diff --git a/crates/native-sidecar/src/execution/javascript/http.rs b/crates/native-sidecar/src/execution/javascript/http.rs
index 6ceb178b43..291303eca5 100644
--- a/crates/native-sidecar/src/execution/javascript/http.rs
+++ b/crates/native-sidecar/src/execution/javascript/http.rs
@@ -4,6 +4,7 @@ use crate::state::DeferredRpcError;
 const HTTP_LOOPBACK_REQUEST_TIMEOUT: Duration = Duration::from_secs(30);
 const VM_FETCH_STREAM_CHUNK_MAX_BYTES: usize = 64 * 1024;
 const VM_FETCH_STREAM_COUNT_LIMIT: usize = 256;
+type VmFetchResponseHead = (u16, String, Vec<(String, String)>, VmFetchBodyMode);
 
 fn http_loopback_request_timeout() -> Duration {
     std::env::var(HTTP_LOOPBACK_REQUEST_TIMEOUT_MS_ENV)
@@ -272,7 +273,7 @@ fn parse_stream_response_head(
     bytes: &[u8],
     request_method: &str,
     max_response_bytes: usize,
-) -> Result<(u16, String, Vec<(String, String)>, VmFetchBodyMode), SidecarError> {
+) -> Result<VmFetchResponseHead, SidecarError> {
     let text = std::str::from_utf8(bytes).map_err(|error| {
         SidecarError::Execution(format!(
             "ERR_AGENTOS_VM_FETCH_INVALID_RESPONSE: response headers were not UTF-8: {error}"
diff --git a/packages/build-tools/bridge-src/builtins/url-resolution.ts b/packages/build-tools/bridge-src/builtins/url-resolution.ts
deleted file mode 100644
index 8638af1e21..0000000000
--- a/packages/build-tools/bridge-src/builtins/url-resolution.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-export function resolveRelativeNonFileUrl(raw, baseUrl, posixPath) {
-	const basePathname = baseUrl.pathname || "/";
-	const origin = `${baseUrl.protocol}//${baseUrl.host}`;
-	if (raw.startsWith("//")) {
-		return `${baseUrl.protocol}${raw}`;
-	}
-	if (raw.startsWith("#")) {
-		return `${origin}${basePathname}${baseUrl.search || ""}${raw}`;
-	}
-	if (raw.startsWith("?")) {
-		return `${origin}${basePathname}${raw}`;
-	}
-	if (raw === "") {
-		return `${origin}${basePathname}${baseUrl.search || ""}`;
-	}
-	const queryIndex = raw.indexOf("?");
-	const hashIndex = raw.indexOf("#");
-	const searchStart = queryIndex === -1 ? raw.length : queryIndex;
-	const hashStart = hashIndex === -1 ? raw.length : hashIndex;
-	const pathEnd = Math.min(searchStart, hashStart);
-	const relativePath = raw.slice(0, pathEnd);
-	const suffix = raw.slice(pathEnd);
-	const baseDirectory = basePathname.endsWith("/")
-		? basePathname
-		: posixPath.dirname(basePathname);
-	let resolvedPath = relativePath.startsWith("/")
-		? posixPath.resolve("/", relativePath)
-		: posixPath.resolve(baseDirectory, relativePath);
-	if (
-		(relativePath.endsWith("/") || /(^|\/)\.\.?$/.test(relativePath)) &&
-		!resolvedPath.endsWith("/")
-	) {
-		resolvedPath += "/";
-	}
-	return `${origin}${resolvedPath}${suffix}`;
-}
diff --git a/packages/build-tools/bridge-src/builtins/whatwg-url.ts b/packages/build-tools/bridge-src/builtins/whatwg-url.ts
index f422b3c8cd..9a9ef5772a 100644
--- a/packages/build-tools/bridge-src/builtins/whatwg-url.ts
+++ b/packages/build-tools/bridge-src/builtins/whatwg-url.ts
@@ -1,489 +1,22 @@
-import { builtinPathStdlibModule } from "./builtin-modules.js";
+import {
+	URL as UpstreamURL,
+	URLSearchParams as UpstreamURLSearchParams,
+} from "whatwg-url";
 import { Blob } from "./network.js";
-import { TextDecoder } from "../polyfills/index.js";
-import { urlStdlibModuleNs } from "../prelude.js";
-import { resolveRelativeNonFileUrl } from "./url-resolution.js";
 
-var inspectCustomSymbol = /* @__PURE__ */ Symbol.for(
-	"nodejs.util.inspect.custom",
-);
-var toStringTagSymbol = Symbol.toStringTag;
-var ERR_INVALID_THIS = "ERR_INVALID_THIS";
-var ERR_MISSING_ARGS = "ERR_MISSING_ARGS";
-var ERR_INVALID_URL = "ERR_INVALID_URL";
-var ERR_ARG_NOT_ITERABLE = "ERR_ARG_NOT_ITERABLE";
-var ERR_INVALID_TUPLE = "ERR_INVALID_TUPLE";
-var URL_SEARCH_PARAMS_TYPE = "URLSearchParams";
-var kLinkedSearchParams = /* @__PURE__ */ Symbol(
-	"secureExecLinkedURLSearchParams",
-);
-var kBlobUrlStore = /* @__PURE__ */ Symbol.for("secureExec.blobUrlStore");
-var kBlobUrlCounter = /* @__PURE__ */ Symbol.for("secureExec.blobUrlCounter");
-var SEARCH_PARAM_METHOD_NAMES = ["append", "delete", "get", "getAll", "has"];
-var SEARCH_PARAM_PAIR_METHOD_NAMES = ["append", "set"];
-var SEARCH_PARAM_SYNC_METHOD_NAMES = ["append", "delete", "set", "sort"];
-var URL_SCHEME_TYPES = {
-	"http:": 0,
-	"https:": 2,
-	"ws:": 4,
-	"wss:": 5,
-	"file:": 6,
-	"ftp:": 8,
-};
-var searchParamsBrand = /* @__PURE__ */ new WeakSet();
-var searchParamsState = /* @__PURE__ */ new WeakMap();
-var searchParamsIteratorBrand = /* @__PURE__ */ new WeakSet();
-var searchParamsIteratorState = /* @__PURE__ */ new WeakMap();
+const kBlobUrlStore = /* @__PURE__ */ Symbol.for("secureExec.blobUrlStore");
+const kBlobUrlCounter = /* @__PURE__ */ Symbol.for("secureExec.blobUrlCounter");
+
 function createNodeTypeError(message, code) {
 	const error = new TypeError(message);
 	error.code = code;
 	return error;
 }
-function createInvalidUrlError() {
-	const error = new TypeError("Invalid URL");
-	error.code = ERR_INVALID_URL;
-	return error;
-}
-function createUrlReceiverTypeError() {
-	return new TypeError("Receiver must be an instance of class URL");
-}
+
 function createMissingArgsError(message) {
-	return createNodeTypeError(message, ERR_MISSING_ARGS);
-}
-function createIterableTypeError() {
-	return createNodeTypeError(
-		"Query pairs must be iterable",
-		ERR_ARG_NOT_ITERABLE,
-	);
-}
-function createTupleTypeError() {
-	return createNodeTypeError(
-		"Each query pair must be an iterable [name, value] tuple",
-		ERR_INVALID_TUPLE,
-	);
-}
-function createSymbolStringError() {
-	return new TypeError("Cannot convert a Symbol value to a string");
-}
-function toNodeString(value) {
-	if (typeof value === "symbol") {
-		throw createSymbolStringError();
-	}
-	return String(value);
-}
-function toWellFormedString(value) {
-	let result = "";
