Hey everyone 
I’m trying to build a workflow where my AI Agent receives a text (like a course summary), and writes it to Notion in a structured way — with titles, bullet points, paragraphs, etc.
I don’t want to map each block manually in n8n, I want the Agent to do the formatting and just send the structured result to Notion.
The problem is: even when I give the Agent instructions to write the right format, I get an error when trying to send the output to Notion.
I feel like I’m missing something obvious, but I can’t figure it out.
Here’s my current n8n workflow:
{
"nodes": [
{
"parameters": {
"formTitle": "Convertir les notes de Coursera",
"formDescription": "=Utilise ce formulaire afin de transformer les transcript de cours coursera en note afin de pouvoir les réviser.",
"formFields": {
"values": [
{
"fieldLabel": "Nom du module",
"placeholder": "Titre module",
"requiredField": true
},
{
"fieldLabel": "Transcription",
"fieldType": "file",
"acceptFileTypes": ".txt",
"requiredField": true
}
]
},
"options": {}
},
"type": "n8n-nodes-base.formTrigger",
"typeVersion": 2.2,
"position": [
-100,
0
],
"id": "f177386a-57b2-46d7-8d00-3961c997a0ed",
"name": "On form submission",
"webhookId": "6348b7ff-2de9-46f1-9a8f-cba8a22d26de"
},
{
"parameters": {
"operation": "text",
"binaryPropertyName": "=Transcription",
"options": {}
},
"type": "n8n-nodes-base.extractFromFile",
"typeVersion": 1,
"position": [
120,
0
],
"id": "4a211079-59eb-43b4-b386-8ea75c0e6c82",
"name": "Extract from File",
"alwaysOutputData": false
},
{
"parameters": {
"promptType": "define",
"text": "={{ $('Extract from File').item.json.data }}",
"options": {
"systemMessage": "=### 🎯 Objectif : Résumer un transcript et ajouter le contenu structuré dans une page Notion\n\nTu reçois un transcript de cours.\n\n1. Tu dois produire un résumé **structuré** (titres, sections, bullet points).\n2. Tu vas l'ajouter à une page Notion **via l'outil appelé `append_notion_blocks`**.\n3. Tu dois découper ton contenu en plusieurs blocs Notion, en utilisant les formats suivants :\n\n- `heading_1`: pour le titre du résumé\n- `heading_2`: pour les sections\n- `bulleted_list_item`: pour les idées principales\n- `paragraph`: pour des explications\n\n4. Tu n’as pas à envoyer tout le contenu en une fois : tu peux appeler plusieurs fois l’outil `append_notion_blocks` avec une liste de blocs à chaque fois (2000 caractères max).\n\n---\n\n### ✅ Exemple de format de bloc à utiliser :\n\n```json\n{\n \"type\": \"heading_2\",\n \"heading_2\": {\n \"rich_text\": [\n { \"type\": \"text\", \"text\": { \"content\": \"Les fondamentaux de la vente\" } }\n ]\n }\n}\n"
}
},
"type": "@n8n/n8n-nodes-langchain.agent",
"typeVersion": 2,
"position": [
960,
0
],
"id": "49e24e0d-73c7-4700-9d04-18a89aebd2c4",
"name": "AI Agent"
},
{
"parameters": {
"model": {
"__rl": true,
"value": "gpt-4.1",
"mode": "list",
"cachedResultName": "gpt-4.1"
},
"options": {}
},
"type": "@n8n/n8n-nodes-langchain.lmChatOpenAi",
"typeVersion": 1.2,
"position": [
880,
200
],
"id": "f01bd74a-47ae-468e-a0eb-509c1d32ea13",
"name": "OpenAI Chat Model",
"credentials": {
"openAiApi": {
"id": "nEUxMYfTBw9JTeMf",
"name": "OpenAi account"
}
}
},
{
"parameters": {
"modelId": {
"__rl": true,
"value": "chatgpt-4o-latest",
"mode": "list",
"cachedResultName": "CHATGPT-4O-LATEST"
},
"messages": {
"values": [
{
"content": "=Lie le texte et extrait le titre dans la même langue du texte : \n\n {{ $json.data }}"
},
{
"content": "Tu dois créer un titre à partir d'un texte, tu ne propose jamais plusieurs titre, rien de superflu juste la réponse .\n\nLe titre doit être dans la même langue du texte",
"role": "system"
}
]
},
"jsonOutput": true,
"options": {}
},
"type": "@n8n/n8n-nodes-langchain.openAi",
"typeVersion": 1.8,
"position": [
340,
0
],
"id": "1d9baa35-acb5-4ade-889d-7086b8b904aa",
"name": "Message a model",
"credentials": {
"openAiApi": {
"id": "nEUxMYfTBw9JTeMf",
"name": "OpenAi account"
}
}
},
{
"parameters": {
"pageId": {
"__rl": true,
"value": "https://www.notion.so/Formation-la-vente-HubSpot-223902c2362080149b2ae62a0d17e378",
"mode": "url"
},
"title": "={{ $json.message.content.titre }}",
"options": {}
},
"type": "n8n-nodes-base.notion",
"typeVersion": 2.2,
"position": [
700,
0
],
"id": "0ba49565-33ef-4a47-9499-f24953001e89",
"name": "Create a page",
"credentials": {
"notionApi": {
"id": "4Y12d0A1j4d7mzEd",
"name": "Notion account"
}
}
},
{
"parameters": {
"resource": "block",
"blockId": {
"__rl": true,
"value": "={{ $json.id }}",
"mode": "id"
},
"blockUi": {
"blockValues": [
{
"richText": "={{ /*n8n-auto-generated-fromAI-override*/ $fromAI('blockValues0_Rich_Text', ``, 'boolean') }}"
}
]
}
},
"type": "n8n-nodes-base.notionTool",
"typeVersion": 2.2,
"position": [
1120,
300
],
"id": "eadfbb9c-22c3-4067-91c3-9d4bd1a0b489",
"name": "Append notion blocks",
"credentials": {
"notionApi": {
"id": "4Y12d0A1j4d7mzEd",
"name": "Notion account"
}
}
}
],
"connections": {
"On form submission": {
"main": [
[
{
"node": "Extract from File",
"type": "main",
"index": 0
}
]
]
},
"Extract from File": {
"main": [
[
{
"node": "Message a model",
"type": "main",
"index": 0
}
]
]
},
"OpenAI Chat Model": {
"ai_languageModel": [
[
{
"node": "AI Agent",
"type": "ai_languageModel",
"index": 0
}
]
]
},
"Message a model": {
"main": [
[
{
"node": "Create a page",
"type": "main",
"index": 0
}
]
]
},
"Create a page": {
"main": [
[
{
"node": "AI Agent",
"type": "main",
"index": 0
}
]
]
},
"Append notion blocks": {
"ai_tool": [
[
{
"node": "AI Agent",
"type": "ai_tool",
"index": 0
}
]
]
}
},
"pinData": {},
"meta": {
"templateCredsSetupCompleted": true,
"instanceId": "1148135d8af09935f1fbc9043e7cde1c4aacf716a7ce6f442c7af6891f4db26e"
}
}```
---
### ❌ Here’s the error I get:
