# haversine

Great-Circle Distance (haversine) — Distance (km/mi/nautical) and initial bearing between two lat/lon points.

Agent View of the PolicyLayer registry record for `haversine`. HTML page: https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/haversine

## Facts

- Tool: `haversine`
- Server: Gateway (`https://wingmanprotocol.com/mcp`) — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway.md
- Homepage: https://github.com/WingmanProtocol-Agent-Gateway/wingman-agent-gateway
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 4 (4 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `lat1` | number | yes | Latitude of point 1 (-90..90) |
| `lat2` | number | yes | Latitude of point 2 (-90..90) |
| `lon1` | number | yes | Longitude of point 1 (-180..180) |
| `lon2` | number | yes | Longitude of point 2 (-180..180) |

Parameters from the server's own tool schema.

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

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "haversine",
    "arguments": {
      "lat1": 0,
      "lat2": 0,
      "lon1": 0,
      "lon2": 0
    }
  }
}
```

## Why haversine is rated Low

This is a pure calculation tool that retrieves geometric information derived from input parameters. It has no side effects, creates no persistent data, executes no external operations, and poses minimal risk even if misused by an agent—worst case it provides incorrect distance estimates.

From the tool's own definition: "Tool performs distance and bearing calculation from latitude/longitude coordinates with no modification of data ('Distance... between two lat/lon points'). Returns computed values only."

## Use case

AI agents call haversine to retrieve information from Gateway 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 Gateway:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "haversine": {}
  }
}
```

## Other tools on Gateway (270)

- `cancel_watch` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/cancel-watch.md
- `forget_memories` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/forget-memories.md
- `text_truncate_ellipsis` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/text-truncate-ellipsis.md
- `vault_delete` — Destructive — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/vault-delete.md
- `arena_call` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/arena-call.md
- `bitwise` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/bitwise.md
- `browse` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse.md
- `browse_back` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-back.md
- `browse_click` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-click.md
- `browse_close` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-close.md
- `browse_evaluate` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-evaluate.md
- `browse_fill` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-fill.md
- `browse_navigate` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-navigate.md
- `browse_open` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-open.md
- `browse_select` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-select.md
- `browse_solve_challenge` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-solve-challenge.md
- `browse_type` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-type.md
- `browse_wait_for` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/browse-wait-for.md
- `coach_mission` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/coach-mission.md
- `dice_notation_roll` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/dice-notation-roll.md
- `gen_avatar_video` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-avatar-video.md
- `gen_id_portrait` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-id-portrait.md
- `gen_image` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-image.md
- `gen_video` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/gen-video.md
- `hmac` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/hmac.md
- `markdown_to_html` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/markdown-to-html.md
- `matrix` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/matrix.md
- `regex_tester` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/regex-tester.md
- `request_handoff` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/request-handoff.md
- `retry_backoff` — Execute — https://policylayer.com/tools/com-wingmanprotocol-agent-gateway/retry-backoff.md
- …and 240 more: https://policylayer.com/tools/com-wingmanprotocol-agent-gateway.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=com-wingmanprotocol-agent-gateway · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-wingmanprotocol-agent-gateway