Generate C API HTML docs from Google Drive headers with GPT-4o and Gmail

🚀 Overview This n8n workflow automatically generates professional API documentation from C header (.h) files using AI. It scans a Google Drive folder for header files, extracts the source code, sends it to GPT-4o for structured analysis, and generates a beautiful HTML documentation page. The final documentation is uploaded back to Google Drive and a completion email is sent. This workflow is ideal for embedded systems teams, firmware engineers, and SDK developers who want an automated documentation pipeline. --- ✨ Key Features ⚡ Fully automated documentation generation 📁 Reads .h files directly from Google Drive 🤖 Uses AI to analyze C APIs and extract documentation 📑 Generates clean HTML documentation 📊 Documents functions, types, enums, and constants 🔁 Processes files one-by-one for reliability ☁️ Saves generated documentation back to Google Drive 📧 Sends a completion email notification --- 🧠 What the AI Extracts The workflow automatically identifies and documents: - 📘 Overview of the header file - 🔧 Functions - Signatures - Parameters - Return values - Usage examples - 🧩 Enumerations - 🧱 Data Types & Structures - 🔢 Constants / Macros - 📝 Developer Notes --- 🖥 Generated Documentation The output is a clean developer-friendly HTML documentation page including: - 🧭 Sidebar navigation - 📌 Function cards - 📊 Parameter tables - 💻 Code examples - 🎨 Professional developer layout Perfect for: - Developer portals - SDK documentation - Internal engineering documentation - Embedded system libraries --- ⚙️ Workflow Architecture | Step | Node | Purpose | |-----|-----|--------| | 1 | ▶️ Manual Trigger | Starts the workflow | | 2 | 📂 Get all files | Reads files from Google Drive | | 3 | 🔎 Filter .h files | Keeps only header files | | 4 | 🔁 Split in Batches | Processes files sequentially | | 5 | ⬇️ Download file | Downloads the header file | | 6 | 📖 Extract text | Extracts code content | | 7 | 🤖 AI Extraction | AI extracts API structure | | 8 | 🧹 Parse JSON | Cleans AI output | | 9 | 🎨 Generate HTML | Builds documentation page | |10 | ☁️ Upload to Drive | Saves documentation | |11 | 📧 Email notification | Sends completion email | --- 🔧 Requirements To run this workflow you need: 🔹 Google Drive OAuth2 credentials 🔹 OpenAI API credentials 🔹 Gmail credentials --- 🛠 Setup Guide 1️⃣ Configure Google Drive Create two folders. Source folder Output folder Update the folder IDs in the nodes: - Get all files from folder - Save documentation to Google Drive --- 2️⃣ Configure OpenAI Add an OpenAI credential in n8n. Model used: The model analyzes C header files and returns structured API documentation. --- 3️⃣ Configure Gmail Add a Gmail OAuth credential. Update the recipient address inside: --- ▶️ Run the Workflow Click Execute Workflow. The workflow will: 1️⃣ Scan the Google Drive folder 2️⃣ Process each .h file 3️⃣ Generate HTML documentation 4️⃣ Upload documentation to Drive 5️⃣ Send a completion email --- 🖼 Documentation Preview !API Documentation Example --- 💡 Use Cases 🔧 Embedded firmware documentation 📦 SDK documentation generation 🧑‍💻 Developer portal automation 📚 C library documentation ⚙️ Continuous documentation pipelines --- 🔮 Future Improvements This workflow can be extended with several enhancements: 📄 PDF Documentation Export Add a step to convert the generated HTML documentation into PDF files using tools such as: - Puppeteer - HTML-to-PDF services - n8n community PDF nodes This allows teams to distribute documentation as downloadable reports. --- 🔐 Local AI for Security (Ollama / Open-Source Models) Instead of using the OpenAI node, the workflow can be modified to run fully locally using AI models such as: - Ollama - Open-source LLMs (Llama, Mistral, CodeLlama) These models can run on your own server, which provides: 🔒 Better data privacy 🏢 No external API calls ⚡ Faster responses on local infrastructure 🛡 Increased security for proprietary source code This can be implemented in n8n using: -