diff --git a/apps/docs/src/pages/utils.mdx b/apps/docs/src/pages/utils.mdx
new file mode 100644
index 0000000..b2c8339
--- /dev/null
+++ b/apps/docs/src/pages/utils.mdx
@@ -0,0 +1,74 @@
+# Utils [Don't waste time on implementing these yourself.]
+
+We've implemented some utilities that you might find useful. You can find them in the `@mina-js/utils` package.
+
+## Units
+
+Utils library provides functions for unit conversion.
+
+### formatMina
+
+Formats micro-Mina to human-readable Mina value.
+
+```typescript twoslash
+import { formatMina } from '@mina-js/utils'
+
+const mina = formatMina(5_000_000_000n)
+// -> "5"
+```
+
+### parseMina
+
+Parses human-readable Mina value to micro-Mina.
+
+```typescript twoslash
+import { parseMina } from '@mina-js/utils'
+
+const mina = parseMina('5')
+// -> 5_000_000_000n
+```
+
+### formatUnit
+
+```typescript twoslash
+import { formatUnits } from '@mina-js/utils'
+
+const formatted = formatUnits(4200000000000n, 10)
+// -> "420"
+```
+
+### parseUnits
+
+```typescript twoslash
+import { parseUnits } from '@mina-js/utils'
+
+const parsed = parseUnits("420", 10)
+// -> 4200000000000n
+```
+
+## Web Workers
+
+Proof related computations can be heavy and can block the main thread. To avoid this, you can use Web Workers to run these computations in a separate thread. We've prepared a JSON-RPC protocol to easily connect the dots.
+
+```typescript twoslash
+// @filename: worker.ts
+import { createRpcHandler } from "@mina-js/utils";
+
+const { messageHandler } = createRpcHandler({
+  methods: {
+    ping: async () => 'pong',
+  }
+})
+
+self.onmessage = messageHandler
+
+// @filename: index.ts
+import { createRpc } from "@mina-js/utils";
+
+const worker = new Worker(new URL('./worker.ts', import.meta.url))
+const rpc = createRpc({ worker })
+const response = await rpc.request({
+  method: 'ping',
+  params: [],
+})
+```
diff --git a/apps/docs/vocs.config.ts b/apps/docs/vocs.config.ts
index 827f167..e730530 100644
--- a/apps/docs/vocs.config.ts
+++ b/apps/docs/vocs.config.ts
@@ -81,6 +81,10 @@ export default defineConfig({
 			text: "Roadmap",
 			link: "/roadmap",
 		},
+		{
+			text: "Utils",
+			link: "/utils",
+		},
 		{
 			text: "MinaJS Connect",
 			link: "/connect",
diff --git a/apps/klesia/src/methods/mina.ts b/apps/klesia/src/methods/mina.ts
index f6d0053..4effa54 100644
--- a/apps/klesia/src/methods/mina.ts
+++ b/apps/klesia/src/methods/mina.ts
@@ -78,7 +78,7 @@ const networkId = async () => {
     `,
 		{},
 	);
-	return data.networkID;
+	return data.networkID === "mina:testnet" ? "mina:devnet" : data.networkID;
 };
 
 const sendTransaction = async ({
diff --git a/bun.lockb b/bun.lockb
index 34fa9dc..1a6e5ca 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/packages/accounts/src/accounts/__snapshots__/private-key-to-account.spec.ts.snap b/packages/accounts/src/accounts/__snapshots__/private-key-to-account.spec.ts.snap
index 4abf2ea..605ab98 100644
--- a/packages/accounts/src/accounts/__snapshots__/private-key-to-account.spec.ts.snap
+++ b/packages/accounts/src/accounts/__snapshots__/private-key-to-account.spec.ts.snap
@@ -53,3 +53,32 @@ exports[`signs fields 1`] = `
   "signature": "7mXCUvhLhFvG9ptrdfNceCrpThkCUyg1ct2z8uwY7eQbKz7UNmhv33TbuDjTznaypJtXRiMJyQWDnf27TH1FSXG7uJHTKAd9",
 }
 `;
+
+exports[`signs a zkapp command 1`] = `
+{
+  "data": {
+    "feePayer": {
+      "fee": "100000000",
+      "feePayer": "B62qmWKtvNQTtUqo1LxfEEDLyWMg59cp6U7c4uDC7aqgaCEijSc3Hx5",
+      "memo": "Test",
+      "nonce": "0",
+      "validUntil": "null",
+    },
+    "zkappCommand": {
+      "accountUpdates": [],
+      "feePayer": {
+        "authorization": "7mXWqNfmqMTM5uSCS2xLfsRBLTjGZKTtpEakdsrdQz1EUgYXogSvKxxtfGbBkqQ2mZRMA3uPAM8riaCF56pkqpZBLr2kNBLa",
+        "body": {
+          "fee": "100000000",
+          "nonce": "0",
+          "publicKey": "B62qmWKtvNQTtUqo1LxfEEDLyWMg59cp6U7c4uDC7aqgaCEijSc3Hx5",
+          "validUntil": null,
+        },
+      },
+      "memo": "E4YVT4x3A9rUhmjkjGn8ZYBLZn7zK4cfvnMtBYZFdWkg37n2s3nrP",
+    },
+  },
+  "publicKey": "B62qmWKtvNQTtUqo1LxfEEDLyWMg59cp6U7c4uDC7aqgaCEijSc3Hx5",
+  "signature": "7mXWqNfmqMTM5uSCS2xLfsRBLTjGZKTtpEakdsrdQz1EUgYXogSvKxxtfGbBkqQ2mZRMA3uPAM8riaCF56pkqpZBLr2kNBLa",
+}
+`;
diff --git a/packages/accounts/src/accounts/private-key-to-account.spec.ts b/packages/accounts/src/accounts/private-key-to-account.spec.ts
index 7ed0724..f370925 100644
--- a/packages/accounts/src/accounts/private-key-to-account.spec.ts
+++ b/packages/accounts/src/accounts/private-key-to-account.spec.ts
@@ -33,6 +33,35 @@ it("signs a transaction", async () => {
 	expect(signedTransaction).toMatchSnapshot();
 });
 
+it("signs a zkapp command", async () => {
+	const account = privateKeyToAccount({
+		privateKey: Test.accounts[0].privateKey,
+	});
+	const command = {
+		zkappCommand: {
+			accountUpdates: [],
+			memo: "E4YM2vTHhWEg66xpj52JErHUBU4pZ1yageL4TVDDpTTSsv8mK6YaH",
+			feePayer: {
+				body: {
+					publicKey: "B62qmWKtvNQTtUqo1LxfEEDLyWMg59cp6U7c4uDC7aqgaCEijSc3Hx5",
+					fee: "100000000",
+					validUntil: "100000",
+					nonce: "1",
+				},
+				authorization: "",
+			},
+		},
+		feePayer: {
+			feePayer: "B62qmWKtvNQTtUqo1LxfEEDLyWMg59cp6U7c4uDC7aqgaCEijSc3Hx5",
+			fee: "100000000",
+			nonce: "0",
+			memo: "Test",
+		},
+	};
+	const signedTransaction = await account.signTransaction({ command });
+	expect(signedTransaction).toMatchSnapshot();
+});
+
 it("creates a nullifier", async () => {
 	const account = privateKeyToAccount({
 		privateKey: Test.accounts[0].privateKey,
diff --git a/packages/accounts/src/accounts/private-key-to-account.ts b/packages/accounts/src/accounts/private-key-to-account.ts
index 6d3ccb6..c276eb2 100644
--- a/packages/accounts/src/accounts/private-key-to-account.ts
+++ b/packages/accounts/src/accounts/private-key-to-account.ts
@@ -29,9 +29,14 @@ export function privateKeyToAccount({
 		async signMessage({ message }) {
 			return SignedMessageSchema.parse(client.signMessage(message, privateKey));
 		},
-		async signTransaction({ transaction }) {
+		async signTransaction(signable) {
+			if ("transaction" in signable) {
+				return SignedTransactionSchema.parse(
+					client.signTransaction(signable.transaction, privateKey),
+				);
+			}
 			return SignedTransactionSchema.parse(
-				client.signTransaction(transaction, privateKey),
+				client.signTransaction(signable.command as never, privateKey),
 			);
 		},
 		async createNullifier({ message }) {
diff --git a/packages/accounts/src/types.ts b/packages/accounts/src/types.ts
index bc23ebc..f8f2be0 100644
--- a/packages/accounts/src/types.ts
+++ b/packages/accounts/src/types.ts
@@ -4,6 +4,7 @@ import type {
 	SignedFields,
 	SignedMessage,
 	SignedTransaction,
+	TransactionOrZkAppCommandProperties,
 } from "@mina-js/utils";
 import type { HDKey } from "@scure/bip32";
 import type { Simplify } from "type-fest";
@@ -12,7 +13,6 @@ import type {
 	CreateNullifierParamsSchema,
 	SignFieldsParamsSchema,
 	SignMessageParamsSchema,
-	SignTransactionParamsSchema,
 } from "./validation";
 
