Magic MCP vs Carbon Interface
A side-by-side look at the Magic MCP and Carbon Interface MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Magic MCP for architecture & design work as a local process; choose Carbon Interface for environment & nature as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Magic MCP when
- You need dedicated capabilities in the Architecture & Design domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: API key required.
- You have the keys it needs:
TWENTY_FIRST_API_KEY, API_KEY_21ST.
Choose Carbon Interface when
- You need dedicated capabilities in the Environment & Nature domain.
- You prefer a local stdio subprocess transport.
- You want tools like
estimate_electricity, estimate_flight, estimate_vehicle.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Architecture & Design | Environment & Nature |
| Quality signal | 53/100 · Good | 52/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | API key required | Not declared |
| Pricing | Paid service | Not declared |
| Required env vars | TWENTY_FIRST_API_KEYAPI_KEY_21ST | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 6,209 | 0 |
| Directory activity | 16 views 1 installs 0 upvotes | 1 views 0 installs 0 upvotes |
| Tools | Not listed | 3 |
| Full listing | View Magic MCP | View Carbon Interface |
Tools & capabilities
Magic MCP tools
No tool names declared yet. Check the project README from the listing page.
Carbon Interface tools 3
estimate_electricityEstimate CO2 emissions from electricity usage. Returns carbon emissions in grams, kg, and metric tons. Example: estimate_electricity(500, "us", "kwh") for 500 kWh in the US.estimate_flightEstimate CO2 emissions from a flight. Provide number of passengers and flight legs (departure/arrival airport IATA codes). Returns per-passenger and total carbon emissions. Example: estimate_flight(2, [{"departure_airport": "SFO", "destination_airport": "JFK"}]).estimate_vehicleEstimate CO2 emissions from driving a vehicle. Provide distance and a vehicle model ID (from Carbon Interface). Returns carbon emissions in grams, kg, and metric tons. Example: estimate_vehicle(100, "7268a9b7-17e8-4c8d-acca-57059252afe9", "mi").
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Magic MCP
{
"mcpServers": {
"21st-dev-magic-mcp": {
"command": "npx",
"args": [
"-y",
"@21st-dev/cli@latest"
],
"env": {
"TWENTY_FIRST_API_KEY": "YOUR_TWENTY_FIRST_API_KEY_HERE",
"API_KEY_21ST": "YOUR_API_KEY_21ST_HERE"
}
}
}
}
Carbon Interface
{
"mcpServers": {
"carbon-interface": {
"command": "npx",
"args": [
"-y",
"@pipeworx/mcp-carbon-interface"
]
}
}
}
Frequently asked questions
Magic MCP is categorized under Architecture & Design and uses a local stdio subprocess. Carbon Interface belongs to Environment & Nature and uses a local stdio subprocess. Pick Magic MCP for architecture & design work and Carbon Interface for environment & nature.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Magic MCP is listed as a paid service. Auth: api key required. Carbon Interface has no declared pricing — check the project's own site. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add 21st-dev-magic-mcp and carbon-interface as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Magic MCP has a quality signal of 53/100 (Good) with 16 views, 1 installs and 6,209 GitHub stars. Carbon Interface has 52/100 (Good) with 1 views, 0 installs and 0 GitHub stars.