diff --git a/packages/preview2-shim/browser/clocks.js b/packages/preview2-shim/browser/clocks.js
new file mode 100644
index 000000000..e62c29705
--- /dev/null
+++ b/packages/preview2-shim/browser/clocks.js
@@ -0,0 +1,47 @@
+export function wallClockNow(clock) {
+  if (clock === 1) {
+    const seconds = BigInt(Math.floor(Date.now() / 1000));
+    const nanoseconds = (Date.now() % 1000) * 1000 * 1000;
+    return { seconds, nanoseconds };
+  }
+  console.log("[clocks] UNKNOWN CLOCK");
+}
+
+export function monotonicClockResolution(clock) {
+  console.log(`[clocks] Monotonic clock resolution ${clock}`);
+}
+
+export function wallClockResolution(clock) {
+  console.log(`[clocks] Wall clock resolution ${clock}`);
+}
+
+let hrStart = hrtimeBigint();
+
+export function monotonicClockNow(clock) {
+  if (clock === 0) {
+    return hrtimeBigint() - hrStart;
+  }
+  console.log("UNKNOWN CLOCK");
+}
+
+function hrtime(previousTimestamp) {
+  const baseNow = Math.floor((Date.now() - performance.now()) * 1e-3);
+  const clocktime = performance.now() * 1e-3;
+  let seconds = Math.floor(clocktime) + baseNow;
+  let nanoseconds = Math.floor((clocktime % 1) * 1e9);
+
+  if (previousTimestamp) {
+    seconds = seconds - previousTimestamp[0];
+    nanoseconds = nanoseconds - previousTimestamp[1];
+    if (nanoseconds < 0) {
+      seconds--;
+      nanoseconds += 1e9;
+    }
+  }
+  return [seconds, nanoseconds];
+}
+
+function hrtimeBigint(time) {
+  const diff = hrtime(time);
+  return BigInt(diff[0] * 1e9 + diff[1]);
+}
diff --git a/packages/preview2-shim/browser/default-clocks.js b/packages/preview2-shim/browser/default-clocks.js
new file mode 100644
index 000000000..3a5854a62
--- /dev/null
+++ b/packages/preview2-shim/browser/default-clocks.js
@@ -0,0 +1,7 @@
+export function defaultMonotonicClock() {
+  return 0;
+}
+
+export function defaultWallClock() {
+  return 1;
+}
diff --git a/packages/preview2-shim/browser/exit.js b/packages/preview2-shim/browser/exit.js
new file mode 100644
index 000000000..5509bdc65
--- /dev/null
+++ b/packages/preview2-shim/browser/exit.js
@@ -0,0 +1,21 @@
+class FailureExit extends Error {
+  code = 1;
+  constructor() {
+    super("failure-exit");
+  }
+}
+
+class SuccessfulExit extends Error {
+  code = 0;
+  constructor() {
+    super("successful-exit");
+  }
+}
+
+export function exit(status) {
+  console.log(`[exit] Exit: ${JSON.stringify(status)}`);
+  if (status.tag === "err") {
+    throw new FailureExit();
+  }
+  throw new SuccessfulExit();
+}
diff --git a/packages/preview2-shim/browser/filesystem.js b/packages/preview2-shim/browser/filesystem.js
new file mode 100644
index 000000000..54daf07ef
--- /dev/null
+++ b/packages/preview2-shim/browser/filesystem.js
@@ -0,0 +1,47 @@
+export function flags(fd) {
+  console.log(`[filesystem] FLAGS FOR ${fd}`);
+}
+
+export function setFlags(fd, flags) {
+  console.log(`[filesystem] SET FLAGS ${fd} ${JSON.stringify(flags)}`);
+}
+
+export function close(fd) {
+  console.log(`[filesystem] CLOSE: ${fd}`);
+}
+
+export function removeDirectoryAt(fd, path) {
+  console.log(`[filesystem] RM DIR: ${fd} ${path}`);
+}
+
+export function unlinkFileAt(fd, path) {
+  console.log(`[filesystem] UNLINK: ${fd} ${path}`);
+}
+
+export function writeViaStream(fd, offset) {
+  console.log(`[filesystem] WRITE STREAM ${fd} ${offset}`);
+}
+
+export function appendViaStream(fd, offset) {
+  console.log(`[filesystem] APPEND STREAM ${fd} ${offset}`);