-	for (let index = 0; index < value.length; index += 1) {
-		const codeUnit = value.charCodeAt(index);
-		if (codeUnit >= 55296 && codeUnit <= 56319) {
-			const nextIndex = index + 1;
-			if (nextIndex < value.length) {
-				const nextCodeUnit = value.charCodeAt(nextIndex);
-				if (nextCodeUnit >= 56320 && nextCodeUnit <= 57343) {
-					result += value[index] + value[nextIndex];
-					index = nextIndex;
-					continue;
-				}
-			}
-			result += "\uFFFD";
-			continue;
-		}
-		if (codeUnit >= 56320 && codeUnit <= 57343) {
-			result += "\uFFFD";
-			continue;
-		}
-		result += value[index];
-	}
-	return result;
-}
-function toNodeUSVString(value) {
-	return toWellFormedString(toNodeString(value));
-}
-function assertUrlSearchParamsReceiver(receiver) {
-	if (!searchParamsBrand.has(receiver)) {
-		throw createNodeTypeError(
-			'Value of "this" must be of type URLSearchParams',
-			ERR_INVALID_THIS,
-		);
-	}
-}
-function assertUrlSearchParamsIteratorReceiver(receiver) {
-	if (!searchParamsIteratorBrand.has(receiver)) {
-		throw createNodeTypeError(
-			'Value of "this" must be of type URLSearchParamsIterator',
-			ERR_INVALID_THIS,
-		);
-	}
-}
-function getUrlSearchParamsImpl(receiver) {
-	const state = searchParamsState.get(receiver);
-	if (!state) {
-		throw createNodeTypeError(
-			'Value of "this" must be of type URLSearchParams',
-			ERR_INVALID_THIS,
-		);
-	}
-	return state.getImpl();
-}
-function countSearchParams(params) {
-	let count = 0;
-	for (const _entry of params) {
-		count++;
-	}
-	return count;
-}
-function isAsciiHexCodeUnit(codeUnit) {
-	return (
-		(codeUnit >= 48 && codeUnit <= 57) ||
-		(codeUnit >= 65 && codeUnit <= 70) ||
-		(codeUnit >= 97 && codeUnit <= 102)
-	);
-}
-function decodeAsciiHexCodeUnit(codeUnit) {
-	if (codeUnit >= 48 && codeUnit <= 57) {
-		return codeUnit - 48;
-	}
-	if (codeUnit >= 65 && codeUnit <= 70) {
-		return codeUnit - 55;
-	}
-	return codeUnit - 87;
-}
-function appendUtf8CodePoint(bytes, codePoint) {
-	if (codePoint <= 127) {
-		bytes.push(codePoint);
-		return;
-	}
-	if (codePoint <= 2047) {
-		bytes.push(192 | (codePoint >> 6), 128 | (codePoint & 63));
-		return;
-	}
-	if (codePoint <= 65535) {
-		bytes.push(
-			224 | (codePoint >> 12),
-			128 | ((codePoint >> 6) & 63),
-			128 | (codePoint & 63),
-		);
-		return;
-	}
-	bytes.push(
-		240 | (codePoint >> 18),
-		128 | ((codePoint >> 12) & 63),
-		128 | ((codePoint >> 6) & 63),
-		128 | (codePoint & 63),
-	);
-}
-function decodeFormUrlencodedComponent(value) {
-	const source = String(value).replace(/\+/g, " ");
-	let output = "";
-	for (let index = 0; index < source.length; index += 1) {
-		if (source.charCodeAt(index) === 37 && index + 2 < source.length) {
-			const bytes = [];
-			let nextIndex = index;
-			while (
-				nextIndex + 2 < source.length &&
-				source.charCodeAt(nextIndex) === 37
-			) {
-				const high = source.charCodeAt(nextIndex + 1);
-				const low = source.charCodeAt(nextIndex + 2);
-				if (!isAsciiHexCodeUnit(high) || !isAsciiHexCodeUnit(low)) {
-					break;
-				}
-				bytes.push(
-					(decodeAsciiHexCodeUnit(high) << 4) + decodeAsciiHexCodeUnit(low),
-				);
-				nextIndex += 3;
-			}
-			if (bytes.length > 0) {
-				output += new TextDecoder().decode(Uint8Array.from(bytes));
-				index = nextIndex - 1;
-				continue;
-			}
-		}
-		const codePoint = source.codePointAt(index);
-		output += String.fromCodePoint(codePoint);
-		if (codePoint > 65535) {
-			index += 1;
-		}
-	}
-	return output;
-}
-function serializeFormUrlencodedComponent(value) {
-	const input = String(value);
-	const bytes = [];
-	for (let index = 0; index < input.length; index += 1) {
-		const codePoint = input.codePointAt(index);
-		appendUtf8CodePoint(bytes, codePoint);
-		if (codePoint > 65535) {
-			index += 1;
-		}
-	}
-	let output = "";
-	for (const byte of bytes) {
-		if (byte === 32) {
-			output += "+";
-			continue;
-		}
-		const isAlphaNumeric =
-			(byte >= 48 && byte <= 57) ||
-			(byte >= 65 && byte <= 90) ||
-			(byte >= 97 && byte <= 122);
-		if (
-			isAlphaNumeric ||
-			byte === 42 ||
-			byte === 45 ||
-			byte === 46 ||
-			byte === 95
-		) {
-			output += String.fromCharCode(byte);
-			continue;
-		}
-		output += `%${byte.toString(16).toUpperCase().padStart(2, "0")}`;
-	}
-	return output;
-}
-function compareCodeUnitStrings(left, right) {
-	const minLength = Math.min(left.length, right.length);
-	for (let index = 0; index < minLength; index += 1) {
-		const diff = left.charCodeAt(index) - right.charCodeAt(index);
-		if (diff !== 0) {
-			return diff;
-		}
-	}
-	return left.length - right.length;
-}
-function normalizeSearchParamsInit(init) {
-	if (init && typeof init === "object" && kLinkedSearchParams in init) {
-		return init;
-	}
-	if (init == null) {
-		return void 0;
-	}
-	if (typeof init === "string") {
-		return toNodeUSVString(init);
-	}
-	if (typeof init === "object" || typeof init === "function") {
-		const iterator2 = init[Symbol.iterator];
-		if (iterator2 !== void 0) {
-			if (typeof iterator2 !== "function") {
-				throw createIterableTypeError();
-			}
-			const pairs2 = [];
-			for (const pair of init) {
-				if (pair == null) {
-					throw createTupleTypeError();
-				}
-				const pairIterator = pair[Symbol.iterator];
-				if (typeof pairIterator !== "function") {
-					throw createTupleTypeError();
-				}
-				const values = Array.from(pair);
-				if (values.length !== 2) {
-					throw createTupleTypeError();
-				}
-				pairs2.push([toNodeUSVString(values[0]), toNodeUSVString(values[1])]);
-			}
-			return pairs2;
-		}
-		const pairs = [];
-		for (const key of Reflect.ownKeys(init)) {
-			if (!Object.prototype.propertyIsEnumerable.call(init, key)) {
-				continue;
-			}
-			pairs.push([toNodeUSVString(key), toNodeUSVString(init[key])]);
-		}
-		return pairs;
-	}
-	return toNodeUSVString(init);
-}
-var NativeURLSearchParams =
-	typeof globalThis.URLSearchParams === "function" &&
