An API is written for a developer who already knows what they want. An MCP server is written for an assistant that has to work out what it wants. The plumbing underneath is usually the same, and that is the entire difference.
Which means the question is not which is better. It is which reader you are serving.
The actual distinction
An API says: here are the endpoints, here are the parameters, here is the documentation. It assumes the caller has read it and knows which endpoint answers their problem. For software that was written on purpose to talk to your software, that assumption is correct.
An MCP server says: here is what you can do here, in sentences, with a description of when each one applies. It assumes the caller has not read anything and is working out what it needs from a question asked thirty seconds ago.
Both end up calling the same code. The difference is that one expects prior knowledge and the other supplies it.
| API | MCP server | |
|---|---|---|
| Written for | A developer | An assistant |
| Assumes | You read the docs | You read nothing |
| Chooses the action | The developer, in advance | The assistant, at the moment |
| Runs when | Your code calls it | Somebody asks a question |
| Changes when | You ship a new version | The published list changes |
Why this was not possible before
It was, technically. People have been pointing language models at APIs for years and the results were unreliable for a boring reason: the model had to be told what existed, that description went stale, and nobody owned keeping it current.
What changed is that the description became part of the interface rather than part of the prompt. The server publishes what it can do, the assistant reads it at the time of asking, and when the vendor adds an action it appears without anybody rewriting anything.
That is a smaller change than the coverage suggests and a more durable one.
Where each belongs
Use an integration or API when the thing must happen on a schedule, the same way, whether or not a person is present. Invoicing on the 15th. The nightly sync. The webhook that fires on a form submission. Determinism is the requirement, and an assistant deciding what to do is the opposite of determinism.
Use MCP when the question is different each time. What slipped this week and why. Which clients have gone quiet. Draft the update from what actually happened. You cannot write an integration for these, because writing one means guessing the question before it is asked.
Most businesses need both, aimed at different problems. The mistake is using one where the other belongs: an assistant asked to run payroll, or an integration built to answer an open question.
What to ask a vendor
Three questions, and they are the same three regardless of which the vendor is selling.
Which actions does it publish, and can I see the list. Does it write or only read. Whose permissions does it use when it acts.
A vendor who answers those three clearly has built something real. One who answers "we support MCP" and moves on has built a feature bullet.
Where Empiraa sits
Empiraa GPS shipped its MCP in version 1.22, alongside the API and the native connections it already had, which is the arrangement this post is arguing for: the scheduled things stay scheduled, and the open question gets a way in. The MCP acts within your permissions and is included on every Professional Services tier. Signal's MCP is in build and not shipped at the time of writing.
Related reading: MCP or integration, which does your business need, and what an MCP server is, and what it is not.
What an MCP actually is covers the concept for a leader rather than a developer.
