MCP is generating a lot of excitement in the AI community, and rightly so. But should you replace all your APIs with MCP servers? The honest answer is: it depends. Here is our decision framework.
MCP and APIs: complementary tools
MCP is not a replacement for REST APIs. It is a communication protocol optimised for AI agents. REST APIs are designed for applications that know exactly what to request. MCP is designed for agents that need to discover capabilities autonomously.
When to use MCP
For AI agents that explore
If your agent must discover which tools are available and decide which to use itself, MCP is superior.
For multi-client integrations
If you want to expose your data to multiple different AI clients, one MCP server saves you from maintaining specific integrations for each.
When to keep your REST API
For deterministic applications
If your application knows exactly what data to retrieve and in what order, a REST API is simpler, faster and more predictable.
Our recommendation: expose your data in MCP for AI agents, keep your REST APIs for your applications. Both can coexist perfectly.
How to migrate progressively
Create an MCP server that wraps your existing APIs. No need to refactor everything. Zero-risk migration, immediate benefit.
With care,
Excellent article, this matches exactly what we're seeing with our enterprise clients. The section on inference costs is especially valuable. It's a topic most articles gloss over but it's make-or-break at scale.
Thanks James! Inference cost optimization is often deprioritized during prototyping but becomes critical in production. Feel free to book a session if you'd like to go deeper on this.
Sharing this with my whole team. The distinction between an impressive demo and robust production is exactly the debate we're having internally right now. The human checkpoint advice is immediately actionable.
Great article. I'd push back slightly on the 18-day deployment estimate, in our experience with enterprise security and GDPR requirements, 4–6 weeks is more realistic for a first production agent.
Completely fair point David. The 18 days refers to a scoped first agent in a test environment. For full enterprise production with security constraints, your estimate is accurate.