A prospect sent us that question about MCP last week.
Word for word.
It took three of our team, an internal debate, and a follow-up call to answer it properly.
Think about that. A serious enterprise, deep into a platform evaluation, asking whether APIs are now legacy. Not a hot take on social media. A real buying committee, with a real budget, genuinely unsure.
That’s worth taking seriously.
Why they’re asking
Because MCP moved absurdly fast.
An Anthropic side project became the de facto standard for agent-to-tool integration. Then it got donated to the Linux Foundation. Now 78% of enterprise AI teams have MCP-backed agents in production.
Eighteen months. That’s all it took.
When a protocol moves that fast, a rational CTO asks: is this the new interface for everything?
Fair question. It deserves a straight answer.
Where the misunderstanding creeps in
MCP is a consumption layer.
It is not a substrate.
Every useful MCP server is wrapping an API. The tool your agent calls to check inventory? A thin skin over the same REST service your mobile app has called for years. The business logic lives in the API. The data contracts live in the API. The security model lives in the API.
MCP changes who the consumer is.
It doesn’t change what’s being consumed.
Three things follow:
Your non-agent consumers aren’t going anywhere. Partners. Mobile apps. Internal services. B2B integrations. None of them are about to start speaking MCP. You’ll run both interfaces over the same capabilities for years. Plan for it. Don’t fight it.
The governance problem transfers. It doesn’t vanish. Auth, rate limiting, audit, least privilege: all of it applies to agent traffic. Except the consumer is now non-deterministic, and much better at finding creative paths through your permissions. The same week that prospect wrote to us, our engineers were working out how to govern MCP servers running loose on developer laptops, no per-call auth, inheriting whatever spawned them. The answer looked exactly like API management: put a policy enforcement point between client and server.
Wrapping an API in MCP doesn’t make it agent-ready. An endpoint designed for a developer reading docs behaves very differently when a model is guessing at parameters. Descriptions, errors, scopes: all need rethinking. That’s API design work. Which rather undermines the idea that the API layer is now someone else’s problem.
Here’s where I might be wrong
The smart version of the opposing view goes like this: fine, APIs persist as plumbing, but the strategic centre of gravity moves to MCP, so that’s where the tooling money should go.
I have some sympathy. Analysts predict 75% of API gateway vendors will ship MCP features by the end of 2026. The market has voted on where attention is heading.
But “the centre of gravity moves” and “the old layer stops mattering” are very different claims.
Mobile didn’t kill the web.
Kubernetes didn’t kill the VM.
Infrastructure accretes. It doesn’t replace. And the winners are always the teams who govern the whole lot through one control plane, not the ones who build a parallel stack for every new protocol.
Full disclosure
I run an API management company.
Of course I’d say APIs still matter. Discount my view accordingly.
But notice: I’d say the same thing if the answer were no. We’d simply pivot to whatever the substrate became, like every vendor in this space. My confidence isn’t commercial. It’s that every MCP deployment I’ve seen in the wild, including our own, sits on top of APIs.
Nobody has yet shown me one that doesn’t.
And here’s my favourite part. Buried inside the prospect’s question was their own answer: “I believe the answer is yes, we still need to support traditional APIs.”
They knew.
They just wanted someone to argue against it convincingly.
Nobody could.
If your board is asking whether AI agents make your API programme legacy, tell them the opposite. Your API programme just acquired its most demanding consumer yet.
Further reading
- Everything your team needs to know about MCP in 2026 (WorkOS)
- The future of MCP: enterprise adoption and what comes next (Toloka)
- MCP adoption statistics 2026 (Digital Applied)
- Is MCP dead in 2026? Why enterprises still need MCP (Tyk)
- MCP Gateway: the control plane for enterprise AI agents (Tyk)
- Building the AI supply chain: how Tyk is shaping MCP in practice (Tyk)