-	globalThis.URLSearchParams.__secureExecBootstrapStub !== true
-		? globalThis.URLSearchParams
-		: class URLSearchParams {
-				constructor(init = "") {
-					this._pairs = [];
-					if (typeof init === "string") {
-						const query = init.replace(/^\?/, "");
-						if (!query) {
-							return;
-						}
-						for (const entry of query.split("&")) {
-							if (!entry) {
-								continue;
-							}
-							const [key, ...rest] = entry.split("=");
-							this._pairs.push([
-								decodeFormUrlencodedComponent(key),
-								decodeFormUrlencodedComponent(rest.join("=")),
-							]);
-						}
-						return;
-					}
-					if (Array.isArray(init)) {
-						for (const pair of init) {
-							if (pair == null || pair.length !== 2) {
-								continue;
-							}
-							this._pairs.push([String(pair[0]), String(pair[1])]);
-						}
-						return;
-					}
-					if (init && typeof init === "object") {
-						for (const [key, value] of Object.entries(init)) {
-							this._pairs.push([String(key), String(value)]);
-						}
-					}
-				}
-				append(name, value) {
-					this._pairs.push([String(name), String(value)]);
-				}
-				delete(name) {
-					const key = String(name);
-					this._pairs = this._pairs.filter(([candidate]) => candidate !== key);
-				}
-				get(name) {
-					const key = String(name);
-					const match = this._pairs.find(([candidate]) => candidate === key);
-					return match ? match[1] : null;
-				}
-				getAll(name) {
-					const key = String(name);
-					return this._pairs
-						.filter(([candidate]) => candidate === key)
-						.map(([, value]) => value);
-				}
-				has(name) {
-					const key = String(name);
-					return this._pairs.some(([candidate]) => candidate === key);
-				}
-				set(name, value) {
-					const key = String(name);
-					const stringValue = String(value);
-					const nextPairs = [];
-					let replaced = false;
-					for (const [candidate, currentValue] of this._pairs) {
-						if (candidate !== key) {
-							nextPairs.push([candidate, currentValue]);
-							continue;
-						}
-						if (!replaced) {
-							replaced = true;
-							nextPairs.push([key, stringValue]);
-						}
-					}
-					if (!replaced) {
-						nextPairs.push([key, stringValue]);
-					}
-					this._pairs = nextPairs;
-				}
-				sort() {
-					this._pairs = this._pairs
-						.map((pair, index) => ({ pair, index }))
-						.sort((left, right) => {
-							const diff = compareCodeUnitStrings(left.pair[0], right.pair[0]);
-							return diff !== 0 ? diff : left.index - right.index;
-						})
-						.map(({ pair }) => pair);
-				}
-				entries() {
-					return this._pairs[Symbol.iterator]();
-				}
-				keys() {
-					return this._pairs.map(([key]) => key)[Symbol.iterator]();
-				}
-				values() {
-					return this._pairs.map(([, value]) => value)[Symbol.iterator]();
-				}
-				[Symbol.iterator]() {
-					return this.entries();
-				}
-				toString() {
-					return this._pairs
-						.map(
-							([key, value]) =>
-								`${serializeFormUrlencodedComponent(key)}=${serializeFormUrlencodedComponent(value)}`,
-						)
-						.join("&");
-				}
-			};
-function createStandaloneSearchParams(init) {
-	if (typeof init === "string") {
-		return new NativeURLSearchParams(init);
-	}
-	return init === void 0
-		? new NativeURLSearchParams()
-		: new NativeURLSearchParams(init);
-}
-function createCollectionBody(items, options, emptyBody) {
-	if (items.length === 0) {
-		return emptyBody;
-	}
-	const oneLine = `{ ${items.join(", ")} }`;
-	const breakLength = options?.breakLength ?? Infinity;
-	if (oneLine.length <= breakLength) {
-		return oneLine;
-	}
-	return `{
-${items.join(",\n  ")} }`;
-}
-function createUrlContext(url) {
-	const href = url.href;
-	const protocolEnd = href.indexOf(":") + 1;
-	const authIndex = href.indexOf("@");
-	const pathnameStart = href.indexOf("/", protocolEnd + 2);
-	const searchStart = href.indexOf("?");
-	const hashStart = href.indexOf("#");
-	const usernameEnd =
-		url.username.length > 0
-			? href.indexOf(":", protocolEnd + 2)
-			: protocolEnd + 2;
-	const hostStart = authIndex === -1 ? protocolEnd + 2 : authIndex;
-	const hostEnd =
-		pathnameStart === -1
-			? href.length
-			: pathnameStart - (url.port.length > 0 ? url.port.length + 1 : 0);
-	const port = url.port.length > 0 ? Number(url.port) : null;
-	return {
-		href,
-		protocol_end: protocolEnd,
-		username_end: usernameEnd,
-		host_start: hostStart,
-		host_end: hostEnd,
-		pathname_start: pathnameStart === -1 ? href.length : pathnameStart,
-		search_start: searchStart === -1 ? href.length : searchStart,
-		hash_start: hashStart === -1 ? href.length : hashStart,
-		port,
-		scheme_type: URL_SCHEME_TYPES[url.protocol] ?? 1,
-		hasPort: url.port.length > 0,
-		hasSearch: url.search.length > 0,
-		hasHash: url.hash.length > 0,
-	};
-}
-function formatUrlContext(url, inspect, options) {
-	const context = createUrlContext(url);
-	const formatValue =
-		typeof inspect === "function"
-			? (value) => inspect(value, options)
-			: (value) => JSON.stringify(value);
-	const portValue = context.port === null ? "null" : String(context.port);
-	return [
-		"URLContext {",
-		`    href: ${formatValue(context.href)},`,
-		`    protocol_end: ${context.protocol_end},`,
-		`    username_end: ${context.username_end},`,
-		`    host_start: ${context.host_start},`,
-		`    host_end: ${context.host_end},`,
-		`    pathname_start: ${context.pathname_start},`,
-		`    search_start: ${context.search_start},`,
-		`    hash_start: ${context.hash_start},`,
-		`    port: ${portValue},`,
-		`    scheme_type: ${context.scheme_type},`,
-		"    [hasPort]: [Getter],",
-		"    [hasSearch]: [Getter],",
-		"    [hasHash]: [Getter]",
-		"  }",
-	].join("\n");
+	return createNodeTypeError(message, "ERR_MISSING_ARGS");
 }
+
 function getBlobUrlStore() {
 	const globalRecord = globalThis;
