Choose an API when your app needs to send requests explicitly defined by your code. Choose MCP when you want a compatible assistant to discover and use tools within a conversation. For mobility data, both approaches can coexist within the same product.
The decision concerns how you access the service, not a contrast between reliable data and approximate data. An API and an MCP server can rely on the same sources; you must compare their contracts, capabilities, and actual limitations.
API: Your Code Controls the Calls
An HTTP API lets your server select the route, parameters, search timing, and response handling. This approach suits a list of stops, a map filter, or a scheduled task whose behavior must be predictable.
Your application handles validation, caching, timeouts, error display, and secrets. An API does not prevent building an assistant: you can also link its routes to functions used by a model.
Example of Proximity Search with the ROOTE API
MCP: Tools Accessible Within the Conversation
An MCP server publishes tools with their argument schemas. The AI application discovers and can use them to respond to a natural language request. This simplifies connection to compatible clients without creating a custom integration for each.
The model is not authorized to invent parameters or interpret an error as an empty result. The client and your application must maintain the service constraints. The discovered capabilities remain the reference.
Understanding the Official MCP Architecture
Choose According to the Result You Want to Achieve
| Project | Starting Choice | Why |
|---|---|---|
| List of Stops on a Site | API | Code controls filters, calls, and rendering |
| Compatible Assistant Searching Around an Address | MCP | Tools accessed from within the conversation |
| Periodic Export or Business Processing | API | Scenario does not depend on conversational interpretation |
| Map Without Developing an Interface | Embed ROOTE | Iframe directly provides a map experience |
| Product Combining Map and Assistant | API and MCP | Each interface addresses a different interaction |
Compare Capabilities Rather Than Just Interfaces
The Data tools of the MCP ROOTE cover geocoding, proximity search, and disruptions with transit_disruptions. Journey and Departures are not yet exposed, even though the REST contract documents corresponding routes. transit_nearby discovers transport locations; it does not announce their upcoming departures. Compare the tools actually announced by the server.
Filter names, types, and limits can also differ. For example, MCP transit modes are a list of strings; modes in a map URL are encoded in a parameter. Do not copy a configuration between interfaces without checking its schema.
Assess Integration Effort
For API, estimate work on response validation, error handling, and rendering. For MCP, check client compatibility, tool discovery, assistant behavior, and how warnings are maintained. A quick connection does not replace testing the entire flow.
In both cases, measure actual calls made and apply the service’s active limits. Do not declare a fixed cost per conversation without observing searches, retries, and account rights.
An Example: A Hotel Helping Its Visitors Get Around
To display a map of bikes and stops near the hotel, an embed may suffice. To customize a list in its interface, the site can call the API server-side. To answer “where can I find toilets and a tram near my address?”, a compatible assistant can use MCP.
These flows should not hide each other: the map shows available information, the list exposes its filters, and the assistant explains what it actually found. An unknown service does not become absent because its field is missing.
Connect Your Assistant to the ROOTE MCP
Integrate a Map into Your Site
Upcoming: Next Departures and Route Calculation
ROOTE plans to extend its MCP to upcoming departures and route calculation. These features are forthcoming and are not yet part of the tools currently exposed by the MCP server. When available, check the tools announced by the server, their arguments, and the information actually returned before announcing a passage or journey.
Frequently Asked Questions
Does MCP Replace REST?
No. MCP can use a REST API in the background, and an app can maintain its REST integration alongside.
Should Automation Use MCP?
Not necessarily. For a defined, repeatable call sequence, an API often suffices. MCP becomes useful if your automation environment already uses it or if an assistant chooses the tools.
Are the Same Features Available Everywhere?
Check each interface’s inventory. REST, MCP, and map capabilities are not automatically identical.