OpenAI DevDay 2026: What Marketers Can Actually Use?

OpenAI DevDay 2026 delivered more than 20 announcements, and one fairly dangerous temptation: turning every new feature into a commercial promise before checking whether we can actually use it. For marketing and ecommerce, it’s time to separate real capabilities from glitter. The volume of announcements hardly matters.

TL;DR: The no-nonsense summary

• Decisions API: classifies inputs and selects actions within defined categories, but remains in limited preview.
• Agents API: arrives in public beta with browsing, tools and computer use; tokens and tools are still billed.
• Plugins and automations: gain new surfaces and events, though restrictions vary by plan, client and chat type.
• Payments: redirecting users to a store is available for approved plugins, but integrated checkout remains in private beta.

Verdict: there is serious material to test, but not yet a revolution you can sell as available in Spain.

OpenAI DevDay 2026 is the event where OpenAI unveiled updates for ChatGPT, Codex, models and AI development. The official recap, published on September 29, 2026, brings together more than 20 announcements.

What does the Decisions API bring to marketing?

Decisions API lets you send text or images and receive a response within finite categories defined by the developer. It can be used to classify content, route requests or choose an agent’s next action.

In marketing terms, it could sort sales leads, review product listings, classify comments or decide which support workflow should continue. The important word is “could”. OpenAI places it in limited preview and says access will expand in the following days, not that it is generally available.

One rather unsexy piece is still missing, but we cannot skip it: pricing. The recap does not publish a standalone rate for Decisions API or make it possible to calculate the cost of a complete workflow involving models, tokens and tools.

The trap is confusing classification with business judgement. An API putting an enquiry in the “angry customer” box does not mean it understands margin, customer history or the reputational cost of getting the response wrong. Automating without a human review path is buying yourself a headache with a very pretty interface.

Agents API: AI agents with browsing and tools

Agents API has launched in public beta for all developers, bringing together tool execution, search, context compaction, long-running sessions and multi-agent capabilities. It has no additional standalone fee, although used tokens and tools are billed.

Its computer use feature operates in an OpenAI-hosted browser. According to the official Agents API introduction, it can browse websites, gather information and operate applications through their interface. It is still in beta: general availability will come later.

For ecommerce, it opens up interesting use cases: checking product pages, walking through checkout processes, spotting inconsistent information or collecting issues from a store. For marketing, it can help with operational checks and repetitive tasks. It does not turn a mediocre campaign into a good one by magic. That still requires someone with judgement.

If you want to dig into costs and limits, we have already analysed Agents API for marketing. Read the fine print before building a demo and calling it an “autonomous system”.

What changes with plugins and MCP Events?

Plugin extensions can create sidebar entry points, interactive panels and file viewers within ChatGPT. The announcement says they are available across all plans, but the extensions documentation adds caveats: some web surfaces for Free and Go are listed as coming soon, while composer mentions are limited to desktop.

MCP Events lets ChatGPT subscribe to events from connected services and run instructions when an update arrives. It could flag an inventory break, process a status change or trigger a review. It is currently limited to certain Work and Dots chat surfaces and uses a specification still in draft, according to the official MCP Events documentation.

This fits with the rise of ChatGPT Dots and their limits in Spain, but it does not authorise anyone to promise universal automations. “Available on one plan” and “available across every surface” are very different things. It seems obvious. Then the sales slide arrives and everyone forgets.

OpenAI DevDay 2026 and ecommerce payments

The prudent option for selling through plugins remains sending the user to the store’s external checkout page. That is the generally available approach for approved plugins, whose commercial acceptance is currently limited to physical goods.

The integrated checkout sheet in ChatGPT remains in private beta for selected marketplaces. The monetisation and payments documentation does not identify participating Spanish or European merchants, nor does it offer a date for general availability.

There is another limit marketing should tattoo on itself: published plugins cannot serve ads or exist primarily as advertising vehicles. Their value must come from genuine utility, content, service or commerce. Stuffing in a catalogue on steroids and calling it a conversational experience will not cut it.

Is OpenAI DevDay 2026 available in Spain?

There is no blanket confirmation for Spain or the European Union as a whole. Spain appears on the OpenAI API supported countries list, but that does not prove every preview, plugin, plan or feature is enabled for Spanish accounts.

You need to check it feature by feature. Decisions API is in limited preview. Agents API is in public beta. Extensions and MCP Events depend on the plan and surface. Integrated checkout remains in private beta.

My take on OpenAI DevDay 2026 is simple: it is worth designing small, measurable and reversible tests. What is not worth doing is selling a European automation today based on access that nobody has confirmed. Check the door first. Then build the shopping centre.