 	const existing = globalRecord[kBlobUrlStore];
@@ -494,6 +27,7 @@ function getBlobUrlStore() {
 	globalRecord[kBlobUrlStore] = store;
 	return store;
 }
+
 function nextBlobUrlId() {
 	const globalRecord = globalThis;
 	const nextId =
@@ -503,725 +37,48 @@ function nextBlobUrlId() {
 	globalRecord[kBlobUrlCounter] = nextId + 1;
 	return nextId;
 }
-var URLSearchParamsIterator = class _URLSearchParamsIterator {
-	constructor(values) {
-		searchParamsIteratorBrand.add(this);
-		searchParamsIteratorState.set(this, { values, index: 0 });
-	}
-	next() {
-		assertUrlSearchParamsIteratorReceiver(this);
-		const state = searchParamsIteratorState.get(this);
-		if (state.index >= state.values.length) {
-			return { value: void 0, done: true };
-		}
-		const value = state.values[state.index];
-		state.index += 1;
-		return { value, done: false };
-	}
-	[inspectCustomSymbol](depth, options, inspect) {
-		assertUrlSearchParamsIteratorReceiver(this);
-		if (depth < 0) {
-			return "[Object]";
-		}
-		const state = searchParamsIteratorState.get(this);
-		const formatValue =
-			typeof inspect === "function"
-				? (value) => inspect(value, options)
-				: (value) => JSON.stringify(value);
-		const remaining = state.values
-			.slice(state.index)
-			.map((value) => formatValue(value));
-		return `URLSearchParams Iterator ${createCollectionBody(remaining, options, "{  }")}`;
-	}
-	get [toStringTagSymbol]() {
-		if (this !== _URLSearchParamsIterator.prototype) {
-			assertUrlSearchParamsIteratorReceiver(this);
-		}
-		return "URLSearchParams Iterator";
-	}
-};
-Object.defineProperties(URLSearchParamsIterator.prototype, {
-	next: {
-		value: URLSearchParamsIterator.prototype.next,
-		writable: true,
-		configurable: true,
-		enumerable: true,
-	},
-	[Symbol.iterator]: {
-		value: function iterator() {
-			assertUrlSearchParamsIteratorReceiver(this);
-			return this;
-		},
-		writable: true,
-		configurable: true,
-		enumerable: false,
-	},
-	[inspectCustomSymbol]: {
-		value: URLSearchParamsIterator.prototype[inspectCustomSymbol],
-		writable: true,
-		configurable: true,
-		enumerable: false,
-	},
-	[toStringTagSymbol]: {
-		get: Object.getOwnPropertyDescriptor(
-			URLSearchParamsIterator.prototype,
-			toStringTagSymbol,
-		)?.get,
-		configurable: true,
-		enumerable: false,
-	},
-});
-Object.defineProperty(
-	Object.getOwnPropertyDescriptor(
-		URLSearchParamsIterator.prototype,
-		Symbol.iterator,
-	)?.value,
-	"name",
-	{
-		value: "entries",
-		configurable: true,
-	},
-);
-var URLSearchParams = class _URLSearchParams {
-	constructor(init) {
-		searchParamsBrand.add(this);
-		const normalized = normalizeSearchParamsInit(init);
-		if (
-			normalized &&
-			typeof normalized === "object" &&
-			kLinkedSearchParams in normalized
-		) {
-			searchParamsState.set(this, {
-				getImpl: normalized[kLinkedSearchParams],
-			});
-			return;
-		}
-		const impl = createStandaloneSearchParams(normalized);
-		searchParamsState.set(this, { getImpl: () => impl });
-	}
-	append(name, value) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 2) {
-			throw createMissingArgsError(
-				'The "name" and "value" arguments must be specified',
-			);
-		}
-		getUrlSearchParamsImpl(this).append(
-			toNodeUSVString(name),
-			toNodeUSVString(value),
-		);
-	}
-	delete(name) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "name" argument must be specified');
-		}
-		getUrlSearchParamsImpl(this).delete(toNodeUSVString(name));
-	}
-	get(name) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "name" argument must be specified');
-		}
-		return getUrlSearchParamsImpl(this).get(toNodeUSVString(name));
-	}
-	getAll(name) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "name" argument must be specified');
-		}
-		return getUrlSearchParamsImpl(this).getAll(toNodeUSVString(name));
-	}
-	has(name) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "name" argument must be specified');
-		}
-		return getUrlSearchParamsImpl(this).has(toNodeUSVString(name));
-	}
-	set(name, value) {
-		assertUrlSearchParamsReceiver(this);
-		if (arguments.length < 2) {
-			throw createMissingArgsError(
-				'The "name" and "value" arguments must be specified',
-			);
-		}
-		getUrlSearchParamsImpl(this).set(
-			toNodeUSVString(name),
-			toNodeUSVString(value),
-		);
-	}
-	sort() {
-		assertUrlSearchParamsReceiver(this);
-		getUrlSearchParamsImpl(this).sort();
-	}
-	entries() {
-		assertUrlSearchParamsReceiver(this);
-		return new URLSearchParamsIterator(
-			Array.from(getUrlSearchParamsImpl(this)),
-		);
-	}
-	keys() {
-		assertUrlSearchParamsReceiver(this);
-		return new URLSearchParamsIterator(
-			Array.from(getUrlSearchParamsImpl(this).keys()),
-		);
-	}
-	values() {
-		assertUrlSearchParamsReceiver(this);
-		return new URLSearchParamsIterator(
-			Array.from(getUrlSearchParamsImpl(this).values()),
-		);
-	}
-	forEach(callback, thisArg) {
-		assertUrlSearchParamsReceiver(this);
-		if (typeof callback !== "function") {
-			throw createNodeTypeError(
-				'The "callback" argument must be of type function. Received ' +
-					(callback === void 0 ? "undefined" : typeof callback),
-				"ERR_INVALID_ARG_TYPE",
-			);
-		}
-		for (const [key, value] of getUrlSearchParamsImpl(this)) {
-			callback.call(thisArg, value, key, this);
-		}
-	}
-	toString() {
-		assertUrlSearchParamsReceiver(this);
-		return getUrlSearchParamsImpl(this).toString();
-	}
-	get size() {
-		assertUrlSearchParamsReceiver(this);
-		return countSearchParams(getUrlSearchParamsImpl(this));
-	}
-	[inspectCustomSymbol](depth, options, inspect) {
-		assertUrlSearchParamsReceiver(this);
-		if (depth < 0) {
-			return "[Object]";
-		}
-		const formatValue =
-			typeof inspect === "function"
-				? (value) => inspect(value, options)
-				: (value) => JSON.stringify(value);
-		const items = Array.from(getUrlSearchParamsImpl(this)).map(
-			([key, value]) => `${formatValue(key)} => ${formatValue(value)}`,