+}
+
+export function readViaStream(fd, offset) {
+  console.log(`[filesystem] READ STREAM ${fd} ${offset}`);
+}
+
+export function openAt(fd, atFlags, path, offset) {
+  console.log(`[filesystem] OPEN AT ${fd}`);
+}
+
+export function stat(fd) {
+  console.log(`[filesystem] STAT: ${fd}`);
+}
+
+export function todoType(fd) {
+  console.log(`[filesystem] TODO TYPE: ${fd}`);
+}
+
+export function closeDirEntryStream(s) {
+  console.log(`[filesystem] CLOSE DIR ENTRY STREAM`);
+}
diff --git a/packages/preview2-shim/browser/http.js b/packages/preview2-shim/browser/http.js
new file mode 100644
index 000000000..c03653b55
--- /dev/null
+++ b/packages/preview2-shim/browser/http.js
@@ -0,0 +1,28 @@
+import { UnexpectedError } from "../http/error.js";
+
+/**
+ * @param {import("../types/wasi-http").Request} req
+ * @returns {string}
+ */
+export function send(req) {
+  console.log(`[http] Send (browser) ${req.uri}`);
+  try {
+    const xhr = new XMLHttpRequest();
+    xhr.open(req.method.toString(), req.uri, false);
+    xhr.responseType = "arraybuffer";
+    for (let [name, value] of req.headers) {
+      xhr.setRequestHeader(name, value);
+    }
+    xhr.send(req.body.length > 0 ? req.body : null);
+    return {
+      status: xhr.status,
+      headers: xhr
+        .getAllResponseHeaders()
+        .trim()
+        .split(/[\r\n]+/),
+      body: xhr.response.byteLength > 0 ? xhr.response : undefined,
+    };
+  } catch (err) {
+    throw new UnexpectedError(err.message);
+  }
+}
diff --git a/packages/preview2-shim/browser/index.js b/packages/preview2-shim/browser/index.js
new file mode 100644
index 000000000..18a399e35
--- /dev/null
+++ b/packages/preview2-shim/browser/index.js
@@ -0,0 +1,21 @@
+import * as clocks from "./clocks.js";
+import * as defaultClocks from "./default-clocks.js";
+import * as exit from "./exit.js";
+import * as filesystem from "./filesystem.js";
+import * as io from "./io.js";
+import * as logging from "./logging.js";
+import * as poll from "./poll.js";
+import * as random from "./random.js";
+import * as stderr from "./stderr.js";
+
+export const importObject = {
+    "wasi-clocks": clocks,
+    "wasi-default-clocks": defaultClocks,
+    "wasi-exit": exit,
+    "wasi-filesystem": filesystem,
+    "wasi-io": io,
+    "wasi-logging": logging,
+    "wasi-poll": poll,
+    "wasi-random": random,
+    "wasi-stderr": stderr,
+};
diff --git a/packages/preview2-shim/browser/io.js b/packages/preview2-shim/browser/io.js
new file mode 100644
index 000000000..50aea15e3
--- /dev/null
+++ b/packages/preview2-shim/browser/io.js
@@ -0,0 +1,34 @@
+export function dropInputStream(f) {
+  console.log(`[io] Drop input stream ${f}`);
+}
+
+export function dropOutputStream(f) {
+  console.log(`[io] Drop output stream ${f}`);
+}
+
+export function read(src, len) {
+  console.log(`[io] Read ${src}`);
+}
+
+export function write(dst, buf) {
+  switch (dst) {
+    case 0:
+      throw new Error(`TODO: write stdin`);
+    case 1:
+      const decoder = new TextDecoder();
+      console.log(decoder.decode(buf));
+      return BigInt(buf.byteLength);
+    case 2:
+      throw new Error(`TODO: write stdout`);
+    default:
+      throw new Error(`TODO: write ${dst}`);
+  }
+}
+
+export function skip(src, len) {
+  console.log(`[io] Skip ${src}`);
+}
+
+export function write_repeated(dst, byte, len) {
+  console.log(`[io] Write repeated ${dst}`);
+}
