n8n - 💡(How to fix) Fix AI Agent tools fail with “schema must be type: 'object', got 'None'” in n8n v2.17 (works in v2.15) [1 comments, 2 participants]

Bug Description

Hi team,

I’m seeing a breaking issue with AI Agent tools after upgrading n8n. The exact same setup works perfectly on v2.15, but fails on v2.17.x.

Environment n8n version: 2.17.x

Deployment: self-hosted

AI provider: OpenAI

Model: (e.g. gpt-4.1-mini, gpt-4o, etc.)

Affected nodes: AI Agent + tools (Google Docs, Google Calendar, etc.)

Summary When using an AI Agent with OpenAI chat models and connecting tools (Google Docs, Google Calendar, etc.), the Agent fails before it can call any tool and returns an error like:

schema must be type: "object", got "None"

If I downgrade the exact same instance to n8n v2.15, and recreate the workflow from scratch with the same tools, credentials, and model, everything works without any errors.

So this looks like a regression in how tool schemas are generated/validated in v2.17.x.

What I’m doing Create a new workflow from scratch on n8n 2.17.x.

Add an AI Agent node using an OpenAI chat model.

Add one or more tools, for example:

Google Docs tool

Google Calendar tool

Connect those tool nodes to the Agent’s Tools input.

Run the workflow and send a prompt that should trigger one of the tools.

Expected behavior The AI Agent should be able to call the tools normally (as it does in n8n 2.15).

No schema errors should be thrown as long as the tool nodes are configured correctly.

Actual behavior The AI Agent fails with an error similar to:

schema must be type: "object", got "None"

This happens even with brand new workflows created directly on 2.17.x (not migrated ones).

Downgrading n8n back to 2.15 and recreating the same workflow makes the issue disappear.

Notes / Observations The error message suggests that the tool’s JSON schema sent to OpenAI has type: None instead of type: "object".

Based on other reports with vector store tools, this kind of error can happen when the tool definition (name/description/schema) is incomplete or when the tool node generates an invalid schema for function calling.

In my case, I’m just using the standard Google Docs / Calendar tools exposed to the AI Agent, not any custom schema. The only variable that changes is the n8n version.

Questions Is there any known change in v2.17.x that would require a different way of defining tools for AI Agents?

Are there known issues around tools generating type: None schemas in 2.17.x similar to the vector-store tool regressions in other versions?

Any recommended workaround besides downgrading back to 2.15?

I’m happy to provide:

Screenshots of the AI Agent and tool node configuration

The full error stack trace from the logs

A minimal export of the failing workflow

Thanks a lot for your help and for n8n!

To Reproduce

Create an AI agent, add google docs tool and run

Expected behavior

In 2.15 works normaly

Debug Info

schema must be type: 'object', got 'None

Operating System

macos

n8n Version

2.7.8

Node.js Version

24

Database

SQLite (default)

Execution mode

main (default)

Hosting

self hosted