Libofcongress MCP Server

Search LOC digital collections, Chronicling America newspapers (full OCR), and LC Subject Headings. This MCP entry surfaces a curated ranking/list from the project README rather than a classic multi-tool integration surface. It still exposes 8 documented tools (including libofcongress_search, libofcongress_get_item, libofcongress_search_newspapers) for browsing or selecting items from that list.

People connecting this server to Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-08-22 · ★ 3 · #208 OF 848 MAINTAINED OTHER · VERIFIED 2026-08-25

Apache-2.0 · TypeScript servers · how we verify → /methodology

01 · Install Libofcongress MCP Server

before you install - you'll need

Set MCP_TRANSPORT_TYPE, MCP_SESSION_MODE, MCP_LOG_LEVEL before connecting.

Claude Code

claude mcp add cyanheads-libofcongress-mcp-server -- npx -y @cyanheads/libofcongress-mcp-server

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "cyanheads-libofcongress-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@cyanheads/libofcongress-mcp-server"
      ]
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions

license Apache-2.0 - declared in the repository

npm package @cyanheads/libofcongress-mcp-server - published under the repo owner's npm scope (@cyanheads)

registry namespace io.github.cyanheads is GitHub-verified and matches the repo owner

03 · What Libofcongress MCP Server can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

What you can build

An agent gets 8 documented tools across libofcongress, filters, ocr, including libofcongress_search, libofcongress_get_item, libofcongress_search_newspapers, libofcongress_get_newspaper_page.

Capability map

Tools grouped from the project's README - what Libofcongress MCP Server lets an agent do.

Libofcongress

6 tools - e.g. Search LOC digital collections by keyword with optional format, date range, subject heading, geographic location, and collection filters. Returns item summaries; Retrieve full metadata for a specific LOC…

libofcongress_search · libofcongress_get_item · libofcongress_search_newspapers · libofcongress_get_newspaper_page · libofcongress_search_subjects · libofcongress_browse_collections

Filters

1 tool - e.g. keyword, date range, US state (full state name), newspaper publication title (partial match)

Filters

Ocr

1 tool - e.g. false when the page has no digitized text (image-only batch) - not an error, a data property

ocr_available

Latest releases

v0.2.17 · 2026-08-22

MCP 2026 compatibility and stateless HTTP · Serves MCP 2026-07-28 alongside 2025-era clients and rejects undeclared tool arguments. · Makes stateless HTTP mode explicit across every runtime and distribution surface.…

v0.2.16 · 2026-07-16

Honest search pagination and content/structuredContent parity · Search pagination stops advertising and discarding pages the LOC API will not serve; two success paths now reach content[] and structuredContent with the…

v0.2.15 · 2026-07-16

Fetch retry/timeout and search_subjects false-empty fix · Internal HTTP resilience for the LOC upstreams, a subject-search false-empty fix, and a test-suite pacing fix. · Added: · Transient-fault resilience - new…

04 · Who maintains Libofcongress MCP Server

libofcongress-mcp-server is maintained by cyanheads. We track 125 MCP servers from cyanheads - 124 actively maintained, 1,730 combined GitHub stars, oldest repo from Dec 2024. Full record: all servers from cyanheads.

05 · Facts

repository: github.com/cyanheads/libofcongress-mcp-server
category: other - ranked #208 of 848 actively-maintained other servers as of 2026-08-25.
release cadence: 10+ releases in the last 90 days (latest 2026-08-22)
registry: io.github.cyanheads/libofcongress-mcp-server (active, first published 2026-05-24 · 18 versions)
packages: npm:@cyanheads/libofcongress-mcp-server · npm:@cyanheads/libofcongress-mcp-server

06 · Libofcongress MCP Server FAQ

Is Libofcongress MCP Server still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-22 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

What can Libofcongress MCP Server do?

An agent gets 8 documented tools across libofcongress, filters, ocr, including libofcongress_search, libofcongress_get_item, libofcongress_search_newspapers, libofcongress_get_newspaper_page.

How do I install Libofcongress MCP Server?

Run `npx -y @cyanheads/libofcongress-mcp-server`. The README documents 3 environment variables (MCP_TRANSPORT_TYPE, MCP_SESSION_MODE, MCP_LOG_LEVEL) to set first. Set MCP_TRANSPORT_TYPE, MCP_SESSION_MODE, MCP_LOG_LEVEL before connecting. You can also paste the ready-made client config above.

Does Libofcongress MCP Server run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Libofcongress MCP Server

Alternatives to Libofcongress MCP Server

Maintained other servers if Libofcongress MCP Server isn't the fit.

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