-		);
-		return `URLSearchParams ${createCollectionBody(items, options, "{}")}`;
-	}
-	get [toStringTagSymbol]() {
-		if (this !== _URLSearchParams.prototype) {
-			assertUrlSearchParamsReceiver(this);
-		}
-		return URL_SEARCH_PARAMS_TYPE;
-	}
-};
-for (const name of SEARCH_PARAM_METHOD_NAMES) {
-	Object.defineProperty(URLSearchParams.prototype, name, {
-		value: URLSearchParams.prototype[name],
-		writable: true,
-		configurable: true,
-		enumerable: true,
-	});
-}
-for (const name of SEARCH_PARAM_PAIR_METHOD_NAMES) {
-	Object.defineProperty(URLSearchParams.prototype, name, {
-		value: URLSearchParams.prototype[name],
-		writable: true,
-		configurable: true,
-		enumerable: true,
-	});
+
+const URL2 = UpstreamURL;
+const URLSearchParams = UpstreamURLSearchParams;
+
+if (globalThis.SharedArrayBuffer?.__agentOSBootstrapStub === true) {
+	delete globalThis.SharedArrayBuffer;
 }
-for (const name of [
-	"sort",
-	"entries",
-	"forEach",
-	"keys",
-	"values",
-	"toString",
-]) {
-	Object.defineProperty(URLSearchParams.prototype, name, {
-		value: URLSearchParams.prototype[name],
+
+Object.defineProperties(URL2, {
+	createObjectURL: {
+		value(obj) {
+			if (typeof Blob === "undefined" || !(obj instanceof Blob)) {
+				throw createNodeTypeError(
+					'The "obj" argument must be an instance of Blob. Received ' +
+						(obj === null ? "null" : typeof obj),
+					"ERR_INVALID_ARG_TYPE",
+				);
+			}
+			const id = `blob:nodedata:${nextBlobUrlId()}`;
+			getBlobUrlStore().set(id, obj);
+			return id;
+		},
 		writable: true,
 		configurable: true,
 		enumerable: true,
-	});
-}
-Object.defineProperties(URLSearchParams.prototype, {
-	size: {
-		get: Object.getOwnPropertyDescriptor(URLSearchParams.prototype, "size")
-			?.get,
-		configurable: true,
-		enumerable: true,
-	},
-	[Symbol.iterator]: {
-		value: URLSearchParams.prototype.entries,
-		writable: true,
-		configurable: true,
-		enumerable: false,
-	},
-	[inspectCustomSymbol]: {
-		value: URLSearchParams.prototype[inspectCustomSymbol],
-		writable: true,
-		configurable: true,
-		enumerable: false,
-	},
-	[toStringTagSymbol]: {
-		get: Object.getOwnPropertyDescriptor(
-			URLSearchParams.prototype,
-			toStringTagSymbol,
-		)?.get,
-		configurable: true,
-		enumerable: false,
 	},
-});
-function canUseNativeUrlImplementation(candidate) {
-	if (
-		typeof candidate !== "function" ||
-		candidate.__secureExecBootstrapStub === true
-	) {
-		return false;
-	}
-	try {
-		return (
-			String(
-				new candidate("./child.mjs", "file:///root/base/entry.mjs").href,
-			) === "file:///root/base/child.mjs"
-		);
-	} catch {
-		return false;
-	}
-}
-function ensureTrailingSlashForFilePath(pathname) {
-	return pathname.endsWith("/") ? pathname : `${pathname}/`;
-}
-function normalizeRelativeFileUrlInput(input, base) {
-	const rawInput = String(input ?? "");
-	if (!rawInput.startsWith("file:")) {
-		return { input: rawInput, base };
-	}
-	const relativeMatch = /^file:(\.\.?(?:\/[^?#]*)?)([?#].*)?$/.exec(rawInput);
-	if (!relativeMatch) {
-		return { input: rawInput, base };
-	}
-	const relativePath = relativeMatch[1];
-	const suffix = relativeMatch[2] ?? "";
-	let baseHref = typeof base === "undefined" ? "file:///" : String(base);
-	try {
-		const parsedBase = new globalThis.URL(baseHref);
-		if (parsedBase.protocol !== "file:") {
-			return { input: rawInput, base };
-		}
-		let basePathname = parsedBase.pathname || "/";
-		if (!basePathname.startsWith("/")) {
-			basePathname = `/${basePathname}`;
-		}
-		const baseDirectory = basePathname.endsWith("/")
-			? basePathname
-			: builtinPathStdlibModule.posix.dirname(basePathname);
-		const resolvedPath = builtinPathStdlibModule.posix.resolve(
-			baseDirectory,
-			relativePath,
-		);
-		const needsTrailingSlash =
-			relativePath === "." ||
-			relativePath === ".." ||
-			relativePath.endsWith("/");
-		const normalizedPath = needsTrailingSlash
-			? ensureTrailingSlashForFilePath(resolvedPath)
-			: resolvedPath;
-		return {
-			input: `file://${normalizedPath}${suffix}`,
-			base: void 0,
-		};
-	} catch {
-		return { input: rawInput, base };
-	}
-}
-var nativeUrlCandidate =
-	typeof urlStdlibModuleNs?.URL === "function"
-		? urlStdlibModuleNs.URL
-		: typeof urlStdlibModuleNs?.default?.URL === "function"
-			? urlStdlibModuleNs.default.URL
-			: globalThis.URL;
-var NativeURL = canUseNativeUrlImplementation(nativeUrlCandidate)
-	? nativeUrlCandidate
-	: class URL {
-			constructor(url, base) {
-				const raw = String(url ?? "");
-				const hasScheme = /^[a-zA-Z][a-zA-Z\d+\-.]*:/.test(raw);
-				if (!hasScheme && typeof base === "undefined") {
-					throw new TypeError(`Invalid URL: ${raw}`);
-				}
-				let full = raw;
-				if (!hasScheme) {
-					const baseUrl = new URL(base);
-					if (baseUrl.protocol === "file:") {
-						const queryIndex2 = raw.indexOf("?");
-						const hashIndex2 = raw.indexOf("#");
-						const searchStart2 = queryIndex2 === -1 ? raw.length : queryIndex2;
-						const hashStart2 = hashIndex2 === -1 ? raw.length : hashIndex2;
-						const pathEnd2 = Math.min(searchStart2, hashStart2);
-						const relativePath = raw.slice(0, pathEnd2);
-						const suffix = raw.slice(pathEnd2);
-						let basePathname = baseUrl.pathname || "/";
-						if (!basePathname.startsWith("/")) {
-							basePathname = `/${basePathname}`;
-						}
-						const baseDirectory = basePathname.endsWith("/")
-							? basePathname
-							: builtinPathStdlibModule.posix.dirname(basePathname);
-						let resolvedPath = builtinPathStdlibModule.posix.resolve(
-							baseDirectory,
-							relativePath,
-						);
-						if (
-							(relativePath.endsWith("/") ||
-								/(^|\/)\.\.?$/.test(relativePath)) &&
-							!resolvedPath.endsWith("/")
-						) {
-							resolvedPath += "/";
-						}
-						full = `file://${resolvedPath}${suffix}`;
-					} else {
-						full = resolveRelativeNonFileUrl(
-							raw,
