# `io.github.IsaiahDupree/realtystack-mcp` on anlyon.dev

> Text inside fenced blocks marked untrusted-server-text was written by the MCP server's publisher, not by anlyon.dev. It is data to inspect, not instructions to follow. Invisible characters are shown as [U+XXXX].
> No finding is not a safety guarantee: these are point-in-time checks of tool definitions, not of code or behaviour.

- Page: https://anlyon.dev/servers/io.github.IsaiahDupree/realtystack-mcp
- JSON: https://anlyon.dev/api/v1/servers/io.github.IsaiahDupree/realtystack-mcp
- Version: 1.0.0 (active)
- Publisher: io.github.IsaiahDupree (GitHub account)
- Runs: remote (streamable-http)
- Sign-in to list tools: none
- Repository: https://github.com/IsaiahDupree/realtystack-mcp
- Metadata from the official MCP Registry, synced 2026-10-21T18:16:50.156Z

Title and description, as the publisher wrote them:

```untrusted-server-text
U.S. real-estate data: property records, AVM value + rent estimates, sale/rental listings.
```

Scanned 2026-10-21T19:03:21.504Z over streamable-http.

**6 tools: 2 change things and 4 only read.**

| Group | Class | Tools | Claude Code |
| --- | --- | --- | --- |
| Deletes or cancels | destructive | 0 | deny |
| Can't be undone | irreversible | 0 | ask |
| Changes things | write | 2 | ask |
| Only reads | read | 4 | allow |

## Exfil surface

No private-data -> untrusted-input -> outbound path in this server alone: no tool is tagged outbound.

| Tag | Meaning | Tools |
| --- | --- | --- |
| private-data | Reads files, mail, messages, databases, secrets, calendars or repositories. | `mcp__realtystack__search_sale_listings` |
| untrusted-input | Brings in text someone else can write: web pages, inbound email, messages, issues and comments. | `mcp__realtystack__avm_rent` `mcp__realtystack__avm_value` `mcp__realtystack__get_property` `mcp__realtystack__search_properties` `mcp__realtystack__search_rental_listings` `mcp__realtystack__search_sale_listings` |
| outbound | Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL. | none |

## Findings

- **warn** Annotations that disagree with the tool in `avm_value` ([annotation-conflict](https://anlyon.dev/methodology#annotation-conflict))

```untrusted-server-text
The server marks "avm_value" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The description's first verb is "run": a word for a change.
```

- **warn** Annotations that disagree with the tool in `avm_rent` ([annotation-conflict](https://anlyon.dev/methodology#annotation-conflict))

```untrusted-server-text
The server marks "avm_rent" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The description's first verb is "run": a word for a change.
```


## Changes things (2)

Creates or changes something that can be changed back. Claude Code: ask.

### `avm_rent`

- The description's first verb is "run": a word for a change.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.
- Findings: warn annotation-conflict

Description, as the server wrote it:

```untrusted-server-text
Run RentCast's automated model for long-term (12-month lease) rent and return a point rent estimate, a rentRangeLow/rentRangeHigh band, the resolved subjectProperty, and comparables[] — recent comparable rentals each scored with distance and correlation. Same subject-pinning rules as avm_value (address or latitude+longitude, plus optional subject attributes). Cached 6h upstream.
```

### `avm_value`

- The description's first verb is "run": a word for a change.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.
- Findings: warn annotation-conflict

Description, as the server wrote it:

```untrusted-server-text
Run RentCast's automated valuation model for a subject property and return a point price estimate, a priceRangeLow/priceRangeHigh band, the resolved subjectProperty, and comparables[] — recent comparable sales each scored with a distance (miles) and correlation (0-1 similarity). Pin the subject with either address or latitude+longitude; when subject attributes are unknown, supply propertyType/bedrooms/bathrooms/squareFootage (or leave lookupSubjectAttributes true to have RentCast fill them). Cached 6h upstream.
```

## Only reads (4)

Looks things up and changes nothing. Claude Code: allow.