diff --git a/packages/preview2-shim/browser/logging.js b/packages/preview2-shim/browser/logging.js
new file mode 100644
index 000000000..2d3f0890a
--- /dev/null
+++ b/packages/preview2-shim/browser/logging.js
@@ -0,0 +1,12 @@
+const levels = ["trace", "debug", "info", "warn", "error"];
+
+let logLevel = levels.indexOf("warn");
+
+export function setLevel(level) {
+  logLevel = levels.indexOf(level);
+}
+
+export function log(level, context, msg) {
+  if (logLevel > levels.indexOf(level)) return;
+  console[level](`(${context}) ${msg}\n`);
+}
diff --git a/packages/preview2-shim/browser/poll.js b/packages/preview2-shim/browser/poll.js
new file mode 100644
index 000000000..316afdd71
--- /dev/null
+++ b/packages/preview2-shim/browser/poll.js
@@ -0,0 +1,3 @@
+export function pollOneoff(f) {
+  console.log(`[poll] Poll oneoff ${f}`);
+}
diff --git a/packages/preview2-shim/browser/random.js b/packages/preview2-shim/browser/random.js
new file mode 100644
index 000000000..775ec5322
--- /dev/null
+++ b/packages/preview2-shim/browser/random.js
@@ -0,0 +1,19 @@
+const MAX_BYTES = 65536;
+
+export function getRandomBytes(len) {
+  const bytes = new Uint8Array(len);
+
+  if (len > MAX_BYTES) {
+    // this is the max bytes crypto.getRandomValues
+    // can do at once see https://developer.mozilla.org/en-US/docs/Web/API/window.crypto.getRandomValues
+    for (var generated = 0; generated < len; generated += MAX_BYTES) {
+      // buffer.slice automatically checks if the end is past the end of
+      // the buffer so we don't have to here
+      crypto.getRandomValues(bytes.slice(generated, generated + MAX_BYTES));
+    }
+  } else {
+    crypto.getRandomValues(bytes);
+  }
+
+  return bytes;
+}
diff --git a/packages/preview2-shim/browser/stderr.js b/packages/preview2-shim/browser/stderr.js
new file mode 100644
index 000000000..d9784ebaa
--- /dev/null
+++ b/packages/preview2-shim/browser/stderr.js
@@ -0,0 +1,3 @@
+export function print(message) {
+  console.error(`${message}\n`);
+}
diff --git a/packages/preview2-shim/http/error.js b/packages/preview2-shim/http/error.js
new file mode 100644
index 000000000..d896b3651
--- /dev/null
+++ b/packages/preview2-shim/http/error.js
@@ -0,0 +1,11 @@
+export class UnexpectedError extends Error {
+  /** @type { import("../types/wasi-http").HttpErrorUnexpectedError } */
+  payload;
+  constructor(message = "unexpected-error") {
+    super(message);
+    this.payload = {
+      tag: "unexpected-error",
+      val: message,
+    };
+  }
+}
diff --git a/packages/preview2-shim/http/make-request.js b/packages/preview2-shim/http/make-request.js
new file mode 100644
index 000000000..0b3dba3ca
--- /dev/null
+++ b/packages/preview2-shim/http/make-request.js
@@ -0,0 +1,29 @@
+import { runAsWorker } from "synckit";
+
+/**
+ * @param {import("../types/wasi-http").Request} req
+ * @returns {Promise<string>}
+ */
+async function makeRequest(req) {
+  try {
+    let headers = new Headers(req.headers);
+    const resp = await fetch(req.uri, {
+      method: req.method.toString(),
+      headers,
+      body: req.body.length > 0 ? req.body : undefined,
+    });
+    let arrayBuffer = await resp.arrayBuffer();
+    return JSON.stringify({
+      status: resp.status,
+      headers: resp.headers,
+      body:
+        arrayBuffer.byteLength > 0
+          ? Buffer.from(arrayBuffer).toString("base64")
+          : undefined,
+    });
+  } catch (err) {
+    return err.message;
+  }
+}