 export enum MinaKeyConst {
@@ -81,7 +81,6 @@ export type { HDKey };
 export type SignFieldsParams = z.infer<typeof SignFieldsParamsSchema>;
 export type SignMessageParams = z.infer<typeof SignMessageParamsSchema>;
 export type CreateNullifierParams = z.infer<typeof CreateNullifierParamsSchema>;
-export type SignTransactionParams = z.infer<typeof SignTransactionParamsSchema>;
 
 /**
  * Signer methods
@@ -92,5 +91,5 @@ export type CreateNullifier = (
 	params: CreateNullifierParams,
 ) => Promise<Nullifier>;
 export type SignTransaction = (
-	params: SignTransactionParams,
+	params: TransactionOrZkAppCommandProperties,
 ) => Promise<SignedTransaction>;
diff --git a/packages/providers/src/validation.ts b/packages/providers/src/validation.ts
index f853702..49cb748 100644
--- a/packages/providers/src/validation.ts
+++ b/packages/providers/src/validation.ts
@@ -102,10 +102,12 @@ export const StorePrivateCredentialRequestParamsSchema =
 export const PresentationRequestParamsSchema = RequestWithContext.extend({
 	method: z.literal("mina_requestPresentation"),
 	params: z.array(
-		z.object({
-			presentationRequest: PresentationRequestSchema,
-			zkAppAccount: zkAppAccountSchema.optional(),
-		}).strict(),
+		z
+			.object({
+				presentationRequest: PresentationRequestSchema,
+				zkAppAccount: zkAppAccountSchema.optional(),
+			})
+			.strict(),
 	),
 }).strict();
 
diff --git a/packages/utils/package.json b/packages/utils/package.json
index c363571..aa55899 100644
--- a/packages/utils/package.json
+++ b/packages/utils/package.json
@@ -17,7 +17,9 @@
 		"cleanup": "rimraf dist .turbo"
 	},
 	"dependencies": {
-		"mina-signer": "3.0.7"
+		"mina-signer": "3.0.7",
+		"serialize-error": "^11.0.3",
+		"superjson": "2.2.1"
 	},
 	"devDependencies": {
 		"zod": "3.23.8"
diff --git a/packages/utils/src/src/format-mina.spec.ts b/packages/utils/src/format-mina.spec.ts
similarity index 100%
rename from packages/utils/src/src/format-mina.spec.ts
rename to packages/utils/src/format-mina.spec.ts
diff --git a/packages/utils/src/src/format-mina.ts b/packages/utils/src/format-mina.ts
similarity index 100%
rename from packages/utils/src/src/format-mina.ts
rename to packages/utils/src/format-mina.ts
diff --git a/packages/utils/src/src/format-units.spec.ts b/packages/utils/src/format-units.spec.ts
similarity index 100%
rename from packages/utils/src/src/format-units.spec.ts
rename to packages/utils/src/format-units.spec.ts
diff --git a/packages/utils/src/src/format-units.ts b/packages/utils/src/format-units.ts
similarity index 100%
rename from packages/utils/src/src/format-units.ts
rename to packages/utils/src/format-units.ts
diff --git a/packages/utils/src/index.ts b/packages/utils/src/index.ts
index e0af0bf..c4581b7 100644
--- a/packages/utils/src/index.ts
+++ b/packages/utils/src/index.ts
@@ -1,7 +1,8 @@
 export * from "./types";
 export * from "./validation";
-export { formatMina } from "./src/format-mina";
-export { formatUnits } from "./src/format-units";
-export { parseMina } from "./src/parse-mina";
-export { parseUnits } from "./src/parse-units";
+export { formatMina } from "./format-mina";
+export { formatUnits } from "./format-units";
+export { parseMina } from "./parse-mina";
+export { parseUnits } from "./parse-units";
+export { createRpc, createRpcHandler } from "./worker-rpc";
 export * as Test from "./test/constants";
diff --git a/packages/utils/src/src/parse-mina.spec.ts b/packages/utils/src/parse-mina.spec.ts
similarity index 100%
rename from packages/utils/src/src/parse-mina.spec.ts
