Move approved records into Grist without duplicate entries. A webhook collects data from any app, but nothing is stored until a human marks the record as confirmed. Great for teams that want a final check before data becomes part of the system.

Here is how it runs. A POST request hits the Webhook node and provides an id and a Confirmed flag. The Confirmed check allows only true values to continue. The flow then queries Grist for a row where the Source field matches the incoming id. If a match is found, the run stops to protect edits already made in Grist. If there is no match, a new row is created with the Source id. Sticky notes in the canvas describe the human review step and the single create policy.

Set up a Grist table with a Source column and connect your Grist API key in n8n. Point a form, app, or service to the webhook URL and send an id with a Confirmed boolean. Expect faster handoffs, fewer manual updates, and a clear audit of what moved. Useful for approved leads, vetted vendor entries, or content items that need sign off.

• Webhook node receives POST requests and reads the payload id
• Boolean gate only proceeds when the Confirmed flag is true
• Grist query checks if a row already exists with the same Source value
• Idempotent create writes a new row only when no match is found
• No update on existing rows to preserve manual edits in Grist
• Simple seven node design that is easy to understand and maintain

• Reduce manual copy and paste from 30 minutes a day to 3 minutes
• Eliminate 100 percent of duplicate creates for the same Source id
• Keep human control with a simple confirmed toggle before data moves
• Streamline approval handoffs by 70 percent with clear gating
• Connect incoming systems to Grist through a reliable webhook

1. Import the template into n8n: Create a new workflow in n8n > Click the three dots menu > Select 'Import from File' > Choose the downloaded JSON file.
2. You'll need accounts with Grist. See the Tools Required section above for links to create accounts with these services.
3. Prepare Grist: Create or open a document and add a table that will store the data. Add a column named Source to hold the incoming id.
4. Create Grist credentials in n8n Cloud: Double click a Grist node, open the Credential to connect with dropdown, click Create new credential, then follow the on screen steps. If using an API key, generate it in your Grist account settings and paste it into the credential along with your Grist base URL.
5. Configure the Grist nodes: In both the get existing and Create Row nodes, select the same Grist document and table. In Create Row, map the field Source to the expression {{ $json.body[0].id }}.
6. Set the lookup filter: In the get existing node, set the filter so the field Source equals {{ $json.body[0].id }}.
7. Adjust the confirmation gate: Open the Confirmed? node and point the condition to the boolean field from the payload that means approved. Set it to only allow true.
8. Copy the webhook URL from the Webhook node and use it in your source system. Send a POST with JSON that includes body[0].id and a Confirmed boolean. Example: { "body": [ { "id": "123", "Confirmed": true } ] }.
9. Test the flow: Send a confirmed record and check Grist for a new row with Source 123. Send the same record again and confirm no duplicate row is created.
10. Troubleshoot common issues: If no row is created, verify the JSON path body[0].id matches your payload. If duplicates appear, confirm the get existing filter points to the Source column and the types match.
11. Secure the endpoint by using a long random webhook path. Limit who can call it in your source system. Activate the workflow when tests pass.