---
title: keycard-upsert-mcp-config | Keycard
description: Add or update an MCP server entry in .mcp.json.
---

Add or update an MCP server entry in `.mcp.json`.

## When to Use

Use this skill when you want to add or update an MCP server in `.mcp.json`.

Do **not** use this skill to set a `keycard.toml` field (use `keycard-upsert-config`), or to discover which MCP servers are available in your zone (use `keycard-discover-entities`).

## Arguments

`add "<name>" command="<cmd>" args=[...] env={...}`

## Examples

- “Add an MCP server called my-server using npx with args -y @my/mcp-server”
- “Add a local MCP tool at /usr/local/bin/my-mcp”