# ssh-keyscan

Retrieves public host keys from a remote SSH server using

Agent View of the PolicyLayer registry record for `ssh-keyscan`. HTML page: https://policylayer.com/tools/io-github-dave-london-http/ssh-keyscan

## Facts

- Tool: `ssh-keyscan`
- Server: Http (`@paretools/http`) — https://policylayer.com/tools/io-github-dave-london-http.md
- Install: `npx -y @paretools/http`
- Homepage: https://github.com/Dave-London/Pare
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "ssh-keyscan",
    "arguments": {}
  }
}
```

## Why ssh-keyscan is rated Low

ssh-keyscan is a standard utility that passively retrieves public SSH host keys for verification purposes. It performs no write operations, does not execute commands, and cannot delete or modify data. While it does perform network reconnaissance, the blast radius is minimal as it only gathers already-public information. Classified as Read with low severity.

From the tool's own definition: "Tool name is 'ssh-keyscan' and description states it 'Retrieves public host keys from a remote SSH server' — a read-only operation that queries public cryptographic material without modifying or executing anything on the target."

## Use case

AI agents call ssh-keyscan to retrieve information from Http without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Http:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "ssh-keyscan": {}
  }
}
```

## Other tools on Http (201)

- `branch` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/branch.md
- `clean` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/clean.md
- `compose-down` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/compose-down.md
- `remove` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/remove.md
- `reset` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/reset.md
- `secret-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/secret-delete.md
- `tag` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/tag.md
- `variable-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/variable-delete.md
- `workspace` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/workspace.md
- `worktree` — Destructive — https://policylayer.com/tools/io-github-dave-london-http/worktree.md
- `add` — Execute — https://policylayer.com/tools/io-github-dave-london-http/add.md
- `add-package` — Execute — https://policylayer.com/tools/io-github-dave-london-http/add-package.md
- `ansible-galaxy` — Execute — https://policylayer.com/tools/io-github-dave-london-http/ansible-galaxy.md
- `ansible-playbook` — Execute — https://policylayer.com/tools/io-github-dave-london-http/ansible-playbook.md
- `api` — Execute — https://policylayer.com/tools/io-github-dave-london-http/api.md
- `apply` — Execute — https://policylayer.com/tools/io-github-dave-london-http/apply.md
- `audit` — Execute — https://policylayer.com/tools/io-github-dave-london-http/audit.md
- `bazel` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bazel.md
- `biome-check` — Execute — https://policylayer.com/tools/io-github-dave-london-http/biome-check.md
- `bisect` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bisect.md
- `black` — Execute — https://policylayer.com/tools/io-github-dave-london-http/black.md
- `build` — Execute — https://policylayer.com/tools/io-github-dave-london-http/build.md
- `bundle-exec` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bundle-exec.md
- `bundle-install` — Execute — https://policylayer.com/tools/io-github-dave-london-http/bundle-install.md
- `check` — Execute — https://policylayer.com/tools/io-github-dave-london-http/check.md
- `cherry-pick` — Execute — https://policylayer.com/tools/io-github-dave-london-http/cherry-pick.md
- `clippy` — Execute — https://policylayer.com/tools/io-github-dave-london-http/clippy.md
- `cmake` — Execute — https://policylayer.com/tools/io-github-dave-london-http/cmake.md
- `compose-build` — Execute — https://policylayer.com/tools/io-github-dave-london-http/compose-build.md
- `compose-up` — Execute — https://policylayer.com/tools/io-github-dave-london-http/compose-up.md
- …and 171 more: https://policylayer.com/tools/io-github-dave-london-http.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-dave-london-http · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dave-london-http