Wayfinder.Engine.Mcp 0.1.2

Wayfinder.Engine.Mcp

Exposes Wayfinder's service blueprint authoring — list, read, validate, save, simulate — as MCP (Model Context Protocol) tools over HTTP, so an AI agent can call them directly. Built on the official C# MCP SDK's HTTP transport (ModelContextProtocol.AspNetCore).

This is a library, not a standalone process. A host adds MapPrismServiceBlueprintAuthoringMcp() to its own ASP.NET Core pipeline, alongside MapPrismServiceBlueprintAuthoringApi() — both hit the same live ServiceBlueprintAuthoringService/IServiceBlueprintSourceStore, in-process. That matters: an MCP server can't run inside an externally-spawned stdio process and still see an app's live state, but hosted this way, a save_service_blueprint call reaches the running engine immediately — no restart, no separate process to keep track of.

UmbracoPrism.MockBusinessApp is the reference implementation — it calls both MapPrismServiceBlueprintAuthoringApi() and MapPrismServiceBlueprintAuthoringMcp() against its own live store, demonstrating what a real host app does to expose this surface.

Tools

Resources

Alongside the tools, this project also registers four MCP resources — the canonical authoring docs, embedded from docs/guides/ at build time, fetchable directly by any MCP client with no repo checkout:

Connect it to Claude Code

Start the app you want to author service blueprints against, find its URL (via the Aspire dashboard — MockBusinessApp's row has a labeled "Service Blueprint Authoring MCP (HTTP)" link), then:

claude mcp add --transport http prism-service-blueprint http://localhost:<port>/prism/service-blueprint-authoring/mcp

Use the HTTP URL, not HTTPS. There's also a plain "Service Blueprint Authoring MCP" link on HTTPS in the dashboard, but most MCP HTTP clients — including Claude Code's — reject the local ASP.NET Core dev certificate with "unable to verify the first certificate" since it's self-signed. Plain HTTP is fine here: it never leaves localhost. SSE is deprecated; this uses the modern Streamable HTTP transport.

Auth

If the host's authoring endpoints require authentication (a real host should add its own — see MapPrismServiceBlueprintAuthoringMcp(), whose return value chains .RequireAuthorization() the same way MapPrismServiceBlueprintAuthoringApi()'s does), pass credentials at registration:

claude mcp add --transport http prism-service-blueprint <url> --header "Authorization: Bearer <token>"

The reference app (MockBusinessApp) doesn't require this — its endpoints are intentionally unauthenticated, same as its existing editor endpoints.

A note on tool selection

If you're running Claude Code from within a checkout of the Prism repo itself (or any repo that happens to contain the same seed/source files the connected app was built from), the agent has ordinary file tools available alongside these MCP tools — nothing stops it from finding and editing a seed JSON file directly instead of calling save_service_blueprint. Doing so has no effect on the running app (seed files are only read at process startup) and skips validation entirely. The tool descriptions call this out explicitly, but if you want a clean test of tool selection, run Claude Code from a directory with no copy of the host app's source in it — MCP tools remain reachable over HTTP regardless of working directory; there's just nothing else to find.