diff --git a/gui/src-tauri/tauri.conf.json b/gui/src-tauri/tauri.conf.json
index 7261850..ac5139d 100644
--- a/gui/src-tauri/tauri.conf.json
+++ b/gui/src-tauri/tauri.conf.json
@@ -19,10 +19,7 @@
         "scope": [
           {
             "name": "../binaries/s3si",
-            "sidecar": true,
-            "args": [
-              "--daemon"
-            ]
+            "sidecar": true
           },
           {
             "name": "deno",
@@ -30,8 +27,7 @@
             "args": [
               "run",
               "-A",
-              "../../s3si.ts",
-              "--daemon"
+              "../../src/daemon.ts"
             ]
           }
         ],
diff --git a/gui/src/ipc/stdio.ts b/gui/src/ipc/stdio.ts
index 84481c9..d7d8eda 100644
--- a/gui/src/ipc/stdio.ts
+++ b/gui/src/ipc/stdio.ts
@@ -15,7 +15,9 @@ export class IPC<T extends { type: string }> {
   child: Promise<Child>;
 
   constructor() {
-    const command = import.meta.env.DEV ? new Command("deno", ["run", "-A", "../../s3si.ts", "--daemon"]) : Command.sidecar('../binaries/s3si', ['--daemon']);
+    const command = import.meta.env.DEV
+      ? new Command("deno", ["run", "-A", "../../src/daemon.ts"])
+      : Command.sidecar('../binaries/s3si');
     command.stdout.on('data', line => {
       this.callback(JSON.parse(line))
     })
diff --git a/s3si.ts b/s3si.ts
index 5020fa3..f904804 100644
--- a/s3si.ts
+++ b/s3si.ts
@@ -1,12 +1,11 @@
 import { App, DEFAULT_OPTS } from "./src/app.ts";
-import { runDaemon } from "./src/daemon.ts";
 import { showError } from "./src/utils.ts";
 import { flags } from "./deps.ts";
 
 const parseArgs = (args: string[]) => {
   const parsed = flags.parse(args, {
     string: ["profilePath", "exporter", "skipMode"],
-    boolean: ["help", "noProgress", "monitor", "withSummary", "daemon"],
+    boolean: ["help", "noProgress", "monitor", "withSummary"],
     alias: {
       "help": "h",
       "profilePath": ["p", "profile-path"],
@@ -39,11 +38,6 @@ Options:
   );
   Deno.exit(0);
 }
-if (opts.daemon) {
-  await runDaemon();
-
-  Deno.exit(0);
-}
 
 const app = new App({
   ...DEFAULT_OPTS,
diff --git a/scripts/compile.ts b/scripts/compile.ts
index cbbb346..3964a73 100644
--- a/scripts/compile.ts
+++ b/scripts/compile.ts
@@ -20,7 +20,7 @@ if (import.meta.main) {
         "-o",
         `../gui/binaries/s3si-${target}`,
         "-A",
-        "../s3si.ts",
+        "../src/daemon.ts",
       ],
       cwd: __dirname,
     });
diff --git a/src/daemon.ts b/src/daemon.ts
index 62ffdfe..92fd8c7 100644
--- a/src/daemon.ts
+++ b/src/daemon.ts
@@ -1,20 +1,131 @@
-import { IPC } from "./ipc/mod.ts";
-import { Command } from "./ipc/types.ts";
+// deno-lint-ignore-file no-empty-interface
 
