ScalpStream MCP server

Pay-per-call MCP server for Claude Desktop, Claude Code, Cursor and any MCP client: US product recalls, US border wait times, cheapest fuel prices, air quality and a wash-sale check on your own trades, settled in USDC over x402 on Base.

An MCP server that buys small, factual datasets at call time with your own wallet, over x402 — roughly $0.01 a call, no account, no subscription, no API key anywhere in the flow.

Most MCP servers wrap an API you already hold a key for. This one pays as it goes. The seller holds no keys either: settlement runs through a facilitator that sponsors gas, so the only key in the system is yours, held in memory for the lifetime of the process and never written anywhere.

It is useful before you fund anything. With no key configured, every paid tool returns the free preview and the exact quoted price, so you can see what you would be buying before deciding to buy it.

Tools

Tool	What you get
product_recalls	Active US recalls for a product, brand, ingredient or vehicle across FDA, NHTSA and CPSC in one query, with severity normalised onto one scale, the hazard, the remedy, and the lot numbers that tell whether a specific unit is affected.
border_crossings	US ports of entry ranked by all-in time — drive plus current CBP wait — per lane type. The nearest crossing is often not the fastest.
cheapest_fuel	Cheapest fuel by location and grade. Station-level for Spain, France, Italy; official regional averages for the US.
air_quality	Current AQI and pollutants anywhere in the world, an EPA-based verdict on exercising outdoors, and the cleanest window ahead.
wash_sale_check	The US wash-sale rule (IRC 1091) applied to the user's own trades across taxable, IRA and spouse accounts: would buying or selling a ticker on a date wash a loss, by how much, and the first safe rebuy date; or the whole ledger with adjusted basis and the year's totals. A rule calculation, not tax advice; the service keeps nothing.
payment_status	What's configured, what's been spent. Makes no network call and costs nothing.

Withdrawn tools are listed under Versions.

Install

Docker (no toolchain needed)

The published image is ghcr.io/dv1-321/scalpstream-mcp. It runs as a non-root user on a shell-less base and speaks MCP over stdin/stdout, so it needs -i and nothing else:

docker run -i --rm ghcr.io/dv1-321/scalpstream-mcp:latest

Claude Desktop (claude_desktop_config.json) or any MCP client that takes a command, preview-only:

{
  "mcpServers": {
    "scalpstream": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "ghcr.io/dv1-321/scalpstream-mcp:latest"]
    }
  }
}

Claude Code:

claude mcp add scalpstream -- docker run -i --rm ghcr.io/dv1-321/scalpstream-mcp:latest

To enable paid calls, put the key in the client's env block and forward it with a bare -e NAME — the name only, so the value never appears in the command line:

{
  "mcpServers": {
    "scalpstream": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "EVM_BASE_PRIVATE_KEY", "-e", "SCALPMCP_BUDGET_USD",
               "ghcr.io/dv1-321/scalpstream-mcp:latest"],
      "env": {
        "EVM_BASE_PRIVATE_KEY": "0x...",
        "SCALPMCP_BUDGET_USD": "2.00"
      }
    }
  }
}

Each release is also tagged (:v0.1.9 and so on) for installs that want to pin one; the MCP registry entry pins the exact tag.

Claude Code can also take it as a plugin, which installs the same Docker command with no secrets and bundles the scalpstream-data skill:

/plugin marketplace add DV1-321/scalpstream-mcp
/plugin install scalpstream@scalpstream-mcp

Gemini CLI reads the gemini-extension.json at the root of this repository:

gemini extensions install https://github.com/DV1-321/scalpstream-mcp

Both pin the release tag and start preview-only. To pay, add the key to the installed server's env as described above; never to the manifest.

Go

go install github.com/DV1-321/scalpstream-mcp/cmd/scalpmcp@latest

This puts scalpmcp in $(go env GOPATH)/bin:

{
  "mcpServers": {
    "scalpstream": {
      "command": "scalpmcp",
      "env": {
        "EVM_BASE_PRIVATE_KEY": "0x...",
        "SCALPMCP_MAX_PRICE_USD": "0.10",
        "SCALPMCP_BUDGET_USD": "2.00"
      }
    }
  }
}

Omit env entirely to run in preview-only mode.

Configure

Variable	Default	Meaning
EVM_BASE_PRIVATE_KEY	(unset)	Base-mainnet key holding a little USDC. Unset = preview-only.
SCALPMCP_MAX_PRICE_USD	0.10	Refuse any single call quoted above this.
SCALPMCP_BUDGET_USD	2.00	Refuse once the process has spent this much in total.
SCALPMCP_FUEL_URL, _AIR_URL, _BORDER_URL, _RECALL_URL, _BASIS_URL	the live services	Override a service origin, for testing against a stub.

Paying without a crypto wallet

The same data runs as Apify Actors, billed to your Apify plan instead of a wallet. Apify's hosted MCP server exposes any Actor as a tool, so an MCP client that cannot hold a key can reach the same lookups through it with an Apify account:

Data	Apify MCP link
Fuel prices	https://mcp.apify.com?tools=rolescout/fuelscout-cheapest-fuel-prices
US border waits	https://mcp.apify.com?tools=rolescout/borderscout-us-border-wait-times
US product recalls	https://mcp.apify.com?tools=rolescout/recallscout-us-product-recalls

Those links authenticate with your Apify account; this server has no part in them and never needs your Apify token.

