# argentina-price-index [Health: Active]

**Category:** 💻 Developer Tools  
**Repository:** https://github.com/oscarlopez-gif/argentina-price-index  
**GitHub Stars:** 0  
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**Installs:** 0  
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**Directory Page:** https://allmcps.com/mcp/argentina-price-index

## Description
Daily Argentina food & beverage price index, source-cited from public retailer prices.

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "argentina-price-index": {
    "command": "npx",
    "args": ["-y","wrangler"]
  }
}
```

## Documentation & README

# Paid Door — Argentina food & beverage price index (Cloudflare sandbox)

A minimal, working test of the video's core mechanic: **one agent request becomes a paid transaction at the edge.** A Cloudflare Worker serves a live-computed price index from D1, gated by an x402-style `402 → pay → retry → data` loop. Payment is **mocked** (shared-secret HMAC) so the whole loop runs with zero wallet setup; swapping in real x402 is a localized change.

> **Data is synthetic.** `seed/observations.sql` is generated placeholder data so the demo runs before a real scraper exists. Do not treat the numbers as real Argentine prices.

## What's here

```
paid-door-index/
├─ wrangler.jsonc         # Worker + D1 binding + sandbox vars
├─ schema.sql            # price_observations + methodology (+ future index_series cache)
├─ seed/
│  ├─ generate.mjs       # deterministic synthetic data generator (60 SKUs x 30 days)
│  └─ observations.sql   # generated seed (1,800 rows)
├─ src/index.ts          # Worker: routes + live index math + mock x402 gate
├─ agent/test-agent.mjs  # the paying "buyer": request → 402 → pay → retry → data
└─ README.md
```

## Endpoints

| Endpoint | Tier | Returns |
|---|---|---|
| `GET /v1/headline?country=AR&category=food_beverages` | free | latest index value + monthly rate (the teaser) |
| `GET /v1/index?country=AR&category=food_beverages` | paid ($0.02) | full daily series |
| `GET /v1/latest?country=AR&category=food_beverages` | paid ($0.02) | latest reading + methodology |
| `POST /mcp` | — | MCP JSON-RPC: `initialize`, `tools/list`, `tools/call` |

### MCP interface (what agents actually call)

The Worker also speaks **MCP over HTTP** at `/mcp`, exposing two tools:

- `get_ar_food_headline` (free) — latest value + 30-day rate
- `get_ar_food_price_index` (paid, $0.02 mock-x402) — full daily series; call once with no `_payment` to receive a challenge, then retry with `arguments._payment = {nonce, resource, amount, signature}`

Test the full agent flow (with `npm run dev` running):

```bash
npm run agent:mcp     # initialize → tools/list → free call → paid call (challenge → pay → data)
```

> **Production note:** `/mcp` here is a minimal JSON request/response subset of the Streamable HTTP transport (no SSE/sessions/auth). For a real deployment use the official MCP SDK or Cloudflare's `agents` `McpAgent`, and replace the mock HMAC with a real x402 facilitator.

Index math (`methodology_version = v0-simple-avg`): `index = 100 × mean(price_t / price_base)` over in-stock SKUs, base = first day in the window. Upgrade path baked into the schema: geometric mean within category + Laspeyres across categories.

## Run it locally

Prereqs: Node 18+ and a Cloudflare account (`npx wrangler login`).

```bash
cd paid-door-index
npm install

# 1. Create the D1 database, then paste the printed database_id into wrangler.jsonc
npm run db:create

# 2. Load schema + seed into LOCAL D1
npm run schema:local
npm run seed:gen        # (optional) regenerate observations.sql
npm run seed:local

# 3. Start the Worker
npm run dev             # serves http://127.0.0.1:8787

# 4. In a second terminal, run the paying agent
npm run agent
```

Expected agent output: the free headline, then a `402` with a price challenge, then a `200` with the full series and a `PAYMENT-RESPONSE` settlement header — one request turned into a transaction.

## Deploy to your account

```bash
npm run schema:remote
npm run seed:remote
npm run deploy
# then point the agent at the deployed URL:
BASE=https://paid-door-index.<your-subdomain>.workers.dev npm run agent
```

Watch live logs with `npx wrangler tail`.

## Sandbox → real (later)

1. **Real data:** replace `seed/generate.mjs` with a scheduled Worker that scrapes 1–2 Argentine online grocers daily into `price_observations`.
2. **Real payment:** replace the HMAC mock in `src/index.ts` (`verifyPayment` / `challenge`) with a real x402 facilitator (`POST /verify`, `POST /settle`) per Cloudflare's Agents x402 docs.
3. **Move the secret:** `npx wrangler secret put MOCK_PAYMENT_SECRET` instead of the plain var.
4. **Expose as MCP** so any AI agent (including this assistant) can call `get_index` directly.
5. **Materialize** `index_series` as a nightly cache once query volume grows.

## Notes / caveats

- Mock payment proves knowledge of a shared secret — it is **not** cryptographic on-chain settlement. It exists only to exercise the request/response shape.
- No replay protection in the sandbox (any valid signature can be reused). Real x402 settlement handles this.
- The synthetic monthly rate is intentionally noisy; single-endpoint inflation reads jump around, which is itself a good classroom point.