n8n Workflow: Explain Pasted Code with GPT-4.1 to Slack

Turn pasted code into a clear explanation—then share it to Slack with approval

This n8n workflow receives a code snippet via webhook, uses GPT-4.1 to generate a structured, line-by-line explanation, and posts the final report to a specified Slack channel—after an approval step. Perfect for teams that want fast, consistent code reviews without manual formatting.

What this workflow does

• Accept code via webhook: Sends a POST request containing the code snippet, optional language, and an optional focus question.
• Detect and measure the snippet: Determines the most likely programming language, extracts basic structure (e.g., function names), and counts code/comment/blank lines. It also estimates rough cyclomatic complexity.
• Ask GPT for a JSON explanation: Passes the code and computed metrics to an OpenAI chat model to produce a JSON explanation including a summary, selected notes, complexity analysis, issues, and suggestions.
• Parse and score quality: Reads the model’s JSON, calculates a composite quality score from complexity and flagged issues, and builds a consolidated report.
• Optional follow-up: Pauses execution for a submitter-provided follow-up question, then queries the model again using a trimmed code excerpt around any referenced line number.
• Approval gate + delivery: Pauses again for delivery confirmation; once approved, posts the final explanation (and follow-up answer, if provided) to the configured Slack channel.

Use cases

• Help developers understand unfamiliar code by sending snippets to a centralized Slack review channel.
• Standardize “code explanation” requests for SaaS support and engineering teams.
• Create a lightweight internal workflow for deterministic analysis + GPT-assisted review with human approval.

Technical details

• Nodes/logic: webhook, if, set, code, wait, slack
• Integrations: OpenAI (or compatible) Chat Model for explanation and follow-up; Slack for posting results
• Requirements: Add an OpenAI credential for the Chat Model and a Slack credential with permission to post messages and target the correct channel