Slack App Mention File Analyzer with E2B + GPT-4o in n8n

Instantly analyze Slack file uploads from app mentions—using E2B sandbox + GPT-4o in n8n

This n8n workflow listens for Slack app_mention events, grabs the mentioned (or most recent) uploaded file, runs analysis inside an E2B isolated environment with GPT-4o, and posts back a concise explanation plus an AI-generated chart directly in the same Slack thread.

What this workflow does

• Receives Slack Events via Webhook: Accepts a POST from a Slack Bolt app containing an app_mention event and immediately returns 202 Accepted.
• Reacts and locates the file: Adds an 👀 reaction to the mentioned message. If no file is attached to the mention, it looks up the most recent file upload in the same channel/user context.
• Normalizes the request: Extracts the user question, thread metadata, and the selected Slack file ID/download URL.
• Downloads and analyzes in E2B: Fetches Slack file metadata, downloads the attachment, creates an E2B code-interpreter sandbox, and uploads the file into the sandbox.
• Runs GPT-4o + Python analysis: Uses OpenAI (GPT-4o) to execute pandas/matplotlib analysis and produce a Slack-ready written summary plus /home/user/analysis.png.
• Uploads chart back to Slack: Verifies the PNG exists; if missing, generates a deterministic fallback chart, then uploads the chart to Slack with the AI’s explanation as the thread comment.
• Cleanup: Terminates the E2B sandbox to clean up resources.

Use cases

• Turn “Hey, analyze this file” Slack mentions into automated insights for ops and support teams.
• For SaaS operators: quickly summarize uploaded CSVs/XLSX files and return a visual in-thread.
• For automation engineers: a ready-to-use pattern combining Slack + E2B + GPT-4o with safe sandbox execution.

Technical details

• n8n nodes: code node, Slack node, Webhook, E2B (e2bn8n-nodes-e2be2b) nodes
• Integrations: Slack (Bolt app + Events API payload forwarded with X-Bolt-Secret), E2B code interpreter sandbox, OpenAI GPT-4o
• Core output: thread comment with concise explanation + chart image upload (analysis.png)