-							baseUrl,
-							builtinPathStdlibModule.posix,
-						);
-					}
-				}
-				const queryIndex = full.indexOf("?");
-				const hashIndex = full.indexOf("#");
-				const searchStart = queryIndex === -1 ? full.length : queryIndex;
-				const hashStart = hashIndex === -1 ? full.length : hashIndex;
-				const pathEnd = Math.min(searchStart, hashStart);
-				const searchValue =
-					queryIndex === -1 ? "" : full.slice(queryIndex, hashStart);
-				const hashValue = hashIndex === -1 ? "" : full.slice(hashIndex);
-				const bindSearchParams = (buildHref) => {
-					this.searchParams = new URLSearchParams(this.search);
-					for (const method of SEARCH_PARAM_SYNC_METHOD_NAMES) {
-						const original = this.searchParams[method]?.bind(this.searchParams);
-						if (!original) {
-							continue;
-						}
-						this.searchParams[method] = (...args) => {
-							const result = original(...args);
-							const query = this.searchParams.toString();
-							this.search = query ? `?${query}` : "";
-							this.href = buildHref();
-							return result;
-						};
-					}
-				};
-				if (full.startsWith("file:")) {
-					let pathname = full.slice(5, pathEnd);
-					if (pathname.startsWith("//")) {
-						const authorityMatch = /^\/\/[^/]*(.*)$/.exec(pathname);
-						pathname = authorityMatch?.[1] || "/";
-					}
-					if (!pathname.startsWith("/")) {
-						pathname = `/${pathname}`;
-					}
-					this.protocol = "file:";
-					this.hostname = "";
-					this.port = "";
-					this.pathname = pathname || "/";
-					this.search = searchValue;
-					this.hash = hashValue;
-					this.host = "";
-					this.href = `file://${this.pathname}${this.search}${this.hash}`;
-					this.origin = "null";
-					bindSearchParams(
-						() => `file://${this.pathname}${this.search}${this.hash}`,
-					);
-					return;
-				}
-				const opaqueSchemeMatch = full.match(
-					/^([a-zA-Z][a-zA-Z\d+\-.]*:)(?!\/\/)/,
-				);
-				if (opaqueSchemeMatch) {
-					const protocol = opaqueSchemeMatch[1];
-					this.protocol = protocol;
-					this.hostname = "";
-					this.port = "";
-					this.host = "";
-					this.pathname = full.slice(protocol.length, pathEnd);
-					this.search = searchValue;
-					this.hash = hashValue;
-					this.href = protocol + this.pathname + this.search + this.hash;
-					this.origin = "null";
-					bindSearchParams(
-						() => protocol + this.pathname + this.search + this.hash,
-					);
-					return;
-				}
-				const match = full.match(/^(\w+:)\/\/([^/:?#]+)(:\d+)?(.*)$/);
-				this.protocol = match?.[1] || "";
-				this.hostname = match?.[2] || "";
-				this.port = (match?.[3] || "").slice(1);
-				this.pathname = (match?.[4] || "/").split("?")[0].split("#")[0] || "/";
-				this.search = full.includes("?")
-					? "?" + full.split("?")[1].split("#")[0]
-					: "";
-				this.hash = full.includes("#") ? "#" + full.split("#")[1] : "";
-				this.host = this.hostname + (this.port ? ":" + this.port : "");
-				this.href =
-					this.protocol +
-					"//" +
-					this.host +
-					this.pathname +
-					this.search +
-					this.hash;
-				this.origin = this.protocol + "//" + this.host;
-				bindSearchParams(
-					() =>
-						this.protocol +
-						"//" +
-						this.host +
-						this.pathname +
-						this.search +
-						this.hash,
-				);
-			}
-			toString() {
-				return this.href;
+	revokeObjectURL: {
+		value(...args) {
+			if (args.length < 1) {
+				throw createMissingArgsError('The "url" argument must be specified');
 			}
-		};
-var URL2 = class _URL {
-	#impl;
-	#searchParams;
-	constructor(input, base) {
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "url" argument must be specified');
-		}
-		const normalizedArgs = normalizeRelativeFileUrlInput(
-			toNodeUSVString(input),
-			arguments.length >= 2 ? toNodeUSVString(base) : void 0,
-		);
-		try {
-			this.#impl =
-				normalizedArgs.base !== void 0
-					? new NativeURL(normalizedArgs.input, normalizedArgs.base)
-					: new NativeURL(normalizedArgs.input);
-		} catch {
-			throw createInvalidUrlError();
-		}
-	}
-	static canParse(input, base) {
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "url" argument must be specified');
-		}
-		try {
-			if (arguments.length >= 2) {
-				new _URL(input, base);
-			} else {
-				new _URL(input);
+			const [url] = args;
+			if (typeof url === "string") {
+				getBlobUrlStore().delete(url);
 			}
-			return true;
-		} catch {
-			return false;
-		}
-	}
-	static createObjectURL(obj) {
-		if (typeof Blob === "undefined" || !(obj instanceof Blob)) {
-			throw createNodeTypeError(
-				'The "obj" argument must be an instance of Blob. Received ' +
-					(obj === null ? "null" : typeof obj),
-				"ERR_INVALID_ARG_TYPE",
-			);
-		}
-		const id = `blob:nodedata:${nextBlobUrlId()}`;
-		getBlobUrlStore().set(id, obj);
-		return id;
-	}
-	static revokeObjectURL(url) {
-		if (arguments.length < 1) {
-			throw createMissingArgsError('The "url" argument must be specified');
-		}
-		if (typeof url !== "string") {
-			return;
-		}
-		getBlobUrlStore().delete(url);
-	}
-	get href() {
-		if (!(this instanceof _URL)) {
-			throw createUrlReceiverTypeError();
-		}
-		return this.#impl.href;
-	}
-	set href(value) {
-		this.#impl.href = toNodeUSVString(value);
-	}
-	get origin() {
-		return this.#impl.origin;
-	}
-	get protocol() {
-		return this.#impl.protocol;
-	}
-	set protocol(value) {
-		this.#impl.protocol = toNodeUSVString(value);
-	}
-	get username() {
-		return this.#impl.username;
-	}
-	set username(value) {
-		this.#impl.username = toNodeUSVString(value);
-	}
-	get password() {
-		return this.#impl.password;
-	}
-	set password(value) {
-		this.#impl.password = toNodeUSVString(value);
-	}
-	get host() {
-		return this.#impl.host;
-	}
-	set host(value) {
-		this.#impl.host = toNodeUSVString(value);
-	}
-	get hostname() {
-		return this.#impl.hostname;
-	}
-	set hostname(value) {
-		this.#impl.hostname = toNodeUSVString(value);
