diff --git a/apps/dokploy/.env.example b/apps/dokploy/.env.example
index 8f801196e7..587307de80 100644
--- a/apps/dokploy/.env.example
+++ b/apps/dokploy/.env.example
@@ -1,3 +1,7 @@
 DATABASE_URL="postgres://dokploy:amukds4wi9001583845717ad2@localhost:5432/dokploy"
 PORT=3000
 NODE_ENV=development
+
+# Maximum members per organization (better-auth default: 100).
+# Set a high value to effectively disable the limit.
+# ORG_MEMBERSHIP_LIMIT=10000
diff --git a/apps/dokploy/__test__/organization/accept-invitation.test.ts b/apps/dokploy/__test__/organization/accept-invitation.test.ts
new file mode 100644
index 0000000000..c50ba6975c
--- /dev/null
+++ b/apps/dokploy/__test__/organization/accept-invitation.test.ts
@@ -0,0 +1,164 @@
+import { describe, expect, it, vi } from "vitest";
+
+/**
+ * Integration-style tests that verify the membership limit enforcement logic
+ * as implemented by better-auth's organization plugin.
+ *
+ * These tests replicate the exact condition from:
+ *   better-auth/dist/plugins/organization/routes/crud-invites.mjs
+ *   better-auth/dist/plugins/organization/routes/crud-members.mjs
+ *
+ * The condition is:
+ *   const membershipLimit = ctx.context.orgOptions?.membershipLimit || 100;
+ *   if (membersCount >= membershipLimit) throw ORGANIZATION_MEMBERSHIP_LIMIT_REACHED;
+ */
+
+function simulateAcceptInvitation(opts: {
+	membershipLimit: number | undefined;
+	currentMemberCount: number;
+}): { allowed: boolean; effectiveLimit: number } {
+	const effectiveLimit = opts.membershipLimit || 100;
+	const allowed = opts.currentMemberCount < effectiveLimit;
+	return { allowed, effectiveLimit };
+}
+
+describe("accept-invitation membership limit enforcement", () => {
+	describe("with default limit (no ORG_MEMBERSHIP_LIMIT env)", () => {
+		it("allows acceptance when org has fewer than 100 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: undefined,
+				currentMemberCount: 50,
+			});
+			expect(result.allowed).toBe(true);
+			expect(result.effectiveLimit).toBe(100);
+		});
+
+		it("blocks acceptance when org has exactly 100 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: undefined,
+				currentMemberCount: 100,
+			});
+			expect(result.allowed).toBe(false);
+			expect(result.effectiveLimit).toBe(100);
+		});
+
+		it("blocks acceptance when org has more than 100 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: undefined,
+				currentMemberCount: 150,
+			});
+			expect(result.allowed).toBe(false);
+		});
+
+		it("allows acceptance when org has exactly 99 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: undefined,
+				currentMemberCount: 99,
+			});
+			expect(result.allowed).toBe(true);
+		});
+	});
+
+	describe("with custom limit via ORG_MEMBERSHIP_LIMIT", () => {
+		it("allows acceptance when limit is 500 and org has 100 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: 500,
+				currentMemberCount: 100,
+			});
+			expect(result.allowed).toBe(true);
+			expect(result.effectiveLimit).toBe(500);
+		});
+
+		it("blocks acceptance when limit is 500 and org has 500 members", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: 500,
+				currentMemberCount: 500,
+			});
+			expect(result.allowed).toBe(false);
+		});
+
+		it("allows acceptance with very high limit (10000) regardless of count", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: 10000,
+				currentMemberCount: 9999,
+			});
+			expect(result.allowed).toBe(true);
+			expect(result.effectiveLimit).toBe(10000);
+		});
+
+		it("blocks acceptance when limit is 10000 and count reaches it", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: 10000,
+				currentMemberCount: 10000,
+			});
+			expect(result.allowed).toBe(false);
+		});
+	});
+
+	describe("interaction between resolveOrgMembershipLimit and better-auth", () => {
+		it("resolveOrgMembershipLimit returns undefined → better-auth uses 100", async () => {
+			const originalEnv = process.env.ORG_MEMBERSHIP_LIMIT;
+			delete process.env.ORG_MEMBERSHIP_LIMIT;
+
+			const { resolveOrgMembershipLimit } = await import(
+				"@dokploy/server/lib/membership-limit"
+			);
+			const limit = resolveOrgMembershipLimit();
+			const result = simulateAcceptInvitation({
+				membershipLimit: limit,
+				currentMemberCount: 100,
+			});
+
+			expect(limit).toBeUndefined();
+			expect(result.allowed).toBe(false);
+			expect(result.effectiveLimit).toBe(100);
+
+			if (originalEnv !== undefined) {
+				process.env.ORG_MEMBERSHIP_LIMIT = originalEnv;
+			}
+		});
+
+		it("resolveOrgMembershipLimit returns 500 → better-auth uses 500", async () => {
+			const originalEnv = process.env.ORG_MEMBERSHIP_LIMIT;
+			process.env.ORG_MEMBERSHIP_LIMIT = "500";
+
+			vi.resetModules();
+			const { resolveOrgMembershipLimit } = await import(
+				"@dokploy/server/lib/membership-limit"
