diff --git a/packages/protocol/src/browser/client.ts b/packages/protocol/src/browser/client.ts
index 4fda7ea..d4e58ad 100644
--- a/packages/protocol/src/browser/client.ts
+++ b/packages/protocol/src/browser/client.ts
@@ -284,8 +284,18 @@ export class Client {
 				return;
 			}
 			const data = new TextDecoder().decode(output.getData_asU8());
-			const stream = output.getFd() === SessionOutputMessage.FD.STDOUT ? s.stdout : s.stderr;
-			stream.emit("data", data);
+			const source = output.getSource();
+			switch (source) {
+				case SessionOutputMessage.Source.STDOUT:
+				case SessionOutputMessage.Source.STDERR:
+					(source === SessionOutputMessage.Source.STDOUT ? s.stdout : s.stderr).emit("data", data);
+					break;
+				case SessionOutputMessage.Source.IPC:
+					s.emit("message", JSON.parse(data));
+					break;
+				default:
+					throw new Error(`Unknown source ${source}`);
+			}
 		} else if (message.hasIdentifySession()) {
 			const s = this.sessions.get(message.getIdentifySession()!.getId());
 			if (!s) {
diff --git a/packages/protocol/src/browser/command.ts b/packages/protocol/src/browser/command.ts
index f6ef21a..ba094d9 100644
--- a/packages/protocol/src/browser/command.ts
+++ b/packages/protocol/src/browser/command.ts
@@ -23,8 +23,11 @@ export interface ChildProcess {
 	readonly pid: number | undefined;
 
 	kill(signal?: string): void;
-	send(message: string | Uint8Array): void;
 
+	send(message: string | Uint8Array, ipc?: false): void;
+	send(message: any, ipc: true): void;
+
+	on(event: "message", listener: (data: any) => void): void;
 	on(event: "error", listener: (err: Error) => void): void;
 	on(event: "exit", listener: (code: number, signal: string) => void): void;
 
@@ -45,10 +48,6 @@ export class ServerProcess extends events.EventEmitter implements ChildProcess {
 		private readonly hasTty: boolean = false,
 	) {
 		super();
-		this.connection.onMessage((message) => {
-			this.emit("message", message);
-		});
-
 		if (!this.hasTty) {
 			delete this.resize;
 		}
@@ -71,10 +70,15 @@ export class ServerProcess extends events.EventEmitter implements ChildProcess {
 		this._killed = true;
 	}
 
-	public send(message: string | Uint8Array): void {
+	public send(message: string | Uint8Array | any, ipc: boolean = false): void {
 		const send = new WriteToSessionMessage();
 		send.setId(this.id);
-		send.setData(typeof message === "string" ? new TextEncoder().encode(message) : message);
+		send.setSource(ipc ? WriteToSessionMessage.Source.IPC : WriteToSessionMessage.Source.STDIN);
+		if (ipc) {
+			send.setData(new TextEncoder().encode(JSON.stringify(message)));
+		} else {
+			send.setData(typeof message === "string" ? new TextEncoder().encode(message) : message);
+		}
 		const client = new ClientMessage();
 		client.setWriteToSession(send);
 		this.connection.send(client.serializeBinary());
diff --git a/packages/protocol/src/node/command.ts b/packages/protocol/src/node/command.ts
index 128dbb5..9f9cd19 100644
--- a/packages/protocol/src/node/command.ts
+++ b/packages/protocol/src/node/command.ts
@@ -8,6 +8,7 @@ import { SendableConnection } from "../common/connection";
 import { ServerOptions } from "./server";
 
 export interface Process {
+	stdio?: Array<stream.Readable | stream.Writable>;
 	stdin?: stream.Writable;
 	stdout?: stream.Readable;
 	stderr?: stream.Readable;
@@ -69,27 +70,34 @@ export const handleNewSession = (connection: SendableConnection, newSession: New
 		};
 	}
 
