Magic MCP vs Agent Output Verifier by SarnAI
A side-by-side look at the Magic MCP and Agent Output Verifier by SarnAI MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
A
Agent Output Verifier by SarnAIDeveloper Tools · Local subprocess (stdio)Verify an agent's output before you pay: JSON Schema + rules, signed receipts. Free during launch.40FairAuth: not declaredVerdict: choose Magic MCP for developer tools work as a local process; choose Agent Output Verifier by SarnAI for developer tools 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 Developer Tools 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.
AChoose Agent Output Verifier by SarnAI when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | A Agent Output Verifier by SarnAI | |
|---|---|---|
| Category | Developer Tools | Developer Tools |
| Quality signal | 53/100 · Good | 40/100 · Fair |
| 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 | 5,997 | 0 |
| Directory activity | 16 views 1 installs 0 upvotes | 0 views 0 installs 0 upvotes |
| Tools | Not listed | Not listed |
| Full listing | View Magic MCP | View Agent Output Verifier by SarnAI |
Tools & capabilities
Magic MCP tools
No tool names declared yet. Check the project README from the listing page.
Agent Output Verifier by SarnAI 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"
}
}
}
}
Agent Output Verifier by SarnAI
{
"mcpServers": {
"agent-output-verifier-by-sarnai": {
"command": "uvx",
"args": [
"sarnai"
]
}
}
}
Frequently asked questions
Magic MCP is categorized under Developer Tools and uses a local stdio subprocess. Agent Output Verifier by SarnAI belongs to Developer Tools and uses a local stdio subprocess. Pick Magic MCP for developer tools work and Agent Output Verifier by SarnAI for developer tools.
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. Agent Output Verifier by SarnAI 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 agent-output-verifier-by-sarnai 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 5,997 GitHub stars. Agent Output Verifier by SarnAI has 40/100 (Fair) with 0 views, 0 installs and 0 GitHub stars.