Kastell vs Semgrep
A side-by-side look at the Kastell and Semgrep MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Kastell for security work as a local process; choose Semgrep for security as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Kastell when
- You need dedicated capabilities in the Security domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
Choose Semgrep when
- You need dedicated capabilities in the Security domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Security | Security |
| Quality signal | 61/100 · Good | 48/100 · Fair |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | No auth required | No auth required |
| Pricing | Free | Free |
| Required env vars | None listed | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 60 | 17,186 |
| Directory activity | 5 views 0 installs 0 upvotes | 1 views 0 installs 0 upvotes |
| Tools | Not listed | Not listed |
| Full listing | View Kastell | View Semgrep |
Tools & capabilities
Kastell tools
No tool names declared yet. Check the project README from the listing page.
Semgrep 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.
Kastell
{
"mcpServers": {
"kastelldev-kastell": {
"command": "npx",
"args": [
"-y",
"kastell"
]
}
}
}
Semgrep
{
"mcpServers": {
"semgrep-semgrep": {
"command": "uvx",
"args": [
"semgrep"
]
}
}
}
Frequently asked questions
Kastell is categorized under Security and uses a local stdio subprocess. Semgrep belongs to Security and uses a local stdio subprocess. Pick Kastell for security work and Semgrep for security.
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.
Kastell is listed as free. Auth: no auth required. Semgrep is listed as free. Auth: no auth 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 kastelldev-kastell and semgrep-semgrep as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Kastell has a quality signal of 61/100 (Good) with 5 views, 0 installs and 60 GitHub stars. Semgrep has 48/100 (Fair) with 1 views, 0 installs and 17,186 GitHub stars.