+
+runAsWorker(makeRequest);
diff --git a/packages/preview2-shim/index.d.ts b/packages/preview2-shim/index.d.ts
new file mode 100644
index 000000000..48b3aa9f4
--- /dev/null
+++ b/packages/preview2-shim/index.d.ts
@@ -0,0 +1,9 @@
+export * as clocks from "./types/wasi-clocks";
+export * as defaultClocks from "./types/wasi-default-clocks";
+export * as exit from "./types/wasi-exit";
+export * as filesystem from "./types/wasi-filesystem";
+export * as io from "./types/wasi-io";
+export * as logging from "./types/wasi-logging";
+export * as poll from "./types/wasi-poll";
+export * as random from "./types/wasi-random";
+export * as stderr from "./types/wasi-stderr";
diff --git a/packages/preview2-shim/index.js b/packages/preview2-shim/index.js
new file mode 100644
index 000000000..a8af064ba
--- /dev/null
+++ b/packages/preview2-shim/index.js
@@ -0,0 +1 @@
+export * from "./nodejs/index.js";
diff --git a/packages/preview2-shim/nodejs/clocks.js b/packages/preview2-shim/nodejs/clocks.js
new file mode 100644
index 000000000..2e81a44a5
--- /dev/null
+++ b/packages/preview2-shim/nodejs/clocks.js
@@ -0,0 +1,27 @@
+import { hrtime } from "node:process";
+
+export function wallClockNow(clock) {
+  if (clock === 1) {
+    const seconds = BigInt(Math.floor(Date.now() / 1000));
+    const nanoseconds = (Date.now() % 1000) * 1000 * 1000;
+    return { seconds, nanoseconds };
+  }
+  console.log("[clocks] UNKNOWN CLOCK");
+}
+
+export function monotonicClockResolution(clock) {
+  console.log(`[clocks] Monotonic clock resolution ${clock}`);
+}
+
+export function wallClockResolution(clock) {
+  console.log(`[clocks] Wall clock resolution ${clock}`);
+}
+
+let hrStart = hrtime.bigint();
+
+export function monotonicClockNow(clock) {
+  if (clock === 0) {
+    return hrtime.bigint() - hrStart;
+  }
+  console.log("[clocks] UNKNOWN CLOCK");
+}
diff --git a/packages/preview2-shim/nodejs/default-clocks.js b/packages/preview2-shim/nodejs/default-clocks.js
new file mode 100644
index 000000000..3a5854a62
--- /dev/null
+++ b/packages/preview2-shim/nodejs/default-clocks.js
@@ -0,0 +1,7 @@
+export function defaultMonotonicClock() {
+  return 0;
+}
+
+export function defaultWallClock() {
+  return 1;
+}
diff --git a/packages/preview2-shim/nodejs/exit.js b/packages/preview2-shim/nodejs/exit.js
new file mode 100644
index 000000000..2fea22774
--- /dev/null
+++ b/packages/preview2-shim/nodejs/exit.js
@@ -0,0 +1,4 @@
+export function exit(status) {
+  console.log(`[exit] Exit: ${JSON.stringify(status)}`);
+  process.exit(status.tag === 'err' ? 1 : 0);
+}
diff --git a/packages/preview2-shim/nodejs/filesystem.js b/packages/preview2-shim/nodejs/filesystem.js
new file mode 100644
index 000000000..b2c41dfa1
--- /dev/null
+++ b/packages/preview2-shim/nodejs/filesystem.js
@@ -0,0 +1,58 @@
+// export interface DescriptorStat {
+//   dev: Device,
+//   ino: Inode,
+//   type: DescriptorType,
+//   nlink: Linkcount,
+//   size: Filesize,
+//   atim: Timestamp,
+//   mtim: Timestamp,
+//   ctim: Timestamp,
+// }
+
+export function flags(fd) {
+  console.log(`[filesystem] FLAGS FOR ${fd}`);
+}
+
+export function setFlags(fd, flags) {
+  console.log(`[filesystem] SET FLAGS ${fd} ${JSON.stringify(flags)}`);
+}
+
+export function close(fd) {
+  console.log(`[filesystem] CLOSE: ${fd}`);
+}
+
+export function removeDirectoryAt(fd, path) {
+  console.log(`[filesystem] RM DIR: ${fd} ${path}`);
+}
+
+export function unlinkFileAt(fd, path) {