-	const sendOutput = (_fd: SessionOutputMessage.FD, msg: string | Uint8Array): void => {
+	const sendOutput = (_source: SessionOutputMessage.Source, msg: string | Uint8Array): void => {
 		const serverMsg = new ServerMessage();
 		const d = new SessionOutputMessage();
 		d.setId(newSession.getId());
 		d.setData(typeof msg === "string" ? new TextEncoder().encode(msg) : msg);
-		d.setFd(SessionOutputMessage.FD.STDOUT);
+		d.setSource(_source);
 		serverMsg.setSessionOutput(d);
 		connection.send(serverMsg.serializeBinary());
 	};
 
 	if (process.stdout && process.stderr) {
 		process.stdout.on("data", (data) => {
-			sendOutput(SessionOutputMessage.FD.STDOUT, data);
+			sendOutput(SessionOutputMessage.Source.STDOUT, data);
 		});
 
 		process.stderr.on("data", (data) => {
-			sendOutput(SessionOutputMessage.FD.STDERR, data);
+			sendOutput(SessionOutputMessage.Source.STDERR, data);
 		});
 	} else {
 		process.on("data", (data) => {
-			sendOutput(SessionOutputMessage.FD.STDOUT, Buffer.from(data));
+			sendOutput(SessionOutputMessage.Source.STDOUT, Buffer.from(data));
+		});
+	}
+
+	if (process.stdio && process.stdio[3]) {
+		// We have ipc fd
+		process.stdio[3].on("data", (data) => {
+			sendOutput(SessionOutputMessage.Source.IPC, data);
 		});
 	}
 
diff --git a/packages/protocol/src/node/server.ts b/packages/protocol/src/node/server.ts
index 2c9f5b3..e7093cd 100644
--- a/packages/protocol/src/node/server.ts
+++ b/packages/protocol/src/node/server.ts
@@ -1,11 +1,11 @@
 import * as os from "os";
 import * as cp from "child_process";
 import * as path from "path";
-import { mkdir } from "fs";
+import { mkdir, WriteStream } from "fs";
 import { promisify } from "util";
 import { TextDecoder } from "text-encoding";
 import { logger, field } from "@coder/logger";
-import { ClientMessage, WorkingInitMessage, ServerMessage, NewSessionMessage } from "../proto";
+import { ClientMessage, WorkingInitMessage, ServerMessage, NewSessionMessage, WriteToSessionMessage } from "../proto";
 import { evaluate } from "./evaluate";
 import { ReadWriteConnection } from "../common/connection";
 import { Process, handleNewSession, handleNewConnection } from "./command";
@@ -120,7 +120,16 @@ export class Server {
 			if (!s) {
 				return;
 			}
-			s.write(new TextDecoder().decode(message.getWriteToSession()!.getData_asU8()));
+			const data = new TextDecoder().decode(message.getWriteToSession()!.getData_asU8());
+			const source = message.getWriteToSession()!.getSource();
+			if (source === WriteToSessionMessage.Source.IPC) {
+				if (!s.stdio || !s.stdio[3]) {
+					throw new Error("Cannot send message via IPC to process without IPC");
+				}
+				(s.stdio[3] as WriteStream).write(data);
+			} else {
+				s.write(data);
+			}
 		} else if (message.hasNewConnection()) {
 			const socket = handleNewConnection(this.connection, message.getNewConnection()!, () => {
 				this.connections.delete(message.getNewConnection()!.getId());
diff --git a/packages/protocol/src/proto/command.proto b/packages/protocol/src/proto/command.proto
index 64419af..740ffcd 100644
--- a/packages/protocol/src/proto/command.proto
+++ b/packages/protocol/src/proto/command.proto
@@ -45,6 +45,11 @@ message IdentifySessionMessage {
 message WriteToSessionMessage {
 	uint64 id = 1;
 	bytes data = 2;
+	enum Source {
+		Stdin = 0;
+		Ipc = 1;
+	}
+	Source source = 3;
 }
 