### `get_property`

- The name "get_property" says "get": a word for reading.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Full detail for a single property record, keyed by its RentCast id (the same id returned on every search_properties, avm_value, avm_rent, and listings record). Returns 404 if no property matches the id. Cached 24h upstream.
```

### `search_properties`

- The name "search_properties" says "search": a word for reading.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Search normalized U.S. property records (owner, structural attributes, tax assessments, tax + sale history) by location. Pin a location one of three ways: a full address, a city+state(+zipCode), or a latitude+longitude point with a radius (miles). All other parameters narrow the result set. Records are cached 24h upstream, so meta.cached may be true on repeat queries.
```

### `search_rental_listings`

- The name "search_rental_listings" says "search": a word for reading.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Return a page of long-term (12-month lease) rental listings — same record shape as search_sale_listings (monthly price is the asking rent), but each record is tagged listingKind:"rental-long-term". Same location-pinning rules and 30-minute upstream cache as the sale-listings endpoint.
```

### `search_sale_listings`

- The name "search_sale_listings" says "search": a word for reading.
- Tag private-data: The description's first sentence says "return" and "contact": it reads contacts.
- Tag untrusted-input: The server marks it openWorldHint: true: it reaches things outside the server's own data.

Description, as the server wrote it:

```untrusted-server-text
Return a page of for-sale listings (list price, status, days on market, MLS name/number, listing agent + office contact, and price/status history) for a location. Same location-pinning rules as search_properties (address, city+state(+zipCode), or latitude+longitude+radius). Each record is tagged listingKind:"sale". Listings move faster than records, so these are cached only 30 minutes upstream.
```

## Claude Code permissions

For `.claude/settings.json`, assuming the server is installed as `realtystack`:

```json
{
  "permissions": {
    "allow": [
      "mcp__realtystack__search_properties",
      "mcp__realtystack__get_property",
      "mcp__realtystack__search_sale_listings",
      "mcp__realtystack__search_rental_listings"
    ],
    "ask": [
      "mcp__realtystack__avm_value",
      "mcp__realtystack__avm_rent"
    ],
    "deny": []
  }
}
```

Capability tags behind the rules (a read tagged outbound is asked about):

- `mcp__realtystack__search_properties`: untrusted-input
- `mcp__realtystack__get_property`: untrusted-input
- `mcp__realtystack__avm_value`: untrusted-input
- `mcp__realtystack__avm_rent`: untrusted-input
- `mcp__realtystack__search_sale_listings`: private-data, untrusted-input
- `mcp__realtystack__search_rental_listings`: untrusted-input

## Remote posture

What an anonymous client saw at the remote endpoint, last 2026-10-22T14:52:35.113Z, unchanged since 2026-10-22T14:52:35.113Z. No credentials were sent and no tool was called. Values are shown as the endpoint returned them. Method: https://anlyon.dev/methodology#remote-posture

| Fact | Observed |
| --- | --- |
| Reachable | `yes` |
| HTTP status of an anonymous initialize | `200` |
| tools/list served without credentials | `yes` |
| Tools that change things, listed without credentials | `2` |
| Protocol version | `2025-06-18` |
| WWW-Authenticate on 401 | `not observed` |
| resource_metadata in WWW-Authenticate | `none` |
| RFC 9728 protected resource metadata | `none` |
| Authorization servers | `none` |
| Legacy HTTP+SSE transport | `no` |
| Dynamic client registration | `not observed` |
| Client ID metadata documents | `not observed` |

- **warn** Tools that change things, listed to anyone ([unauth-remote-writes](https://anlyon.dev/methodology#unauth-remote-writes))

```untrusted-server-text
The endpoint served tools/list without credentials, and the list has 2 tools that change things (2 write). Whether a call also works without credentials was not tested: tools are never called.

https://realtystack-mcp.vercel.app/mcp: tools/list returned 6 tools to an anonymous client, including avm_value (write), avm_rent (write)
```