-export async function runDaemon() {
-  const ipc = new IPC<Command>({
-    reader: Deno.stdin,
-    writer: Deno.stdout,
+import {
+  JSONRPCServer,
+  ResponseError,
+  RPCResult,
+  Service,
+} from "./jsonrpc/mod.ts";
+import { DenoIO } from "./jsonrpc/deno.ts";
+import { loginSteps } from "./iksm.ts";
+import { DEFAULT_ENV, Env } from "./env.ts";
+import { Queue } from "./jsonrpc/channel.ts";
+
+export interface S3SINetworkError extends ResponseError<100> {
+}
+
+export interface S3SIService {
+  loginSteps(): Promise<
+    RPCResult<
+      {
+        authCodeVerifier: string;
+        url: string;
+      },
+      S3SINetworkError
+    >
+  >;
+  loginSteps(step2: {
+    authCodeVerifier: string;
+    login: string;
+  }): Promise<
+    RPCResult<
+      {
+        sessionToken: string;
+      },
+      S3SINetworkError
+    >
+  >;
+}
+
+enum LoggerLevel {
+  Debug = "debug",
+  Log = "log",
+  Warn = "warn",
+  Error = "error",
+}
+
+class S3SIServiceImplement implements S3SIService, Service {
+  loginMap: Map<string, {
+    step1: (url: string) => void;
+    promise: Promise<string>;
+  }> = new Map();
+  loggerQueue: Queue<{ level: LoggerLevel; msg: unknown[] }> = new Queue();
+  env: Env = {
+    prompts: {
+      promptLogin: () => {
+        return Promise.reject("Not implemented");
+      },
+      prompt: () => {
+        return Promise.reject("Not implemented");
+      },
+    },
+    logger: {
+      debug: (...msg) =>
+        this.loggerQueue.push({ level: LoggerLevel.Debug, msg }),
+      log: (...msg) => this.loggerQueue.push({ level: LoggerLevel.Log, msg }),
+      warn: (...msg) => this.loggerQueue.push({ level: LoggerLevel.Warn, msg }),
+      error: (...msg) =>
+        this.loggerQueue.push({ level: LoggerLevel.Error, msg }),
+    },
+    newFetcher: DEFAULT_ENV.newFetcher,
+  };
+
+  loginSteps(): Promise<
+    RPCResult<
+      {
+        authCodeVerifier: string;
+        url: string;
+      },
+      S3SINetworkError
+    >
+  >;
+  loginSteps(step2: {
+    authCodeVerifier: string;
+    login: string;
+  }): Promise<
+    RPCResult<
+      {
+        sessionToken: string;
+      },
+      S3SINetworkError
+    >
+  >;
+  async loginSteps(step2?: {
+    authCodeVerifier: string;
+    login: string;
+  }): Promise<
+    RPCResult<
+      {
+        authCodeVerifier: string;
+        url: string;
+      } | {
+        sessionToken: string;
+      },
+      S3SINetworkError
+    >
+  > {
+    if (!step2) {
+      return {
+        result: await loginSteps(this.env),
+      };
+    }
+    return {
+      result: await loginSteps(this.env, step2),
+    };
+  }
+  // deno-lint-ignore no-explicit-any
+  [key: string]: any;
+}
+
+if (import.meta.main) {
+  const service = new S3SIServiceImplement();
+  const server = new JSONRPCServer({
+    transport: new DenoIO({
+      reader: Deno.stdin,
+      writer: Deno.stdout,
+    }),
+    service,
   });
 
-  while (true) {
-    const cmd = await ipc.recv();
-    switch (cmd.type) {
-      case "hello":
-        await ipc.send(cmd);
-        break;
-      default:
-        continue;
-    }
-  }
+  await server.serve();
 }
diff --git a/src/iksm.ts b/src/iksm.ts
index 0690ae4..05ef440 100644
--- a/src/iksm.ts
+++ b/src/iksm.ts
@@ -8,70 +8,123 @@ import {
 import { APIError } from "./APIError.ts";
 import { Env, Fetcher } from "./env.ts";
 
-export async function loginManually(
-  { newFetcher, prompts: { promptLogin } }: Env,
-): Promise<string> {
+export async function loginSteps(
+  env: Env,
+): Promise<
+  {
+    authCodeVerifier: string;
+    url: string;
+  }
+>;
+export async function loginSteps(
+  env: Env,
+  step2: {
+    authCodeVerifier: string;
+    login: string;
+  },
+): Promise<
+  {
+    sessionToken: string;
+  }
+>;
+export async function loginSteps(
+  { newFetcher }: Env,
+  step2?: {
+    authCodeVerifier: string;
+    login: string;
+  },
+): Promise<
+  {
+    authCodeVerifier: string;
+    url: string;
+  } | {
+    sessionToken: string;
+  }
+> {
   const fetch = newFetcher();
 