 // Resizes the TTY of the session identified by the id.
@@ -67,11 +72,12 @@ message ShutdownSessionMessage {
 // SessionOutputMessage carries data read from the stdout or stderr of the session identified by the id.
 message SessionOutputMessage {
 	uint64 id = 1;
-	enum FD {
+	enum Source {
 		Stdout = 0;
 		Stderr = 1;
+		Ipc = 2;
 	}
-	FD fd = 2;
+	Source source = 2;
 	bytes data = 3;
 }
 
diff --git a/packages/protocol/src/proto/command_pb.d.ts b/packages/protocol/src/proto/command_pb.d.ts
index 0c55527..bb13404 100644
--- a/packages/protocol/src/proto/command_pb.d.ts
+++ b/packages/protocol/src/proto/command_pb.d.ts
@@ -144,6 +144,9 @@ export class WriteToSessionMessage extends jspb.Message {
   getData_asB64(): string;
   setData(value: Uint8Array | string): void;
 
+  getSource(): WriteToSessionMessage.Source;
+  setSource(value: WriteToSessionMessage.Source): void;
+
   serializeBinary(): Uint8Array;
   toObject(includeInstance?: boolean): WriteToSessionMessage.AsObject;
   static toObject(includeInstance: boolean, msg: WriteToSessionMessage): WriteToSessionMessage.AsObject;
@@ -158,6 +161,12 @@ export namespace WriteToSessionMessage {
   export type AsObject = {
     id: number,
     data: Uint8Array | string,
+    source: WriteToSessionMessage.Source,
+  }
+
+  export enum Source {
+    STDIN = 0,
+    IPC = 1,
   }
 }
 
@@ -235,8 +244,8 @@ export class SessionOutputMessage extends jspb.Message {
   getId(): number;
   setId(value: number): void;
 
-  getFd(): SessionOutputMessage.FD;
-  setFd(value: SessionOutputMessage.FD): void;
+  getSource(): SessionOutputMessage.Source;
+  setSource(value: SessionOutputMessage.Source): void;
 
   getData(): Uint8Array | string;
   getData_asU8(): Uint8Array;
@@ -256,13 +265,14 @@ export class SessionOutputMessage extends jspb.Message {
 export namespace SessionOutputMessage {
   export type AsObject = {
     id: number,
-    fd: SessionOutputMessage.FD,
+    source: SessionOutputMessage.Source,
     data: Uint8Array | string,
   }
 
-  export enum FD {
+  export enum Source {
     STDOUT = 0,
     STDERR = 1,
+    IPC = 2,
   }
 }
 
diff --git a/packages/protocol/src/proto/command_pb.js b/packages/protocol/src/proto/command_pb.js
index a24d067..0b6ab6c 100644
--- a/packages/protocol/src/proto/command_pb.js
+++ b/packages/protocol/src/proto/command_pb.js
@@ -22,10 +22,11 @@ goog.exportSymbol('proto.NewSessionMessage', null, global);
 goog.exportSymbol('proto.ResizeSessionTTYMessage', null, global);
 goog.exportSymbol('proto.SessionDoneMessage', null, global);
 goog.exportSymbol('proto.SessionOutputMessage', null, global);
-goog.exportSymbol('proto.SessionOutputMessage.FD', null, global);
+goog.exportSymbol('proto.SessionOutputMessage.Source', null, global);
 goog.exportSymbol('proto.ShutdownSessionMessage', null, global);
 goog.exportSymbol('proto.TTYDimensions', null, global);
 goog.exportSymbol('proto.WriteToSessionMessage', null, global);
+goog.exportSymbol('proto.WriteToSessionMessage.Source', null, global);
 
 /**
  * Generated by JsPbCodeGenerator.
@@ -1047,7 +1048,8 @@ proto.WriteToSessionMessage.prototype.toObject = function(opt_includeInstance) {
 proto.WriteToSessionMessage.toObject = function(includeInstance, msg) {
   var f, obj = {
     id: msg.getId(),
-    data: msg.getData_asB64()
+    data: msg.getData_asB64(),
+    source: msg.getSource()
   };
 
   if (includeInstance) {
@@ -1092,6 +1094,10 @@ proto.WriteToSessionMessage.deserializeBinaryFromReader = function(msg, reader)
       var value = /** @type {!Uint8Array} */ (reader.readBytes());
       msg.setData(value);
       break;
+    case 3:
+      var value = /** @type {!proto.WriteToSessionMessage.Source} */ (reader.readEnum());
+      msg.setSource(value);
+      break;
     default:
       reader.skipField();
       break;
@@ -1144,6 +1150,13 @@ proto.WriteToSessionMessage.prototype.serializeBinaryToWriter = function (writer
       f
     );
   }
+  f = this.getSource();
+  if (f !== 0.0) {
+    writer.writeEnum(
+      3,
+      f
+    );
+  }
 };
 
