# fhfa_hpi_compare

Compare two to eight US geographies on a consistent FHFA HPI series and rank them by one-year price-index change. Returns latest level, one-year and five-year change, CAGR, recent direction, stable place_id/geography_level fields, and source provenance for later property-market evidence packs. Use this for 'compare home-price momentum in Texas and Florida' or 'which of these metros has stronger five-year appreciation?'. Not a property valuation or investment recommendation.

Agent View of the PolicyLayer registry record for `fhfa_hpi_compare`. HTML page: https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/fhfa-hpi-compare

## Facts

- Tool: `fhfa_hpi_compare`
- Server: Livedatalink (`https://livedatalink.ai/mcp`) — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink.md
- Homepage: https://github.com/blackboxfoundry/livedatalink
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server CORS policy: *
- Server rate-limited: no
- Parameters: 6 (1 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `places` | array | yes | Two to eight exact FHFA place ids or geography names. |
| `frequency` | string | no | Observation frequency. Default quarterly. |
| `hpi_flavor` | string | no | FHFA index flavor. Default purchase-only. |
| `index_basis` | string | no | Index column to use. Default seasonally_adjusted. |
| `geography_level` | string | no | Optional exact FHFA geography level to disambiguate state, metro, division, or national series. |
| `response_format` | string | no | Human-readable markdown or machine-readable JSON. Default markdown. |

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": "fhfa_hpi_compare",
    "arguments": {
      "places": []
    }
  }
}
```

## Why fhfa_hpi_compare is rated Low

Even though fhfa_hpi_compare only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

## Use case

AI agents call fhfa_hpi_compare to retrieve information from Livedatalink 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 Livedatalink:

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

## Other tools on Livedatalink (380)

- `beneficial_owner_screen` — Destructive — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/beneficial-owner-screen.md
- `bea_state_economic_profile` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bea-state-economic-profile.md
- `bts_transport_border_activity_pack` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bts-transport-border-activity-pack.md
- `cftc_cot_evidence_pack` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/cftc-cot-evidence-pack.md
- `clinical_site_selector` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/clinical-site-selector.md
- `edgar_recent_filings` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/edgar-recent-filings.md
- `entity_dossier` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/entity-dossier.md
- `fed_board_h15_evidence_pack` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/fed-board-h15-evidence-pack.md
- `fed_board_h15_yield_curve` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/fed-board-h15-yield-curve.md
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- `govinfo_legislation_evidence_pack` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/govinfo-legislation-evidence-pack.md
- `patent_recent` — Execute — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/patent-recent.md
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- `affordable_housing_refinance_evidence_pack` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/affordable-housing-refinance-evidence-pack.md
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- `bank_health_report` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bank-health-report.md
- `bea_compare_states` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bea-compare-states.md
- `bea_search_state_indicators` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bea-search-state-indicators.md
- `bea_state_economic_trend` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bea-state-economic-trend.md
- `bls_indicator` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bls-indicator.md
- `bls_series` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bls-series.md
- `book_details` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/book-details.md
- `book_fulltext_search` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/book-fulltext-search.md
- `book_get_text` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/book-get-text.md
- `book_search` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/book-search.md
- `book_status` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/book-status.md
- `bounce_scanner` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bounce-scanner.md
- `bts_transport_border_trend` — Read — https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink/bts-transport-border-trend.md
- …and 350 more: https://policylayer.com/tools/io-github-blackboxfoundry-livedatalink.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-blackboxfoundry-livedatalink · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-blackboxfoundry-livedatalink