-  const state = urlBase64Encode(random(36));
-  const authCodeVerifier = urlBase64Encode(random(32));
-  const authCvHash = await crypto.subtle.digest(
-    "SHA-256",
-    new TextEncoder().encode(authCodeVerifier),
-  );
-  const authCodeChallenge = urlBase64Encode(authCvHash);
+  if (!step2) {
+    const state = urlBase64Encode(random(36));
+    const authCodeVerifier = urlBase64Encode(random(32));
+    const authCvHash = await crypto.subtle.digest(
+      "SHA-256",
+      new TextEncoder().encode(authCodeVerifier),
+    );
+    const authCodeChallenge = urlBase64Encode(authCvHash);
 
-  const body = {
-    "state": state,
-    "redirect_uri": "npf71b963c1b7b6d119://auth",
-    "client_id": "71b963c1b7b6d119",
-    "scope": "openid user user.birthday user.mii user.screenName",
-    "response_type": "session_token_code",
-    "session_token_code_challenge": authCodeChallenge,
-    "session_token_code_challenge_method": "S256",
-    "theme": "login_form",
-  };
-  const url = "https://accounts.nintendo.com/connect/1.0.0/authorize?" +
-    new URLSearchParams(body);
+    const body = {
+      "state": state,
+      "redirect_uri": "npf71b963c1b7b6d119://auth",
+      "client_id": "71b963c1b7b6d119",
+      "scope": "openid user user.birthday user.mii user.screenName",
+      "response_type": "session_token_code",
+      "session_token_code_challenge": authCodeChallenge,
+      "session_token_code_challenge_method": "S256",
+      "theme": "login_form",
+    };
+    const url = "https://accounts.nintendo.com/connect/1.0.0/authorize?" +
+      new URLSearchParams(body);
 
-  const res = await fetch.get(
-    {
-      url,
-      headers: {
-        "Host": "accounts.nintendo.com",
-        "Connection": "keep-alive",
-        "Cache-Control": "max-age=0",
-        "Upgrade-Insecure-Requests": "1",
-        "User-Agent": DEFAULT_APP_USER_AGENT,
-        "Accept":
-          "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8n",
-        "DNT": "1",
-        "Accept-Encoding": "gzip,deflate,br",
+    const res = await fetch.get(
+      {
+        url,
+        headers: {
+          "Host": "accounts.nintendo.com",
+          "Connection": "keep-alive",
+          "Cache-Control": "max-age=0",
+          "Upgrade-Insecure-Requests": "1",
+          "User-Agent": DEFAULT_APP_USER_AGENT,
+          "Accept":
+            "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8n",
+          "DNT": "1",
+          "Accept-Encoding": "gzip,deflate,br",
+        },
       },
-    },
-  );
+    );
 
-  const login = (await promptLogin(res.url)).trim();
+    return {
+      authCodeVerifier,
+      url: res.url,
+    };
+  } else {
+    const { login, authCodeVerifier } = step2;
+    const loginURL = new URL(login);
+    const params = new URLSearchParams(loginURL.hash.substring(1));
+    const sessionTokenCode = params.get("session_token_code");
+    if (!sessionTokenCode) {
+      throw new Error("No session token code provided");
+    }
+
+    const sessionToken = await getSessionToken({
+      fetch,
+      sessionTokenCode,
+      authCodeVerifier,
+    });
+    if (!sessionToken) {
+      throw new Error("No session token found");
+    }
+
+    return { sessionToken };
+  }
+}
+
+export async function loginManually(
+  env: Env,
+): Promise<string> {
+  const { prompts: { promptLogin } } = env;
+
+  const step1 = await loginSteps(env);
+
+  const { url, authCodeVerifier } = step1;
+
+  const login = (await promptLogin(url)).trim();
   if (!login) {
     throw new Error("No login URL provided");
   }
-  const loginURL = new URL(login);
-  const params = new URLSearchParams(loginURL.hash.substring(1));
-  const sessionTokenCode = params.get("session_token_code");
-  if (!sessionTokenCode) {
-    throw new Error("No session token code provided");
-  }
 