 
@@ -1210,6 +1223,29 @@ proto.WriteToSessionMessage.prototype.setData = function(value) {
 };
 
 
+/**
+ * optional Source source = 3;
+ * @return {!proto.WriteToSessionMessage.Source}
+ */
+proto.WriteToSessionMessage.prototype.getSource = function() {
+  return /** @type {!proto.WriteToSessionMessage.Source} */ (jspb.Message.getFieldProto3(this, 3, 0));
+};
+
+
+/** @param {!proto.WriteToSessionMessage.Source} value  */
+proto.WriteToSessionMessage.prototype.setSource = function(value) {
+  jspb.Message.setField(this, 3, value);
+};
+
+
+/**
+ * @enum {number}
+ */
+proto.WriteToSessionMessage.Source = {
+  STDIN: 0,
+  IPC: 1
+};
+
 
 /**
  * Generated by JsPbCodeGenerator.
@@ -1805,7 +1841,7 @@ proto.SessionOutputMessage.prototype.toObject = function(opt_includeInstance) {
 proto.SessionOutputMessage.toObject = function(includeInstance, msg) {
   var f, obj = {
     id: msg.getId(),
-    fd: msg.getFd(),
+    source: msg.getSource(),
     data: msg.getData_asB64()
   };
 
@@ -1848,8 +1884,8 @@ proto.SessionOutputMessage.deserializeBinaryFromReader = function(msg, reader) {
       msg.setId(value);
       break;
     case 2:
-      var value = /** @type {!proto.SessionOutputMessage.FD} */ (reader.readEnum());
-      msg.setFd(value);
+      var value = /** @type {!proto.SessionOutputMessage.Source} */ (reader.readEnum());
+      msg.setSource(value);
       break;
     case 3:
       var value = /** @type {!Uint8Array} */ (reader.readBytes());
@@ -1900,7 +1936,7 @@ proto.SessionOutputMessage.prototype.serializeBinaryToWriter = function (writer)
       f
     );
   }
-  f = this.getFd();
+  f = this.getSource();
   if (f !== 0.0) {
     writer.writeEnum(
       2,
@@ -1942,16 +1978,16 @@ proto.SessionOutputMessage.prototype.setId = function(value) {
 
 
 /**
- * optional FD fd = 2;
- * @return {!proto.SessionOutputMessage.FD}
+ * optional Source source = 2;
+ * @return {!proto.SessionOutputMessage.Source}
  */
-proto.SessionOutputMessage.prototype.getFd = function() {
-  return /** @type {!proto.SessionOutputMessage.FD} */ (jspb.Message.getFieldProto3(this, 2, 0));
+proto.SessionOutputMessage.prototype.getSource = function() {
+  return /** @type {!proto.SessionOutputMessage.Source} */ (jspb.Message.getFieldProto3(this, 2, 0));
 };
 
 
-/** @param {!proto.SessionOutputMessage.FD} value  */
-proto.SessionOutputMessage.prototype.setFd = function(value) {
+/** @param {!proto.SessionOutputMessage.Source} value  */
+proto.SessionOutputMessage.prototype.setSource = function(value) {
   jspb.Message.setField(this, 2, value);
 };
 
