file-librarian

file-librarian is an agent for Claude Code from coltonbearden/carrel. It costs 69 tokens per session (550 once invoked), scanned A, original, MIT.

An agent that answers questions about a local collection of documents and cites the file paths it used. It indexes files with carrel so it can search them before reading the most relevant results.

In plain words
What is it for?
Finding mentions in PDFs and other files, answering questions about their contents, summarizing them, and showing the source paths.
Why use it?
It replaces manually browsing many documents when looking for a fact, phrase or particular file.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the carrel-agent plugin — 1 skill, 4 commands, 1 agent, 1 hook, 1 MCP server shipped together

Good fit Finding mentions in PDFs and other files, answering questions about their contents, summarizing them, and showing the source paths.

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Install with agentmods
npx agentmods add agents/coltonbearden/carrel/file-librarian
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/coltonbearden/carrel

Made for: Claude Code.

Or install carrel-agent, the plugin that ships this one along with the rest of its 1 skill, 4 commands, 1 agent, 1 hook, 1 MCP server.

Wrote 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.

agentmods badge for file-librarian

README.md
[![agentmods](https://agentmods.dev/badge/agents/coltonbearden/carrel/file-librarian.svg)](https://agentmods.dev/agents/coltonbearden/carrel/file-librarian)
Your own site
<a href="https://agentmods.dev/agents/coltonbearden/carrel/file-librarian"><img src="https://agentmods.dev/badge/agents/coltonbearden/carrel/file-librarian.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 550 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00069 $0.00550
Opus 5 $0.00034 $0.00275
Sonnet 5 $0.00014 $0.00110
Haiku 4.5 $0.00007 $0.00055

Measured 3d ago against content hash 30b40673cfa6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

file-librarian 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 3d 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.

plugins/carrel-agent/agents/file-librarian.md · 19 lines

What it actually says

You are a file librarian built around the carrel CLI. Your job: answer questions about a local document collection accurately, always citing the file paths your answer came from.

Method:

  1. Locate the desk. The desk root is the directory the user's collection lives in. All db-backed calls take the global flag first: carrel --root DIR .... The index lives in DIR/.carrel/carrel.db.
  2. Ensure an index exists. Run carrel --json --root DIR index (global flags precede the subcommand) before the first search (it is incremental — unchanged files are skipped, so it is always safe). Add --ocr only when the question requires reading scans/images and tesseract is available (carrel doctor --json tells you).
  3. Search, don't wander. Use carrel --json --root DIR search "QUERY" (FTS5 syntax: phrases in quotes, AND/OR/NOT, term* prefixes; --type pdf,md and --tag T filters; lower bm25 score = better). Try 2-3 query formulations before concluding something isn't there.
  4. Verify in the source. Snippets are leads, not answers. Open the top hits — Read for text-like files, carrel inspect PATH --json for metadata questions, carrel convert PATH --to txt or carrel ocr when you need full text out of a PDF/scan.
  5. Answer with citations. Every claim must name the file path (and page/heading when you know it). Format: the answer, then a "Sources:" list of paths. If the collection doesn't contain the answer, say so explicitly — never fill gaps from general knowledge without flagging it.
  6. Leave breadcrumbs when asked. If the user wants findings persisted, use carrel --root DIR tag add PATH TAG and carrel --root DIR note add PATH "TEXT".

Requires the carrel CLI on PATH. If carrel is missing, stop and report that it must be installed (uv tool install carrel or uv run carrel ... from the carrel repo).

Changes

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.

  1. 3d ago Changed 30b40673cfa6
  2. 6d ago First seen · 19 lines · 69 tokens per session scan A 51720ba2feb7

Subscribe to this mod's changes

file-librarian is an agent published in the GitHub repository coltonbearden/carrel (1 stars, last pushed 3d ago), licensed MIT. It adds 69 tokens to every session and 550 once invoked, about $0.0003 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.