diff --git a/UAT_PLAYBOOK.md b/UAT_PLAYBOOK.md
index 68d6d25..8f3d171 100644
--- a/UAT_PLAYBOOK.md
+++ b/UAT_PLAYBOOK.md
@@ -28,6 +28,12 @@ GroomBook API is a Hono-based REST service (TypeScript/Node.js) powering the pet
 | TC-API-1.1 | Login via OIDC | POST to OIDC provider callback, verify JWT token issued | 200 OK, JWT returned with valid claims |
 | TC-API-1.2 | Session persistence | Make authenticated request, verify session token valid | 200 OK, request succeeds |
 | TC-API-1.3 | Logout | Call logout endpoint, verify token invalidated | 200 OK, subsequent requests return 401 |
+| TC-API-1.4 | Email+password login (UAT) | POST /api/auth/sign-in/email with uat-super@groombook.dev + SEED_UAT_SUPER_PASSWORD | 200 OK, session cookie returned |
+| TC-API-1.5 | Email+password login — groomer | POST /api/auth/sign-in/email with uat-groomer@groombook.dev + SEED_UAT_GROOMER_PASSWORD | 200 OK, session cookie returned |
+| TC-API-1.6 | Email+password login — customer | POST /api/auth/sign-in/email with uat-customer@groombook.dev + SEED_UAT_CUSTOMER_PASSWORD | 200 OK, session cookie returned |
+| TC-API-1.7 | Email+password login — tester | POST /api/auth/sign-in/email with uat-tester@groombook.dev + SEED_UAT_TESTER_PASSWORD | 200 OK, session cookie returned |
+| TC-API-1.8 | Email+password — invalid password | POST /api/auth/sign-in/email with wrong password | 400 Bad Request, error returned |
+| TC-API-1.9 | Email+password — unknown user | POST /api/auth/sign-in/email with non-existent email | 400 Bad Request, error returned |
 
 ### 4.2 Client Management
 
diff --git a/apps/api/src/db/seed.ts b/apps/api/src/db/seed.ts
index 2ff67bf..a12699a 100644
--- a/apps/api/src/db/seed.ts
+++ b/apps/api/src/db/seed.ts
@@ -18,7 +18,7 @@
 
 import postgres from "postgres";
 import { drizzle } from "drizzle-orm/postgres-js";
-import { eq, sql } from "drizzle-orm";
+import { eq, and, sql } from "drizzle-orm";
 import * as schema from "./schema.js";
 
 // ── Seed profile configuration ─────────────────────────────────────────────
@@ -511,6 +511,92 @@ async function seedKnownUsers() {
     }
   }
 
+  // ── Better-Auth email+password credentials for UAT accounts ──────────────────
+  // Provisions Better-Auth user + account records so UAT testers can log in
+  // via email+password (POST /api/auth/sign-in/email) instead of Authentik SSO.
+  const uatPasswordAccounts = [
+    { email: "uat-super@groombook.dev", name: "UAT Super User", passwordEnv: "SEED_UAT_SUPER_PASSWORD", staffEmail: "uat-super@groombook.dev" },
+    { email: "uat-groomer@groombook.dev", name: "UAT Staff Groomer", passwordEnv: "SEED_UAT_GROOMER_PASSWORD", staffEmail: "uat-groomer@groombook.dev" },
+    { email: "uat-customer@groombook.dev", name: "UAT Customer", passwordEnv: "SEED_UAT_CUSTOMER_PASSWORD", staffEmail: null },
+    { email: "uat-tester@groombook.dev", name: "UAT Tester", passwordEnv: "SEED_UAT_TESTER_PASSWORD", staffEmail: "uat-tester@groombook.dev" },
+  ];
+
+  for (const acct of uatPasswordAccounts) {
+    const password = process.env[acct.passwordEnv];
+    if (!password) {
+      console.warn(`⚠ Skipping ${acct.email} — ${acct.passwordEnv} not set`);
+      continue;
+    }
+
+    // 1. Find or create the Better-Auth user
+    const [existingUser] = await db
+      .select()
+      .from(schema.user)
+      .where(eq(schema.user.email, acct.email))
+      .limit(1);
+
+    let userId: string;
+    if (existingUser) {
+      userId = existingUser.id;
+      console.log(`✓ Better-Auth user '${acct.name}' already exists — skipping user creation`);
+    } else {
+      userId = uuid();
+      await db.insert(schema.user).values({
+        id: userId,
+        name: acct.name,
+        email: acct.email,
+        emailVerified: true,
+      });
+      console.log(`✓ Created Better-Auth user '${acct.name}' (${acct.email})`);
+    }
+
+    // 2. Check if credential account already exists
+    const [existingAccount] = await db
+      .select()
+      .from(schema.account)
+      .where(and(
+        eq(schema.account.userId, userId),
+        eq(schema.account.providerId, "credential")
+      ))
+      .limit(1);
+
+    if (existingAccount) {
+      console.log(`✓ Credential account for '${acct.email}' already exists — skipping`);
+    } else {
+      // Hash password using the same scrypt derivation as crypto.ts (AES-256-GCM key derivation).
+      // Better-Auth defaults to scrypt for password hashing; match those parameters here.
+      const { scryptSync, randomBytes } = await import("node:crypto");
+      const salt = randomBytes(16);
+      // scryptSync(password, salt, keylen=64, N=32768, r=8, p=1) — matches common better-auth scrypt params
+      const hashed = scryptSync(password, salt, 64, { N: 32768, r: 8, p: 1 }).toString("base64");
+      const passwordHash = `${salt.toString("base64")}:${hashed}`;
+
+      await db.insert(schema.account).values({
+        id: uuid(),
+        accountId: userId,
+        providerId: "credential",
+        userId,
+        password: passwordHash,
+      });
+      console.log(`✓ Created credential account for '${acct.email}'`);
+    }
+
+    // 3. Link staff record to Better-Auth user (for accounts that have staff records)
+    if (acct.staffEmail) {
+      const [existingStaff] = await db
+        .select()
+        .from(schema.staff)
+        .where(eq(schema.staff.email, acct.staffEmail))
+        .limit(1);
+      if (existingStaff && !existingStaff.userId) {
+        await db.update(schema.staff)
+          .set({ userId })
+          .where(eq(schema.staff.id, existingStaff.id));
+        console.log(`✓ Linked staff '${acct.staffEmail}' → Better-Auth user`);
+      }
+    }
+  }
+
   // ── Services: idempotent upsert using name as unique key ─────────────────────
   // UNIQUE constraint on services.name (migration 0020) must exist first.
   // Uses b0000001-... IDs to match main seed servicesDef for same-named services.