-  const sessionToken = await getSessionToken({
-    fetch,
-    sessionTokenCode,
-    authCodeVerifier,
-  });
-  if (!sessionToken) {
-    throw new Error("No session token found");
-  }
+  const step2 = await loginSteps(env, { authCodeVerifier, login });
 
-  return sessionToken;
+  return step2.sessionToken;
 }
 
 export async function getGToken(
diff --git a/src/ipc/channel.ts b/src/ipc/channel.ts
deleted file mode 100644
index a1eece1..0000000
--- a/src/ipc/channel.ts
+++ /dev/null
@@ -1,54 +0,0 @@
-/// <reference no-default-lib="true" />
-/// <reference lib="ESNext" />
-/// <reference lib="dom" />
-/// <reference lib="dom.iterable" />
-/// <reference lib="dom.asynciterable" />
-
-import type { ExtractType } from "./types.ts";
-
-export class WorkerChannel<T extends { type: string }> {
-  queue: T[] = [];
-  waiting: ((value: T) => void)[] = [];
-
-  constructor(private worker?: Worker) {
-    const callback = ({ data }: { data: unknown }) => {
-      const waiting = this.waiting.shift();
-      if (waiting) {
-        waiting(data as T);
-      } else {
-        this.queue.push(data as T);
-      }
-    };
-    if (worker) {
-      worker.addEventListener("message", callback);
-    } else {
-      self.addEventListener("message", callback);
-    }
-  }
-  async recvType<K extends T["type"]>(
-    type: K,
-  ): Promise<ExtractType<T, K>> {
-    const data = await this.recv();
-    if (data.type !== type) {
-      throw new Error(`Unexpected type: ${data.type}`);
-    }
-    return data as ExtractType<T, K>;
-  }
-  recv(): Promise<T> {
-    return new Promise<T>((resolve) => {
-      const data = this.queue.shift();
-      if (data) {
-        resolve(data);
-      } else {
-        this.waiting.push(resolve);
-      }
-    });
-  }
-  send(data: T) {
-    if (this.worker) {
-      this.worker.postMessage(data);
-    } else {
-      self.postMessage(data);
-    }
-  }
-}
diff --git a/src/ipc/mod.ts b/src/ipc/mod.ts
index 39d68ba..f0cfe10 100644
--- a/src/ipc/mod.ts
+++ b/src/ipc/mod.ts
@@ -1,2 +1 @@
 export { IPC } from "./stdio.ts";
-export { WorkerChannel } from "./channel.ts";
diff --git a/src/jsonrpc/channel.ts b/src/jsonrpc/channel.ts
new file mode 100644
index 0000000..d1ef783
--- /dev/null
+++ b/src/jsonrpc/channel.ts
@@ -0,0 +1,50 @@
+export class Queue<T> {
+  queue: T[] = [];
+  waiting: ((value: T | undefined) => void)[] = [];
+
+  pop = (): Promise<T | undefined> => {
+    return new Promise<T | undefined>((resolve) => {
+      const data = this.queue.shift();
+      if (data) {
+        resolve(data);
+      } else {
+        this.waiting.push(resolve);
+      }
+    });
+  };
+  // TODO: wait until the data is queued if queue has limit
+  push = (data: T): Promise<void> => {
+    const waiting = this.waiting.shift();
+    if (waiting) {
+      waiting(data);
+    } else {
+      this.queue.push(data);
+    }
+    return Promise.resolve();
+  };
+  close = (): Promise<void> => {
+    for (const resolve of this.waiting) {
+      resolve(undefined);
+    }
+    return Promise.resolve();
+  };
+}
+
+export function channel<T>() {
+  const q1 = new Queue<T>();
+  const q2 = new Queue<T>();
+  const close = async () => {
+    await q1.close();
+    await q2.close();
+  };
+
+  return [{
+    send: q1.push,
+    recv: q2.pop,
+    close,
+  }, {
+    send: q2.push,
+    recv: q1.pop,
