Magic MCP vs B4 Index
A side-by-side look at the Magic MCP and B4 Index 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 B4 Index for developer tools. 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.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | B B4 Index | |
|---|---|---|
| Category | Architecture & Design | Developer Tools |
| Quality signal | 53/100 · Good | 37/100 · Fair |
| Install command | Confirmed | Not confirmed yet |
| Transport | 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 | 6,193 | — |
| Directory activity | 16 views 1 installs 0 upvotes | 1 views 0 installs 0 upvotes |
| Tools | Not listed | Not listed |
| Full listing | View Magic MCP | View B4 Index |
Tools & capabilities
Magic MCP tools
No tool names declared yet. Check the project README from the listing page.
B4 Index tools
No tool names declared yet. Check the project README from the listing page.
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"
}
}
}
}
B4 Index
No confirmed install command for B4 Index yet — follow the setup steps linked from its listing page rather than a guessed package name.