From 5bf2a71c9e9ab88cd74c5437163cc73967dcaeb1 Mon Sep 17 00:00:00 2001
From: Gustavo Valverde <g.valverde02@gmail.com>
Date: Thu, 15 Oct 2026 12:09:11 +0100
Subject: [PATCH] fix(prisma-adapter): route insensitive id increments through
 the lookup path

---
 .../prisma-adapter/src/prisma-adapter.test.ts | 35 +++++++++++++++++++
 packages/prisma-adapter/src/prisma-adapter.ts |  9 ++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/packages/prisma-adapter/src/prisma-adapter.test.ts b/packages/prisma-adapter/src/prisma-adapter.test.ts
index fcd0944a38..cadbd57b4f 100644
--- a/packages/prisma-adapter/src/prisma-adapter.test.ts
+++ b/packages/prisma-adapter/src/prisma-adapter.test.ts
@@ -607,6 +607,41 @@ describe("prisma-adapter", () => {
 		});
 	});
 
+	it("incrementOne resolves an insensitive id before the keyed update", async () => {
+		const update = vi.fn().mockResolvedValue({ id: "row-1", remaining: 4 });
+		const txClient = {
+			verification: {
+				findFirst: vi.fn().mockResolvedValue({ id: "row-1" }),
+				update,
+			},
+		};
+		const adapter = prismaAdapter(
+			{
+				$transaction: vi.fn(async (cb) => cb(txClient)),
+				verification: {},
+			} as never,
+			{ provider: "postgresql" },
+		)({
+			verification: {
+				additionalFields: { remaining: { type: "number" } },
+			},
+		} as BetterAuthOptions);
+
+		await adapter.incrementOne({
+			model: "verification",
+			where: [{ field: "id", value: "row-1", mode: "insensitive" }],
+			increment: { remaining: -1 },
+		});
+
+		expect(update).toHaveBeenCalledWith({
+			where: {
+				id: "row-1",
+				AND: [{ id: { equals: "row-1", mode: "insensitive" } }],
+			},
+			data: { remaining: { increment: -1 } },
+		});
+	});
+
 	it("update keeps an insensitive predicate next to a unique key", async () => {
 		const update = vi.fn().mockResolvedValue({ id: "user-id" });
 		const adapter = prismaAdapter(
diff --git a/packages/prisma-adapter/src/prisma-adapter.ts b/packages/prisma-adapter/src/prisma-adapter.ts
index 8acf194212..96651b1320 100644
--- a/packages/prisma-adapter/src/prisma-adapter.ts
+++ b/packages/prisma-adapter/src/prisma-adapter.ts
@@ -746,7 +746,14 @@ export const prismaAdapter = (prisma: PrismaClient, config: PrismaConfig) => {
 					// transaction and update by id. Either way the original guard stays in
 					// the where, so a racer that invalidated it (e.g. remaining dropped to
 					// 0) yields P2025 and we report no mutation.
-					const hasIdField = where?.some((w) => w.field === "id");
+					// Only a case-sensitive AND eq on id can stay a flat key for update().
+					const hasIdField = where?.some(
+						(w) =>
+							w.field === "id" &&
+							(w.operator === "eq" || !w.operator) &&
+							w.connector !== "OR" &&
+							!isInsensitiveForPrisma(w),
+					);
 					if (hasIdField) {
 						const whereClause = convertWhereClause({
 							model: modelKey,