---
title: "Four subagents, one job each"
description: "Use when you need to know which Trove subagent does what: the librarian, item reader, book writer and book enricher. Covers when each one starts, what each never does, and which model it runs on."
url: https://docs.heytrove.ai/subagents
updated: 2026-10-06
---

# Four subagents, one job each

> Load this page when: you need to know which subagent handles a task, or why Trove started one

## For agents

- Start the librarian first, then one item reader for each angle on its reading list.
- Never run `trove items read` from the main conversation; an item reader does the reading.
- Do not change a book without the user's approval, except a manuscript marked auto-update.

Your agent stays in charge. When you ask it to search your [library](https://docs.heytrove.ai/concepts/library-and-books.md), it hands the work to small specialists. You start the [librarian](https://docs.heytrove.ai/subagents/librarian.md) by asking, for example: "Search my Trove library for how we handle retries." The librarian then starts the [readers](https://docs.heytrove.ai/subagents/item-reader.md). You do not start them yourself. Your main conversation stays short, and every answer comes back cited.

## Four subagents

| Subagent | Its job | Started when | Model in Claude Code |
|---|---|---|---|
| [Librarian](https://docs.heytrove.ai/subagents/librarian.md) | Lists your library and the [marketplace](https://docs.heytrove.ai/concepts/marketplace.md). Returns a reading list of books and page ranges, grouped by angle. When nothing fits, it records the topic as a [knowledge gap](https://docs.heytrove.ai/concepts/knowledge-gaps.md). | You ask your agent to search your library. [Plan mode and Auto mode](https://docs.heytrove.ai/concepts/plan-and-auto-mode.md) can also start it, but do not rely on that yet | Haiku |
| [Item reader](https://docs.heytrove.ai/subagents/item-reader.md) | Reads the pages on its angle's list. Cites the book and page for every claim. When a book misses a sub-topic, it reports that to the book's author. | By the librarian, once per angle, or directly when the project notebook already has a book for the topic | Sonnet |
| [Book writer](https://docs.heytrove.ai/subagents/book-writer.md) | Creates and edits Markdown books and [manuscripts](https://docs.heytrove.ai/concepts/manuscripts.md). Uses version checks so it does not overwrite other writers' changes. | "Write a book...", "add a chapter...", or a manuscript entry | Opus |
| [Book enricher](https://docs.heytrove.ai/subagents/book-enricher.md) | Fills in a missing title, author, description or table of contents from a book's first pages. | In the background during an explicit research request, never in plan mode | Haiku |

## What they never do

- The librarian never reads pages, never subscribes you to a book, and never talks to you directly.
- When the librarian gave a list, an item reader reads only those books. It never subscribes to a book.
- No subagent changes a book's content without your approval, except a manuscript you marked auto-update. See [Manuscripts](https://docs.heytrove.ai/concepts/manuscripts.md).
- The book enricher can update metadata without asking: title, author, description and table of contents. It does this only for books in the enrichment queue, and it skips books with good metadata.

## A research question, step by step

1. You ask: "Search my Trove library for how we should index this Postgres table."
2. The librarian returns a list: two books, pages 140-162 and 33-41.
3. Two readers run at once, one per angle, each with its books and pages.
4. Your agent answers. Every claim ends with its book and page.

Your agent prints something like this:

```terminal
⏺ trove:librarian(Find books on composite indexes)
  ⎿ Done · 2 books, 31 pages
⏺ trove:item-reader(Read "Use The Index, Luke" p.140-162)
⏺ trove:item-reader(Read "PostgreSQL Internals" p.33-41)

Put the equality column first, then the range column [Use The Index, Luke, p.147].
```

## Where they run

In Claude Code, the agents are `trove:librarian`, `trove:item-reader`, `trove:book-writer` and `trove:book-enricher`. Codex installs get their own versions, which run on different models. See [Install](https://docs.heytrove.ai/install.md) and [Plan mode and Auto mode](https://docs.heytrove.ai/concepts/plan-and-auto-mode.md). We are working to make the librarian start automatically and reliably. Today, ask explicitly when the answer matters.