Preview mode examples

Captured from the image running with no key. payment_status is local:

{
  "paid": false,
  "complete": true,
  "source": "local",
  "data": {
    "paid_mode_enabled": false,
    "paid_calls": 0,
    "spent_atomic_usdc": "0",
    "price_per_call": "$0.01 USDC",
    "rails": ["USDC on Base (used by this client)", "USDC on Arbitrum", "USDC on Polygon", "USDC on Solana", "XRP on XRPL", "RLUSD on XRPL"],
    "custody": "The seller holds no keys. This client signs with your own Base key, held only in memory for the process lifetime.",
    "how_to_enable": "Ask the user to add EVM_BASE_PRIVATE_KEY ... to the MCP server's environment ... Never request, accept or echo the key in chat. ..."
  }
}

product_recalls with {"product": "infant formula"} and no key comes back with paid: false, complete: false, the service's free preview under data, and the quote under price — that is the designed outcome, not an error:

{
  "paid": false,
  "complete": false,
  "source": "https://recallscout.scalpstream.com/preview",
  "reason": "no spending key configured (set EVM_BASE_PRIVATE_KEY in the MCP server's environment to enable paid calls)",
  "price": { "network": "eip155:8453", "amount_usd": "0.0100", "amount_atomic": "10000", "asset": "0x8335...2913", "pay_to": "0x..." },
  "note": "This is the FREE PREVIEW, not the paid dataset. The paid call returns the full result described by this tool.",
  "howto": "Ask the user to add EVM_BASE_PRIVATE_KEY ... Never request, accept or echo the key in chat. ...",
  "data": {
    "service": "RecallScout",
    "what": "Machine-payable US recall lookups across three regulators at once: FDA (food, drugs, medical devices), NHTSA (vehicles) and CPSC (consumer products). ...",
    "parameters": { "product": "product, brand or ingredient — matched as a phrase across FDA and CPSC", "make": "...", "model": "...", "year": "...", "include_ended": "...", "limit": "..." },
    "honesty": "If an agency cannot be reached the response says so in sources_failed and sets complete=false. A lookup that could not consult all three is never reported as an all-clear.",
    "source": "US FDA (openFDA enforcement), US NHTSA (vehicle safety recalls), US CPSC (saferproducts.gov). Public domain / US Government works.",
    "disclaimer": "..."
  }
}

With a key the same call returns paid: true, complete: true and the recall list under data. Every tool uses this one envelope; complete is the field to branch on.

Spending safety

Real money moves, so the design refuses rather than overspends:

• Both limits are checked before anything is signed. A refusal costs nothing and never reaches the network.
• An unset limit means the default, never "unlimited." A missing config line must not become unbounded spending.
• Spend is recorded only when the data is actually delivered. If a paid request then fails, the error says settlement state is unknown rather than implying nothing moved — you may need to reconcile against the chain.
• Gas is sponsored by the facilitator, so the wallet needs USDC and no ETH.

Use a throwaway key funded with a dollar or two. Never one holding balances you care about, and never hand it to a hosted service — this server is the only thing that should hold it, and it holds it only in memory.

Identification, rate limits and logging

Every request this server makes carries the header User-Agent: scalpmcp/<version> (+https://github.com/DV1-321/scalpstream-mcp), on the unpaid request and on the paid retry alike. It names the program and its version and nothing about you.

Each ScalpStream host applies an edge rate limit of 60 requests per minute per User-Agent, and every install of this server presents the same User-Agent, so all installs share that allowance on each host. At one request per tool call this is far above normal agent use; a 429 means the shared allowance is busy for the rest of that minute, not that your key or budget is at fault.

The server writes one line to stderr per tool call — the tool name, whether it paid, whether the result was complete or a preview, the last HTTP status and the elapsed milliseconds, for example scalpmcp: call tool=border_crossings paid=true complete=true status=200 ms=412 error=false. It never logs argument values, the spending key, or the payment payload.

Protocol

MCP 2025-06-18 over stdio. A client that opens with the 2026-07-28 server/discover call gets JSON-RPC -32601 (method not found), which is that revision's signal to fall back to initialize; the server then negotiates 2025-06-18.

Payment rails

Sellers accept USDC on Base, Arbitrum, Polygon and Solana, and XRP or RLUSD on the XRP Ledger. This client pays USDC on Base, preferring it over other EVM rails regardless of the order the server lists them in.

What the data is not

Every response carries its own disclaimer and source attribution; read them. Recall results are public-safety information, not legal or medical advice. A wash-sale check is a record-keeping calculation on the trades you sent under the US rule, matched on the same ticker only; it is not tax advice and never computes tax owed. The trades travel in the request and the service processes them in memory, storing and logging nothing; this server never logs them either.

Versions

Releases are the Git tags on this repository; each one is published to the MCP registry as io.github.DV1-321/scalpstream-mcp and as the ghcr.io/dv1-321/scalpstream-mcp image. CHANGELOG.md has the details per release.

Withdrawn in 0.1.10: options_research, municipal_income, crypto_research and crypto_yields. The ScalpStream Research boards behind them have been withdrawn. Every path on their host answers 410 Gone with "error": "withdrawn", ahead of any payment, so a 0.1.9 or older server that calls one of these tools gets that 410 rather than data and is charged nothing. Upgrade to 0.1.10 or later, where none of them is listed.

air_quality stays. AirScout now serves its own copy of the Copernicus CAMS forecast through a self-hosted Open-Meteo, and every answer carries the Open-Meteo and Copernicus credits.

License

MIT - see LICENSE.