+			);
+			const limit = resolveOrgMembershipLimit();
+			const result = simulateAcceptInvitation({
+				membershipLimit: limit,
+				currentMemberCount: 100,
+			});
+
+			expect(limit).toBe(500);
+			expect(result.allowed).toBe(true);
+			expect(result.effectiveLimit).toBe(500);
+
+			if (originalEnv !== undefined) {
+				process.env.ORG_MEMBERSHIP_LIMIT = originalEnv;
+			} else {
+				delete process.env.ORG_MEMBERSHIP_LIMIT;
+			}
+		});
+	});
+
+	describe("add-member endpoint uses same limit logic", () => {
+		it("adding a member is blocked at default limit of 100", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: undefined,
+				currentMemberCount: 100,
+			});
+			expect(result.allowed).toBe(false);
+		});
+
+		it("adding a member is allowed with custom limit above current count", () => {
+			const result = simulateAcceptInvitation({
+				membershipLimit: 200,
+				currentMemberCount: 100,
+			});
+			expect(result.allowed).toBe(true);
+		});
+	});
+});
diff --git a/apps/dokploy/__test__/organization/membership-limit.test.ts b/apps/dokploy/__test__/organization/membership-limit.test.ts
new file mode 100644
index 0000000000..35649db9d8
--- /dev/null
+++ b/apps/dokploy/__test__/organization/membership-limit.test.ts
@@ -0,0 +1,70 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+describe("resolveOrgMembershipLimit", () => {
+	const originalEnv = process.env;
+
+	afterEach(() => {
+		process.env = originalEnv;
+		vi.resetModules();
+	});
+
+	async function importFresh() {
+		const mod = await import("@dokploy/server/lib/membership-limit");
+		return mod.resolveOrgMembershipLimit;
+	}
+
+	it("returns undefined when ORG_MEMBERSHIP_LIMIT is not set", async () => {
+		process.env = { ...originalEnv };
+		delete process.env.ORG_MEMBERSHIP_LIMIT;
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("returns undefined for empty string", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("returns the parsed number for a valid positive integer", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "500" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBe(500);
+	});
+
+	it("returns the parsed number for a large value (effectively unlimited)", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "10000" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBe(10000);
+	});
+
+	it("returns undefined for zero", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "0" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("returns undefined for negative numbers", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "-5" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("returns undefined for non-numeric strings", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "abc" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("returns undefined for NaN-producing values like Infinity", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "Infinity" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBeUndefined();
+	});
+
+	it("handles decimal values by returning them as-is", async () => {
+		process.env = { ...originalEnv, ORG_MEMBERSHIP_LIMIT: "150.5" };
+		const resolveOrgMembershipLimit = await importFresh();
+		expect(resolveOrgMembershipLimit()).toBe(150.5);
+	});
+});
diff --git a/packages/server/src/lib/auth.ts b/packages/server/src/lib/auth.ts
index c8dbf18073..ce5d2c50a2 100644
--- a/packages/server/src/lib/auth.ts
+++ b/packages/server/src/lib/auth.ts
@@ -28,6 +28,7 @@ import {
 import { getPublicIpWithFallback } from "../wss/utils";
 import { ac, adminRole, memberRole, ownerRole } from "./access-control";
 import { betterAuthSecret } from "./auth-secret";
+import { resolveOrgMembershipLimit } from "./membership-limit";
 
 const { handler, api } = betterAuth({
 	database: drizzleAdapter(db, {
@@ -402,6 +403,9 @@ const { handler, api } = betterAuth({
 		twoFactor(),
 		organization({
 			ac,
+			...(resolveOrgMembershipLimit() !== undefined
+				? { membershipLimit: resolveOrgMembershipLimit() }
+				: {}),
 			roles: {
 				owner: ownerRole,
 				admin: adminRole,
diff --git a/packages/server/src/lib/membership-limit.ts b/packages/server/src/lib/membership-limit.ts
new file mode 100644
index 0000000000..e7f220d04d
--- /dev/null
+++ b/packages/server/src/lib/membership-limit.ts
@@ -0,0 +1,13 @@
+/**
+ * Resolves the organization membership limit from the environment.
+ *
+ * - If ORG_MEMBERSHIP_LIMIT is set to a valid positive number, returns that number.
+ * - Otherwise returns undefined, letting better-auth use its built-in default (100).
+ */
+export function resolveOrgMembershipLimit(): number | undefined {
+	const raw = process.env.ORG_MEMBERSHIP_LIMIT;
+	if (!raw) return undefined;
+	const parsed = Number(raw);
+	if (!Number.isFinite(parsed) || parsed <= 0) return undefined;
+	return parsed;
+}