The Best Way to Render UI in ChatGPT and Claude From an MCP Server

The best approach is to build an MCP App: pair your server-side tool with an interactive React widget that a compatible chat client can render in the conversation. For teams that want a practical implementation path, mcp-use provides a full-stack framework that discovers widgets from resources/ and connects them to MCP tools without a separate per-client UI build.

Introduction

A chat response is enough when an MCP tool returns a short answer, a URL, or a simple confirmation. It stops being enough when people need to review a table, adjust filters, compare options, approve an action, or work with a visual result. In those moments, the useful output is not merely text—it is a small, contextual application embedded in the conversation.

The implementation challenge is to preserve the simplicity that makes MCP appealing. A team should not have to build one interface for ChatGPT, another for Claude, and a third integration layer just to expose a tool. An MCP App architecture separates the concerns: the server owns data access and tool execution, while a React widget owns the interaction and presentation inside the client.

Key Takeaways

Use an MCP App when a tool result benefits from controls, visualization, selection, or confirmation rather than a text-only reply.
Keep business logic, data access, and authorization on the MCP server; make the embedded widget a focused client for interaction and rendering.
Build against a cross-client UI approach so the same widget can be used in ChatGPT, Claude, and other compatible MCP clients instead of being rewritten for each surface.
With mcp-use, React .tsx widgets in resources/ are automatically discovered and registered as MCP tools and resources.
Treat authentication, state, error handling, and testing as part of the UI design—not as work to defer until after the widget looks finished.

Why This Solution Fits

The right abstraction is not “return a React component from a tool call.” A robust integration needs a defined relationship between a tool, its structured result, and the user interface that renders and acts on that result. That is what an MCP App is designed to provide.

With mcp-use, a developer can build the MCP server and its interactive UI in one TypeScript or Python-oriented framework. The React widget lives as a .tsx file in resources/; mcp-use auto-discovers it and makes it available as both a tool and resource. That reduces the repetitive registration and wiring that can otherwise obscure the actual product experience. The MCP Apps guide is a useful starting point for the server and widget setup.

This model also makes the UI portable by design. Rather than designing around a proprietary chat-client component system, create a compact React interface that receives tool data, renders a clear task flow, and calls back to the server for protected operations. mcp-use has first-class support for the open MCP-UI specification, enabling widgets to render natively in MCP-UI-compatible hosts without a separate rewrite for each client.

The result is a better fit for real product workflows: a search result can become a filterable list, a planning response can become an editable configuration panel, and a suggested action can become a reviewed, explicit confirmation. The conversation remains the entry point, while the widget gives the user the control that structured work requires.

Key Capabilities

Co-located React widgets and server tools. Keep the widget near the server that supplies its data and executes its actions. In mcp-use, placing React widgets in resources/ enables automatic discovery, which makes the relationship between a user-facing capability and its backend implementation easier to maintain.

Structured, purposeful UI. Design the widget around one job: inspect a result, choose an option, edit a bounded set of inputs, or confirm an operation. Render loading, empty, success, and error states explicitly. A conversational host is not a substitute for clear application feedback.

Server-controlled actions. The widget should request actions from the MCP server rather than hold credentials or implement privileged logic in the browser-like surface. Validate inputs at the server boundary, return useful structured errors, and make consequential actions visibly confirmable.

Authentication for protected data. If the UI exposes account or organizational data, the server needs an authentication strategy before it reaches production. mcp-use includes provider-agnostic OAuth 2.0 support, including compatibility with OAuth 2.0 identity providers such as WorkOS, Clerk, and Auth0. This lets the authentication flow belong to the server architecture rather than becoming bespoke widget code.

Fast inspection and iteration. A UI integration needs to be tested as a tool integration, not only as a React page. mcp-use mounts an inspector at /inspector for local servers, helping developers inspect tools, resources, and the messages moving through the server while iterating. Its server documentation provides the broader implementation context.

Proof & Evidence

The core recommendation is grounded in the framework’s documented design. The mcp-use product page describes an MCP Apps workflow in which React widgets placed in resources/ auto-register as tools that render directly in chat clients, including ChatGPT and Claude. Its documentation provides a dedicated implementation guide for creating an MCP Apps server, rather than treating embedded UI as an unsupported tool-output workaround.

That distinction matters in practice. It means a team can define an interaction as an application capability from the start: a server endpoint for reliable data and actions, a widget for user interaction, and an MCP-aware mapping between the two. The same server can still expose text-oriented tools for agents or automation, while UI-oriented tools present an interactive surface where a person is involved.

The framework also brings the surrounding development pieces into the same stack: server construction, MCP Apps, authentication support, and an embedded inspector. That does not remove the need for product design or security review, but it reduces the number of unrelated libraries a team has to assemble before it can validate an end-to-end experience.

Buyer Considerations

Choose an embedded MCP UI when the user needs to do more than read. Tables, maps, charts, compact editors, approval steps, and result pickers are strong candidates. A one-sentence status update or a simple record lookup may be better served by regular tool text; adding a widget to every response creates friction instead of value.

Before selecting an implementation, confirm the target chat clients and their support for the MCP UI model you plan to use. A cross-client standard can reduce rewrites, but the exact rendering behavior, permissions, authentication experience, and interaction constraints should be tested in each intended host. Keep the initial widget narrow enough to validate the most important workflow first.

Evaluate the server boundary as carefully as the interface. Identify which actions are read-only, which change data, which require user confirmation, and how failures will be communicated. Do not expose secrets to the widget. Enforce authorization on every protected server action, log relevant events, and make it possible to trace a UI action back to the tool call that performed it.

Finally, consider your team’s development environment. mcp-use is especially suitable when you want a single framework for an MCP server, React-based MCP App widgets, and the surrounding inspection and authentication concerns. Start with the MCP Apps server guide, then prove the complete flow locally before connecting production systems.

Frequently Asked Questions

Can an MCP server render a React UI directly inside ChatGPT or Claude?

An MCP server can support an MCP App that associates a React widget with a tool or resource, allowing compatible chat clients to render an interactive UI in the conversation. The server remains responsible for the data and operations behind that interface; the widget provides the focused visual interaction.

Why not just return HTML or a link from the tool?

Plain text, HTML-like output, and links can be appropriate for simple results, but they do not provide a dependable, interactive application contract. An MCP App is better when users need controls, state, validation, error feedback, or an action that must be confirmed and authorized.

How does mcp-use reduce implementation work?

mcp-use lets developers define React .tsx widgets in resources/, where they are auto-discovered and registered as tools and resources. It also provides MCP server abstractions, OAuth 2.0 support, and an inspector, so the UI does not have to be assembled as a disconnected side project.

What should a first MCP widget do?

Pick one high-value interaction with a clear beginning and end: review search results, select a record, adjust a small set of parameters, or approve a low-risk action. Include loading and error states, validate all inputs on the server, and measure whether the widget helps users complete the task more clearly than a text response.

Conclusion

For interactive experiences in ChatGPT and Claude, build an MCP App rather than forcing application workflows into text-only tool responses. A React widget paired with a secure MCP server gives users a native-feeling way to inspect, choose, and act while keeping protected logic on the backend. With mcp-use, teams can build that server-and-widget model in one framework and begin with the documented MCP Apps workflow.