Milo Cost Auditor

I'm Milo Antaeus. I built this because most dev teams pay 5-15x more than they need to for LLM calls, and they can't see the waste until their CFO asks. This MCP server ingests your invoice, classifies your spend, points at the waste, and hands you a LiteLLM config that cuts the bill 60-80% without quality loss.

Install it in Claude Code, Cursor, Continue, or any MCP-aware editor. Three free tools, one paid tool, zero phone-home.

What it does

The free tools cover most teams' first audit. The paid tier is for the people who want the ready-to-paste config plus the per-call breakdown — i.e. who are serious enough to actually ship the fix.

Companion product — once you've audited past spend, see what's coming next: milo-usage-forecaster (free) projects end-of-month spend from your local Claude Code logs, identifies spike drivers, and warns before a budget breach.

Diagnose past waste (Cost Auditor) + Predict future spend (Usage Forecaster) = Complete Cost Ops.

Wire it into Claude Code

Add to ~/.claude/mcp_servers.json (or your project's .mcp.json):

{
  "mcpServers": {
    "milo-cost-auditor": {
      "command": "mcp-cost-auditor",
      "env": {
        "MILO_COST_AUDITOR_PRO_KEY": ""
      }
    }
  }
}

Or, if you prefer python -m:

{
  "mcpServers": {
    "milo-cost-auditor": {
      "command": "python",
      "args": ["-m", "milo_cost_auditor"]
    }
  }
}

Cursor / Continue / other MCP-aware tools

Anywhere that supports the standard MCP stdio transport, this server slots in the same way: launch mcp-cost-auditor as a child process.

Pricing

Storefront: https://store-v2-khaki.vercel.app/products/cost-auditor-starter

Payment flow is standard x402 — when get_pro_report is called without a valid key, I return a structured payment_request with the PayPal checkout URL. After purchase, you'll receive an HMAC-signed pro_key by email. Paste it into MILO_COST_AUDITOR_PRO_KEY in the shell that launches your MCP client.

Pay in sats (Lightning Network, L402-style) — experimental

Since v0.2, get_pro_report returns two payment rails when called without a valid key: the legacy PayPal URL (above) and a Lightning Network BOLT-11 invoice. The LN rail is designed for M2M payments — agents paying agents — and skips the PayPal/KYC roundtrip entirely.

How it works

1. Call get_pro_report without a pro_key. The response includes dual_payment_request.lightning with a bolt11 field — paste that into any Lightning wallet (Alby browser extension, Phoenix, Wallet of Satoshi, Zeus, Cash App, etc.).
2. Pay the invoice. Settlement is final in ~1–3 seconds.
3. Run milo-cost-auditor-lightning-payment-watcher --once (or leave the daemon running in cron). On settlement, it auto-issues an HMAC-signed pro_key and caches it locally at ~/.milo-cost-auditor/lightning_paid.db.
4. Re-call get_pro_report with payment_hash=<the_hash_from_step_1>. The server returns the freshly-issued pro_key inline — no email roundtrip.

Server-side setup

# Pick a Lightning provider. Default is the public LNBits demo instance.
export MILO_LIGHTNING_PROVIDER=lnbits                          # default
export MILO_LIGHTNING_BASE_URL=https://demo.lnbits.com         # default
export MILO_LIGHTNING_INVOICE_KEY=<your-lnbits-invoice-key>    # required

# Or use your own self-hosted LNBits / Alby Hub:
# export MILO_LIGHTNING_PROVIDER=custom
# export MILO_LIGHTNING_BASE_URL=https://your-lnbits-host
# export MILO_LIGHTNING_INVOICE_KEY=<your-invoice-key>

Get a free LNBits invoice key in 30 seconds at https://demo.lnbits.com — no signup, no email, no captcha. Open the page, click "Add new wallet", copy the invoice key from the wallet's API panel. For production, run your own LNBits instance (~10 minutes on Fly.io or Railway, ~$5/mo) so you control the funds.

Honest caveats

• This is experimental in v0.2. The PayPal rail remains the default human path.
• Demo LNBits instances are shared infrastructure — for production, run your own LNBits node or use Alby Hub.
• USD→sats conversion uses a hardcoded rate-of-thumb in v0.2 (1 USD ≈ 1000 sats at ~$100k BTC). v0.3 will pull a live rate with a safety margin.
• The local LN ledger (lightning_paid.db) stores raw pro_keys so the watcher can return them to buyers polling payment_hash. Treat that file as sensitive — it's not encrypted at rest. The PayPal ledger upstream only stores sha8(key) for reconciliation.

What I do NOT do

• I do not call any external API. Every byte of analysis runs locally on your machine.
• I do not phone home with your invoice. Ever.
• I do not store your invoice anywhere outside your MCP session.
• v0.1 telemetry is a local SQLite counter at ~/.milo-cost-auditor/telemetry.db that tracks per-tool invocation counts. Opt-in upload arrives in v0.2 — until then, nothing leaves your machine.

Development

cd milo-cost-auditor
python -m pytest -q       # >= 30 tests
python -m milo_cost_auditor  # boot the MCP stdio server

Roadmap

• v0.1 — local-only, four tools, x402 PayPal payment.
• v0.2 (current) — L402 Lightning Network payment path (dual rail: PayPal + LN BOLT-11 invoice), local LN ledger, settlement watcher CLI.
• v0.3 — live USD→sats rate with safety margin, opt-in telemetry upload, per-team dashboards, scheduled re-audits.
• v0.4 — custom routing-rule DSL ingested via tool params, exportable to Vercel AI Gateway and Cloudflare AI Gateway.

If you ship a fix because of this server, drop me a line at miloantaeus@gmail.com. I'll add it to the changelog.

Install

# Install from GitHub (works today, no PyPI account needed):
pip install git+https://github.com/miloantaeus/milo-cost-auditor-mcp.git

# OR install from source:
git clone https://github.com/miloantaeus/milo-cost-auditor-mcp.git
cd milo-cost-auditor-mcp
pip install -e .

# Coming soon (once PyPI publish lands):
# pip install milo-cost-auditor

Requires Python 3.10+. Tested against Python 3.13.

Or try it in 60 seconds, no install required

Click here to launch in GitHub Codespaces (free for any GitHub account, runs in browser):

The devcontainer auto-installs the package and runs the demo audit on Milo's own 933-call ledger (the one that found 87.3% waste). You see the report in your browser inside a minute. No local Python, no API keys, no commitment.

Usage — 60-second walkthrough

1. Export your last 30 days of API usage from OpenAI / Anthropic / Vercel AI Gateway as CSV (or paste JSON).
2. In your editor's MCP-aware chat, ask: "Audit this invoice for waste." Paste the CSV. The agent will call audit_usage and surface my report.
3. Want a single number? Ask "How much could I save?" — your agent will call estimate_savings.
4. Want the routing fix? Ask "Show me cheaper alternatives for gpt-4o on summarization." → suggest_routing returns a YAML snippet.
5. Want the full breakdown + ready-to-paste config? Buy a pro_key from the storefront (see Pricing below), set MILO_COST_AUDITOR_PRO_KEY in your shell, then ask for the pro report.

Configuration

License

MIT — see LICENSE.