cheapinboxes-mcp

MCP server for the CheapInboxes API plus Porkbun domain buying — run the whole cold-email infrastructure pipeline from any MCP client (Claude Code, Cursor, Claude Desktop, …) instead of clicking through dashboards:

buy domains on Porkbun → import them into CheapInboxes → provision Google/Microsoft mailboxes → grab credentials / sync to Instantly, Smartlead, EmailBison, PlusVibe.

32 tools: 8 for Porkbun, 21 for CheapInboxes, two raw escape hatches that reach every endpoint of both APIs, and a runbook tool that teaches the model the end-to-end flow.

Setup

Requires Node 18+ (uses global fetch).

git clone https://github.com/cosankov/cheapinboxes-mcp.git
cd cheapinboxes-mcp
npm install

Keys

The two sides are independent — with only a CheapInboxes key the porkbun_* tools error cleanly and everything else works, and vice versa.

Keys are read from process.env first, then from the first .env file found: $CHEAPINBOXES_MCP_ENV → .env next to server.mjs. Easiest: copy your keys into a .env in the repo root (gitignored):

CHEAPINBOXES_API_KEY=ci_live_...
PORKBUN_API_KEY=pk1_...
PORKBUN_SECRET_KEY=sk1_...

Register with your MCP client

Claude Code / Cursor (.mcp.json):

{
  "mcpServers": {
    "cheapinboxes": {
      "command": "node",
      "args": ["/absolute/path/to/cheapinboxes-mcp/server.mjs"]
    }
  }
}

(Or pass the keys via the "env" block instead of a .env file.)

Verify

npm run smoke

Boots the server over stdio, lists all tools, live-pings Porkbun, and checks the CheapInboxes key — each side reports [OK] or a clean error telling you which key is missing.

Related MCP server: smartlead-cli

The flow

Ask your MCP client to run the runbook tool, or follow it yourself:

1. porkbun_check_domain per candidate — availability + live price. Rate limit: 1 check / 10 s.

2. porkbun_register_domain — dry_run defaults to true (preview, no charge); pass dry_run: false to buy. cost_cents must exactly match the checked price (Porkbun's own guard). Live runs auto-send an Idempotency-Key, so retries can't double-charge.

3. ci_stage_imports with the purchased domains (source_provider: "porkbun").

4. ci_quote — cart of {domain, tld, staged_import_id, mailboxes: {provider, count}}; imported domains are $0.

5. ci_checkout — same cart with mailbox personas {first_name, last_name, email_prefix}; optional integration_id auto-connects mailboxes to a sending platform. Charges the card on file.

6. Poll ci_list_domains with the returned order_id until nameservers appear (or ci_domain_nameservers per domain).

7. porkbun_set_nameservers — point each domain at the CheapInboxes nameservers.

8. Poll ci_get_domain until status: "active" (include_runs: true adds provisioning-step history for debugging).

9. ci_mailbox_credentials for logins (password, app password, IMAP/SMTP) or ci_sync_integration to push mailboxes to your sequencer.

Tool map

⚠💰 = spends real money. 🔐 = returns secrets.

The escape hatches cover everything not curated: CheapInboxes DNS records, DMARC, forwarding, webhooks, cancellations, invoices, TOTP codes, org members; Porkbun SSL bundles, glue records, email forwarding, contacts, marketplace.

Safety rails

• porkbun_register_domain previews by default; a purchase requires an explicit dry_run: false, an exact cost_cents match, and gets an idempotency key.

• ci_checkout has no server-side dry run — always run ci_quote first (identical cart shape, so it's a copy-paste).

• Rate limits: CheapInboxes 120 req/min; Porkbun 1 availability check / 10 s, 1 registration attempt / 10 s, 50 registrations / day.

• Porkbun sandbox: use pk1_sb_ / sk1_sb_ keys (and PORKBUN_BASE_URL if needed) to rehearse purchases with fake credit.

License

MIT