/src/actions/app/status.test.ts

@@ -16,6 +16,10 @@ describe("status", () => {
     state: "pending",
     nonce: "abcd1234",
     url: "https://warpcast.com/~/sign-in-with-farcaster?nonce=abcd1234[...]",
+    signatureParams: {
+      domain: "example.com",
+      siweUri: "https://example.com/login",
+    },
   };
 
   test("constructs API request", async () => {

packages/auth-client/src/actions/app/status.ts

@@ -20,8 +20,17 @@ export interface StatusAPIResponse {
   bio?: string;
   displayName?: string;
   pfpUrl?: string;
-  verifications?: Hex[];
+  verifications?: string[];
   custody?: Hex;
+  signatureParams: {
+    siweUri: string;
+    domain: string;
+    nonce?: string;
+    notBefore?: string;
+    expirationTime?: string;
+    requestId?: string;
+    redirectUrl?: string;
+  };
 }
 
 const path = "channel/status";

packages/auth-kit/src/components/AuthKitProvider/AuthKitProvider.tsx

@@ -19,7 +19,7 @@ export interface Profile {
   displayName?: string;
   bio?: string;
   custody?: `0x${string}`;
-  verifications?: `0x${string}`[];
+  verifications?: string[];
 }
 
 export interface SignInMessage {