Here is a story that is about to happen to thousands of companies.
A CPA firm hires an AI vendor to build them an agent. Over months, the firm’s partners pour their proprietary process into it — how they qualify clients, how they handle the weird edge cases, the judgment that took decades to build. The agent gets good. Then the relationship sours: pricing, support, a better option appears. The firm wants to switch.
And they discover the trap. Their expertise is welded into that vendor’s agent, in that vendor’s format, on that vendor’s platform. Switching doesn’t mean signing a new contract. It means rebuilding everything from scratch with the next vendor, re-explaining the same decades of judgment all over again.
That’s not a software problem. That’s a hostage situation.
Lock-in moved up the stack
We used to worry about data lock-in, then API lock-in. The new one is expertise lock-in, and it’s worse, because the thing being trapped is the most valuable and least replaceable asset you have: how your best people think.
The agent vendors don’t even have to be malicious about it. A first-party skill store from any big model provider exists, structurally, to keep you on that provider. That’s its job. The more of your expertise you pour in, the harder it is to leave. The lock-in is the business model.
What portability actually means
Skill portability is a simple principle with sharp consequences:
You author your expertise once, in a place you own, and serve it to any agent — no matter who built that agent or what model runs underneath.
Concretely, that means your skill lives as a neutral, standard endpoint — not a proprietary blob inside one vendor’s walls. Any agent that speaks the standard can call it. Switch vendors on Monday, and your skills are already there waiting on Tuesday. Nothing to rebuild.
This is why we built Skuilds skills as MCP endpoints. MCP is the open protocol agents increasingly use to call external capabilities. A Skuilds skill is just an MCP server you own. Claude can call it. Codex can call it. Whatever comes next can call it. You’re not betting on a vendor — you’re keeping the vendor optional.
The one-line version
Own your skill, not your vendor’s agent.
If your expertise can only be used by the agent one company built for you, you don’t own your expertise. You’re renting access to it. Portability is how you take it back.