ScalpStream Data

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

Each paid tool calls one ScalpStream service, and every service has its own page with a free preview and an OpenAPI document: RecallScout (product_recalls), BorderScout (border_crossings), FuelScout (cheapest_fuel), AirScout (air_quality) and BasisScout (wash_sale_check).

Withdrawn tools are listed under Versions.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 (:v0.1.13 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

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:

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.
• A paid reply that cannot be delivered is reported as paid, not as an error. If the seller answers a paid request with 200 and a body that is not JSON, is empty, or is over the 1 MiB limit, the result says paid: true, complete: false, names the reason in undelivered, and carries the payment reference in payment (the terms signed, the EIP-3009 authorization nonce, and the seller's transaction hash when it sent one), so the charge can be found rather than repeated by a retry.
• 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/ (+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 l