Move a Custom GPT to Chat Thing

Rebuild an OpenAI Custom GPT as a Chat Thing bot, so the people who used it can keep using it after Custom GPTs retire.

If your GPT was only for you, OpenAI's own migration to a ChatGPT plugin may suit you better. This guide is for GPTs that other people use: customers, clients, students or your team.

How a GPT maps to a bot

Image generation and code or data analysis have no equivalent in Chat Thing. If your GPT depends on them, keep that part of the work in ChatGPT.

Before you start

• A Chat Thing account. Sign up for free.
• Who can do this: team owners and admins.
• Access to your GPT's editor in ChatGPT, where its Configure tab shows the instructions, conversation starters, knowledge and actions.
• The original copies of the knowledge files you uploaded to the GPT.

Steps

1. Copy everything out of your GPT

1. In ChatGPT, open your GPT's Configure tab.
2. Copy the Name, Description, Instructions and Conversation starters into a document.
3. List the knowledge files and find your original copies of them.
4. If the GPT has actions, note what each one does and copy its schema and authentication details.

2. Create the bot

New bot opens Chat Thing's setup assistant, which can do most of the move in one conversation. Use it unless you want your instructions copied across word for word, in which case set the bot up yourself.

With the setup assistant

1. In Chat Thing, go to My Bots and click New bot. Set up your agent with AI opens.
2. Tell the assistant you're moving a Custom GPT. Paste the GPT's description, instructions and conversation starters, and ask it to use the instructions as the bot's prompt and the starters as its example questions.
3. Drag the GPT's knowledge files onto the chat, or click the paperclip by the message box. The assistant takes PDF, Word (.docx), CSV, Markdown and text files.
4. If your GPT answered questions about your website or business, give the assistant your website address too, so it can add your pages as knowledge.
5. Try the bot in the Live preview, then click Open dashboard.
6. In General settings, check the Prompt and Example questions. The assistant may adapt your instructions to fit the bot it built, so edit anything you want back as it was.

Set it up yourself

1. In Chat Thing, go to My Bots and click New bot, then click Set up manually.
2. In General settings, enter the GPT's name as the Bot name.
3. Write a Welcome message, the first thing the bot says.
4. Paste the GPT's conversation starters into Example questions.
5. Paste the GPT's instructions into Prompt. Remove any lines about features Chat Thing doesn't have, such as image generation.
6. Click Next: Add data source, then click Skip: I don’t need a data source. You'll add the knowledge files in the next step.

See Write your bot's instructions to tune the prompt once the bot is working.

3. Add the knowledge files

If you dropped all your files into the setup assistant, skip this step. Otherwise, or for file types the assistant doesn't take:

1. Open your bot, go to the Data sources tab and click New data source.
2. Choose Upload files and click Create data source.
3. On the Content tab, click Upload files and add the GPT's knowledge files. One data source can hold all of them.
4. Click Synchronise and wait until each file's Status shows Finished.

PDFs, Word, CSV, Markdown, text, HTML and JSON files are supported here. See Upload files for the full list. If the files came from your website, add the website instead so the bot stays up to date when your pages change.

4. Choose a model

On Standard and above, open General settings, scroll to Model settings (advanced) and pick a Model. Your GPT's model setting doesn't come across, so start with a capable model and compare answers in step 6. See Choose your bot's AI model.

5. Rebuild actions as power-ups

1. Open your bot, go to the Power-ups tab and click New power-up.
2. Choose the power-up that matches the action:
   • API request to call an HTTP API, such as looking up an order. See Call your API from your bot.
   • MCP server if the service publishes an MCP server. See Give your bot tools from an MCP server.
   • A ready-made power-up for common jobs, such as booking meetings, sending email or handing off to a human.
3. Write a clear Description so the bot knows when to use it, and click Save.

6. Test against your GPT

Ask the GPT and your bot the same 10 to 20 real questions and compare the answers. If an answer is weaker, adjust the prompt, add missing knowledge or try another model. Test cases let you rerun the same questions after every change.

7. Share the bot and update your links

1. Choose how people will reach the bot:
   • Bot page link: click Open bot on your bot's dashboard and copy the address. Use it anywhere you shared the GPT link: emails, documents, newsletters and QR codes.
   • Website widget or inline embed: see Add the chat widget to your website.
   • WhatsApp, Slack and other channels (Standard and up): see Channels.
2. To limit the bot to certain people, turn on Require a password. See Control who can use your web chat.
3. Replace the old GPT link everywhere you published it, and tell your users where to find the bot.

Check it works

1. Open the bot page link in a private or incognito window. The bot loads without asking you to sign in (or asks for the password, if you set one).
2. Click one of the Example questions and check the answer uses your knowledge files.
3. Ask something that should trigger each power-up and check it runs.
4. Open Conversations and check your test chats appear.

Troubleshooting

I don't have my GPT's knowledge files any more

The Configure tab lists the files' names. Export the same content again from where it came from, or, if it was published on your website, add the website as a data source instead.

My bot answers differently from my GPT

Your GPT ran on a different model with its own defaults. Try a more capable model, make the prompt more explicit about tone and format, and check the answer came from your files. See Improve your bot's answers.

My GPT used an action that needs each user to sign in

Power-ups call services with the access you set up, not each visitor's own account. For per-user data, pass the visitor's details from your site with the JavaScript SDK and look them up in your API.