+    close,
+  }] as const;
+}
diff --git a/src/jsonrpc/client.ts b/src/jsonrpc/client.ts
new file mode 100644
index 0000000..ccfe2ea
--- /dev/null
+++ b/src/jsonrpc/client.ts
@@ -0,0 +1,128 @@
+// deno-lint-ignore-file no-explicit-any
+import {
+  ID,
+  Request,
+  Response,
+  ResponseError,
+  RPCResult,
+  Service,
+  Transport,
+} from "./types.ts";
+
+export class JSONRPCClient<S extends Service> {
+  protected nextId = 1;
+  protected transport: Transport;
+  protected requestMap: Map<
+    ID,
+    (result: RPCResult<any, ResponseError>) => void
+  > = new Map();
+  protected fatal: unknown = undefined;
+  protected task: Promise<void>;
+
+  constructor(
+    { transport }: { transport: Transport },
+  ) {
+    this.transport = transport;
+    this.task = this.run();
+  }
+
+  protected setFatal(e: unknown) {
+    if (!this.fatal) {
+      this.fatal = e;
+    }
+  }
+
+  protected handleResponse(
+    resp: Response<unknown, ResponseError>,
+  ) {
+    const { id } = resp;
+    const callback = this.requestMap.get(id);
+    if (callback) {
+      this.requestMap.delete(id);
+      callback(resp);
+    } else {
+      this.setFatal(new Error("invalid response id: " + String(id)));
+    }
+  }
+
+  // receive response from server
+  protected async run() {
+    try {
+      while (true) {
+        const data = await this.transport.recv();
+        if (data === undefined) {
+          this.setFatal(new Error("transport closed"));
+          break;
+        }
+        const result = JSON.parse(data);
+        if (Array.isArray(result)) {
+          for (const resp of result) {
+            this.handleResponse(resp);
+          }
+        } else {
+          this.handleResponse(result);
+        }
+      }
+    } catch (e) {
+      this.setFatal(e);
+    }
+  }
+
+  makeRequest<
+    K extends keyof S & string,
+    P extends Parameters<S[K]>,
+  >(
+    method: K,
+    params: P,
+  ): Request<K, P> {
+    const req = {
+      jsonrpc: "2.0",
+      id: this.nextId,
+      method,
+      params,
+    } as const;
+    this.nextId += 1;
+    return req;
+  }
+
+  async call<
+    K extends keyof S & string,
+    P extends Parameters<S[K]>,
+    R extends ReturnType<S[K]>,
+  >(
+    method: K,
+    ...params: P
+  ): Promise<R> {
+    if (this.fatal) {
+      throw this.fatal;
+    }
+    const req = this.makeRequest(method, params);
+    await this.transport.send(JSON.stringify(req));
+
+    return new Promise<R>((res, rej) => {
+      this.requestMap.set(req.id, (result) => {
+        if (result.error) {
+          rej(result.error);
+        } else {
+          res(result.result);
+        }
+      });
+    });
+  }
+
+  getProxy(): S {
+    const proxy = new Proxy({}, {
+      get: (_, method: string) => {
+        return (...params: unknown[]) => {
+          return this.call(method, ...params as any);
+        };
+      },
+    });
+    return proxy as S;
+  }
+
+  async close() {
+    await this.transport.close();
+    await this.task;
+  }
+}
diff --git a/src/jsonrpc/deno.ts b/src/jsonrpc/deno.ts
new file mode 100644
index 0000000..d984990
--- /dev/null
+++ b/src/jsonrpc/deno.ts
@@ -0,0 +1,32 @@
+import { io, writeAll } from "../../deps.ts";
+import { Transport } from "./types.ts";
+
+export class DenoIO implements Transport {
+  lines: AsyncIterableIterator<string>;
