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

# WRITER PDF Parser

This guide provides a quick overview for getting started with the WRITER `PDFParser` [document loader](/oss/python/concepts/document_loaders/).

WRITER's [PDF Parser](https://dev.writer.com/api-guides/api-reference/tool-api/pdf-parser#parse-pdf) converts PDF documents into other formats like text or Markdown. This is particularly useful when you need to extract and process text content from PDF files for further analysis or integration into your workflow. In `langchain-writer`, we provide usage of WRITER's PDF Parser as a LangChain document parser.

## Overview

### Integration details

| Class                                                                                                | Package                                                        | Local | Serializable | JS support |                                             Downloads                                             |                                             Version                                            |
| :--------------------------------------------------------------------------------------------------- | :------------------------------------------------------------- | :---: | :----------: | :--------: | :-----------------------------------------------------------------------------------------------: | :--------------------------------------------------------------------------------------------: |
| [PDFParser](https://github.com/writer/langchain-writer/blob/main/langchain_writer/pdf_parser.py#L55) | [langchain-writer](https://pypi.org/project/langchain-writer/) |   ❌   |       ❌      |      ❌     | ![PyPI - Downloads](https://img.shields.io/pypi/dm/langchain-writer?style=flat-square\&label=%20) | ![PyPI - Version](https://img.shields.io/pypi/v/langchain-writer?style=flat-square\&label=%20) |

## Setup

The `PDFParser` is available in the `langchain-writer` package:

```python theme={null}
%pip install --quiet -U langchain-writer
```

### Credentials

Sign up for [WRITER AI Studio](https://app.writer.com/aistudio/signup?utm_campaign=devrel) to generate an API key (you can follow this [Quickstart](https://dev.writer.com/api-guides/quickstart)). Then, set the WRITER\_API\_KEY environment variable:

```python theme={null}
import getpass
import os

if not os.getenv("WRITER_API_KEY"):
    os.environ["WRITER_API_KEY"] = getpass.getpass("Enter your WRITER API key: ")
```

It's also helpful (but not needed) to set up [LangSmith](https://smith.langchain.com/) for best-in-class observability. If you wish to do so, you can set the `LANGSMITH_TRACING` and `LANGSMITH_API_KEY` environment variables:

```python theme={null}
# os.environ["LANGSMITH_TRACING"] = "true"
# os.environ["LANGSMITH_API_KEY"] = getpass.getpass()
```

### Instantiation

Next, instantiate an instance of the WRITER PDF Parser with the desired output format:

```python theme={null}
from langchain_writer.pdf_parser import PDFParser

parser = PDFParser(format="markdown")
```

## Usage

There are two ways to use the PDF Parser, either synchronously or asynchronously. In either case, the PDF Parser will return a list of `Document` objects, each containing the parsed content of a page from the PDF file.

### Synchronous usage

To invoke the PDF Parser synchronously, pass a `Blob` object to the `parse` method referencing the PDF file you want to parse:

```python theme={null}
from langchain_core.documents.base import Blob

file = Blob.from_path("../example_data/layout-parser-paper.pdf")

parsed_pages = parser.parse(blob=file)
parsed_pages
```

### Asynchronous usage

To invoke the PDF Parser asynchronously, pass a `Blob` object to the `aparse` method referencing the PDF file you want to parse:

```python theme={null}
parsed_pages_async = await parser.aparse(blob=file)
parsed_pages_async
```

## API reference

For detailed documentation of all `PDFParser` features and configurations, head to the [API reference](https://python.langchain.com/api_reference/writer/pdf_parser/langchain_writer.pdf_parser.PDFParser.html#langchain_writer.pdf_parser.PDFParser).

## Additional resources

You can find information about WRITER's models (including costs, context windows, and supported input types) and tools in the [WRITER docs](https://dev.writer.com/home).