n8n 3.0 自託管版僅支援 Docker：升級前檢查指南

If you self-host n8n, version 3.0 is the upgrade you cannot put off planning for. It changes how you install it, how long your Code nodes can run, which nodes still exist, and how one popular credential works. None of it is hard to handle, but every one of these changes can break a workflow that is running fine today.
Here is what is changing, and the checklist I would run through before touching the upgrade button. The release window is October 2026.
Docker becomes the only supported install
Self-hosted n8n becomes Docker-only in 3.0. npm and npx installs stop being supported. If you installed n8n with npm or npx and have been upgrading that way, that path ends here.
The move is to migrate your instance to Docker before you upgrade. That means exporting your workflows and credentials, standing up the Docker container, and confirming everything imports and runs before you point your real traffic at it. Do the migration on a copy first if you can, and keep the old instance running until the Docker one has handled a full day of real workflows without errors.
The Code node timeout drops from 5 minutes to 1 minute
The Code node timeout goes from 5 minutes down to 1 minute. Any Code node that runs longer than 60 seconds will fail after the upgrade.
This is the change most likely to catch people out, because a slow node can sit quietly in a workflow for months. Search your workflows for Code nodes that call slow APIs, process large files, or loop over big datasets. If a node is close to the limit, split the work, move the heavy part to an external service, or cache the result so the node does not have to do it every run.
Three nodes are removed
The Function, Cron, and Interval nodes are removed in 3.0. If any workflow still uses them, it will not run after the upgrade.
Function nodes are replaced by the Code node, which most people already use. Cron and Interval nodes are replaced by the Schedule Trigger node. The fix is a search and replace job: list every workflow that uses one of these nodes, rebuild the logic with the replacement, and test the workflow end to end before upgrading.
AI Agent v1 modes are retired
The AI Agent v1 modes are retired in favor of the Tools Agent. If you built agents on the v1 modes, they need to move to the Tools Agent before the upgrade.
Check each agent workflow, rebuild it on the Tools Agent, and compare the outputs. Agent behavior can shift when the underlying mode changes, so do not assume the new version will answer exactly like the old one. Test with real prompts from your own work, not just a hello world example.
The Slack credential now needs a signing secret
The Slack API credential now requires a signing secret. Workflows that post to Slack or listen for Slack events will fail if the credential is not updated.
Add the signing secret from your Slack app settings to the credential in n8n, then trigger one of the affected workflows and confirm the Slack message actually arrives. This is a five minute fix that is easy to forget and annoying to debug in production.
The prep checklist, in order
List every workflow that uses Function, Cron, or Interval nodes, and rebuild those with the Code node or Schedule Trigger.
Find Code nodes that run longer than 60 seconds and split or move the heavy work.
Move AI Agent v1 workflows to the Tools Agent and test them with real prompts.
Add the Slack signing secret to your Slack API credential and test a Slack workflow.
Migrate your npm or npx install to Docker, and run the Docker instance alongside the old one until it has handled a full day of real workflows.
Back up your workflows and credentials before the upgrade, so you can roll back if something unexpected breaks.
The theme across all of these is the same: 3.0 rewards the people who prepare and punishes the people who click upgrade on a Friday afternoon. The changes are all manageable, but they are breaking changes, which means the old way stops working rather than warning you first.
For the full breakdown with the complete prep checklist and the details on each change, the guide is here: N8n 3.0 Breaking Changes: How to Prepare