-	}
-	get port() {
-		return this.#impl.port;
-	}
-	set port(value) {
-		this.#impl.port = toNodeUSVString(value);
-	}
-	get pathname() {
-		return this.#impl.pathname;
-	}
-	set pathname(value) {
-		this.#impl.pathname = toNodeUSVString(value);
-	}
-	get search() {
-		if (!(this instanceof _URL)) {
-			throw createUrlReceiverTypeError();
-		}
-		return this.#impl.search;
-	}
-	set search(value) {
-		this.#impl.search = toNodeUSVString(value);
-	}
-	get searchParams() {
-		if (!this.#searchParams) {
-			this.#searchParams = new URLSearchParams({
-				[kLinkedSearchParams]: () => this.#impl.searchParams,
-			});
-		}
-		return this.#searchParams;
-	}
-	get hash() {
-		return this.#impl.hash;
-	}
-	set hash(value) {
-		this.#impl.hash = toNodeUSVString(value);
-	}
-	toString() {
-		if (!(this instanceof _URL)) {
-			throw createUrlReceiverTypeError();
-		}
-		return this.#impl.href;
-	}
-	toJSON() {
-		if (!(this instanceof _URL)) {
-			throw createUrlReceiverTypeError();
-		}
-		return this.#impl.href;
-	}
-	[inspectCustomSymbol](depth, options, inspect) {
-		const inspectName =
-			this.constructor === _URL ? "URL" : this.constructor.name;
-		if (depth < 0) {
-			return `${inspectName} {}`;
-		}
-		const formatValue =
-			typeof inspect === "function"
-				? (value) => inspect(value, options)
-				: (value) => JSON.stringify(value);
-		const lines = [
-			`${inspectName} {`,
-			`  href: ${formatValue(this.href)},`,
-			`  origin: ${formatValue(this.origin)},`,
-			`  protocol: ${formatValue(this.protocol)},`,
-			`  username: ${formatValue(this.username)},`,
-			`  password: ${formatValue(this.password)},`,
-			`  host: ${formatValue(this.host)},`,
-			`  hostname: ${formatValue(this.hostname)},`,
-			`  port: ${formatValue(this.port)},`,
-			`  pathname: ${formatValue(this.pathname)},`,
-			`  search: ${formatValue(this.search)},`,
-			`  searchParams: ${this.searchParams[inspectCustomSymbol](depth - 1, void 0, inspect)},`,
-			`  hash: ${formatValue(this.hash)}`,
-		];
-		if (options?.showHidden) {
-			lines[lines.length - 1] += ",";
-			lines.push(
-				`  [Symbol(context)]: ${formatUrlContext(this, inspect, options)}`,
-			);
-		}
-		lines.push("}");
-		return lines.join("\n");
-	}
-	get [toStringTagSymbol]() {
-		return "URL";
-	}
-};
-for (const name of ["toString", "toJSON"]) {
-	Object.defineProperty(URL2.prototype, name, {
-		value: URL2.prototype[name],
+		},
 		writable: true,
 		configurable: true,
 		enumerable: true,
-	});
-}
-for (const name of [
-	"href",
-	"protocol",
-	"username",
-	"password",
-	"host",
-	"hostname",
-	"port",
-	"pathname",
-	"search",
-	"hash",
-	"origin",
-	"searchParams",
-]) {
-	const descriptor = Object.getOwnPropertyDescriptor(URL2.prototype, name);
-	if (!descriptor) {
-		continue;
-	}
-	descriptor.enumerable = true;
-	Object.defineProperty(URL2.prototype, name, descriptor);
-}
-Object.defineProperties(URL2.prototype, {
-	[inspectCustomSymbol]: {
-		value: URL2.prototype[inspectCustomSymbol],
-		writable: true,
-		configurable: true,
-		enumerable: false,
-	},
-	[toStringTagSymbol]: {
-		get: Object.getOwnPropertyDescriptor(URL2.prototype, toStringTagSymbol)
-			?.get,
-		configurable: true,
-		enumerable: false,
 	},
 });
-for (const name of ["canParse", "createObjectURL", "revokeObjectURL"]) {
-	Object.defineProperty(URL2, name, {
-		value: URL2[name],
-		writable: true,
-		configurable: true,
-		enumerable: true,
-	});
-}
+
 function installWhatwgUrlGlobals(target = globalThis) {
 	Object.defineProperty(target, "URL", {
 		value: URL2,
@@ -1236,60 +93,15 @@ function installWhatwgUrlGlobals(target = globalThis) {
 		enumerable: false,
 	});
 }
+
 export {
-	inspectCustomSymbol,
-	toStringTagSymbol,
-	ERR_INVALID_THIS,
-	ERR_MISSING_ARGS,
-	ERR_INVALID_URL,
-	ERR_ARG_NOT_ITERABLE,
-	ERR_INVALID_TUPLE,
-	URL_SEARCH_PARAMS_TYPE,
-	kLinkedSearchParams,
-	kBlobUrlStore,
-	kBlobUrlCounter,
-	SEARCH_PARAM_METHOD_NAMES,
-	SEARCH_PARAM_PAIR_METHOD_NAMES,
-	URL_SCHEME_TYPES,
-	searchParamsBrand,
-	searchParamsState,
-	searchParamsIteratorBrand,
-	searchParamsIteratorState,
-	createNodeTypeError,
-	createInvalidUrlError,
-	createUrlReceiverTypeError,
 	createMissingArgsError,
-	createIterableTypeError,
-	createTupleTypeError,
-	createSymbolStringError,
-	toNodeString,
-	toWellFormedString,
-	toNodeUSVString,
-	assertUrlSearchParamsReceiver,
-	assertUrlSearchParamsIteratorReceiver,
-	getUrlSearchParamsImpl,
-	countSearchParams,
-	isAsciiHexCodeUnit,
-	decodeAsciiHexCodeUnit,
-	appendUtf8CodePoint,
-	decodeFormUrlencodedComponent,
-	serializeFormUrlencodedComponent,
-	compareCodeUnitStrings,
-	normalizeSearchParamsInit,
-	NativeURLSearchParams,
-	createStandaloneSearchParams,
-	createCollectionBody,
-	createUrlContext,
-	formatUrlContext,
+	createNodeTypeError,
 	getBlobUrlStore,
+	installWhatwgUrlGlobals,
+	kBlobUrlCounter,
+	kBlobUrlStore,
 	nextBlobUrlId,
-	URLSearchParamsIterator,
-	URLSearchParams,
-	canUseNativeUrlImplementation,
-	ensureTrailingSlashForFilePath,
-	normalizeRelativeFileUrlInput,
-	nativeUrlCandidate,
-	NativeURL,
 	URL2,
-	installWhatwgUrlGlobals,
+	URLSearchParams,
 };
diff --git a/packages/build-tools/bridge-src/polyfills/text-encoding.ts b/packages/build-tools/bridge-src/polyfills/text-encoding.ts
index cbd5dfb055..04b98119cf 100644
--- a/packages/build-tools/bridge-src/polyfills/text-encoding.ts
+++ b/packages/build-tools/bridge-src/polyfills/text-encoding.ts
@@ -199,7 +199,7 @@ function decodeUtf8(bytes, fatal, stream, encoding) {
           throw createEncodingInvalidDataError(encoding);
         }
         output.push("\uFFFD");
-        index += 1;
+        index += 2;
         continue;
       }
       codePoint = codePoint << 6 | third & 63;
@@ -211,7 +211,7 @@ function decodeUtf8(bytes, fatal, stream, encoding) {
           throw createEncodingInvalidDataError(encoding);
         }
         output.push("\uFFFD");