rename to packages/utils/src/parse-mina.spec.ts
diff --git a/packages/utils/src/src/parse-mina.ts b/packages/utils/src/parse-mina.ts
similarity index 100%
rename from packages/utils/src/src/parse-mina.ts
rename to packages/utils/src/parse-mina.ts
diff --git a/packages/utils/src/src/parse-units.spec.ts b/packages/utils/src/parse-units.spec.ts
similarity index 100%
rename from packages/utils/src/src/parse-units.spec.ts
rename to packages/utils/src/parse-units.spec.ts
diff --git a/packages/utils/src/src/parse-units.ts b/packages/utils/src/parse-units.ts
similarity index 100%
rename from packages/utils/src/src/parse-units.ts
rename to packages/utils/src/parse-units.ts
diff --git a/packages/utils/src/test/worker.ts b/packages/utils/src/test/worker.ts
new file mode 100644
index 0000000..1048622
--- /dev/null
+++ b/packages/utils/src/test/worker.ts
@@ -0,0 +1,9 @@
+import { createRpcHandler } from "../worker-rpc";
+
+const { messageHandler } = createRpcHandler({
+	methods: {
+		ping: async () => "pong",
+	},
+});
+
+self.onmessage = messageHandler;
diff --git a/packages/utils/src/types.ts b/packages/utils/src/types.ts
index c12ba4c..525626f 100644
--- a/packages/utils/src/types.ts
+++ b/packages/utils/src/types.ts
@@ -15,6 +15,7 @@ import type {
 	SignedTransactionSchema,
 	StoredCredentialSchema,
 	TransactionBodySchema,
+	TransactionOrZkAppCommandSchema,
 	TransactionPayloadSchema,
 	TransactionReceiptSchema,
 	ZkAppCommandBodySchema,
@@ -33,6 +34,9 @@ export type TransactionPayload = z.infer<typeof TransactionPayloadSchema>;
 export type PartialTransaction = z.infer<typeof PartialTransactionSchema>;
 export type ZkAppCommandBody = z.infer<typeof ZkAppCommandBodySchema>;
 export type ZkAppCommandProperties = z.infer<typeof ZkAppCommandPayload>;
+export type TransactionOrZkAppCommandProperties = z.infer<
+	typeof TransactionOrZkAppCommandSchema
+>;
 export type Sendable = z.infer<typeof SendableSchema>;
 
 /**
diff --git a/packages/utils/src/validation.ts b/packages/utils/src/validation.ts
index f1633b5..2c661fd 100644
--- a/packages/utils/src/validation.ts
+++ b/packages/utils/src/validation.ts
@@ -87,6 +87,10 @@ export const FieldsAndPassphraseSchema = z
 		passphrase: z.string(),
 	})
 	.strict();
+export const TransactionOrZkAppCommandSchema = z.union([
+	TransactionPayloadSchema,
+	ZkAppCommandPayload,
+]);
 
 /**
  * Return type schemas
@@ -131,7 +135,7 @@ export const NullifierSchema = z
 
 export const SignedTransactionSchema = z
 	.object({
-		signature: SignatureSchema,
+		signature: z.union([SignatureSchema, z.string()]),
 		publicKey: PublicKeySchema,
 		data: z.union([TransactionBodySchema, ZkAppCommandBodySchema]),
 	})
diff --git a/packages/utils/src/worker-rpc.spec.ts b/packages/utils/src/worker-rpc.spec.ts
new file mode 100644
index 0000000..6aee4e8
--- /dev/null
+++ b/packages/utils/src/worker-rpc.spec.ts
@@ -0,0 +1,34 @@
+import { beforeAll, describe, expect, it, mock } from "bun:test";
+import { createRpc, createRpcHandler } from "./worker-rpc";
+
+describe("Worker RPC", () => {
+	let worker: Worker;
+
+	beforeAll(() => {
+		worker = new Worker(new URL("./test/worker.ts", import.meta.url));
+	});
+
+	it("creates RPC handler", async () => {
+		const mockedHandler = mock(async () => "pong");
+		const { messageHandler } = createRpcHandler({
+			methods: {
+				ping: mockedHandler,
+			},
+		});
+		await messageHandler(
+			new MessageEvent("message", { data: { method: "ping", params: [] } }),
+		);
+		expect(mockedHandler).toHaveBeenCalled();
+	});
+