+  console.log(`[filesystem] UNLINK: ${fd} ${path}`);
+}
+
+export function writeViaStream(fd, offset) {
+  console.log(`[filesystem] WRITE STREAM ${fd} ${offset}`);
+}
+
+export function appendViaStream(fd, offset) {
+  console.log(`[filesystem] APPEND STREAM ${fd} ${offset}`);
+}
+
+export function readViaStream(fd, offset) {
+  console.log(`[filesystem] READ STREAM ${fd} ${offset}`);
+}
+
+export function openAt(fd, atFlags, path, offset) {
+  console.log(`[filesystem] OPEN AT ${fd}`);
+}
+
+export function stat(fd) {
+  console.log(`[filesystem] STAT: ${fd}`);
+}
+
+export function todoType(fd) {
+  console.log(`[filesystem] TODO TYPE: ${fd}`);
+}
+
+export function closeDirEntryStream(s) {
+  console.log(`[filesystem] CLOSE DIR ENTRY STREAM`);
+}
diff --git a/packages/preview2-shim/nodejs/http.js b/packages/preview2-shim/nodejs/http.js
new file mode 100644
index 000000000..e9591a8ec
--- /dev/null
+++ b/packages/preview2-shim/nodejs/http.js
@@ -0,0 +1,19 @@
+import { createSyncFn } from "synckit";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { UnexpectedError } from "../http/error.js";
+
+export function send(req) {
+  console.log(`[http] Send (nodejs) ${req.uri}`);
+  const dirname = path.dirname(fileURLToPath(import.meta.url));
+  const syncFn = createSyncFn(path.resolve(dirname, "../http/make-request.js"));
+  let rawResponse = syncFn(req);
+  let response = JSON.parse(rawResponse);
+  if (response.status) {
+    return {
+      ...response,
+      body: response.body ? Buffer.from(response.body, "base64") : undefined,
+    };
+  }
+  throw new UnexpectedError(response);
+}
diff --git a/packages/preview2-shim/nodejs/index.js b/packages/preview2-shim/nodejs/index.js
new file mode 100644
index 000000000..18a399e35
--- /dev/null
+++ b/packages/preview2-shim/nodejs/index.js
@@ -0,0 +1,21 @@
+import * as clocks from "./clocks.js";
+import * as defaultClocks from "./default-clocks.js";
+import * as exit from "./exit.js";
+import * as filesystem from "./filesystem.js";
+import * as io from "./io.js";
+import * as logging from "./logging.js";
+import * as poll from "./poll.js";
+import * as random from "./random.js";
+import * as stderr from "./stderr.js";
+
+export const importObject = {
+    "wasi-clocks": clocks,
+    "wasi-default-clocks": defaultClocks,
+    "wasi-exit": exit,
+    "wasi-filesystem": filesystem,
+    "wasi-io": io,
+    "wasi-logging": logging,
+    "wasi-poll": poll,
+    "wasi-random": random,
+    "wasi-stderr": stderr,
+};
diff --git a/packages/preview2-shim/nodejs/io.js b/packages/preview2-shim/nodejs/io.js
new file mode 100644
index 000000000..178adc1ef
--- /dev/null
+++ b/packages/preview2-shim/nodejs/io.js
@@ -0,0 +1,33 @@
+export function dropInputStream(f) {
+  console.log(`[io] Drop input stream ${f}`);
+}
+
+export function dropOutputStream(f) {
+  console.log(`[io] Drop output stream ${f}`);
+}
+
+export function read(src, len) {
+  console.log(`[io] Read ${src}`);
+}
+
+export function write(dst, buf) {
+  switch (dst) {
+    case 0:
+      throw new Error(`TODO: write stdin`);
+    case 1:
+      process.stdout.write(buf);
+      return BigInt(buf.byteLength);
+    case 2:
+      throw new Error(`TODO: write stdout`);
+    default:
+      throw new Error(`TODO: write ${dst}`);
+  }
+}
+
+export function skip(src, len) {
+  console.log(`[io] Skip ${src}`);
+}
+
+export function write_repeated(dst, byte, len) {
