How to Humanize AI Text Inside ChatGPT (Developer Mode Connector)

ChatGPT drafts beautifully and humanizes nothing. So the usual routine is: generate in ChatGPT, copy out, humanize elsewhere, paste back. Adding SupWriter as a connector collapses that into a single conversation: ChatGPT calls our humanizer, paraphraser, grammar checker, and AI detector as tools, with your permission, without leaving the chat.

ChatGPT is a little different from Claude here: custom MCP connectors live behind Developer mode, and they need a paid plan. Here's the flow, based on OpenAI's developer mode guide as of September 2026. OpenAI renames these menus fairly often, so if a label doesn't match, that guide has the current path.

Before you start

Use ChatGPT on the web (chatgpt.com). Custom connectors can't be added from the mobile apps.
You need a paid plan: Plus, Pro, Business, Enterprise, or Edu. Developer mode isn't available on the Free plan.
On Business, Enterprise, and Edu workspaces, admins and owners control developer mode and custom apps (OpenAI Help Center). If you don't see it, ask your admin.

The 60-second version

Settings → Security and login → turn on Developer mode → open Plugins and click + to create an app with URL https://supwriter.com/api/mcp and OAuth auth → sign in to SupWriter → in a chat, pick Developer mode from the + menu and select SupWriter. Then ask ChatGPT to humanize anything.

Step 1: Turn on Developer mode

Click your profile picture → Settings → Security and login, and toggle Developer mode on. Read any warning ChatGPT shows you: custom apps run third-party tools on your behalf, so only add servers you trust.

(Older builds put this toggle under Apps & Connectors → Advanced settings. It's the same switch.)

Step 2: Create the SupWriter connector

Open Plugins (some builds call this section Apps) and click + to create a developer-mode app for a remote MCP server. Fill in:

Name — SupWriter
Description (optional) — "Humanize, paraphrase, grammar-check, and AI-detect text."
MCP Server URL — paste:

https://supwriter.com/api/mcp

Authentication — choose OAuth.

Confirm that you trust the app if ChatGPT asks, then click Create. The new app appears under Drafts in your app settings, where you can see its tools.

ChatGPT connects to SupWriter over OAuth, not an API key — there's no field to paste a token. That's fine: SupWriter registers ChatGPT automatically, so you don't copy any client ID or secret.

Step 3: Sign in and approve

A SupWriter window opens. Log in with your SupWriter account if you aren't already, then review the consent screen. It lists exactly what's being granted: humanize, paraphrase, grammar-check, and AI detection. Approve, and the connector is linked. (If a window doesn't appear, allow pop-ups for chatgpt.com.)

Step 4: Enable it for the chat and make your first call

In the message composer, open the + menu, choose Developer mode, and select SupWriter. Then ask:

"Humanize the draft above with a professional tone."
"Paraphrase this in academic mode."
"Run SupWriter's AI detector on this text and show me the flagged sentences."

By default, ChatGPT asks you to confirm a tool call before it runs, then drops the result back into the thread. You can save your choice for a tool within a conversation; a new conversation asks again. Every call uses your SupWriter word credits, including AI detection, which costs 1 credit per word over MCP.

Troubleshooting

The connector doesn't appear in a chat. Make sure Developer mode is on and that SupWriter is selected in that conversation. If a follow-up message doesn't call SupWriter, select it (or @mention it) again for that message.
You don't see Developer mode at all. It needs a paid plan and the web app; on Business, Enterprise, or Edu, your admin controls it.
You get asked to reconnect. OAuth tokens are short-lived; just re-approve. Your SupWriter account stays linked.
INSUFFICIENT_CREDITS / PLAN_LIMIT. You're out of word credits, or the text exceeds your plan's per-request cap (500 free/basic, 2,000 Pro, 5,000 Ultra). Trim the text or top up.
LANGUAGE_NOT_AVAILABLE. The language you asked for isn't enabled for your account, and the error message says why. English works on every plan.