Lock down n8n webhooks with shared-secret header auth

[Frezertade]

Summary

Closes the open-webhook security gap. Every data-mutating webhook now requires X-Webhook-Secret: <N8N_WEBHOOK_SECRET> on every call; n8n returns 401 otherwise.

Locked down (require auth)

• 01 - AI Listing Generator
• 02 - AI Visual Studio
• 03 - AI Ads Studio
• 04a - Etsy Connect (start OAuth)
• 05 - Etsy Listing Publish
• 07 - POD Route Order

Public exemptions

• 04 - Etsy OAuth Callback — Etsy is the caller; can't send custom headers. State + PKCE provide CSRF protection.
• 02b - Mockup View — used by <img src="…">; browsers can't send custom headers on image requests.

Internal call updates

• wf 06 - Etsy Order Sync → wf 07 ("Dispatch POD") now sends X-Webhook-Secret.
• wf 03 - Ads Studio → wf 02 (visual gen, optional) now sends X-Webhook-Secret.

Workflow 04a behavior change

Switched from rendering an HTML "Authorise on Etsy" page to returning JSON { auth_url, state, shop_name }. Without this, the ToolJet Shops tab button could no longer reach 04a (browsers can't send custom headers on window.open). The flow is now: button → REST query (with the auth header) → onSuccess opens the returned auth_url in a new tab.

ToolJet

• New workspace constant N8N_WEBHOOK_SECRET (operator sets to match n8n's env var).
• n8n_api datasource sends X-Webhook-Secret on every call.
• Shops tab "Authorise on Etsy" button uses the new query → redirect pattern.

Setup (one-time, after merge)

1. openssl rand -hex 32 → set N8N_WEBHOOK_SECRET in .env; docker compose restart n8n.
2. n8n UI → Credentials → New → Header Auth: name n8n Webhook Secret, header X-Webhook-Secret, value = the secret.
3. ToolJet UI → Workspace constants → N8N_WEBHOOK_SECRET = same value.

Test plan

• curl http://localhost:5678/webhook/listing-generate -d '{}' -H 'content-type: application/json' returns 401
• Same call with -H "x-webhook-secret: $N8N_WEBHOOK_SECRET" succeeds
• In ToolJet AI Tools tab, Generate button still works end-to-end
• In ToolJet Shops tab, "Authorise on Etsy" opens an etsy.com tab with a valid auth_url
• Etsy redirects back to /webhook/etsy-oauth-callback with no auth header (public exemption) and the shop upserts
• <img src="http://localhost:5678/webhook/mockup-view?id=1"> still renders (public exemption)
• Trigger wf 06 manually; confirm new orders dispatch to wf 07 successfully (internal call carries the header)

https://claude.ai/code/session_019vtZjGwcACasFeauRYTQnj

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Generated by Claude Code

[gitguardian]

⚠️ GitGuardian has uncovered 1 secret following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secret in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
32453737	Triggered	Generic High Entropy Secret	9036391	tooljet-apps/etsy_dashboard.json	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
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To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

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