+  console.log(`[io] Write repeated ${dst}`);
+}
diff --git a/packages/preview2-shim/nodejs/logging.js b/packages/preview2-shim/nodejs/logging.js
new file mode 100644
index 000000000..b19b831f8
--- /dev/null
+++ b/packages/preview2-shim/nodejs/logging.js
@@ -0,0 +1,12 @@
+const levels = ["trace", "debug", "info", "warn", "error"];
+
+let logLevel = levels.indexOf("warn");
+
+export function setLevel(level) {
+  logLevel = levels.indexOf(level);
+}
+
+export function log(level, context, msg) {
+  if (logLevel > levels.indexOf(level)) return;
+  process.stdout.write(`${level}: (${context}) ${msg}\n`);
+}
diff --git a/packages/preview2-shim/nodejs/poll.js b/packages/preview2-shim/nodejs/poll.js
new file mode 100644
index 000000000..316afdd71
--- /dev/null
+++ b/packages/preview2-shim/nodejs/poll.js
@@ -0,0 +1,3 @@
+export function pollOneoff(f) {
+  console.log(`[poll] Poll oneoff ${f}`);
+}
diff --git a/packages/preview2-shim/nodejs/random.js b/packages/preview2-shim/nodejs/random.js
new file mode 100644
index 000000000..8f0a03f13
--- /dev/null
+++ b/packages/preview2-shim/nodejs/random.js
@@ -0,0 +1,5 @@
+import { randomBytes } from "node:crypto";
+
+export function getRandomBytes(len) {
+  return randomBytes(len);
+}
diff --git a/packages/preview2-shim/nodejs/stderr.js b/packages/preview2-shim/nodejs/stderr.js
new file mode 100644
index 000000000..7a3eb082c
--- /dev/null
+++ b/packages/preview2-shim/nodejs/stderr.js
@@ -0,0 +1,3 @@
+export function print(message) {
+  process.stderr.write(`${message}\n`);
+}
diff --git a/packages/preview2-shim/package.json b/packages/preview2-shim/package.json
new file mode 100644
index 000000000..ca43e21e5
--- /dev/null
+++ b/packages/preview2-shim/package.json
@@ -0,0 +1,23 @@
+{
+    "name": "@bytecodealliance/preview2-shim",
+    "version": "0.0.1",
+    "description": "WASI Preview2 shim in JavaScript for the Browser and Node.js",
+    "author": "Guy Bedford, Eduardo Rodrigues<16357187+eduardomourar@users.noreply.github.com>",
+    "type": "module",
+    "exports": {
+      "node": "./nodejs/index.js",
+      "default": "./browser/index.js"
+    },
+    "types": "index.d.ts",
+    "files": [
+        "index.js",
+        "index.d.ts",
+        "browser/",
+        "http/",
+        "nodejs/",
+        "types/"
+    ],
+    "dependencies": {
+        "synckit": "^0.8.5"
+    }
+}
diff --git a/packages/preview2-shim/types/wasi-clocks.d.ts b/packages/preview2-shim/types/wasi-clocks.d.ts
new file mode 100644
index 000000000..68aadaec5
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-clocks.d.ts
@@ -0,0 +1,11 @@
+export type MonotonicClock = number;
+export type Instant = bigint;
+export type WallClock = number;
+export interface Datetime {
+  seconds: bigint,
+  nanoseconds: number,
+}
+export namespace WasiClocks {
+  export function monotonicClockNow(clock: MonotonicClock): Instant;
+  export function wallClockNow(clock: WallClock): Datetime;
+}
diff --git a/packages/preview2-shim/types/wasi-default-clocks.d.ts b/packages/preview2-shim/types/wasi-default-clocks.d.ts
new file mode 100644
index 000000000..17d83411e
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-default-clocks.d.ts
@@ -0,0 +1,6 @@
+export type MonotonicClock = MonotonicClock;
+export type WallClock = WallClock;
+export namespace WasiDefaultClocks {
+  export function defaultMonotonicClock(): MonotonicClock;
+  export function defaultWallClock(): WallClock;
+}
