Generate Summaries from Uploaded Files using OpenAI Assistants API

📑 Overview

Upload a document (PDF, DOCX, PPTX, TXT, CSV, JSON, or Markdown) and receive an AI-generated summary containing:

• title – 5-10 words
• summary – 1-2 sentences
• bullets – 3-5 key points
• tags – 3-6 short keywords

The workflow:

1. Stores the file in OpenAI.
2. Runs an Assistant with File Search and Code Interpreter enabled.
3. Polls until the run finishes.
4. Retrieves the summary JSON.

✅ Prerequisites

OpenAI Assistant

• Create one at <https://platform.openai.com/assistants&gt;
• Enable File Search and Code Interpreter
• Note: The assistant ID starts with asst_

OpenAI API credential setup in n8n

• Go to Credentials → New → HTTP Header Auth
• Header name: Authorization
• Value: Bearer YOUR-OPENAI-API-KEY (replace YOUR-OPENAI-API-KEY with your OpenAI API secret key for your assistant, starts with sk-)
• Name it: openAIApiHeader

🔧 Setup

1. Import the workflow JSON.

2. When n8n prompts for a credential, choose openAIApiHeader for every HTTP Request node.

3. Open Run Assistant → Body and replace

   "assistant_id": "REPLACE_WITH_YOUR_ASSISTANT_ID"

with your real ID (starts with asst_…). Save.

🚀 How it works

| Node | Purpose

---|---|---
1 | On form submission | User uploads a file (File).
2 | Upload File | POST /v1/files (multipart) → returns file_id.
3 | Create Thread | Creates a thread and attaches the uploaded file.
4 | Run Assistant | Starts the run using your assistant_id.
5 | Poll Run Status → Wait 2 s → IF | Loops until status = completed.
6 | Fetch Summary | GET /v1/threads/{thread_id}/messages → summary JSON.

🖌️ Customisation ideas

• Edit the user prompt in Create Thread to change summary length, tone, or language.
• Add an HTTP Response node after Fetch Summary to return plaintext to the uploader.
• Replace the polling loop with OpenAI’s forthcoming wait-for-run endpoint when available.

No community nodes required. Works on any n8n Cloud plan (Starter, Pro, Enterprise) or self-hosted Community Edition.