> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getspine.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Folder Synthesis Block

> Run prompts against every file in a folder via map-reduce

## Overview

The Folder Synthesis Block runs a prompt against every file in a [Folder Block](/app/blocks/folder-block) via map-reduce and outputs a combined result. The synthesis processes each file individually, then aggregates and synthesizes the results into a single output.

This is fundamentally different from just dumping all files into a context window: it scales to large document collections and handles each file with full attention.

## Key Features

* **Map-reduce processing** — Each file is processed individually with its own dedicated context, then results are aggregated into a final synthesis
* **Scales to large collections** — Works with document collections too large to fit in a single context window
* **Full attention per file** — Each document gets dedicated processing, not diluted attention shared across all files
* **Combined output** — Final synthesis aggregates and reconciles findings across all files into one coherent result

## How to Use

1. **Create a Folder Block** — Group your files into a [Folder Block](/app/blocks/folder-block) first
2. **Add a Folder Synthesis Block** — Click on the canvas → Select "Folder Synthesis Block"
3. **Connect to folder** — Link the Folder Synthesis Block to your Folder Block
4. **Write your prompt** — Describe what you want to extract or analyze across the files
5. **Run** — The block processes each file individually, then synthesizes results
6. **Connect downstream** — Link the output to Memo, Document, Table, or Slides blocks for further refinement

## Example Use Cases

* **"Summarize all my meeting notes"** — Get a unified summary across dozens of meeting documents
* **"Extract action items across these 20 documents"** — Pull out every action item from a collection
* **"Find all mentions of budget changes in this folder"** — Search across a collection for specific topics
* **"Identify common themes across these research papers"** — Cross-document theme extraction and pattern identification
* **Compliance checking** — Check policy compliance across a folder of documents
* **Data extraction** — Extract specific data points across receipt or invoice collections
* **Legal / compliance pass** — Folder of policies → Folder Synthesis → checklist of obligations
* **Research consolidation** — Many PDFs → Folder Synthesis → single structured memo