Score ICP fit with Claude or ChatGPT when a lead replies positively

When a reply is labeled Interested, a webhook sends the thread to n8n, which asks Claude or ChatGPT to score ICP fit and writes the score back to a custom field through the Master Inbox API.

AI agents

n8n

OpenAIRevOpsFounderTeam plan

When

Add LabelInterested

Then

Send a webhookSend the prospect id, company, reply text and thread URL to n8n, which scores fit and calls update-prospect

Why teams run it

Replaces copying threads into a chat window, and the score is ready for routing and reply agents.

Set it up in Master Inbox

In Master Inbox, open Settings, then Workflows, and click Add a workflow.
Name it Score ICP fit with Claude or ChatGPT when a lead replies positively.
Set the trigger to Add Label and choose Interested.
Add the action Send a webhook: Send the prospect id, company, reply text and thread URL to n8n, which scores fit and calls update-prospect.
Save the workflow and switch it to Active.

Or create it with the API

Everything in the workflow builder is also in the Master Inbox API. This request creates the same workflow. Replace the example ids with your own label, list and campaign ids from GET /workflows/filter-fields.

curl -X POST https://api.masterinbox.com/api/api-webhook/v1/api/workflows/create-workflow \
  -H "Authorization: Bearer $MASTER_INBOX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "name": "Score ICP fit with Claude or ChatGPT when a lead replies positively",
  "trigger_type": "add_label",
  "trigger_config": {
    "label_ids": [
      176479
    ]
  },
  "action_configs": [
    {
      "action_type": "webhook",
      "webhook_url": "https://hooks.example.com/master-inbox",
      "webhook_payload_variables": [
        "name",
        "email",
        "company_name",
        "label_names",
        "thread_url",
        "text"
      ]
    }
  ]
}'

Full reference: workflow API guide and API docs.

Or ask Claude, ChatGPT or Grok to build it

Our workflow guide is written for AI agents to read. Give your assistant your API key and this prompt:

Read https://app.masterinbox.com/public-workflow-api.md and use my Master Inbox API key to create this workflow: "Score ICP fit with Claude or ChatGPT when a lead replies positively". First call GET /workflows/filter-fields and look up my label, list and channel ids, then create the workflow and tell me what you set up.

Questions

Can the reply agent use the score?

Yes. Custom fields can be used as variables in reply agent prompts.

Which endpoint writes the field?

PATCH /update-prospect with the custom field.

Can I build this workflow through the API?

Yes. Send the create-workflow request shown on this page with your Master Inbox API key. The API checks the payload first and lists every problem by field if anything is off.

Which plan includes this?

This workflow works on the Team plan. Every plan has unlimited users and starts with a free 7-day POC.