Gems refine Google's AI approach. Gemini's customizable Gems expand possibilities but require a subscription for access.
Just about everyone who enjoys candy has a favorite candy. Candy was invented as a treat, a mini serving of chocolate, bubble gum, or favored lollypop given out every Halloween.
AI practitioners are developing a taste for "AI candy" -- the appearance of AI agents within the main AI solutions like ChatGPT or Google Gemini.
The popularity of AI has made extensions to ChatGPT, Claude, Gemini and other solutions also popular. The most notable arrival is the increasing usage of customized agents. OpenAI launched CustomGPTs last fall for all users, and with creator access for ChatGPT Plus and Enterprise users. Google also introduced Gems, a similar customized agent for its Gemini AI solution.
Marketers who have customers using ChatGPT or Gemini extensively should look at custom agents as a way to serve those customers better. These agents are viable AI options for choosing search engines, social media, office software or any other digital solution.
CustomGPTs and Gemini Gems are user-created agents that provide reasoning guidance within a given AI. These agents operate from a subset of prompt instructions. Sometimes the agents can be enhanced with supporting documents that contain additional data for the agent. The user creates a prompt that provides query details, including role-playing for the AI, and chain of thought descriptions that outline how agents process new information.
All of this allows a custom agent to provide users with a consistent agent output that makes query responses more accurate and useful. Custom agents narrow the task focus so that ChatGPT users gain a more personalized experience.
The idea of CustomGPTs was launched when OpenAI launched the GPT Builder, and then later the GPT Store, to feature CustomGPTs available to the ChatGPT users. I explained how to set up a CustomGPT in 2023.
The GPT Builder provides a set of pre-formed prompt details, letting ChatGPT users create agents that offer automated service when ChatGPT completes a task. With a CustomGPT, users are essentially getting a ChatGPT within ChatGPT.
The creation process remains the same for 2025. The major difference is the variety of CustomGPTs that have formed a marketplace. When CustomGPT was introduced, brands leapt at the chance to create a CustomGPT, similar to how apps were adopted for discovery in the Apple App or Google Play stores.
The purpose behind brands launching CustomGPTs is to let users determine their own micro use cases. AI that solves a very specific problem, instead of a wide range of problems seen in the main UI. The biggest challenge for OpenAI is encouraging people to use CustomGPTs to determine the best where to start.
Users can also define custom actions by making one or more APIs available to the GPT. Custom actions allow GPTs to integrate external data or interact with features with real-world influences. This means users can incorporate access to databases and then use the stored data for delivering assistant responses. For example, you could integrate a travel listings database to offer up-to-date reservation information in a CustomGPT that facilitates travel information for customers seeking nearby vacation spots.
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As expected, ChatGPT's fiercest competitor, Google, has begun to offer its version of a CustomGPT for its ChatGPT competitor, Gemini. These mini-agents are called Gemini Gems. Gemini Gems are designed to enhance responses on Gemini with additional information.
Gemini Advanced users have access to Premade Gems, Gems in which parameters are preset for different scenarios. Five premade Gems consist of the following:
The Gems are activated in the Gem manager, which appears in the lower left. Once activated, the Gem operates when the user accesses the standard Gemini chat interface. The listed chat that is saved in Gemini "memory" has an indicator of the color of each Premade Gem used.
This year Google introduced Customize Gems, a modification feature similar to that of CustomGPTs, as an exclusive to Gemini Advanced subscribers. The agentic role of Customized Gems is up to the user. They can act as an expert on topics or refine them toward your specific goals.
Users simply write instructions for a given Gem. The Gem manager operates in the same spirit as the GPT builder: to provide prompt engineering for the Gem. The most common purpose is to explain a role and associated chain of thought. The user can also upload documents to complement the instructions. A preview panel allows users to test the output and refine the Gem further.
Both CustomGPT and Gems have significant value for brands and independent developers who are discovering ideas to augment their online experiences. Agent customization is a strong play for marketers who need to augment a customer experience while the customer is using an AI solution. A good agent can be a calling card to remind the customer who brought meaningful assistance.
So which is best? The answer lies partly in what budget you have - Gems can only be searched, accessed and created by Gemini Advanced users, which is a paid account.
In contrast, ChatGPT allows users of any tier to search for a CustomGPT and use it. For creating CustomGPT, however, you must have a Plus account, which is a paid tier. All of this means you must have a subscription account to use Gems, while ChatGPT lets free accounts access CustomGPTs. A subscription is not a heavy cost, but for simply exploring the CustomGPT, free access can reduce the exploration cost a little.
The subscription cost difference is small, but it plays into the other part -- how marketers spot opportunities where mini agents can assist. Having free access alongside ChatGPT gives its ecosystems an advantage.
Users of the free tier and ChatGPT Plus subscribers can search for a CustomGPT using the GPT store. This lets ChatGPT users regardless of account find a CustomGPT for a specific purpose in categories like productivity, education, and entertainment. This can be a significant play for marketers planning on a shoestring budget. More CustomGPTs means more use case examples that highlight customer experience opportunities.
Do not count out Gems entirely, because Gemini can also provide a similar purpose. But Gem is just developing its ecosystem now, so we should see how that marketplace plays out in the year ahead.
All of these features prove that pragmatic use cases beyond wizardry exist for AI agents. Every company with a software solution has been racing to add AI to their list of features. Exploring the variety of CustomGPTs and the rising number of Gems can reveal some of the most interesting AI use cases that can well elevate the online customer experience.