diff --git a/src/client/dom/serviceworker.ts b/src/client/dom/serviceworker.ts
index 841a600..04ef2d1 100644
--- a/src/client/dom/serviceworker.ts
+++ b/src/client/dom/serviceworker.ts
@@ -2,11 +2,14 @@ import { config, rewriteUrl } from "../../shared";
 import { ScramjetClient } from "../client";
 import { type MessageC2W } from "../../worker";
 import { getOwnPropertyDescriptorHandler } from "../helpers";
+import { flagEnabled } from "../../scramjet";
 
 // we need a late order because we're mangling with addEventListener at a higher level
 export const order = 2;
 
-export const enabled = () => config.flags.serviceworkers;
+export const enabled = (client: ScramjetClient) =>
+	flagEnabled("serviceworkers", client.url);
+
 export function disabled(_client: ScramjetClient, _self: Self) {
 	Reflect.deleteProperty(Navigator.prototype, "serviceWorker");
 }
diff --git a/src/client/shared/err.ts b/src/client/shared/err.ts
index 7125fcc..75b5f09 100644
--- a/src/client/shared/err.ts
+++ b/src/client/shared/err.ts
@@ -1,7 +1,9 @@
+import { flagEnabled } from "../../scramjet";
 import { config } from "../../shared";
 import { ScramjetClient } from "../client";
 
-export const enabled = () => config.flags.captureErrors;
+export const enabled = (client: ScramjetClient) =>
+	flagEnabled("captureErrors", client.url);
 export function argdbg(arg, recurse = []) {
 	switch (typeof arg) {
 		case "string":
diff --git a/src/client/shared/error.ts b/src/client/shared/error.ts
index 3ae407a..8e79675 100644
--- a/src/client/shared/error.ts
+++ b/src/client/shared/error.ts
@@ -1,7 +1,9 @@
+import { flagEnabled } from "../../scramjet";
 import { config, unrewriteUrl } from "../../shared";
 import { ScramjetClient } from "../client";
 
-export const enabled = () => self.$scramjet.config.flags.cleanerrors;
+export const enabled = (client: ScramjetClient) =>
+	flagEnabled("cleanerrors", client.url);
 export default function (client: ScramjetClient, _self: Self) {
 	// v8 only. all we need to do is clean the scramjet urls from stack traces
 	const closure = (error, stack) => {
@@ -10,7 +12,7 @@ export default function (client: ScramjetClient, _self: Self) {
 		for (let i = 0; i < stack.length; i++) {
 			const url = stack[i].getFileName();
 
-			if (url.endsWith(config.client)) {
+			if (url.endsWith(config.files.client)) {
 				// strip stack frames including scramjet handlers from the trace
 				const lines = newstack.split("\n");
 				const line = lines.find((l) => l.includes(url));
diff --git a/src/client/shared/requests/xmlhttprequest.ts b/src/client/shared/requests/xmlhttprequest.ts
index 6e24132..dd035e6 100644
--- a/src/client/shared/requests/xmlhttprequest.ts
+++ b/src/client/shared/requests/xmlhttprequest.ts
@@ -1,3 +1,4 @@
+import { flagEnabled } from "../../../scramjet";
 import { config, unrewriteUrl, rewriteUrl } from "../../../shared";
 import { ScramjetClient } from "../../client";
 let nativeworker;
@@ -35,8 +36,8 @@ export default function (client: ScramjetClient, self: Self) {
 			const args = ctx.this[ARGS];
 			if (!args || args[2]) return;
 
-			if (!self.$scramjet.config.flags.syncxhr) {
-				console.warn("sync xhr disabled in flags");
+			if (!flagEnabled("syncxhr", client.url)) {
+				console.warn("ignoring request - sync xhr disabled in flags");
 
 				return;
 			}
diff --git a/src/client/shared/sourcemaps.ts b/src/client/shared/sourcemaps.ts
index fd5ed0a..80747dc 100644
--- a/src/client/shared/sourcemaps.ts
+++ b/src/client/shared/sourcemaps.ts
@@ -1,10 +1,12 @@
+import { flagEnabled } from "../../scramjet";
 import { ScramjetClient } from "../client";
 
 type Mapping = [string, number, number];
 
 const sourcemaps: Record<string, Mapping[]> = {};
 
-export const enabled = () => self.$scramjet.config.flags.sourcemaps;
+export const enabled = (client: ScramjetClient) =>
+	flagEnabled("sourcemaps", client.url);
 
 export default function (client: ScramjetClient, self: Self) {
 	// every script will push a sourcemap
diff --git a/src/controller/index.ts b/src/controller/index.ts
index 265e94b..9cdc4e3 100644
--- a/src/controller/index.ts
+++ b/src/controller/index.ts
@@ -26,7 +26,7 @@ export class ScramjetController {
 				client: "/scramjet.client.js",
 				sync: "/scramjet.sync.js",
 			},
-			flags: {
+			defaultFlags: {
 				serviceworkers: false,
 				naiiveRewriter: false,
 				captureErrors: true,
@@ -35,6 +35,7 @@ export class ScramjetController {
 				scramitize: false,
 				sourcemaps: false,
 			},
+			siteFlags: {},
 			codec: {
 				encode: `if (!url) return url;
 					return encodeURIComponent(url);`,
diff --git a/src/scramjet.ts b/src/scramjet.ts
index c05449f..e168734 100644
--- a/src/scramjet.ts
+++ b/src/scramjet.ts
@@ -1,4 +1,4 @@
-import { ScramjetConfig } from "./types";
+import { ScramjetConfig, ScramjetFlags } from "./types";
 
 if (!("$scramjet" in self)) {
 	// @ts-expect-error ts stuff
@@ -24,3 +24,15 @@ export function loadCodecs() {
 		$scramjet.config.codec.decode
 	) as any;
 }
+
+export function flagEnabled(flag: keyof ScramjetFlags, url: URL): boolean {
+	let value = $scramjet.config.defaultFlags[flag];
+	for (const regex in $scramjet.config.siteFlags) {
+		const partialflags = $scramjet.config.siteFlags[regex];
+		if (new RegExp(regex).test(url.href) && "flag" in partialflags) {
+			return partialflags[flag];
+		}
+	}
+
+	return value;
+}
diff --git a/src/types.d.ts b/src/types.d.ts
index 611f387..6797819 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -52,8 +52,8 @@ interface ScramjetConfig {
 		client: string;
 		sync: string;
 	};
-	flags: ScramjetFlags;
-	siteflags: Record<string, ScramjetFlags>;
+	defaultFlags: ScramjetFlags;
+	siteFlags: Record<string, Partial<ScramjetFlags>>;
 	codec: {
 		encode: string;
 		decode: string;