SoloStack

Email marketing that your AI agent deploys and runs. No sign-ups, no dashboards, no SaaS subscriptions.

You say: "Set up email marketing for my site." Your AI agent provisions a Cloudflare Worker, creates a database, verifies your sending domain, and hands you a working email stack. Then it runs it — subscribing users, sending broadcasts, tracking delivery — all through conversation.

The Demo

You:    Set up email marketing on zeroheadcount.com
Claude: I'll provision your email stack now.

        ✅ Worker deployed: solostack-zeroheadcount.ivy-audit.workers.dev
        ✅ D1 database created with subscriber + email log tables
        ✅ Secrets configured (API keys, bearer token)
        ✅ Health check passing

        Next: I need to verify your sending domain.
        Add these DNS records to zeroheadcount.com:
          CNAME  bounce  →  bounce.resend.net
          TXT    ...     →  v=spf1 include:...
          TXT    ...     →  v=DKIM1; p=...

You:    Done, added them.
Claude: Verifying... ✅ Domain verified. Webhook registered.

You:    Send a welcome email to [email protected]
Claude: ✅ Sent "Welcome to Zero Headcount" to [email protected]

You:    How many subscribers do I have?
Claude: 47 active subscribers. 3 unsubscribed this week.

No CLI commands. No config files. No dashboard tabs. Just conversation.

How It Works

SoloStack is two things:

1. A provisioner — a local MCP server that creates your email infrastructure via Cloudflare and Resend APIs
2. An email engine — a Cloudflare Worker that handles subscribers, sends emails, and tracks delivery

The provisioner runs locally (your AI agent connects via stdio). After setup, it acts as a gateway — proxying your email commands to the deployed worker.

Your AI Agent (Claude, Cursor, etc.)
    │
    │  stdio
    │
    ▼
Local Provisioner (12 MCP tools)
    │
    ├── Provisioning tools → Cloudflare API + Resend API
    │   (provision, upgrade, domain setup, migrate)
    │
    └── Gateway proxy → Deployed Worker /mcp
        (subscribe, send_email, broadcast, etc.)
            │
            ├── D1 database (subscribers, email log)
            ├── Resend API (email delivery)
            └── Webhook endpoint (delivery tracking)

Tools

Provisioning (runs locally)

| Tool | What it does | |------|-------------| | provision_solostack | Creates Worker + D1 database + schema + secrets. One call, full stack. | | check_status | Health check — is the worker running, what version, subscriber count | | setup_email_domain | Adds your domain to Resend, returns DNS records to add | | verify_email_domain | Polls until domain is verified, then auto-registers webhook | | migrate_subscribers | Import subscribers from CSV (any provider — just needs an email column) | | upgrade_solostack | Upload new worker bundle with rollback on health failure |

Email operations (proxied to deployed worker)

| Tool | What it does | |------|-------------| | subscribe | Add or re-activate a subscriber (idempotent) | | unsubscribe | Mark subscriber as unsubscribed | | list_subscribers | List subscribers with status/tag filtering + pagination | | get_subscriber_count | Count subscribers by status or tag | | send_email | Send a single email to one recipient | | send_broadcast | Send to all active subscribers (max 100, filterable by tag) |

Quick Start

Prerequisites

• Node.js 18+
• A Cloudflare account (free tier — 100K requests/day)
• A Resend account (free tier — 3,000 emails/month)

Let the AI do it

Add SoloStack as an MCP server in your AI client:

{
  "mcpServers": {
    "solostack": {
      "command": "npx",
      "args": ["-y", "solostack-mcp"]
    }
  }
}

Then tell your AI: "Set up email marketing on mydomain.com" and provide your Cloudflare API token, account ID, and Resend API key when asked.

The AI handles the rest — provisioning, domain verification, and all ongoing operations.

{
  "mcpServers": {
    "solostack": {
      "command": "npx",
      "args": ["tsx", "src/provisioner/index.ts"],
      "cwd": "/path/to/solostack"
    }
  }
}

Self-hosted (manual path)

npm install

# Create D1 database
npx wrangler d1 create solostack
# Copy database_id into wrangler.toml

# Set FROM_EMAIL in wrangler.toml [vars]

# Local development
cat > .dev.vars << 'EOF'
SOLOSTACK_API_KEY=your-local-dev-key
RESEND_API_KEY=re_your_resend_key
RESEND_WEBHOOK_SECRET=whsec_your_webhook_secret
EOF

npm run db:local
npm run dev

# Deploy to production
npx wrangler secret put SOLOSTACK_API_KEY
npx wrangler secret put RESEND_API_KEY
npm run db:remote
npm run deploy

After deploying, add a Resend webhook pointing to https://your-worker.workers.dev/webhook/resend for delivery tracking.

Tech Stack

• Runtime: Cloudflare Workers (serverless, free tier: 100K req/day)
• Database: Cloudflare D1 (SQLite, free tier: 5GB)
• Email: Resend API (free tier: 3,000 emails/month)
• Protocol: MCP Streamable HTTP transport
• Language: TypeScript

Architecture

src/
  index.ts              # Worker entry: routing, auth, MCP handler
  tools/
    subscribers.ts      # subscribe, unsubscribe, list, count
    email.ts            # send_email, send_broadcast
  webhooks/
    resend.ts           # Delivery tracking (Svix signature verification)
  db/
    schema.sql          # D1 schema (subscribers + email_log)
  lib/
    types.ts            # Env interface
    resend.ts           # Resend API client
  provisioner/
    index.ts            # Local MCP server (stdio transport)
    gateway.ts          # Proxy pattern — forwards tool calls to worker
    cf-api.ts           # Cloudflare API client
    resend-api.ts       # Resend API client (domain setup)
    config.ts           # ~/.solostack/config.json storage
    tools/              # Provisioning tool implementations
scripts/
  build-bundle.ts       # esbuild pipeline for worker bundle
  e2e-test.ts           # End-to-end provisioning test

Current Limitations

• Broadcast cap: 100 recipients per call (Resend free tier: 100 emails/day)
• No drip sequences yet — subscribe + broadcast only (drip engine planned)
• No analytics dashboard — query email_log via D1 for delivery stats
• Single sending domain per worker instance
• Cloudflare-only — Workers + D1 (multi-platform planned)

License

MIT