MCP basics
MCP vs API:
what’s actually different?
MCP does not replace REST APIs, and it isn't a faster version of one. It answers a different question: how should an AI assistant discover and use a capability during a conversation, with permission that belongs to the person rather than the developer?
Five real differences
Same wires. Different contract.
Who initiates
Traditional API
A developer writes code that calls the endpoint at a moment they chose in advance.
MCP
The model decides mid-conversation that a capability is relevant, and calls it then.
Discovery
Traditional API
Read documentation, then hard-code the routes and shapes you need.
MCP
The client asks the server for its capabilities and their descriptions at connection time.
Who holds permission
Traditional API
Usually the developer's own key, shared by every user of the product.
MCP
The end user authorises a specific client with specific scopes, and can revoke it alone.
Shape of the surface
Traditional API
Resources and verbs — rows, records, collections.
MCP
Named outcomes — 'find the relevant context for this task' rather than 'select from memory'.
Integration cost
Traditional API
One custom integration per product pair.
MCP
One server; any compatible client can connect to it.
Practical guidance
Deterministic work still belongs in an API.
If the flow is fixed — a webhook, a nightly sync, a checkout — write an API call. You want the same thing to happen every time, and a model choosing when to fire it adds risk without adding value.
If the useful moment can't be predicted — the assistant might need your writing style, or the context of one project, depending on what you ask — MCP is the better shape. The capability sits there, described, and gets used only when it's relevant.
Kelven's Gateway is deliberately the second kind: six narrow read-only capabilities that describe outcomes, not tables. There is no 'dump everything' endpoint to call, by design.
The future isn’t another AI model. It’s an intelligence layer that’s yours.
Kelven is the user-controlled intelligence layer between you and AI — with one memory that’s always yours.
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