diff --git a/examples/mixture-of-agents/index.html b/examples/mixture-of-agents/index.html
index a35d275..e971b73 100644
--- a/examples/mixture-of-agents/index.html
+++ b/examples/mixture-of-agents/index.html
@@ -165,7 +165,7 @@
         "GPT-4o Mini",
         "Llama 3.1 8B",
         "Mixtral 8x7B",
-      ]
+      ];
       const individualResults = "{{ individual }}";
       const aggResults = "{{ summaries }}";
 
@@ -190,7 +190,7 @@
           contentArea.textContent =
             individualResults[currentLayer][currentIndex].trim();
 
-          cardTitle.textContent = `${modelNames[currentIndex]} - Layer ${ currentLayer + 1 }`;
+          cardTitle.textContent = `${modelNames[currentIndex]} - Layer ${currentLayer + 1}`;
         } else {
           contentArea.textContent = aggResults[currentLayer].trim();
           cardTitle.textContent = `MoA Layer ${currentLayer + 1}`;
diff --git a/examples/module.ts b/examples/module.ts
new file mode 100755
index 0000000..8411089
--- /dev/null
+++ b/examples/module.ts
@@ -0,0 +1,62 @@
+#!/usr/bin/env -S npx ts-node --transpileOnly
+
+import { Substrate, Box, Module, sb } from "substrate";
+
+async function main() {
+  const SUBSTRATE_API_KEY = process.env["SUBSTRATE_API_KEY"];
+  const substrate = new Substrate({ apiKey: SUBSTRATE_API_KEY });
+
+  const x = sb.var({ type: "string", default: "hello" });
+  const y = sb.var({ type: "string" });
+  const z = sb.var({ type: "object", properties: {} });
+
+  const a = new Box({ value: { a: x, z: z, array: [x, x, x] } }, { id: "A" });
+  const b = new Box(
+    { value: { b: sb.interpolate`x=${a.future.value.get("a")}, y=${y}` } },
+    { id: "B" },
+  );
+
+  // publish the module on substrate.run
+  const publication = await substrate.module.publish({
+    name: "my reusable graph",
+    nodes: [a, b],
+    inputs: { x, y, z },
+  });
+  console.log("published:", publication.json);
+
+  // using the module from JSON
+  const mod = new Module({
+    module_json: substrate.module.serialize({
+      nodes: [a, b],
+      inputs: { x, y, z },
+    }),
+    inputs: {
+      // when commented will use "hello" because it is defined as the default above
+      // x: 123,
+      y: "yyy",
+      z: {
+        arr: ["123"],
+      },
+    },
+  });
+
+  // using the module from publication/module id
+  // const mod = new Module({
+  //   module_id: publication.id,
+  //   inputs: { y: "yyy", z: { arr: ["123"] } },
+  // });
+
+  const c = new Box(
+    {
+      value: {
+        "1": mod.future.get("A.value.z.arr[0]"),
+        "2": mod.future.get("B.value.b"),
+      },
+    },
+    { id: "C" },
+  );
+
+  const res = await substrate.run(mod, c);
+  console.log(JSON.stringify(res.json, null, 2));
+}
+main();
diff --git a/package-lock.json b/package-lock.json
index c11e188..f8879ac 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,6 +9,7 @@
       "version": "120240617.1.7",
       "license": "MIT",
       "dependencies": {
+        "@types/json-schema": "^7.0.15",
         "@types/node-fetch": "^2.6.11",
         "node-fetch": "2.7.0",
         "pako": "^2.1.0"
@@ -798,6 +799,11 @@
       "integrity": "sha512-/kYRxGDLWzHOB7q+wtSUQlFrtcdUccpfy+X+9iMBpHK8QLLhx2wIPYuS5DYtR9Wa/YlZAbIovy7qVdB1Aq6Lyw==",
       "dev": true
     },
+    "node_modules/@types/json-schema": {
+      "version": "7.0.15",
+      "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.15.tgz",
+      "integrity": "sha512-5+fP8P8MFNC+AyZCDxrB2pkZFPGzqQWUzpSeuuVLvm8VMcorNYavBqoFcxK8bQz4Qsbn4oUEEem4wDLfcysGHA=="
+    },
     "node_modules/@types/node": {
       "version": "20.14.11",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-20.14.11.tgz",
diff --git a/package.json b/package.json
index f778af3..234dbe5 100644
--- a/package.json
+++ b/package.json
@@ -43,6 +43,7 @@
     "vitest": "^1.0.4"
   },
   "dependencies": {
+    "@types/json-schema": "^7.0.15",
     "@types/node-fetch": "^2.6.11",
     "node-fetch": "2.7.0",
     "pako": "^2.1.0"
diff --git a/src/Future.ts b/src/Future.ts
index 75559a5..601f81c 100644
--- a/src/Future.ts
+++ b/src/Future.ts
@@ -1,5 +1,6 @@
 import { idGenerator } from "substrate/idGenerator";
 import { Node } from "substrate/Node";
+import { type JSONSchema7 } from "json-schema";
 
