Guide — real sending live in production; free sandbox available — verified 2026-07-19

Run your entire cold email operation with Cursor

Cursor drives the same Coldrig MCP server, the same 24 tools, and the same sandboxed-today boundary as Claude Code — the full provisioning-to-reply lifecycle is identical. What's genuinely different is how you connect it and how you make the workflow repeatable: Cursor takes a hand-edited mcp.json instead of a CLI command, and it has its own convention (Rules) for storing reusable agent instructions instead of Claude Code's Skills. This page covers only that delta; for the full step-by-step lifecycle (provisioning through reply triage) see the Claude Code guide — every tool call there works identically from Cursor.

Honest status disclosure The hosted API, MCP endpoint, and npm CLI are live in production. Real sending is live (Gmail API, HTTPS/443) for activated accounts; new accounts activate through a short concierge step while self-serve activation rolls out, and the free sandbox remains available with no real domains, mailboxes, or sends. See FAQ for the exact status boundary.

How is Cursor's setup different from Claude Code?

Exact Cursor config

Mint a tenant token first (no card required):

curl -s -X POST https://agent-cold-email-api.yaakovscher.workers.dev/signup \
  -H 'Content-Type: application/json' \
  -d '{"brand":"Acme","contactEmail":"[email protected]"}'
# → { "tenantId": "ten_...", "token": "..." }

Then add this to personal ~/.cursor/mcp.json:

{
  "mcpServers": {
    "coldrig": {
      "url": "https://agent-cold-email-api.yaakovscher.workers.dev/mcp",
      "headers": {
        "Authorization": "Bearer ${env:COLDRIG_TOKEN}"
      }
    }
  }
}

Set COLDRIG_TOKEN where the Cursor desktop process can read it, restart Cursor, and inspect all 24 tools before you rely on the connection. Full side-by-side with Codex and Cline: the connect reference.

The lifecycle, from Cursor

Identical tool calls to every other client — Cursor just makes them through its own agent chat instead of a terminal session. Full schemas: the MCP tool reference.

StepTool call
Provision domains + mailboxes, start warmupsetup_infrastructure
Poll provisioning + warmup healthinfrastructure_status
Write and launch the campaignlaunch_campaign
Triage repliesinbox, thread, reply, mark, label_thread
Check health, pausemetrics, activity, account, pause / pause_all

What's a Cursor Rule for this, and should I write one?

Cursor's convention for repeatable, project-scoped agent instructions is a Rules file — typically a .mdc file under .cursor/rules/ in your project (the legacy single-file form is .cursorrules at the project root). Nothing below ships with Coldrig; it's a rule you write yourself so Cursor applies the same operating discipline to this project every time, instead of you restating it in chat.

---
description: Operate Coldrig-backed cold email infrastructure for this project
alwaysApply: false
---

Coldrig is connected as the `coldrig` MCP server. Read the bearer token from
the `COLDRIG_TOKEN` environment variable — never hardcode it in this repo.

- Write the offer and sequence content yourself before calling `launch_campaign`;
  Coldrig does not generate outreach copy.
- Check `activity` for new events, or subscribe a URL via `configure_webhook`
  for push delivery instead of polling.
- Never claim a real send occurred while the tenant is in demo/sandbox mode.
- Never claim guaranteed inbox placement or deliverability.

The reply-handling boundary, in short

Push webhooks are live — configure_webhook delivers reply, bounce, soft_bounce, and complaint events (HMAC-signed) to your own HTTPS endpoint. activity and inbox remain pollable too if you'd rather run Cursor on your own cadence. Full honest capability matrix: see the detailed breakdown.

Cost

Same platform, same meter, regardless of client: $99/month for 5 provisioned mailboxes, then $10/month per additional mailbox. Full worked examples and the live calculator: pricing.

Try it now

npx agent-cold-email demo

Runs the same fault-injecting sandbox end to end — no real domain, mailbox, or send. Free sign up to get a token and connect Cursor for real.

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