diff --git a/packages/preview2-shim/types/wasi-exit.d.ts b/packages/preview2-shim/types/wasi-exit.d.ts
new file mode 100644
index 000000000..7c9a74ba7
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-exit.d.ts
@@ -0,0 +1,3 @@
+export namespace WasiExit {
+  export function exit(status: { tag: 'err' | 'ok' }): void;
+}
diff --git a/packages/preview2-shim/types/wasi-filesystem.d.ts b/packages/preview2-shim/types/wasi-filesystem.d.ts
new file mode 100644
index 000000000..681ec11e7
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-filesystem.d.ts
@@ -0,0 +1,150 @@
+export type Descriptor = number;
+export type Filesize = bigint;
+export type InputStream = InputStream;
+/**
+ * # Variants
+ * 
+ * ## `"access"`
+ * 
+ * ## `"again"`
+ * 
+ * ## `"already"`
+ * 
+ * ## `"badf"`
+ * 
+ * ## `"busy"`
+ * 
+ * ## `"deadlk"`
+ * 
+ * ## `"dquot"`
+ * 
+ * ## `"exist"`
+ * 
+ * ## `"fbig"`
+ * 
+ * ## `"ilseq"`
+ * 
+ * ## `"inprogress"`
+ * 
+ * ## `"intr"`
+ * 
+ * ## `"inval"`
+ * 
+ * ## `"io"`
+ * 
+ * ## `"isdir"`
+ * 
+ * ## `"loop"`
+ * 
+ * ## `"mlink"`
+ * 
+ * ## `"msgsize"`
+ * 
+ * ## `"nametoolong"`
+ * 
+ * ## `"nodev"`
+ * 
+ * ## `"noent"`
+ * 
+ * ## `"nolck"`
+ * 
+ * ## `"nomem"`
+ * 
+ * ## `"nospc"`
+ * 
+ * ## `"nosys"`
+ * 
+ * ## `"notdir"`
+ * 
+ * ## `"notempty"`
+ * 
+ * ## `"notrecoverable"`
+ * 
+ * ## `"notsup"`
+ * 
+ * ## `"notty"`
+ * 
+ * ## `"nxio"`
+ * 
+ * ## `"overflow"`
+ * 
+ * ## `"perm"`
+ * 
+ * ## `"pipe"`
+ * 
+ * ## `"rofs"`
+ * 
+ * ## `"spipe"`
+ * 
+ * ## `"txtbsy"`
+ * 
+ * ## `"xdev"`
+ */
+export type Errno = 'access' | 'again' | 'already' | 'badf' | 'busy' | 'deadlk' | 'dquot' | 'exist' | 'fbig' | 'ilseq' | 'inprogress' | 'intr' | 'inval' | 'io' | 'isdir' | 'loop' | 'mlink' | 'msgsize' | 'nametoolong' | 'nodev' | 'noent' | 'nolck' | 'nomem' | 'nospc' | 'nosys' | 'notdir' | 'notempty' | 'notrecoverable' | 'notsup' | 'notty' | 'nxio' | 'overflow' | 'perm' | 'pipe' | 'rofs' | 'spipe' | 'txtbsy' | 'xdev';
+export type OutputStream = OutputStream;
+export type DirEntryStream = number;
+export type Device = bigint;
+export type Inode = bigint;
+/**
+ * # Variants
+ * 
+ * ## `"unknown"`
+ * 
+ * ## `"block-device"`
+ * 
+ * ## `"character-device"`
+ * 
+ * ## `"directory"`
+ * 
+ * ## `"fifo"`
+ * 
+ * ## `"symbolic-link"`
+ * 
+ * ## `"regular-file"`
+ * 
+ * ## `"socket"`
+ */
+export type DescriptorType = 'unknown' | 'block-device' | 'character-device' | 'directory' | 'fifo' | 'symbolic-link' | 'regular-file' | 'socket';
+export type Linkcount = bigint;
+export type Datetime = Datetime;
+export interface DescriptorStat {
+  dev: Device,
+  ino: Inode,
+  type: DescriptorType,
+  nlink: Linkcount,
+  size: Filesize,
+  atim: Datetime,
+  mtim: Datetime,
+  ctim: Datetime,
+}
+export interface AtFlags {
+  symlinkFollow?: boolean,
+}
+export interface OFlags {
+  create?: boolean,
+  directory?: boolean,
+  excl?: boolean,
+  trunc?: boolean,
+}
+export interface DescriptorFlags {
+  read?: boolean,
+  write?: boolean,
+  dsync?: boolean,
+  nonblock?: boolean,
+  rsync?: boolean,
+  sync?: boolean,
+}
+export interface Mode {
+  readable?: boolean,
+  writeable?: boolean,
+  executable?: boolean,
+}
+export namespace WasiFilesystem {
+  export function readViaStream(fd: Descriptor, offset: Filesize): InputStream;
+  export function writeViaStream(fd: Descriptor, offset: Filesize): OutputStream;
+  export function appendViaStream(fd: Descriptor): OutputStream;
