AI-Native or Dead | Elacity Labs
Karpathy spent an hour reverse-engineering the Woodway treadmill's API to get one number. By 2028, every product without an AI-native surface will be invisible to the agent buying on behalf of the customer. MCP, A2A, x402 — and the 24-month window every business has to ship.
AI-Native or Dead: Why Every API Will Be Rewritten for Agents by 2028
Karpathy spent an hour debugging the Woodway treadmill's cloud API to get one number out of it. Heart rate. Time on belt. Elevation. The API existed. It was online. It had documentation. It was almost unusable.
That story is now playing out in every product category at once. The age of the developer portal is ending. The age of the agent-discoverable surface is starting. Any business that does not show up on the second side of that line will be invisible to the agent buying on behalf of the customer.
Two Kinds of Discoverable
For thirty years, "discoverable" meant human-discoverable. You got listed on search. You wrote docs. You explained your auth flow. You answered support tickets. Some humans found your API and integrated it. Most did not.
The agent does not care about your blog post. It will not find you in search results. It will not parse your hand-written reference manual. It will not click through your OAuth screen. The agent is looking for one thing: a self-describing, machine-readable schema that says what you can do, what it costs, and how to call it.
If you ship that, you exist. If you do not, you do not.
The Three Protocols That Make It Possible
Three open standards landed in 2025-2026 and now define the agent-discoverable surface.
Model Context Protocol, shipped by Anthropic, is the USB-C of agent tools. An MCP server publishes a list of tools and resources in a typed schema. Any MCP-aware client — Claude, Cursor, the OpenAI Agents SDK, half the new IDEs — can plug in and use them. No SDK. No custom integration.
Agent-to-Agent (A2A) and the Agent Communication Protocol, sponsored by Google and IBM, do the same thing one layer up. They let agents discover, negotiate with, and delegate sub-tasks to other agents. REST-based, federated, asynchronous-first.
x402, the open payments standard from Coinbase, gives every API endpoint a way to charge an agent in stablecoins on the response. We covered the architecture in Programmable Money for Programmable Goods. The agent calls. The endpoint replies 402 with a price. The agent signs. The endpoint serves.
Stripe, Shopify, Salesforce, Twilio, and Plaid have all shipped MCP servers or equivalent agent SDKs in the last twelve months. The list is growing weekly. The companies that are not on it are increasingly conspicuous.
What Replaces the Developer Portal
The developer portal — the login page, the API key dashboard, the docs site — was a workaround for the lack of an agent layer. Humans needed a place to find your API and learn how to use it. Once an agent is doing both jobs, the developer portal is overhead.
Three new primitives replace it.
1. The /llms.txt Manifest
A growing standard. You publish a small manifest at the root of your site describing what your API does, where to find its MCP server, what its prices are, and which scopes are available. The agent reads it, understands you, and integrates. No human in the loop.
2. The Skill Registry
Skill registries — directories of agent-callable services, indexed by capability — are doing for the agent web what npm did for JavaScript. Find a skill. Wire it up. Pay per call. Move on. The work that used to be a six-month integration is now a thirty-second discovery.
3. The Capsule
The Wealth Capsule ships its own MCP-compatible surface by default. Drop a Capsule onto a node and it announces itself to the local agent grid — what it contains, what it licenses, what it costs. The integration is the manifest.
The 24-Month Window
Every product in the world has roughly two years to ship an AI-native surface or accept irrelevance. That is not a sales pitch. That is the rate at which agents are taking over purchasing flows.
Cursor decides which APIs your developer reaches. Claude decides which research sources your assistant cites. Operator decides which storefronts your shopping agent buys from. Once a domain flips to agent-mediated, the API surface is all that matters. The buying decision is made by something with no eyes.
This is why the next 18 months belong to whoever rewrites their backend for the agent. The companies that do it first will own the next decade of plumbing. The companies that do it last will be a footnote in someone's MCP registry — assuming they make it in at all. The death of negotiation was the warning shot.
Karpathy's hour-long detour through the Woodway API is the eulogy for the old way. The new way is the agent finding your endpoint in a directory, calling it in a millisecond, paying for it on the response, and never opening a single page you designed.
That is not a future. It is what is being shipped now.
Make your service agent-callable on Elacity.