+	it("exchanges messages with Web Worker", async () => {
+		const rpc = createRpc({ worker });
+		const response = await rpc.request({ method: "ping", params: [] });
+		expect(response.result).toBe("pong");
+	});
+
+	it("calls non-existing method", async () => {
+		const rpc = createRpc({ worker });
+		expect(rpc.request({ method: "pang", params: [] })).rejects.toThrow();
+	});
+});
diff --git a/packages/utils/src/worker-rpc.ts b/packages/utils/src/worker-rpc.ts
new file mode 100644
index 0000000..7bdeaa7
--- /dev/null
+++ b/packages/utils/src/worker-rpc.ts
@@ -0,0 +1,99 @@
+import { deserializeError, serializeError } from "serialize-error";
+import superjson from "superjson";
+import { z } from "zod";
+
+const DEFAULT_TIMEOUT = 60000;
+
+export const RequestSchema = z.object({
+	method: z.string(),
+	params: z.array(z.string()).optional(),
+});
+
+type RequestParams = z.infer<typeof RequestSchema>;
+
+export const ResponseSchema = z
+	.object({
+		id: z.string(),
+		result: z.any().optional(),
+		error: z.string().optional(),
+	})
+	.strict();
+
+type Response = z.infer<typeof ResponseSchema>;
+
+export type RequestFn = (params: RequestParams) => Promise<Response>;
+
+export const createRpc = ({
+	worker,
+	timeout,
+}: {
+	worker: Worker;
+	timeout?: number;
+}) => {
+	const request: RequestFn = async ({ method, params }) => {
+		let resolved = false;
+		return new Promise((resolve, reject) => {
+			setTimeout(() => {
+				if (resolved) return;
+				return reject(new Error("[WorkerRPC] Timeout reached."));
+			}, timeout ?? DEFAULT_TIMEOUT);
+			const responseListener = (event: MessageEvent) => {
+				resolved = true;
+				worker.removeEventListener("message", responseListener);
+				const data = superjson.parse(event.data);
+				const response = ResponseSchema.parse(data);
+				if (response.error) {
+					const errorObject = superjson.parse(response.error);
+					const deserializedError = deserializeError(errorObject);
+					return reject(deserializedError);
+				}
+				return resolve(response);
+			};
+			worker.addEventListener("message", responseListener);
+			worker.postMessage({ method, params });
+		});
+	};
+	return {
+		request,
+	};
+};
+
+type Method = (params: string[]) => Promise<unknown>;
+type MethodsMap = Record<string, Method>;
+
+const respond = (data: unknown) => postMessage(superjson.stringify(data));
+
+export const createRpcHandler = ({ methods }: { methods: MethodsMap }) => {
+	const methodKeys = Object.keys(methods);
+	if (methodKeys.length === 0) throw new Error("No methods provided.");
+	const MethodEnum = z.enum(["error", ...methodKeys]);
+	const ExtendedRequestSchema = RequestSchema.extend({
+		method: MethodEnum,
+	}).strict();
+	const ExtendedResponseSchema = ResponseSchema.extend({
+		id: MethodEnum,
+	}).strict();
+	const messageHandler = async (event: MessageEvent) => {
+		try {
+			const action = ExtendedRequestSchema.parse(event.data);
+			const callable = methods[action.method];
+			if (!callable) throw new Error(`Method "${action.method}" not found.`);
+			const result = await callable(action.params ?? []);
+			const parsedResult = ExtendedResponseSchema.parse({
+				id: action.method,
+				result,
+			});
+			return respond(parsedResult);
+			// biome-ignore lint/suspicious/noExplicitAny: Error handling
+		} catch (error: any) {
+			const serializedError = superjson.stringify(serializeError(error));
+			return respond(
+				ExtendedResponseSchema.parse({
+					id: "error",
+					error: serializedError,
+				}),
+			);
+		}
+	};
+	return { messageHandler };
+};