From cbef689903cfd30d2fa56912614115427004a92b Mon Sep 17 00:00:00 2001
From: samialabri <sami.alabri@gmail.com>
Date: Thu, 15 Oct 2026 21:31:46 +0900
Subject: [PATCH] kv-proto: add PreloginResponse for GET /v1/auth/prelogin

A new device needs account_id and the KDF params to derive AUTH_INPUT
before it can build KE1, so they cannot come only from login/start.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 crates/kv-proto/src/lib.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/crates/kv-proto/src/lib.rs b/crates/kv-proto/src/lib.rs
index bae488a..e495cf1 100644
--- a/crates/kv-proto/src/lib.rs
+++ b/crates/kv-proto/src/lib.rs
@@ -134,6 +134,14 @@ pub struct SetupRequest {
     pub device: DeviceEnroll,
 }
 
+/// `GET /v1/auth/prelogin`: the public inputs a new device needs to derive `AUTH_INPUT`
+/// before it can build `ke1` (docs/02 "Key derivation"). Unauthenticated, rate limited.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PreloginResponse {
+    pub account_id: Uuid,
+    pub kdf: KdfParams,
+}
+
 /// `POST /v1/auth/login/start`.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct LoginStart {