+  export function closeDirEntryStream(s: DirEntryStream): void;
+  export function stat(fd: Descriptor): DescriptorStat;
+  export function openAt(fd: Descriptor, atFlags: AtFlags, path: string, oFlags: OFlags, flags: DescriptorFlags, mode: Mode): Descriptor;
+  export function close(fd: Descriptor): void;
+}
diff --git a/packages/preview2-shim/types/wasi-http.d.ts b/packages/preview2-shim/types/wasi-http.d.ts
new file mode 100644
index 000000000..80416d7dd
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-http.d.ts
@@ -0,0 +1,55 @@
+/**
+ * # Variants
+ * 
+ * ## `"get"`
+ * 
+ * ## `"post"`
+ * 
+ * ## `"put"`
+ * 
+ * ## `"delete"`
+ * 
+ * ## `"patch"`
+ * 
+ * ## `"head"`
+ * 
+ * ## `"options"`
+ */
+export type Method = 'get' | 'post' | 'put' | 'delete' | 'patch' | 'head' | 'options';
+export type Uri = string;
+export type Headers = [string, string][];
+export type Params = [string, string][];
+export type Body = Uint8Array;
+export interface Request {
+  method: Method,
+  uri: Uri,
+  headers: Headers,
+  params: Params,
+  body?: Body,
+}
+export type HttpStatus = number;
+export interface Response {
+  status: HttpStatus,
+  headers?: Headers,
+  body?: Body,
+}
+export type HttpError = HttpErrorInvalidUrl | HttpErrorTimeoutError | HttpErrorProtocolError | HttpErrorUnexpectedError;
+export interface HttpErrorInvalidUrl {
+  tag: 'invalid-url',
+  val: string,
+}
+export interface HttpErrorTimeoutError {
+  tag: 'timeout-error',
+  val: string,
+}
+export interface HttpErrorProtocolError {
+  tag: 'protocol-error',
+  val: string,
+}
+export interface HttpErrorUnexpectedError {
+  tag: 'unexpected-error',
+  val: string,
+}
+export namespace WasiHttp {
+  export function send(req: Request): Response;
+}
diff --git a/packages/preview2-shim/types/wasi-io.d.ts b/packages/preview2-shim/types/wasi-io.d.ts
new file mode 100644
index 000000000..5cd70ae10
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-io.d.ts
@@ -0,0 +1,10 @@
+export type InputStream = number;
+export interface StreamError {
+}
+export type OutputStream = number;
+export namespace WasiIo {
+  export function read(src: InputStream, len: bigint): [Uint8Array | ArrayBuffer, boolean];
+  export function write(dst: OutputStream, buf: Uint8Array): bigint;
+  export function dropInputStream(f: InputStream): void;
+  export function dropOutputStream(f: OutputStream): void;
+}
diff --git a/packages/preview2-shim/types/wasi-poll.d.ts b/packages/preview2-shim/types/wasi-poll.d.ts
new file mode 100644
index 000000000..f349f1a35
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-poll.d.ts
@@ -0,0 +1,4 @@
+export type Pollable = number;
+export namespace WasiPoll {
+  export function pollOneoff(input: Pollable[]): Uint8Array;
+}
diff --git a/packages/preview2-shim/types/wasi-random.d.ts b/packages/preview2-shim/types/wasi-random.d.ts
new file mode 100644
index 000000000..e9a642225
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-random.d.ts
@@ -0,0 +1,3 @@
+export namespace WasiRandom {
+  export function getRandomBytes(len: number): Uint8Array | ArrayBuffer;
+}
diff --git a/packages/preview2-shim/types/wasi-stderr.d.ts b/packages/preview2-shim/types/wasi-stderr.d.ts
new file mode 100644
index 000000000..a959b8ebd
--- /dev/null
+++ b/packages/preview2-shim/types/wasi-stderr.d.ts
@@ -0,0 +1,3 @@
+export namespace WasiStderr {
+  export function print(message: string): void;
+}