# Cyanheads Libofcongress MCP server

Source: https://glimind.com/server/mcp-registry%2Fio.github.cyanheads%2Flibofcongress-mcp-server
Registry id: `mcp-registry/io.github.cyanheads/libofcongress-mcp-server`
Status: live (checked 2026-10-27T06:19:56.579Z)

## Verdict

Cyanheads Libofcongress MCP server answered 99.79% of Glimind's liveness checks over 30 days, better than 23% of MCP servers, with 418 ms median handshake and 6 outages in 90 days. Its agent-readiness grade is A (98/100) across 6 tools, costing an agent about 3,543 tokens to load. Checked every few minutes; no tool is ever called.

## Measurements (30 days)

| Metric | Value | Better than |
|---|---|---|
| Uptime, 30 days | 99.79% | 23% of MCP servers |
| Median handshake latency | 418 ms | 53% of MCP servers |
| p95 handshake latency | 2573 ms | — |
| Checks in 30 days | 4,967 | — |
| Outages, 90 days | 6 | — |
| Median recovery | 7 min | — |
| Agent-readiness score | 98/100 (A) | 91% of MCP servers |
| Tools | 6 | — |
| Tool-list size for an agent | ~3,543 tokens | 43% of MCP servers |
| Days observed | 29 | — |

## Install

```json
{
  "mcpServers": {
    "cyanheads-libofcongress-mcp-server": {
      "type": "http",
      "url": "https://libofcongress.caseyjhand.com/mcp"
    }
  }
}
```

Claude Code:

```sh
claude mcp add --transport http cyanheads-libofcongress-mcp-server https://libofcongress.caseyjhand.com/mcp
```

## Tools (6)

- `libofcongress_browse_collections`: List and browse Library of Congress curated digital collections. Returns collection names, descriptions, item counts, slugs, and URLs. Optionally filter by keyw
- `libofcongress_get_item`: Retrieve the full metadata record for a specific LOC digital item. Returns the imprint (place, publisher, and date of publication), contributors, LCSH subject h
- `libofcongress_get_newspaper_page`: Retrieve the full text of one LOC page — a historical newspaper page, or a book or manuscript page — or, with match, only the passages around your search terms,
- `libofcongress_search_items`: Search the Library of Congress digital collections by keyword. Optionally filter by material format (photos, maps, newspapers, audio, etc.), date range, subject
- `libofcongress_search_newspapers`: Search historical newspaper pages in the Chronicling America corpus. Returns matching pages with the opening of each page's OCR text (~500 characters), publicat
- `libofcongress_search_subjects`: Search Library of Congress Subject Headings (LCSH) by keyword. Returns authorized subject headings and their URIs, ranked by relevance with a heading that exact

Measured by Glimind (https://glimind.com): MCP handshake + tool list only, no tool is ever called. CC BY 4.0.