+  writer: Deno.Writer & Deno.Closer;
+  constructor({ reader, writer }: {
+    reader: Deno.Reader;
+    writer: Deno.Writer & Deno.Closer;
+  }) {
+    this.lines = io.readLines(reader);
+    this.writer = writer;
+  }
+  async recv(): Promise<string | undefined> {
+    const result = await this.lines.next();
+
+    if (!result.done) {
+      return JSON.parse(result.value);
+    }
+
+    return undefined;
+  }
+  async send(data: string) {
+    await writeAll(
+      this.writer,
+      new TextEncoder().encode(data + "\n"),
+    );
+  }
+  async close() {
+    await this.writer.close();
+  }
+}
diff --git a/src/jsonrpc/jsonrpc.test.ts b/src/jsonrpc/jsonrpc.test.ts
new file mode 100644
index 0000000..b150b03
--- /dev/null
+++ b/src/jsonrpc/jsonrpc.test.ts
@@ -0,0 +1,43 @@
+import { channel } from "./channel.ts";
+import { JSONRPCClient } from "./client.ts";
+import { JSONRPCServer } from "./server.ts";
+import { RPCResult, Service } from "./types.ts";
+import { assertEquals } from "../../dev_deps.ts";
+
+export interface SimpleService {
+  add(a: number, b: number): Promise<
+    RPCResult<number>
+  >;
+  // deno-lint-ignore no-explicit-any
+  [key: string]: any;
+}
+
+class SimpleServiceImplement implements SimpleService, Service {
+  async add(a: number, b: number): Promise<RPCResult<number>> {
+    return {
+      result: a + b,
+    };
+  }
+  // deno-lint-ignore no-explicit-any
+  [key: string]: any;
+}
+
+Deno.test("jsonrpc", async () => {
+  const [c1, c2] = channel<string>();
+
+  const service = new SimpleServiceImplement();
+  const server = new JSONRPCServer({
+    transport: c1,
+    service,
+  });
+  const serverTask = server.serve().catch((e) => console.error(e));
+  const client = new JSONRPCClient<SimpleService>({
+    transport: c2,
+  });
+  const p = client.getProxy();
+  assertEquals((await p.add(1, 2)).result, 3);
+
+  await client.close();
+  await server.close();
+  await serverTask;
+});
diff --git a/src/jsonrpc/mod.ts b/src/jsonrpc/mod.ts
new file mode 100644
index 0000000..ccdf324
--- /dev/null
+++ b/src/jsonrpc/mod.ts
@@ -0,0 +1,2 @@
+export * from "./types.ts";
+export * from "./server.ts";
diff --git a/src/jsonrpc/server.ts b/src/jsonrpc/server.ts
new file mode 100644
index 0000000..efdca86
--- /dev/null
+++ b/src/jsonrpc/server.ts
@@ -0,0 +1,113 @@
+// deno-lint-ignore-file no-explicit-any
+import {
+  ERROR_INVALID_REQUEST,
+  ERROR_METHOD_NOT_FOUND,
+  ERROR_PARSEE_ERROR,
+  ID,
+  Request,
+  Response,
+  ResponseError,
+  Service,
+  Transport,
+} from "./types.ts";
+
+export class JSONRPCServer {
+  protected transport: Transport;
+  protected service: Service;
+  protected fatal = false;
+  protected task: Promise<void> = Promise.resolve();
+
+  constructor(
+    { transport, service }: { transport: Transport; service: Service },
+  ) {
+    this.transport = transport;
+    this.service = service;
+  }
+  async handleRequest(
+    req: Request<string, any>,
+  ): Promise<Response<any, ResponseError>> {
+    const { jsonrpc, id, method, params } = req;
+    const res = {
+      jsonrpc: "2.0",
+      id,
+    } as const;
+    if (jsonrpc !== "2.0") {
+      this.fatal = true;
+      return {
+        ...res,
+        error: ERROR_INVALID_REQUEST,
+      };
+    }
+
+    const func = this.service[method];
+    if (!func) {
+      return {
+        ...res,
