Create Custom PDF Documents from Templates with Gemini & Google Drive

This workflow contains community nodes that are only compatible with the self-hosted version of n8n. ## 1 - What Does It Do / Which Problem Does It Solve? This workflow turns Google Docs-based contract & form templates into **ready-to-sign PDFs in minutes**—all from a single chat flow. - **Automates repetitive document creation.** Instead of copying a rental, sales, or NDA template and filling it by hand every time, the bot asks for the required values and fills them in. - **Eliminates human error.** It lists every mandatory field so nothing is missed, and removes unnecessary clauses via conditional blocks. - **Speeds up approvals.** The final draft arrives as a direct PDF link—one click to send for signing. - **One template—unlimited variations.** Every new template you drop in Drive is auto-listed with **zero workflow edits**—it scales effortlessly. - **100% no-code.** Runs on n8n + Google Apps Script—no extra backend, self-hosted or cloud. --- ## 2 - How It Works (Detailed Flow) 1. **Template Discovery** The **TemplateList** node scans the Drive folder you specify via the `?mode=meta` endpoint and returns an `id / title / desc` list. The bot shows this list in chat. 2. **Selection & Metadata Fetch** The user types a template name. **GetMetaData** opens the chosen Doc, extracts `META_JSON`, placeholders, and conditional blocks, then lists mandatory & optional fields. 3. **Data-Collection Loop** - The bot asks for every **placeholder** value. - For each **conditional block** it asks **Yes** / **No**. Answers are accumulated in a `data` JSON object. 4. **Final Confirmation** The bot summarizes the inputs—when the user clicks **Confirm**, the *DocProcess* sub-workflow starts. 5. **DocProcess Sub-Workflow** | Step | Node | Task | | --- | --- | --- | | 1 | **User Choice Match Check** | Verifies name-ID match; throws if wrong | | 2 | **GetMetaData (renew)** | Gets the latest placeholder list | | 3 | **Validate JSON Format** | Checks for missing / unknown fields | | 4 | **CopyTemplate** | Copies the Doc via Drive API | | 5 | **FillDocument** | Apps Script fills placeholders & removes blocks | | 6 | **Generate PDF Link** | Builds an `export?format=pdf` URL | 6. **Delivery** The master agent sends **Download PDF** & **Open Google Doc** links. 7. **Error Paths** - `status:ERROR, missing:[]`—bot lists missing fields and re-asks. - `unknown:[]`—template list is outdated; rerun *TemplateList*. - Any Apps Script error—the returned `message` is shown verbatim in chat. --- ## 3 - Setup Steps (Full Checklist) > Goal: Get a flawless PDF on the first run. > > Mentally **tick** the ☑️ in front of every line as you go. > ### A. Google Drive Preparation | Step | Do This | Watch Out For | | --- | --- | --- | | 1 | Create a `Templates/` folder—put every template Doc inside | Exactly **one** folder; **no** sub-folders | | 2 | Placeholders in every Doc are **`{{UPPER_CASE}}`** | No Turkish chars or spaces | | 3 | Wrap optional clauses with **`[[BLOCK_NAME:START]][[BLOCK_NAME:END]]`** | The `START` tag must have a **blank line above** | | 4 | Add a `META_JSON` block at the very end | Script deletes it automatically after fill | | 5 | Right-click Doc > **Details & Description** = 1-line human description | Shown by the bot in the list | | 6 | Create a second `Generated/` folder (for copies) | Keeps Drive tidy | > ☑️ Folder ID (long alphanumerical) = <TEMPLATE_PARENT_ID> > > We'll paste this into the TemplateList node next. > [Simple sample template—Template Link](https://www.notion.so/Simple-sample-template-Template-Link-22b3f8a1e57f8070beacd034ba6f557f?pvs=4) --- ### B. Import the Workflow into n8n ```bash Settings – Import Workflow – DocAgent.json ``` If nodes look **Broken** afterwards—no community-node problem; you only need to select credentials. --- ### C. Customize the TemplateList Node 1. Open **Template List** node – replace `%3CYOUR_PARENT_ID%3E in parents` with the real **folder ID** in the **URL**. 2. Right-click node > **Execute Node**. 3. Copy the entire JSON response. 4. In the editor paste it into: - **DocAgent**—*System Prompt* (top) - **User Choice Match Check**—*System Prompt* (top) Save. > Why manual? Caching the list saves API tokens. Whenever you add a template, rerun the node and update the prompts. --- ### D. Deploy the Apps Script | Step | Screen | Note | | --- | --- | --- | | 1 | Open Gist files **GetMetaData.gs** + **FillDocument.gs**—*File – Make a copy* | Both files may live in one project | | 2 | *Project Settings* > enable **Google Docs API** & **Google Drive API** | Otherwise, you'll see 403 errors | | 3 | *Deploy*