# PPN Hub — public APIs over MCP

> One MCP endpoint over 69 public PPN APIs: search_apis to discover, execute_api to call. Free tier.

- name: com.ppn-hub/ppn-hub
- version: 1.2.1
- connection class: R0 (autonomous)
- trust: 79/100 flags: no-repository
- quality: 79/100 (good)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/com.ppn-hub%2Fppn-hub
- tools: https://api.protogrid.dev/v1/servers/com.ppn-hub%2Fppn-hub/tools

**An agent can connect right now, no human step.** Remote endpoint, no authentication, reachable on the last probe.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "ppn-hub": {
      "type": "http",
      "url": "https://mcp.ppn-hub.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 98
- freshness: 85
- provenance: 55
- drivers: +dns-namespace +website +reachable +uptime-94% ~updated-78d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 79/100 (good)

### protocol: 75 (weight 25)

- warn `protocol.modern`: newest supported version is 2025-11-25; 2026-07-28 not supported, older versions are deprecated until 2027-07-28
- n/a `protocol.stateless`: only applies to 2026-07-28 servers
- pass `protocol.transport`: streamable HTTP
- n/a `protocol.list_ttl`: only applies to 2026-07-28 servers

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 71 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- fail `tools.annotations`: no tool declares readOnlyHint or destructiveHint, so clients cannot tell safe calls from risky ones
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: search_apis (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); execute_api (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); environment_brief (readOnlyHint, destructiveHint, idempotentHint, openWorldHint)
- pass `tools.token_cost`: about 930 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 100 (weight 15)

- pass `stability.changes`: no tool changes in 30 days
- pass `stability.rug_pull`: no tool changed its meaning under the same name

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 3, about 930 tokens to load them all
- tool set hash: 4f80983a932e61de14dea7ff3d480e47
- badge: [![protogrid quality](https://protogrid.dev/badge/com.ppn-hub/ppn-hub.svg)](https://protogrid.dev/servers/com.ppn-hub/ppn-hub)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

_No tool definition changes recorded._

## Remotes

- https://mcp.ppn-hub.com/mcp (streamable-http, auth none, reachable true, uptime30d 0.9380531)

## Packages

_none_

## Tools (3)

- `environment_brief`: Environmental brief for one location: fans out to every public geo-aware API (weather, terrain, environment, …) and returns a merged JSON. Partial results come back with an errors[] list. Requires 'Authorization: Bearer ppn_live_*'.
- `execute_api`: Execute a request against any of the 59 registered APIs. Use search_apis first to find the correct api name and operationId. Requires 'Authorization: Bearer ppn_live_*'.
- `search_apis`: Search across 484 endpoints in 59 APIs (cultural, earth, energy-calc, green-path, harmonias, hydrogen, internal, nanobase, nanosnap, natura, platform, sakurahub, science, sim, space, stocks). Returns matching endpoints with method, path, summary, parameters, and a ready-to-run example. Use this to discover available API endpoints before calling execute_api. Results carry a "coverage" field (e.g. ["JP"]) for region-limited APIs; use the "region" filter to narrow.