About mcp-chat
mcp-chat is an open-source client for testing and evaluating MCP servers and agents. It offers interactive CLI and web chats, with tool-call details that help developers inspect server behavior.
Key features
- 01Interactive CLI chat
- 02Web-based chat interface
- 03Connect to local or remote MCP servers
- 04Select models and customize system prompts
- 05Save chats and command history
- 06Inspect tool-call arguments and output
Use cases
- 01Test a local MCP server during development
- 02Inspect MCP tool-call results
- 03Configure servers and chat through the web UI
MCP support
As an MCP client, it connects to servers launched with local commands or to Streamable HTTP endpoints, and can read Claude Desktop configuration. It displays tool-call arguments and results in chat.
Configuration
Local server config is the same for every client. Copy it into your client’s MCP config file.
Tools
Local servers expose tools only once running on your machine, and the maintainer has not provided a tool list.
Details
From the project READMEmcp-chat
Open Source Generic MCP Client for testing & evaluating mcp servers and agents
Quickstart
Make sure that you have ANTHROPIC_API_KEY exported in your environment or in a .env file in the root of the project. You can get an API key by signing up at the Anthropic Console keys page.
Simple use case that spawns an interactive chat prompt with the filesystem MCP server from CLI:
npx mcp-chat --server "npx -y @modelcontextprotocol/server-filesystem /Users/$USER/Desktop"
This will open up a chat prompt that you can use to interact with the servers and chat with an LLM.
Config
You can also just specify your claude_desktop_config.json (Mac):
npx mcp-chat --config "~/Library/Application Support/Claude/claude_desktop_config.json"
Or (Windows):
npx mcp-chat --config "%APPDATA%\Claude\claude_desktop_config.json"
Web mode
https://github.com/user-attachments/assets/b7e8a648-8084-4955-8cdf-fc6eb141572e
You can also run mcp-chat in web mode by specifying the --web flag (make sure to have ANTHROPIC_API_KEY exported in your environment):
npx mcp-chat --web
In web mode, you can start new chats, send messages to the model, and dynamically configure the mcp servers via the UI - no need to specify on the command line. In addition, chats created via the Web UI are saved to ~/.mcpchats/chats just like chats created via the CLI.
Features
- Run via CLI in interactive mode or directly pass prompts with
-p - Web mode to chat with models via a web interface
--web - Connect to any MCP server (JS, Python, Docker) in production or during development
- Choose between models with
-m - Customize system prompt with
--system - Saves chat history with settings in
~/.mcpchat/chatsincluding web chats - Save and restore commands in
~/.mcpchat/history - View tool call output and arguments directly in chat to help debug mcp servers
CLI Usage
Run prompts via CLI with the -p flag:
npx mcp-chat --server "npx mcp-server-kubernetes" -p "List the pods in the default namespace"
This runs the prompt with the kubenertes mcp-server & exits after the response is received on stdout.
Choose a model to chat with via CLI with the -m flag:
npx mcp-chat --server "npx mcp-server-kubernetes" -m "claude-3.5"
Uses the model claude-3.5 to chat with. Note that currently only Anthropic models are supported.
Custom system prompt:
--system flag can be used to specify a system prompt:
npx mcp-chat --system "Explain the output to the user in pirate speak." --server "npx mcp-server-kubernetes" -p "List the pods in the default namespace"
Remote MCP servers
Pass a Streamable HTTP endpoint URL to --server instead of a local command:
npx mcp-chat --server "https://example.com/mcp" -p "What tools do you have available?"
Any http:// or https:// server string is treated as a Streamable HTTP endpoint, both in the CLI and in web mode chat settings. Legacy SSE endpoints and servers that require authentication are not currently supported.
ENV vars
Mcp-chat supports passing through env vars to mcp servers. This is not standardized in the mcp spec though and other clients may not do this with dynamic env var values - read more here about standard stdio mcp clients.
KUBECONFIG="~/.kube/config" npx mcp-chat --server "npx mcp-server-kubernetes"
For developers of mcp-servers
You can pass in a local build of a python or node mcp-server to test it out with mcp-chat:
Node JS:
# Directly executing built script
npx mcp-chat --server "/path/to/mcp-server-kubernetes/dist/index.js"
# Using node / bun
npx mcp-chat --server "node /path/to/mcp-server-kubernetes/dist/index.js"
Python:
# Python: Using uv
npx mcp-chat --server "uv --directory /path/to/mcp-server-weather/ run weather.py"
# Using python / python3 - make sure to run in venv or install deps globally
npx mcp-chat --server "/path/to/mcp-server-weather/weather.py"
Development
Install dependencies & run the CLI:
git clone https://github.com/Flux159/mcp-chat
bun install
bun run dev
To develop mcp-chat while connecting to an mcp-server, make a build & run the CLI with the server flag:
npm run build && node dist/index.js --server "npx mcp-server-kubernetes" -p "List the pods in the default namespace"
Testing:
bun run test
Building:
bun run build
Publishing:
bun run publish
Publishing Docker:
bun run dockerbuild
Project Structure
├── src/
│ ├── index.ts # Main client implementation & CLI params
│ ├── constants.ts # Default constants
│ ├── interactive.ts # Interactive chat prompt handling & logic
├── test/ # Test files
│ ├── cli.test.ts # Test CLI params
│ ├── config.test.ts # Test config file parsing
Publishing new release
Go to the releases page, click on "Draft New Release", click "Choose a tag" and create a new tag by typing out a new version number using "v{major}.{minor}.{patch}" semver format. Then, write a release title "Release v{major}.{minor}.{patch}" and description / changelog if necessary and click "Publish Release".
This will create a new tag which will trigger a new release build via the cd.yml workflow. Once successful, the new release will be published to npm. Note that there is no need to update the package.json version manually, as the workflow will automatically update the version number in the package.json file & push a commit to main.
License
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.