Composition-first discovery
Roles
Roles explain how a server fits into an advisory workflow. Category tells you what it connects to; role tells you whether it is a source, a system of action, a gateway, an aggregator, a directory, a domain expert or a composition layer.
The 7 role categories
Source
Provides data. A read-only feed from one provider; it answers questions, doesn't act, and doesn't expect other servers alongside it.
Example · Morningstar
Browse Source servers →System
Provides one system's data and actions. Reads and writes inside a single product of record; it can act, but only within its own walls.
Example · Salesforce
Browse System servers →Gateway
Reaches many systems at once. One connection that fans out to hundreds of apps, trading depth for breadth.
Example · Zapier
Browse Gateway servers →Aggregator
Normalizes several systems behind one interface. Hides many underlying providers behind a single normalized shape.
Example · Truthifi
Browse Aggregator servers →Directory
Helps you find capabilities. Doesn't hold the data itself. It points you to the servers that do.
Example · WealthMCP
Browse Directory servers →Domain
Specialized public intelligence. Turns a public dataset into a queryable, agent-ready domain expert.
Example · ADVmcp, 5500mcp
Browse Domain servers →Composition
Combines other servers' capabilities to reach an outcome. Orchestrates data and domain servers into a finished decision, not just a data point.
Example · ValuationMCP
Browse Composition servers →
Try roles in the directory
Role pages narrow the directory to servers with the same composition pattern. Listings are informational only. Always verify a server with its publisher before connecting it to client data.
Open the directory