API reference
Every export mcp-vitest ships, grouped by what you reach for it to do.
Everything here builds on one entry point. mcpTest() connects a server and hands back a harness; the rest of the API is what that harness can do and how you assert on it.
New to the package? Getting started is a shorter path in.
Connecting
mcpTest(serverOrFactory, options?) connects a server and returns an McpHarness, the entry point every other API builds on.
McpHarness covers the methods and properties available on the harness, including the raw SDK client as an escape hatch.
Asserting
Matchers are the typed vitest matchers for tools, resources, prompts, and tool results.
Snapshot testing snapshots a server's tool, resource, and prompt surface, and validates structured output against its declared schema.
Answering the server
Testing sampling and elicitation answers a server's sampling, elicitation, and roots requests from inside a test.
Notifications collects and waits on notifications a server pushes to the client.
Where the server runs
Testing an external server tests a server you cannot import, over stdio or HTTP, with serveHandler and detectServerKind.
Lifecycles runs the same suite across MCP protocol revisions with createMcpTest.
Migrating
Upgrading from an older release? Migration notes lists what changed and what to do about it.