+        error: ERROR_METHOD_NOT_FOUND,
+      };
+    }
+
+    const result = await func(...params);
+
+    return {
+      ...res,
+      result,
+    };
+  }
+  // `handle` will never throw error
+  async handle(
+    data: string,
+  ): Promise<Response<any, ResponseError> | Response<any, ResponseError>[]> {
+    let req: Request<string, any>;
+    try {
+      req = JSON.parse(data);
+    } catch (_) {
+      this.fatal = true;
+      return {
+        jsonrpc: "2.0",
+        id: null,
+        error: ERROR_PARSEE_ERROR,
+      };
+    }
+
+    const internalError: (id: ID) => (
+      e: unknown,
+    ) => Response<any, ResponseError<32000, unknown>> = (id) =>
+    (
+      e,
+    ) => ({
+      jsonrpc: "2.0",
+      id: id,
+      error: {
+        code: 32000,
+        message: "Internal error",
+        data: e,
+      },
+    });
+
+    // batch request
+    if (Array.isArray(req)) {
+      return await Promise.all(
+        req.map((req) => this.handleRequest(req).catch(internalError(req.id))),
+      );
+    } else {
+      return await this.handleRequest(req).catch(internalError(req.id));
+    }
+  }
+  async serve() {
+    while (!this.fatal) {
+      const data = await this.transport.recv();
+      if (data === undefined) {
+        break;
+      }
+      this.handle(data).then((result) =>
+        this.transport.send(JSON.stringify(result))
+      ).catch((e) => {
+        console.error("Failed to handle request", e);
+      });
+    }
+  }
+  async close() {
+    await this.transport.close();
+  }
+}
diff --git a/src/jsonrpc/types.ts b/src/jsonrpc/types.ts
new file mode 100644
index 0000000..b8b58c9
--- /dev/null
+++ b/src/jsonrpc/types.ts
@@ -0,0 +1,66 @@
+export type ID = string | number | null;
+
+// deno-lint-ignore no-explicit-any
+export type ResponseError<Code extends number = number, Data = any> = {
+  code: Code;
+  message: string;
+  data?: Data;
+};
+
+export type Request<Method extends string, Params> = {
+  jsonrpc: "2.0";
+  method: Method;
+  params: Params;
+  id: ID;
+};
+
+export type Notification<Method extends string, Params> = {
+  jsonrpc: "2.0";
+  method: Method;
+  params: Params;
+};
+
+// deno-lint-ignore no-explicit-any
+export type Response<Result, Error extends ResponseError<number, any>> = {
+  jsonrpc: "2.0";
+  id: ID;
+} & RPCResult<Result, Error>;
+
+export type Transport = {
+  send: (data: string) => Promise<void>;
+  recv: () => Promise<string | undefined>;
+  close: () => Promise<void>;
+};
+
+export type RPCResult<Result, Error extends ResponseError = ResponseError> = {
+  result?: Result;
+  error?: Error;
+};
+
+export type Service = {
+  [P in string]: (
+    // deno-lint-ignore no-explicit-any
+    ...args: any[]
+  ) => Promise<RPCResult<unknown, ResponseError>>;
+};
+
+export const ERROR_PARSEE_ERROR: ResponseError<-32700> = {
+  code: -32700,
+  message: "Parse error",
+};
+export const ERROR_INVALID_REQUEST: ResponseError<-32600> = {
+  code: -32600,
+  message: "Invalid Request",
+};
+export const ERROR_METHOD_NOT_FOUND: ResponseError<-32601> = {
+  code: -32601,
+  message: "Method not found",
+};
+export const ERROR_INVALID_PARAMS: ResponseError<-32602> = {
+  code: -32602,
+  message: "Invalid params",
+};
+export const ERROR_INTERNAL_ERROR: ResponseError<-32603> = {
+  code: -32603,
+  message: "Internal error",
+};