Borrowing it
Nothing to install: this file belongs to nestordemeure/loc-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/nestordemeure/loc-mcp/main/CLAUDE.mdgit clone --depth 1 https://github.com/nestordemeure/loc-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/nestordemeure/loc-mcp/claude-md)<a href="https://agentmods.dev/instructions/nestordemeure/loc-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/nestordemeure/loc-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/nestordemeure/loc-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/nestordemeure/loc-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.02574 | $0.02574 |
| Opus 5 | $0.01287 | $0.01287 |
| Sonnet 5 | $0.00515 | $0.00515 |
| Haiku 4.5 | $0.00257 | $0.00257 |
Grade A, and why
loc-mcp CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Library of Congress MCP Server
A CLI and an MCP server for the JSON API of the Library of Congress: newspapers, books and manuscripts. Each item has a full-text index, and each item resolves to the individual page.
Stack
- Python ≥3.12, uv, fastMCP ≥2.0.0, httpx ≥0.27.0
Functions
- A full-text search at page level across all of loc.gov, or limited to one collection
- Filters for the date range, the language, the US state, the title, the material format, the contributor and the subject heading
- Keyword-in-context snippets for any page-level reference, with citation URLs
- An OCR text download with a local cache, for one page or for a full item
- Pagination at up to 150 results for each request
Structure
loc-mcp/
├── .claude/skills/loc-search/ # Skill documenting the CLI
├── src/loc_mcp/
│ ├── __init__.py
│ ├── client.py # API client + caching
│ ├── cli.py # `locgov` command-line interface
│ ├── paths.py # Cache location resolution
│ ├── ratelimit.py # Cross-process request pacing
│ ├── server.py # FastMCP tools
│ └── install.py # MCP server installer
├── pyproject.toml
└── CLAUDE.md # This file
client.py holds all the behaviour. server.py and cli.py are thin presentation layers over it, so the search semantics and the cache stay identical for each method of access. The CLI shows each filter without a condition. The MCP server hides them behind --enable-advanced-search.
API Details
The dedicated chroniclingamerica.loc.gov API does not exist now. You can reach Chronicling America only as a collection of loc.gov. Thus this client uses the general API, and it treats that collection as one --collection value and not as a special case. The default scope is the full site.
Three services, all without a key and without authentication:
| Service | URL | Returns |
|---|---|---|
| Search | https://www.loc.gov/collections/<slug>/?fo=json or /search/?fo=json |
JSON |
| Resource metadata | the same host with at=resources |
JSON |
| Snippets and OCR | https://tile.loc.gov/text-services/word-coordinates-service |
JSON |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 10d ago First seen · 103 lines · 2,574 tokens per session scan A 40e02f00d3ee
loc-mcp CLAUDE.md is an instructions file published in the GitHub repository nestordemeure/loc-mcp (0 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 2,574 tokens to every session, about $0.0129 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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