mcp-apps-builder

SKILL.md

Mandatory reference guide for building production MCP servers with tools, resources, prompts, and widgets.

Covers foundational concepts (Tool, Resource, Prompt, Widget primitives), server architecture, authentication patterns (OAuth, Supabase, custom), and deployment strategies

Includes detailed guides for implementing tools, resources, prompts, response formatting, and widget-based UIs with state management and theming

Documents common anti-patterns (missing validation, improper error handling, widget state mistakes) and golden rules (one tool per capability, widgets own their state, validate at boundaries)

Provides decision trees, quick references, and end-to-end examples for weather apps, todo lists, and other common use cases

Build with mcp-use

Treat the installed mcp-use package, its exported types, generated declarations, and the project's existing code as the source of truth. Inspect the installed version before choosing APIs or changing code.

Workflow

Inspect package.json, the server entry, exported tool refs, mcp-env.d.ts, views/, skills/, and the installed mcp-use version.

Scaffold a new stable project with create-mcp-use-app@latest and the appropriate template. Match the package version or dist-tag when working on beta, canary, or an existing versioned project.

Read only the references needed for the task:

Server for tools, resources, prompts, MCP middleware, request context, and result envelopes.

Views for interactive MCP Apps, React hooks, model context, host capabilities, assets, and CSP.

Authentication for OAuth providers, verified identity, scopes, permissions, and authorization.

Skills over MCP when a server should ship reusable workflows alongside its tools.

Advanced features for OpenAPI, proxying, notifications, subscriptions, and elicitation.

Migration only when retired or compatibility-only imports, helpers, registration shapes, UI patterns, or session assumptions are present.

Verification before reporting implementation work complete.

Implement against installed types. Prefer the framework's current conventions over copied examples or historical changelogs.

Validate the smallest real lifecycle that proves the changed behavior, then expand checks in proportion to risk.