JK

A local coding bridge that lets ChatGPT read, modify, test, and run Git operations on projects on my PC.

English | Korean

JK is an unofficial project, not an official OpenAI product. It is a modified fork based on ezBuilder/chatgpt2codex. First check the license/redistribution terms of the original code in Attribution & Compliance.

First, Know This

JK is not a second AI.

나
→ ChatGPT
→ JK
→ 내 PC의 프로젝트 / 터미널 / Git / 테스트

ChatGPT makes the decisions, and JK does the actual work on my PC.

Instead of the old term "ChatGPT plugin", it now connects in one of the following two ways:

1. Recommended for personal Plus users: Custom GPT + Actions

2. Supported Business / Enterprise / Edu environments: ChatGPT Apps + MCP

Both can authenticate ownership using JK's Owner Token.

1. Installation

Prerequisites

• Windows 10/11 recommended

• Git

• Node.js 22 or later

• npm

• ChatGPT account

• One personal domain (e.g., example.com — used to create an HTTPS address that ChatGPT web can use to reach JK)

Installation:

git clone https://github.com/Anjingyeong/jk-mcp.git
cd jk-mcp
npm ci
npm run build

Running

Windows:

npm run chatgpt:windows

macOS / Linux:

npm run chatgpt

If the first run succeeds, you should see information roughly like the following:

JK is ready
MCP URL: http://127.0.0.1:7979/mcp
Dashboard: http://127.0.0.1:7979/

You can also open the following address in your browser:

http://127.0.0.1:7979/

2. Saving the Owner Token

On first run, JK automatically creates an Owner Token and shows it in the terminal only once.

chatgpt2codex init: generated a new HTTP owner token (shown once, never logged again)

Keep this token like a password.

• Don't upload it to GitHub.

• Don't expose it in screenshots.

• Don't share it with anyone else.

• Store it in a password manager if possible.

If you lose the token, you can issue a new one.

node dist/cli.js owner-token --generate

Creating a new token may require existing OAuth connections to be re-authenticated.

This is not the old JK personal desktop version where you retrieved the token from a GUI. In the current public jk-mcp, the first-run CLI/launcher issues the token.

3. Connecting to ChatGPT

Important requirement: You need an HTTPS address accessible from the internet

The installation guide for acquaintances treats a single personal domain as a required prerequisite. For example, if you have example.com, use a subdomain like jk.example.com for JK connections. JK does not purchase domains or configure DNS/HTTPS for you.

Technically, you could also use another public HTTPS hostname you manage, but the deployment steps in this README assume you use a domain you own.

By default, JK runs only on the following local address:

http://127.0.0.1:7979

Since ChatGPT web cannot connect directly to your 127.0.0.1, a real ChatGPT connection needs an address like the one below:

https://내가-관리하는-주소.example.com

The public version of JK does not automatically create any specific tunnel, DNS, or cloud service. You need to prepare an HTTPS reverse proxy or tunnel separately.

Once the external address is ready, give JK the hostname when you run it.

powershell.exe -NoProfile -ExecutionPolicy Bypass -File .\start-chatgpt.ps1 `
  -Workspace "C:\workspace" `
  -PublicHostname "jk.example.com"

Then the main URLs become as follows:

MCP:     https://jk.example.com/mcp
Actions: https://jk.example.com/actions/openapi.json

4-A. ChatGPT Plus: Connecting with Custom GPT Actions

For personal Plus users, this is the simplest method.

1. In ChatGPT, go to Create a GPT.

2. In the new GPT's Actions, select Create new action.

3. In Schema, load the OpenAPI from the address below.

https://jk.example.com/actions/openapi.json

4. Set Authentication to API Key → Bearer.

5. Enter the Owner Token you received on JK's first run as the API Key value.

6. In Preview, test action_health or a simple project lookup.

The JK Actions server accepts both of the following authentication methods:

• Owner Token used directly as a Bearer token

• JK OAuth access token used

For a personal installation for acquaintances, the Bearer Owner Token method requires the least configuration.

Prompt to check the connection

JK로 현재 등록된 프로젝트 목록 보여줘.

Or:

JK로 이 프로젝트 구조만 확인해줘. 파일은 수정하지 마.

When connected successfully, ChatGPT calls the JK Action and retrieves local project information.

4-B. Connecting with ChatGPT Apps / MCP

This can be used if your ChatGPT account/workspace supports custom MCP apps and the required write actions.

1. Enable Developer Mode in ChatGPT.

2. Create a custom app in Apps.

3. Enter the address below as the MCP endpoint.

https://jk.example.com/mcp

4. Proceed with OAuth authentication.

5. When the JK approval page opens, enter your Owner Token.

6. After approval, Scan/Connect the JK tools.

On JK's OAuth approval screen, the Owner Token is verified locally as a hash and is not stored in plain text.

The feature scope and plan support for ChatGPT Apps/MCP may change. If you don't see these options in the current product UI, try the Custom GPT Actions method first.

5. Usage

After the connection is set up, you don't need to memorize JK's internal tool names.

Just say what you want in natural language.

@JK 이 프로젝트 구조 설명해줘. 수정은 하지 마.

@JK 이 오류 원인 찾아서 수정하고 관련 테스트까지 돌려줘.

@JK 지금 diff 리뷰하고 문제 없으면 커밋해줘.

@JK e2e 테스트하고 화면 확인해줘.

For long tasks, including the following four items together makes them more reliable.

프로젝트 + 목표 + 제약 + 완료 조건

Example:

@JK paba 프로젝트에서 급여명세서 출력 오류를 고쳐줘.
기존 DB 구조는 가능한 건드리지 말고,
관련 테스트와 build가 통과하면 끝내줘.

6. Safety Features

JK is not a tool that gives ChatGPT unlimited access to your entire PC.

• Access centered on the selected workspace/project scope

• Hash-based conflict protection when modifying existing files

• Secret value redaction

• Safety gates on sensitive shell/network/destructive commands

• commit/push requires your explicit intent

• Stores work sessions and recent verification results

Even so, anyone with the Owner Token can access JK, so you must keep the token secret.

7. Troubleshooting

JK Won't Start

npm ci
npm run build
npm run chatgpt:windows

Lost Owner Token

node dist/cli.js owner-token --generate

ChatGPT Can't Connect to JK

First check locally:

http://127.0.0.1:7979/

If the local side is fine but ChatGPT still won't connect, the issue is usually with the external HTTPS endpoint / reverse proxy / tunnel.

Check the Actions Schema

https://내주소/actions/openapi.json

MCP Endpoint

https://내주소/mcp

Further Documentation

• Installation guide

• Usage guide

• Execution/Permission Policy

• Local override settings

• Attribution & Compliance

Attribution

JK is an independent, unofficial fork based on ezBuilder/chatgpt2codex.

OpenAI, ChatGPT, GPT, and Codex are trademarks of their respective owners. JK is not an official OpenAI product, official plugin, or official partner project.