ChatGPT - Firmable

Add Firmable to ChatGPT so it can query Firmable data inside your conversations. Firmable is a verified ChatGPT app (ChatGPT calls these apps and plugins interchangeably), so the quickest way is to add it straight from the in-app store — no Client ID or developer setup required.

Add from the ChatGPT store

Find Firmable

In ChatGPT, open Apps (also labelled Plugins) from the sidebar (under More if it’s not pinned), or go directly to chatgpt.com/plugins?q=firmable. Search for firmable, then click Firmable to open it.

ChatGPT Plugins page with 'firmable' searched, showing the Firmable app with an add button

Install the plugin

On the Firmable page, click Install plugin.

Firmable plugin page in ChatGPT with the Install plugin button

In the Add Firmable to ChatGPT dialog, click Sign in with Firmable.

Add Firmable to ChatGPT dialog with the Sign in with Firmable button and data-sharing notice

Follow the prompts to finish

Follow the remaining prompts and click Allow to authorize access. Once connected, enable Firmable from the + → More menu in a chat to start using it.

Add manually (custom connector)

Only needed if the Firmable app isn’t available in your ChatGPT plan. You’ll need the MCP URL and Client ID — see URL & Client ID.

Open Settings

In ChatGPT, click your profile at the bottom of the sidebar and choose Settings.

Open Apps → Advanced settings

Go to the Apps tab, then click Advanced settings.

ChatGPT Settings Apps tab with the Advanced settings row

Enable Developer mode and create an app

Turn on Developer mode (this is what lets you add an unverified custom connector), then click Create app.

ChatGPT Advanced settings with Developer mode enabled and the Create app button

Enter the Firmable MCP details

Fill in the New App form:

Name: anything you like — this guide uses Firmable
Description (optional): e.g. Firmable MCP connector
Connection: keep Server URL selected and enter the MCP URL (from URL & Client ID)
Authentication: OAuth

ChatGPT New App form with name, description, server URL, OAuth, and the risk acknowledgment checkbox

Configure OAuth and create

Expand Advanced OAuth settings and set the Registration method to User-Defined OAuth Client — this lets you use the Firmable credentials. Enter the Client ID (from URL & Client ID; leave the secret blank unless Firmable gives you one). If Firmable asks for a redirect/callback URL, copy the Callback URL shown here.Finally, tick I understand and want to continue to acknowledge that custom MCP servers aren’t reviewed by OpenAI, then click Create.