Cosmic vs Magic MCP
A side-by-side look at the Cosmic and Magic MCP MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Cosmic for developer tools work as a local process; choose Magic MCP for architecture & design as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Cosmic when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- You have the keys it needs:
COSMIC_BUCKET_SLUG, COSMIC_READ_KEY, COSMIC_WRITE_KEY. - You want tools like
cosmic_objects_list, cosmic_objects_get, cosmic_objects_create.
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 | ||
|---|---|---|
| Category | Developer Tools | Architecture & Design |
| Quality signal | 56/100 · Good | 53/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | Not declared | API key required |
| Pricing | Not declared | Paid service |
| Required env vars | COSMIC_BUCKET_SLUGCOSMIC_READ_KEYCOSMIC_WRITE_KEY | TWENTY_FIRST_API_KEYAPI_KEY_21ST |
| Verified owner | Community listing | Community listing |
| GitHub stars | 1 | 6,209 |
| Directory activity | 1 views 0 installs 0 upvotes | 16 views 1 installs 0 upvotes |
| Tools | 18 | Not listed |
| Full listing | View Cosmic | View Magic MCP |
Tools & capabilities
Cosmic tools 18
cosmic_objects_listList objects with optional type filter, status, and paginationcosmic_objects_getGet a single object by ID or slugcosmic_objects_createCreate a new object (requires write key)cosmic_objects_updateUpdate an existing object (requires write key)cosmic_objects_deleteDelete an object (requires write key)cosmic_media_listList media files with optional folder filtercosmic_media_getGet media details by IDcosmic_media_uploadUpload media from URL or base64 (requires write key)cosmic_media_deleteDelete a media file (requires write key)cosmic_types_listList all object types in the bucketcosmic_types_getGet object type schema by slugcosmic_types_createCreate a new object type (requires write key)- +6 more on the listing page
Magic MCP 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.
Cosmic
{
"mcpServers": {
"cosmic": {
"command": "npx",
"args": [
"-y",
"@cosmicjs/mcp"
],
"env": {
"COSMIC_BUCKET_SLUG": "YOUR_COSMIC_BUCKET_SLUG_HERE",
"COSMIC_READ_KEY": "YOUR_COSMIC_READ_KEY_HERE",
"COSMIC_WRITE_KEY": "YOUR_COSMIC_WRITE_KEY_HERE"
}
}
}
}
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"
}
}
}
}
Frequently asked questions
Cosmic is categorized under Developer Tools and uses a local stdio subprocess. Magic MCP belongs to Architecture & Design and uses a local stdio subprocess. Pick Cosmic for developer tools work and Magic MCP for architecture & design.
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.
Cosmic has no declared pricing — check the project's own site. Magic MCP is listed as a paid service. Auth: api key required. 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 cosmic and 21st-dev-magic-mcp as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Cosmic has a quality signal of 56/100 (Good) with 1 views, 0 installs and 1 GitHub stars. Magic MCP has 53/100 (Good) with 16 views, 1 installs and 6,209 GitHub stars.