diff --git a/src/call-credentials.ts b/src/call-credentials.ts
new file mode 100644
index 00000000..89f782e1
--- /dev/null
+++ b/src/call-credentials.ts
@@ -0,0 +1 @@
+export class CallCredentials {}
diff --git a/src/call-stream.ts b/src/call-stream.ts
new file mode 100644
index 00000000..16c5348d
--- /dev/null
+++ b/src/call-stream.ts
@@ -0,0 +1,14 @@
+import * as stream from 'stream';
+import { Status } from './constants';
+
+/**
+ * This class represents a duplex stream associated with a single gRPC call.
+ */
+export class CallStream extends stream.Duplex {
+  /**
+   * Cancels the call associated with this stream with a given status.
+   */
+  cancelWithStatus(status: Status) {
+    throw new Error();
+  }
+}
diff --git a/src/channel-credentials.ts b/src/channel-credentials.ts
new file mode 100644
index 00000000..75d72802
--- /dev/null
+++ b/src/channel-credentials.ts
@@ -0,0 +1,20 @@
+import { CallCredentials } from './call-credentials';
+
+/**
+ * A class that contains credentials for communicating over a channel.
+ */
+export class ChannelCredentials {
+  private constructor() {}
+
+  static createSsl(rootCerts: Buffer, privateKey?: Buffer, certChain?: Buffer) : ChannelCredentials {
+    throw new Error();
+  }
+
+  static createInsecure() : ChannelCredentials {
+    throw new Error();
+  }
+
+  compose(callCredentials: CallCredentials) : ChannelCredentials {
+    throw new Error();
+  }
+}
diff --git a/src/channel.ts b/src/channel.ts
new file mode 100644
index 00000000..28c91738
--- /dev/null
+++ b/src/channel.ts
@@ -0,0 +1,25 @@
+import { CallStream } from './call-stream';
+import { ChannelCredentials } from './channel-credentials';
+import { Metadata } from './metadata';
+
+/**
+ * An interface that contains options used when initializing a Channel instance.
+ */
+export interface ChannelOptions {}
+
+/**
+ * A class that represents a communication channel to a server specified by a given address.
+ */
+export class Channel {
+  constructor(address: string, credentials?: ChannelCredentials, options?: ChannelOptions) {
+    throw new Error();
+  }
+
+  createStream(methodName: string, metadata: Metadata) : CallStream {
+    throw new Error();
+  }
+
+  close() {
+    throw new Error();
+  }
+}
diff --git a/src/constants.ts b/src/constants.ts
new file mode 100644
index 00000000..a72f3388
--- /dev/null
+++ b/src/constants.ts
@@ -0,0 +1,19 @@
+export enum Status {
+  OK = 0,
+  CANCELLED,
+  UNKNOWN,
+  INVALID_ARGUMENT,
+  DEADLINE_EXCEEDED,
+  NOT_FOUND,
+  ALREADY_EXISTS,
+  PERMISSION_DENIED,
+  RESOURCE_EXHAUSTED,
+  FAILED_PRECONDITION,
+  ABORTED,
+  OUT_OF_RANGE,
+  UNIMPLEMENTED,
+  INTERNAL,
+  UNAVAILABLE,
+  DATA_LOSS,
+  UNAUTHENTICATED
+}
diff --git a/src/metadata.ts b/src/metadata.ts
new file mode 100644
index 00000000..2845639c
--- /dev/null
+++ b/src/metadata.ts
@@ -0,0 +1 @@
+export class Metadata {}