letta-server/fern/pages/tutorials/pdf_chat.mdx

---
title: "Talk to Your PDF"
subtitle: Upload PDFs and query them with an AI agent
slug: tutorials/pdf-chat
---

## Overview

This tutorial demonstrates how to build a PDF chat application using Letta. You'll learn how to upload PDF documents to the [Letta Filesystem](/guides/agents/filesystem), attach them to an agent, and query the agent about the content. Letta automatically extracts text from PDFs using OCR, making the content accessible to your agents.

By the end of this guide, you'll understand how to create document analysis workflows where agents can read, understand, and answer questions about PDF files.

<Note>
**This tutorial uses Letta Cloud.** Generate an API key at [app.letta.com/api-keys](https://app.letta.com/api-keys) and set it as `LETTA_API_KEY` in your environment. Self-hosted servers only need an API key if authentication is enabled. You can learn more about self-hosting [here](/guides/selfhosting).
</Note>

## What You'll Learn

- Creating folders to organize documents
- Uploading PDF files to Letta
- Creating agents configured for document analysis
- Attaching folders to give agents access to files
- Querying agents about PDF content
- Understanding how Letta processes PDFs

## Prerequisites

Install the required dependencies:

<CodeGroup>
```sh TypeScript
npm install @letta-ai/letta-client
```
```sh Python
pip install letta-client requests
```
</CodeGroup>

## Steps

### Step 1: Initialize Client

<CodeGroup>
```typescript TypeScript
import { LettaClient } from '@letta-ai/letta-client';

// Initialize the Letta client using LETTA_API_KEY environment variable
const client = new LettaClient({ token: process.env.LETTA_API_KEY });

// If self-hosting, specify the base URL:
// const client = new LettaClient({ baseUrl: "http://localhost:8283" });
```
```python Python
from letta_client import Letta
import os

# Initialize the Letta client using LETTA_API_KEY environment variable
client = Letta(token=os.getenv("LETTA_API_KEY"))

# If self-hosting, specify the base URL:
# client = Letta(base_url="http://localhost:8283")
```
</CodeGroup>

### Step 2: Create a Folder for PDFs

[Folders](/guides/agents/filesystem) in the Letta Filesystem organize files and make them accessible to agents. Create a folder specifically for storing PDF documents:

<CodeGroup>
```typescript TypeScript
// Create a folder to store PDF documents (or use existing one)
// API Reference: https://docs.letta.com/api-reference/folders/create
let folderId: string;
try {
    // Try to retrieve existing folder by name
    folderId = await client.folders.retrieveByName("PDF Documents");
    console.log(`Using existing folder: ${folderId}\n`);
} catch (error: any) {
    // If folder doesn't exist (404), create it
    if (error.statusCode === 404) {
        const folder = await client.folders.create({
            name: "PDF Documents",
            description: "A folder containing PDF files for the agent to read",
        });
        folderId = folder.id;
        console.log(`Created folder: ${folderId}\n`);
    } else {
        throw error;
    }
}
```
```python Python
# Create a folder to store PDF documents (or use existing one)
# API Reference: https://docs.letta.com/api-reference/folders/create
from letta_client.core.api_error import ApiError

try:
    # Try to retrieve existing folder by name
    folder_id = client.folders.retrieve_by_name("PDF Documents")
    print(f"Using existing folder: {folder_id}\n")
except ApiError as e:
    # If folder doesn't exist (404), create it
    if e.status_code == 404:
        folder = client.folders.create(
            name="PDF Documents",
            description="A folder containing PDF files for the agent to read",
        )
        folder_id = folder.id
        print(f"Created folder: {folder_id}\n")
    else:
        raise
```
</CodeGroup>

<Accordion title="Expected Output">
```
Created folder: folder-a1b2c3d4-e5f6-7890-abcd-ef1234567890
```
If the folder already exists, you'll see:
```
Using existing folder: folder-a1b2c3d4-e5f6-7890-abcd-ef1234567890
```
</Accordion>

### Step 3: Download and Upload a PDF

Let's download a sample PDF (the MemGPT research paper) and upload it to the folder. Letta will automatically extract the text content using OCR.