 type Accessor = "item" | "attr";
 type TraceOperation = {
@@ -122,7 +123,7 @@ export class JQ extends Directive {
     rawValue: (val: JQCompatible) => ({ future_id: null, val }),
   };
 
-  override next(...items: TraceProp[]) {
+  override next(..._items: TraceProp[]) {
     return new JQ(this.query, this.target);
   }
 
@@ -315,3 +316,39 @@ export class FutureAnyObject extends Future<Object> {
     return super._result();
   }
 }
+
+export class Variable extends Directive {
+  items: any[]; // NOTE: unused field (will remove this from direcitve in a later refactor)
+  name: string | null;
+
+  constructor(items: any[]) {
+    super();
+    this.items = items;
+  }
+
+  override next(...args: any[]) {
+    return new Variable(args);
+  }
+
+  override async result(): Promise<any> {
+    return;
+  }
+
+  override toJSON() {
+    return {
+      type: "variable",
+      source: "input",
+      name: this.name,
+    };
+  }
+}
+
+export class FutureVariable extends Future<any> {
+  declare _directive: Variable;
+  schema: JSONSchema7;
+
+  constructor(schema?: JSONSchema7, id: string = newFutureId()) {
+    super(new Variable([]), id);
+    this.schema = schema ?? {};
+  }
+}
diff --git a/src/Module.ts b/src/Module.ts
new file mode 100644
index 0000000..9950e50
--- /dev/null
+++ b/src/Module.ts
@@ -0,0 +1,36 @@
+import { Node, Options } from "substrate/Node";
+import { FutureVariable } from "substrate/Future";
+
+type ModuleId = `mod_${string}`;
+
+export type SerializableModule = {
+  nodes: Node[];
+  inputs: ModuleInputs;
+};
+
+export type NewModule = SerializableModule & { name: string };
+export type UpdateModule = NewModule & { id: ModuleId };
+export type PublishableModule = NewModule; // | UpdateModule; (TODO: implement update module)
+export type PublishedModule = {
+  id: ModuleId;
+  uri: string;
+};
+
+export type ModuleInputs = Record<string, FutureVariable>;
+
+type ModuleIn =
+  | {
+      module_json: any;
+      inputs: Record<string, any>;
+    }
+  | {
+      module_id: ModuleId;
+      inputs: Record<string, any>;
+    };
+
+export class Module extends Node {
+  constructor(args: ModuleIn, options?: Options) {
+    super(args, options);
+    this.node = "Module";
+  }
+}
diff --git a/src/Substrate.ts b/src/Substrate.ts
index e123c9f..6523dd6 100644
--- a/src/Substrate.ts
+++ b/src/Substrate.ts
@@ -1,13 +1,17 @@
 import { SubstrateError, RequestTimeoutError } from "substrate/Error";
 import { VERSION } from "substrate/version";
 import OpenAPIjson from "substrate/openapi.json";
-import { SubstrateResponse } from "substrate/SubstrateResponse";
+import {
+  asSubstratePublishedModuleResponse,
+  SubstrateResponse,
+} from "substrate/SubstrateResponse";
 import { SubstrateStreamingResponse } from "substrate/SubstrateStreamingResponse";
 import { Node } from "substrate/Node";
 import { Future } from "substrate/Future";
 import { getPlatformProperties } from "substrate/Platform";
 import { deflate } from "pako";
 import { randomString } from "substrate/idGenerator";
+import { SerializableModule, PublishableModule } from "substrate/Module";
 
