ChatGPT Wants to Be Where Your Customers Do Business. DevDay 2026 Just Showed How.

On 29 September, OpenAI held its DevDay 2026 developer conference, and the through-line was hard to miss: ChatGPT is no longer positioning itself as a chatbot your customers occasionally consult. It is positioning itself as a place where they sign in, use software and get work done — with other companies' products living inside it.

For business owners and product leaders, that framing matters more than any single feature. The last time a platform made this move — the smartphone app store — the companies that showed up early with something useful got a decade of distribution out of it.

What was announced, in business terms

The detail below comes from OpenAI's own DevDay round-up.

Plugins got a real interface. Plugin extensions now support sidebar entries, interactive panels and file viewers inside ChatGPT. Translation: a third-party product inside ChatGPT no longer has to behave like a text conversation. It can look and work like a focused version of your app.

Sign in with ChatGPT launched with 16 partners. ChatGPT accounts can now authenticate users into external products, with eligible subscription usage carried through those partners. This is the clearest platform-brick of the lot. "Sign in with Google" turned Google accounts into infrastructure across the web; OpenAI is making the same play with identity — and bundling usage entitlements with it.

An Agents API in public beta, with hosted execution, memory, tools, multi-agent support and — notably — computer use, which lets an agent operate software through its interface the way a person would.

Collaboration surfaces and an enterprise marketplace, plus "Dots", persistent agents with connected apps, which rolled out to higher tiers in eligible markets only — a reminder that regional availability still fragments these platforms.

Why this matters even if you will never build a plugin

Strip away the developer vocabulary and three shifts remain.

Distribution is moving inside the conversation. A meaningful share of product discovery already happens in AI assistants — it is why we have written about getting your brand cited by AI. DevDay extends that from being mentioned in ChatGPT to being usable in it. For a service business, that could mean a booking or quoting flow where the customer already is, rather than hoping they click through to your website.

Identity and trust are being intermediated. If Sign in with ChatGPT spreads the way social logins did, the assistant sits between you and your customer at the account level, not just the answer level. Convenient for users, strategically double-edged for brands: lower sign-up friction, less direct relationship.

Agents will use software nobody designed for them. Computer use means agents operating normal interfaces — including, eventually, your website's forms, logins and checkouts. Whether those flows are legible to an agent — clear labels, sane error states, structured data, no dark patterns — is quietly becoming a revenue question rather than a code-quality one.

What to do this quarter

Decide whether you are a candidate for the surface. Products with a clear, repeatable job — booking, quoting, tracking, configuring, reporting — map well to a plugin or agent experience. Brand-only businesses probably gain more right now from being reliably citable than from building inside ChatGPT.

Run the agent test on your own site. Can a capable agent complete your most valuable journey — enquiry form, lead magnet, checkout — without human rescue? Ambiguous field labels, CAPTCHA walls on everything, and error messages that only make sense visually are the new broken links. Fixing them helps human accessibility too, which is rarely a coincidence.

Treat it as a channel experiment, not a replatform. Platform risk is real: policies, marketplace rankings and revenue-share terms will all move, and regional exclusions show availability is not uniform. The sensible posture for most businesses is a small, genuinely useful integration plus a website that remains the system of record — not a bet of the whole funnel on someone else's surface.

Keep measurement honest. If customers start arriving via assistant surfaces, last-click analytics will undercount them. Decide now which events you will log from any integration, and benchmark your direct traffic before the channel muddies it.

The uncomfortable question for your roadmap

Every platform shift reallocates margin toward whoever owns the customer interface. The web rewarded companies with good websites; mobile rewarded companies with good apps; this one will reward companies whose services are invocable — easy for an assistant to call on a customer's behalf, with clean APIs, clear permissions and trustworthy data.

That is less about chasing each DevDay headline and more about engineering hygiene: structured data, documented APIs, accessible interfaces, and a product that does one job well enough to be worth invoking. Companies with those foundations can show up on any new surface in weeks. Companies without them will be rebuilding basics while competitors take the shelf space.