-        index += 1;
+        index += 3;
         continue;
       }
       codePoint = codePoint << 6 | fourth & 63;
diff --git a/packages/build-tools/package.json b/packages/build-tools/package.json
index 08b1590e5f..a03c2a6df1 100644
--- a/packages/build-tools/package.json
+++ b/packages/build-tools/package.json
@@ -29,6 +29,7 @@
 		"readable-stream": "4.7.0",
 		"undici": "^7.24.6",
 		"web-streams-polyfill": "^3.3.3",
+		"whatwg-url": "15.1.0",
 		"ws": "8.21.0"
 	}
 }
diff --git a/packages/build-tools/scripts/build-v8-bridge.mjs b/packages/build-tools/scripts/build-v8-bridge.mjs
index 5aa1338a4a..1e3084b465 100644
--- a/packages/build-tools/scripts/build-v8-bridge.mjs
+++ b/packages/build-tools/scripts/build-v8-bridge.mjs
@@ -86,6 +86,13 @@ const customAlias = {
 	url: path.join(undiciShimDir, "url.js"),
 	"node:url": path.join(undiciShimDir, "url.js"),
 	"agentos-legacy-url-polyfill": nodeStdlibUrlPackageEntry,
+	"agentos-text-encoding-polyfill": path.join(
+		packageRoot,
+		"bridge-src",
+		"polyfills",
+		"text-encoding.ts",
+	),
+	"whatwg-url": require.resolve("whatwg-url"),
 	stream: path.join(undiciShimDir, "stream.js"),
 	"node:stream": path.join(undiciShimDir, "stream.js"),
 	"secure-exec-stream-stdlib": require.resolve("readable-stream"),
@@ -399,6 +406,22 @@ async function buildWebStreamsPrelude() {
 				'  WritableStream,',
 				'  TransformStream,',
 				'} from "web-streams-polyfill/ponyfill/es2018";',
+				'import { TextDecoder as AgentOSTextDecoder, TextEncoder2 as AgentOSTextEncoder } from "agentos-text-encoding-polyfill";',
+				'if (typeof globalThis.TextEncoder === "undefined") {',
+				"  globalThis.TextEncoder = AgentOSTextEncoder;",
+				"}",
+				'if (typeof globalThis.TextDecoder === "undefined") {',
+				"  globalThis.TextDecoder = AgentOSTextDecoder;",
+				"}",
+				'if (typeof globalThis.SharedArrayBuffer === "undefined") {',
+				"  class SharedArrayBufferBootstrapStub {}",
+				'  Object.defineProperties(SharedArrayBufferBootstrapStub.prototype, {',
+				'    byteLength: { configurable: true, get() { if (!(this instanceof SharedArrayBufferBootstrapStub)) throw new TypeError("incompatible receiver"); return 0; } },',
+				'    growable: { configurable: true, get() { if (!(this instanceof SharedArrayBufferBootstrapStub)) throw new TypeError("incompatible receiver"); return false; } },',
+				"  });",
+				"  SharedArrayBufferBootstrapStub.__agentOSBootstrapStub = true;",
+				"  globalThis.SharedArrayBuffer = SharedArrayBufferBootstrapStub;",
+				"}",
 				'if (typeof globalThis.ReadableStream === "undefined") {',
 				"  globalThis.ReadableStream = ReadableStream;",
 				"}",
diff --git a/packages/build-tools/scripts/whatwg-url.test.mjs b/packages/build-tools/scripts/whatwg-url.test.mjs
deleted file mode 100644
index cadeff014a..0000000000
--- a/packages/build-tools/scripts/whatwg-url.test.mjs
+++ /dev/null
@@ -1,22 +0,0 @@
-import assert from "node:assert/strict";
-import test from "node:test";
-import path from "node:path";
-import { resolveRelativeNonFileUrl } from "../bridge-src/builtins/url-resolution.ts";
-
-test("fallback URL resolution follows HTTP base URL semantics", () => {
-	const base = {
-		protocol: "http:",
-		host: "example.test:8080",
-		pathname: "/parent/entry",
-		search: "?old=1",
-	};
-	const resolve = (input) => resolveRelativeNonFileUrl(input, base, path.posix);
-
-	assert.equal(resolve("/hello?q=1"), "http://example.test:8080/hello?q=1");
-	assert.equal(resolve("child"), "http://example.test:8080/parent/child");
-	assert.equal(resolve("../child/"), "http://example.test:8080/child/");
-	assert.equal(resolve("?next=1"), "http://example.test:8080/parent/entry?next=1");
-	assert.equal(resolve("#result"), "http://example.test:8080/parent/entry?old=1#result");
-	assert.equal(resolve(""), "http://example.test:8080/parent/entry?old=1");
-	assert.equal(resolve("//cdn.test/file.js"), "http://cdn.test/file.js");
-});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index da4abfde05..2ab0b2e609 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2764,6 +2764,9 @@ importers:
       web-streams-polyfill:
         specifier: ^3.3.3
         version: 3.3.3
+      whatwg-url:
+        specifier: 15.1.0
+        version: 15.1.0
       ws:
         specifier: 8.21.0
         version: 8.21.0(bufferutil@4.1.0)
@@ -13981,6 +13984,10 @@ packages:
   tr46@0.0.3:
     resolution: {integrity: sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw==}
 
+  tr46@6.0.0:
+    resolution: {integrity: sha512-bLVMLPtstlZ4iMQHpFHTR7GAGj2jxi8Dg0s2h2MafAE4uSWF98FC/3MomU51iQAMf8/qDUbKWf5GxuvvVcXEhw==}
+    engines: {node: '>=20'}
+
   tree-kill@1.2.2:
     resolution: {integrity: sha512-L0Orpi8qGpRG//Nd+H90vFB+3iHnue1zSSGmNOOCh1GLJ7rUKVwV2HvijphGQS2UmhUZewS9VgvxYIdgr+fG1A==}
     hasBin: true
@@ -14651,6 +14658,14 @@ packages:
   webidl-conversions@3.0.1:
     resolution: {integrity: sha512-2JAn3z8AR6rjK8Sm8orRC0h/bcl/DqL7tRPdGZ4I1CjdF+EaMLmYxBHyXuKL849eucPFhvBoxMsflfOb8kxaeQ==}
 
+  webidl-conversions@8.0.1:
+    resolution: {integrity: sha512-BMhLD/Sw+GbJC21C/UgyaZX41nPt8bUTg+jWyDeg7e7YN4xOM05YPSIXceACnXVtqyEw/LMClUQMtMZ+PGGpqQ==}
+    engines: {node: '>=20'}
+
+  whatwg-url@15.1.0:
+    resolution: {integrity: sha512-2ytDk0kiEj/yu90JOAp44PVPUkO9+jVhyf+SybKlRHSDlvOOZhdPIrr7xTH64l4WixO2cP+wQIcgujkGBPPz6g==}
+    engines: {node: '>=20'}
+
   whatwg-url@5.0.0:
     resolution: {integrity: sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw==}
 
@@ -26875,6 +26890,10 @@ snapshots:
 
   tr46@0.0.3: {}
 
+  tr46@6.0.0:
+    dependencies:
+      punycode: 2.3.1
+
   tree-kill@1.2.2: {}
 
   trim-lines@3.0.1: {}
@@ -27522,6 +27541,13 @@ snapshots:
 
   webidl-conversions@3.0.1: {}
 
+  webidl-conversions@8.0.1: {}
+
+  whatwg-url@15.1.0:
+    dependencies:
+      tr46: 6.0.0
+      webidl-conversions: 8.0.1
+
   whatwg-url@5.0.0:
     dependencies:
       tr46: 0.0.3