 type Configuration = {
   /**
@@ -291,4 +295,83 @@ export class Substrate {
 
     return headers;
   }
+
+  module = {
+    /**
+     * Returns an object that represents a publishable "module" or code that can be used to construct
+     * a `Module` node.
+     */
+    serialize: ({ nodes, inputs }: SerializableModule) => {
+      const inputIdToName = {};
+      const inputNameToSchema = {};
+
+      for (let name in inputs) {
+        let input = inputs[name];
+        // @ts-ignore
+        inputIdToName[input._id] = name;
+        // @ts-ignore
+        inputNameToSchema[name] = input.schema;
+      }
+
+      const dag = Substrate.serialize(...nodes);
+
+      // update variable name bindings in dag using inputs
+      dag.futures = dag.futures.map((future: any) => {
+        if (future.directive.type === "variable" && !future.directive.name) {
+          // @ts-ignore
+          future.directive.name = inputIdToName[future.id];
+        }
+        return future;
+      });
+
+      return {
+        dag,
+        inputs: inputNameToSchema,
+        api_version: this.apiVersion,
+      };
+    },
+
+    /**
+     * Publishes a module on substrate.run
+     *
+     */
+    publish: async (
+      publishable: PublishableModule,
+      endpoint: string = "https://www.substrate.run/api/modules",
+    ) => {
+      /**
+       * NOTE: Because the Module publishing API lives in another app and subdomain, the `baseUrl` configuration
+       * will not be applied to this request like we do with `.run`
+       */
+      const serialized = this.module.serialize({
+        nodes: publishable.nodes,
+        inputs: publishable.inputs,
+      });
+
+      const body = {
+        module: { name: publishable.name },
+        module_version: serialized,
+      };
+
+      const requestOptions = {
+        method: "POST",
+        headers: this.headers(),
+        body: JSON.stringify(body),
+      };
+
+      const request = new Request(endpoint, requestOptions);
+      const requestId = request.headers.get("x-substrate-request-id");
+      const apiResponse = await fetch(request);
+
+      if (apiResponse.ok) {
+        const json = await apiResponse.json();
+        const res = new SubstrateResponse(request, apiResponse, json);
+        return asSubstratePublishedModuleResponse(res);
+      } else {
+        throw new SubstrateError(
+          `[Request failed] status=${apiResponse.status} statusText=${apiResponse.statusText} requestId=${requestId}`,
+        );
+      }
+    },
+  };
 }
diff --git a/src/SubstrateResponse.ts b/src/SubstrateResponse.ts
index 65d00cf..61f67e6 100644
--- a/src/SubstrateResponse.ts
+++ b/src/SubstrateResponse.ts
@@ -1,5 +1,6 @@
 import { AnyNode, NodeOutput } from "substrate/Nodes";
 import { NodeError } from "substrate/Error";
+import { PublishedModule } from "substrate/Module";
 
 /**
  * Response to a run request.
@@ -39,3 +40,19 @@ export class SubstrateResponse {
     return node.output() as NodeOutput<T>;
   }
 }
+
+// TODO: create an alternate SubstrateResponse for non-compose responses
+// For now using a type assertions and modifying the object.
+export type SubstratePublishModuleResponse = Omit<
+  SubstrateResponse,
+  "get" | "getError"
+> & { json: PublishedModule };
+export const asSubstratePublishedModuleResponse = (
+  res: SubstrateResponse,
+): SubstratePublishModuleResponse => {
+  // @ts-ignore
+  delete res.get;
+  // @ts-ignore
+  delete res.getError;
+  return res as SubstratePublishModuleResponse;
+};
diff --git a/src/index.ts b/src/index.ts
index bf57663..2120dd7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -51,6 +51,8 @@ export {
   DeleteVectors,
 } from "substrate/Nodes";
 
+export { Module } from "substrate/Module";
+
 export { sb } from "substrate/sb";
 export { Substrate };
 import { Substrate } from "substrate/Substrate";
diff --git a/src/sb.ts b/src/sb.ts
index f94848c..9e41861 100644
--- a/src/sb.ts
+++ b/src/sb.ts
@@ -1,10 +1,27 @@
-import { FutureAnyObject, FutureString } from "substrate/Future";
+import {
+  FutureAnyObject,
+  FutureVariable,
+  FutureString,
+} from "substrate/Future";
 import { StreamingResponse } from "substrate/SubstrateStreamingResponse";
 
 export const sb = {
   concat: FutureString.concat,
   jq: FutureAnyObject.jq,
   interpolate: FutureString.interpolate,
+  /**
+   * `var` is used to specify a variable that can be bound to a name when creating a `module` (re-usable Substrate Graph)
+   * * Input types and validation paramters may optionally be described using a JSON Schema object.
+   * * Default values may also be specified here and will be used if user input is not provided for this input.
+   */
+  var: (schema: FutureVariable["schema"]) => {
+    // NOTE: using `any` as the return type here for now to ease using
+    // this in general node input args or helper functions.
+    //
+    // Once we ship our Future type reorganization work, we can just
+    // use this as-is (Future<any>)
+    return new FutureVariable(schema) as any;
+  },
   streaming: {
     fromSSEResponse: StreamingResponse.fromReponse,
   },