AI-powered document chat with Nextcloud files using LangChain and OpenAI
### Main Workflow “AI Nextcloud”
* **Entry point**: A public chat-trigger greets the user; every incoming chat message starts the flow.
* **AI agent**: A LangChain agent (“AI Nextcloud”) uses the configured OpenAI model plus short-term memory to continue the dialogue in context.
* **Purpose**: Answers questions about files stored in a Nextcloud folder. The user simply includes the folder path in their question.
* **Tool integration**: Calls the sub-workflow “Nextcloud Tool” whenever it needs to read files and pass their text back to the AI.
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### Sub-Workflow “Nextcloud Tool”
1. **Invocation**: Triggered by other workflows with the input parameter `path` (folder path).
2. **File listing**: Retrieves every file in the specified folder via the Nextcloud API.
3. **Filter**: Allows only readable formats (PDF, Markdown, DOCX).
4. **Download & text extraction**
* **PDF** → Text via *Extract From File*
* **Markdown** → Raw text
* **DOCX** → Text via community node *word2text*
5. **Aggregation**: Combines all extracted text into a single `output` field and returns it.
> **Outcome**: Each call yields the plain content of every supported file in a Nextcloud folder—providing rich context for the AI agent to answer user questions accurately.
