n8n is the most popular automation platform for AI agencies. If you're running AI workflows for multiple clients, Vol 4 shows you exactly what each client costs — per workflow, per model, per day.
Setup
Step 1
Get your Vol 4 proxy URL
Sign up at vol4.ai and copy your unique proxy URL from the dashboard. It looks like
https://proxy.vol4.ai/v1/your-key.Step 2
Open your n8n workflow
Find the HTTP Request node that calls OpenAI (or Anthropic/Google). It usually points to
https://api.openai.com/v1/chat/completions.Step 3
Swap the base URL
Replace the OpenAI URL with your Vol 4 proxy URL. Your API key stays the same — Vol 4 passes it through.
Step 4
Add the client header
In the HTTP Request node, add a header:
X-Vol4-Client: client-name. This tags every request to a specific client.Step 5
Deploy and check
Run the workflow. Within 60 seconds, your Vol 4 dashboard shows the request, cost, tokens, and which client it belongs to.
Code
// n8n HTTP Request node settings: URL: https://proxy.vol4.ai/v1/chat/completions Method: POST Headers: Authorization: Bearer sk-your-openai-key X-Vol4-Client: haufe-group Content-Type: application/json // That's it. One URL change + one header.
Why this matters
Most n8n agencies track costs by eyeballing the OpenAI dashboard at the end of the month. With Vol 4, every request is tagged to a client the moment it fires. You'll catch unprofitable clients in days, not months.
Start tracking in 5 minutes
Sign up for Vol 4, get your proxy URL, and see per-client costs on your first API call.
Get Early Access