@@ -1998,9 +2034,10 @@ proto.SessionOutputMessage.prototype.setData = function(value) {
 /**
  * @enum {number}
  */
-proto.SessionOutputMessage.FD = {
+proto.SessionOutputMessage.Source = {
   STDOUT: 0,
-  STDERR: 1
+  STDERR: 1,
+  IPC: 2
 };
 
 
diff --git a/packages/protocol/test/command.test.ts b/packages/protocol/test/command.test.ts
index f299f8a..a9a6a40 100644
--- a/packages/protocol/test/command.test.ts
+++ b/packages/protocol/test/command.test.ts
@@ -1,3 +1,4 @@
+import * as cp from "child_process";
 import * as net from "net";
 import * as os from "os";
 import * as path from "path";
@@ -8,7 +9,15 @@ import { createClient } from "./helpers";
 (<any>global).TextEncoder = TextEncoder;
 
 describe("spawn", () => {
-	const client = createClient();
+	const client = createClient({
+		dataDirectory: "",
+		workingDirectory: "",
+		forkProvider: (msg) => {
+			return cp.spawn(msg.getCommand(), msg.getArgsList(), {
+				stdio: [null, null, null, "pipe"],
+			});
+		},
+	});
 
 	it("should execute command and return output", (done) => {
 		const proc = client.spawn("echo", ["test"]);
@@ -124,11 +133,13 @@ describe("spawn", () => {
 		proc.on("exit", () => done());
 	});
 	
-	it("should fork", (done) => {
+	it("should fork and echo messages", (done) => {
 		const proc = client.fork(path.join(__dirname, "forker.js"));
-		proc.stdout.on("data", (data) => {
-			expect(data).toEqual("test");
+		proc.on("message", (msg) => {
+			expect(msg.bananas).toBeTruthy();
+			proc.kill();
 		});
+		proc.send({ bananas: true }, true);
 		proc.on("exit", () => done());
 	});
 });
diff --git a/packages/protocol/test/forker.js b/packages/protocol/test/forker.js
index 02525d0..6f8b959 100755
--- a/packages/protocol/test/forker.js
+++ b/packages/protocol/test/forker.js
@@ -1 +1,3 @@
-console.log("test");
\ No newline at end of file
+process.on("message", (data) => {
+	process.send(data);
+});
\ No newline at end of file
diff --git a/packages/server/src/vscode/bootstrapFork.ts b/packages/server/src/vscode/bootstrapFork.ts
index 281e4ff..03361fe 100644
--- a/packages/server/src/vscode/bootstrapFork.ts
+++ b/packages/server/src/vscode/bootstrapFork.ts
@@ -1,5 +1,6 @@
 import * as cp from "child_process";
 import * as fs from "fs";
+import * as net from "net";
 import * as path from "path";
 import { logger, field } from "@coder/logger/src";
 
@@ -8,6 +9,18 @@ declare var __non_webpack_require__: typeof require;
 export const requireModule = (modulePath: string): void => {
 	process.env.AMD_ENTRYPOINT = modulePath;
 	process.env.VSCODE_ALLOW_IO = "true";
+
+	if (!process.send) {
+		const socket = new net.Socket({ fd: 3 });
+		socket.on("data", (data) => {
+			process.emit("message", JSON.parse(data.toString()), undefined);
+		});
+
+		process.send = (message: any): void => {
+			socket.write(JSON.stringify(message));
+		};
+	}
+
 	const content = fs.readFileSync(path.join(process.env.BUILD_DIR as string || path.join(__dirname, "../.."), "./build/bootstrap-fork.js"));
 	eval(content.toString());
 };
@@ -36,13 +49,13 @@ export const forkModule = (modulePath: string, stdio?: boolean): cp.ChildProcess
 	let proc: cp.ChildProcess | undefined;
 
 	const args = ["--bootstrap-fork", modulePath];
+	const options: cp.SpawnOptions = {
+		stdio: [null, null, null, "pipe"],
+	};
 	if (process.env.CLI === "true") {
-		proc = stdio ? cp.spawn(process.execPath, args) : cp.fork(process.execPath, args);
-	} else if (stdio) {
-		proc = cp.spawn("npm", ["start", "--scripts-prepend-node-path", "--", ...args]);
+		proc = stdio ? cp.spawn(process.execPath, args, options) : cp.fork(process.execPath, args, options);
 	} else {
-		// TODO: need to fork somehow so we get send/onMessage.
-		proc = cp.spawn("npm", ["start", "--scripts-prepend-node-path", "--", ...args]);
+		proc = cp.spawn(process.execArgv[0], ["-r", "tsconfig-paths/register", process.argv[1], ...args], options);
 	}
 
 	proc.stdout.on("data", (message) => {