<CodeGroup>
```typescript TypeScript
import * as fs from 'fs';
import * as https from 'https';

// Download the PDF if it doesn't exist locally
const pdfFilename = "memgpt.pdf";

if (!fs.existsSync(pdfFilename)) {
    console.log(`Downloading ${pdfFilename}...`);

    await new Promise<void>((resolve, reject) => {
        const file = fs.createWriteStream(pdfFilename);
        https.get("https://arxiv.org/pdf/2310.08560", (response) => {
            response.pipe(file);
            file.on('finish', () => {
                file.close();
                console.log("Download complete\n");
                resolve();
            });
            file.on('error', reject);
        }).on('error', reject);
    });
}

// Upload the PDF to the folder
// API Reference: https://docs.letta.com/api-reference/folders/files/upload
const uploadedFile = await client.folders.files.upload(
    fs.createReadStream(pdfFilename),
    folderId,
    { duplicateHandling: "skip" }
);

console.log(`Uploaded PDF: ${uploadedFile.id}\n`);
```
```python Python
import requests

# Download the PDF if it doesn't exist locally
pdf_filename = "memgpt.pdf"

if not os.path.exists(pdf_filename):
    print(f"Downloading {pdf_filename}...")
    response = requests.get("https://arxiv.org/pdf/2310.08560")
    with open(pdf_filename, "wb") as f:
        f.write(response.content)
    print("Download complete\n")

# Upload the PDF to the folder
# API Reference: https://docs.letta.com/api-reference/folders/files/upload
with open(pdf_filename, "rb") as f:
    file = client.folders.files.upload(
        folder_id=folder_id,
        file=f,
        duplicate_handling="skip",
    )

print(f"Uploaded PDF: {file.id}\n")
```
</CodeGroup>

<Accordion title="Expected Output">
```
Downloading memgpt.pdf...
Download complete

Uploaded PDF: file-a1b2c3d4-e5f6-7890-abcd-ef1234567890
```
</Accordion>

<Note>
**PDF Processing**: Letta extracts text from PDFs using OCR automatically during upload. The extracted text becomes searchable and accessible to agents attached to the folder.
</Note>

### Step 4: Create an Agent for Document Analysis

Create an [agent](/guides/agents/overview) with a persona configured for analyzing documents. The agent's [memory blocks](/guides/agents/memory-blocks) define its purpose and capabilities:

<CodeGroup>
```typescript TypeScript
// Create an agent configured to analyze documents
// API Reference: https://docs.letta.com/api-reference/agents/create
const agent = await client.agents.create({
    name: "pdf_assistant",
    model: "openai/gpt-4o-mini",
    memoryBlocks: [
        {
            label: "persona",
            value: "I am a helpful research assistant that analyzes PDF documents and answers questions about their content."
        },
        {
            label: "human",
            value: "Name: User\nTask: Analyzing PDF documents"
        }
    ],
});

console.log(`Created agent: ${agent.id}\n`);
```
```python Python
# Create an agent configured to analyze documents
# API Reference: https://docs.letta.com/api-reference/agents/create
agent = client.agents.create(
    name="pdf_assistant",
    model="openai/gpt-4o-mini",
    memory_blocks=[
        {
            "label": "persona",
            "value": "I am a helpful research assistant that analyzes PDF documents and answers questions about their content."
        },
        {
            "label": "human",
            "value": "Name: User\nTask: Analyzing PDF documents"
        }
    ],
)

print(f"Created agent: {agent.id}\n")
```
</CodeGroup>

<Accordion title="Expected Output">
```
Created agent: agent-a1b2c3d4-e5f6-7890-abcd-ef1234567890
```
</Accordion>

### Step 5: Attach the Folder to the Agent

Attach the folder containing the PDF to the agent. This gives the agent the ability to search through all files in the folder:

<CodeGroup>
```typescript TypeScript
// Attach the folder to the agent
// API Reference: https://docs.letta.com/api-reference/agents/folders/attach
await client.agents.folders.attach(agent.id, folderId);

console.log(`Attached folder to agent\n`);
```
```python Python
# Attach the folder to the agent
# API Reference: https://docs.letta.com/api-reference/agents/folders/attach
client.agents.folders.attach(
    agent_id=agent.id,
    folder_id=folder_id,
)

print(f"Attached folder to agent\n")
```
</CodeGroup>

<Accordion title="Expected Output">
```
Attached folder to agent
```
</Accordion>

<Note>
Once a folder is attached, the agent can use search tools to retrieve relevant content from files in the folder. Learn more in the [Letta Filesystem guide](/guides/agents/filesystem).
</Note>

### Step 6: Query the PDF Content

Now ask the agent questions about the PDF. The agent will search through the document content to find relevant information:

<CodeGroup>
```typescript TypeScript
// Ask the agent to summarize the PDF
// API Reference: https://docs.letta.com/api-reference/agents/messages/create
const response = await client.agents.messages.create(agent.id, {
    messages: [{
        role: "user",
        content: "Can you summarize the main ideas from the MemGPT paper?"
    }]
});

for (const msg of response.messages) {
    if (msg.messageType === "assistant_message") {
        console.log(`Assistant: ${msg.content}\n`);
    }
}
```
```python Python
# Ask the agent to summarize the PDF
# API Reference: https://docs.letta.com/api-reference/agents/messages/create
response = client.agents.messages.create(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "Can you summarize the main ideas from the MemGPT paper?"}],
)

for msg in response.messages:
    if msg.message_type == "assistant_message":
        print(f"Assistant: {msg.content}\n")
```
</CodeGroup>

<Accordion title="Expected Output">
```
Assistant: The MemGPT paper introduces a system that enables LLMs to manage their own
memory hierarchy, similar to how operating systems manage memory. It addresses the limited
context window problem in large language models by introducing a memory management system
inspired by traditional operating systems. The key innovation is allowing LLMs to explicitly
move information between main context (limited) and external storage (unlimited), enabling
extended conversations and document analysis that exceed typical context limits.
```
</Accordion>

### Step 7: Ask Specific Questions

You can continue the conversation to ask more specific questions about the document:

<CodeGroup>
```typescript TypeScript
// Ask a specific question about the PDF content
const response2 = await client.agents.messages.create(agent.id, {
    messages: [{
        role: "user",
        content: "What problem does MemGPT solve?"
    }]
});

for (const msg of response2.messages) {
    if (msg.messageType === "assistant_message") {
        console.log(`Assistant: ${msg.content}\n`);
    }
}
```
```python Python
# Ask a specific question about the PDF content
response = client.agents.messages.create(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "What problem does MemGPT solve?"}],
)

for msg in response.messages:
    if msg.message_type == "assistant_message":
        print(f"Assistant: {msg.content}\n")
```
</CodeGroup>

<Accordion title="Expected Output">
```
Assistant: MemGPT addresses the limited context window problem in large language models.
Traditional LLMs can only process a fixed amount of text at once (their context window),
which makes it difficult to maintain long conversations or analyze large documents. MemGPT
solves this by introducing a memory management system that allows the model to intelligently
move information between its limited context and unlimited external storage, enabling
extended conversations and document analysis beyond typical context limits.
```
</Accordion>

## Complete Example

Here's the full code in one place that you can run:

<CodeGroup>
```typescript TypeScript
import { LettaClient } from '@letta-ai/letta-client';
import * as fs from 'fs';
import * as https from 'https';

async function main() {
    // Initialize client
    const client = new LettaClient({ token: process.env.LETTA_API_KEY });

    // Create folder (or use existing one)
    let folderId: string;
    try {
        folderId = await client.folders.retrieveByName("PDF Documents");
        console.log(`Using existing folder: ${folderId}\n`);
    } catch (error: any) {
        if (error.statusCode === 404) {
            const folder = await client.folders.create({
                name: "PDF Documents",
                description: "A folder containing PDF files for the agent to read",
            });
            folderId = folder.id;
            console.log(`Created folder: ${folderId}\n`);
        } else {
            throw error;
        }
    }

    // Download and upload PDF
    const pdfFilename = "memgpt.pdf";

    if (!fs.existsSync(pdfFilename)) {
        console.log(`Downloading ${pdfFilename}...`);
        await new Promise<void>((resolve, reject) => {
            const file = fs.createWriteStream(pdfFilename);
            https.get("https://arxiv.org/pdf/2310.08560", (response) => {
                response.pipe(file);
                file.on('finish', () => {
                    file.close();
                    console.log("Download complete\n");
                    resolve();
                });
                file.on('error', reject);
            }).on('error', reject);
        });
    }

    const uploadedFile = await client.folders.files.upload(
        fs.createReadStream(pdfFilename),
        folderId,
        { duplicateHandling: "skip" }
    );

    console.log(`Uploaded PDF: ${uploadedFile.id}\n`);

    // Create agent
    const agent = await client.agents.create({
        name: "pdf_assistant",
        model: "openai/gpt-4o-mini",
        memoryBlocks: [
            {
                label: "persona",
                value: "I am a helpful research assistant that analyzes PDF documents and answers questions about their content."
            },
            {
                label: "human",
                value: "Name: User\nTask: Analyzing PDF documents"
            }
        ],
    });

    console.log(`Created agent: ${agent.id}\n`);

    // Attach folder to agent
    await client.agents.folders.attach(agent.id, folderId);

    console.log(`Attached folder to agent\n`);

    // Query the PDF
    const response = await client.agents.messages.create(agent.id, {
        messages: [{
            role: "user",
            content: "Can you summarize the main ideas from the MemGPT paper?"
        }]
    });

    for (const msg of response.messages) {
        if (msg.messageType === "assistant_message") {
            console.log(`Assistant: ${msg.content}\n`);
        }
    }

    // Ask specific question
    const response2 = await client.agents.messages.create(agent.id, {
        messages: [{
            role: "user",
            content: "What problem does MemGPT solve?"
        }]
    });

    for (const msg of response2.messages) {
        if (msg.messageType === "assistant_message") {
            console.log(`Assistant: ${msg.content}\n`);
        }
    }
}

main();
```
```python Python
from letta_client import Letta
from letta_client.core.api_error import ApiError
import os
import requests

# Initialize client
client = Letta(token=os.getenv("LETTA_API_KEY"))

# Create folder (or use existing one)
try:
    folder_id = client.folders.retrieve_by_name("PDF Documents")
    print(f"Using existing folder: {folder_id}\n")
except ApiError as e:
    if e.status_code == 404:
        folder = client.folders.create(
            name="PDF Documents",
            description="A folder containing PDF files for the agent to read",
        )
        folder_id = folder.id
        print(f"Created folder: {folder_id}\n")
    else:
        raise

# Download and upload PDF
pdf_filename = "memgpt.pdf"

if not os.path.exists(pdf_filename):
    print(f"Downloading {pdf_filename}...")
    response = requests.get("https://arxiv.org/pdf/2310.08560")
    with open(pdf_filename, "wb") as f:
        f.write(response.content)
    print("Download complete\n")

with open(pdf_filename, "rb") as f:
    file = client.folders.files.upload(
        folder_id=folder_id,
        file=f,
        duplicate_handling="skip",
    )

print(f"Uploaded PDF: {file.id}\n")

# Create agent
agent = client.agents.create(
    name="pdf_assistant",
    model="openai/gpt-4o-mini",
    memory_blocks=[
        {
            "label": "persona",
            "value": "I am a helpful research assistant that analyzes PDF documents and answers questions about their content."
        },
        {
            "label": "human",
            "value": "Name: User\nTask: Analyzing PDF documents"
        }
    ],
)

print(f"Created agent: {agent.id}\n")

# Attach folder to agent
client.agents.folders.attach(
    agent_id=agent.id,
    folder_id=folder_id,
)

print(f"Attached folder to agent\n")

# Query the PDF
response = client.agents.messages.create(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "Can you summarize the main ideas from the MemGPT paper?"}],
)

for msg in response.messages:
    if msg.message_type == "assistant_message":
        print(f"Assistant: {msg.content}\n")

# Ask specific question
response = client.agents.messages.create(
    agent_id=agent.id,
    messages=[{"role": "user", "content": "What problem does MemGPT solve?"}],
)

for msg in response.messages:
    if msg.message_type == "assistant_message":
        print(f"Assistant: {msg.content}\n")
```
</CodeGroup>

## Key Concepts

<CardGroup cols={2}>
<Card title="Folder Organization" icon="folder">
Folders in the Letta Filesystem organize and group files, making them easy to manage and attach to agents
</Card>

<Card title="Automatic OCR" icon="file-pdf">
PDFs are automatically processed using OCR to extract searchable text content during upload
</Card>

<Card title="Document Access" icon="link">
Attaching folders gives agents search capabilities to retrieve relevant content from files
</Card>

<Card title="Contextual Search" icon="magnifying-glass">
Agents use search tools to find relevant passages in documents when answering questions
</Card>
</CardGroup>

## Use Cases

<AccordionGroup>
<Accordion title="Research Paper Analysis">
Upload academic papers and have agents summarize findings, extract key concepts, or compare methodologies.
</Accordion>

<Accordion title="Document Q&A">
Build customer support systems that answer questions based on product documentation or manuals.
</Accordion>

<Accordion title="Legal Document Review">
Analyze contracts, agreements, or legal documents to extract clauses, identify risks, or summarize terms.
</Accordion>

<Accordion title="Knowledge Base Creation">
Process multiple PDFs to build a searchable knowledge base that agents can query for information.
</Accordion>
</AccordionGroup>

## Next Steps

<CardGroup cols={2}>
<Card title="Letta Filesystem" icon="folder" href="/guides/agents/filesystem">
Learn more about the Letta Filesystem, folders, and managing file uploads
</Card>

<Card title="Agent Overview" icon="robot" href="/guides/agents/overview">
Deep dive into building stateful agents with Letta
</Card>

<Card title="Memory Blocks" icon="brain" href="/guides/agents/memory-blocks">
Understand how memory blocks shape agent behavior and knowledge
</Card>
</CardGroup>