Best API tooling MCP servers

API-tooling MCP servers connect an agent to the platforms where you design, document, and test APIs — collections, workspaces, environments, mock servers, and specs. With them an agent can look up an endpoint's contract before writing client code, run a saved request, scaffold tests against a collection, or keep an OpenAPI spec and the implementation in sync. The main thing to weigh is how much of the platform's surface a server exposes: a minimal tool set is easier for a model to drive reliably, while a full set unlocks deeper automation at the cost of more tool noise. These often offer both a local key-based mode and a hosted remote endpoint over OAuth, so pick the deployment that matches whether you want local control or no setup.