SkewCast plugs into Claude. You add it once — about a minute — and from then on you just ask weather questions in plain English in any chat. Claude pulls live National Weather Service data through SkewCast and, on the right plan, runs the probability math weather markets are priced on.
Add it to Claude · Bought a plan? Linking your key · What it can do · Plans & pricing · Things to ask · Other ways to connect (technical) · Data & privacy
This is the whole setup. You only do it once.
https://skewcast.com/mcpFree plan: 25 questions/day your first week, 10/day after. Every feature included.
When you subscribe, we show you a key once — a long code starting with wx_ — right after checkout, and that page walks you through these same steps. The only difference from the free setup is on the approval screen:
Lost your key? Email hello@sixthrule.dev from the address you used at checkout and we'll issue a replacement within a day. Your subscription is the account; the key is just a handle.
Already connected free and then upgraded? Remove SkewCast in Settings → Connectors, add it again, and pick the link-your-key option this time.
You never pick from this list — you just ask, and Claude reaches for the right one. This is so you know what's on the menu.
| Ability | What it answers | Unlimited on |
|---|---|---|
| Forecast | The standard forecast for any U.S. spot, day and night, up to 7 days out — temperature, rain chance, wind, conditions. | All plans |
| Severe-weather alerts | Active warnings, watches, and advisories for a state or an exact spot — know before the crew loads the truck. | All plans |
| Hour-by-hour | The forecast hour by hour up to 6½ days ahead. How you find a dry 6-hour window or check overnight lows for a concrete pour. | All plans |
| Past weather | What actually happened — the last week from the weather service, or up to a year back from NOAA's climate records. "How hot was Phoenix last July 4th?" | Standard & Pro |
| Probability (Monte Carlo) | Plays the forecast out 10,000 times and hands you the odds: P(high above 92°F), the percentile spread, the tail risk. The number you compare to a contract price. | Pro |
| Compare places | 2 to 8 spots side by side, ranked — a multi-job-site morning brief, or several market cities in one ask. | Pro |
Free plan: every ability above, within the daily question limit.
On the free plan you get everything — including the probability engine — capped at the daily question limit. If you ask for something your paid plan doesn't include, Claude answers from the basic forecast and tells you which plan has it. Nothing breaks.
| Free | Standard | Pro | |
|---|---|---|---|
| Price | $0 | $19/mo Subscribe → | $49/mo Subscribe → |
| Questions per day | 10/day (25/day your first week) | Unlimited (fair-use 2,000/day) | Unlimited (fair-use 5,000/day) |
| Forecasts, hourly & alerts | ✓ | ✓ | ✓ |
| Probability (Monte Carlo) | ✓ (within daily limit) | — | ✓ unlimited |
| Past weather (up to a year) | ✓ (within daily limit) | ✓ | ✓ |
| Compare places (2–8) | ✓ (within daily limit) | — | ✓ |
| Best for | Trying it this week | Daily scheduling & planning | Trading & high-stakes calls |
Subscribing takes one click: pay through Stripe, your key appears immediately after, and that page (plus the guide above) walks you through linking it. The free plan needs no card. When you hit the daily limit, Claude tells you and the counter resets at midnight UTC — nothing breaks and you lose nothing.
Tip: batch your asks. "Compare Tuesday, Wednesday, and Thursday in one answer" costs one question, not three.
Ask the way you'd ask a colleague. Claude figures out the rest.
Everything below is optional. If you connected through Claude's Connectors screen above, you're done — skip this.
If you prefer the local config-file route, add this to claude_desktop_config.json with your own key:
{
"mcpServers": {
"skewcast": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://skewcast.com/mcp",
"--header", "Authorization: Bearer wx_YOUR_API_KEY"]
}
}
}SkewCast is a hosted MCP server (streamable HTTP). Connect any MCP client to:
URL: https://skewcast.com/mcp
Header: Authorization: Bearer wx_YOUR_API_KEYClients that speak the MCP authorization spec can instead use OAuth 2.1 — discovery at /.well-known/oauth-protected-resource (dynamic registration, authorization code + PKCE). OAuth sign-in either provisions a free account or links an existing wx_ key on the consent page.
Generic clients: POST JSON-RPC to /mcp with the Authorization header above and Accept: application/json, text/event-stream. No credential returns HTTP 401. Need a key? Subscribe at skewcast.com or email hello@sixthrule.dev.
Weather data comes from the U.S. National Weather Service / NOAA (api.weather.gov, NOAA Climate Data Online) — the same primary government sources professional forecasters use and that weather-market contracts settle against. NWS data is in the public domain and not subject to copyright protection (17 U.S.C. § 403). SkewCast is not endorsed by or affiliated with NOAA or the NWS.
We collect as little as possible: your account key, its plan, connected-app records, and a per-day log of questions (which ability, when, allowed/denied) kept 35 days for billing and the daily limit. The places you ask about pass through to the weather sources to answer your question and are not retained; we never send your key or identity to them. Full details in the Privacy Policy.
Stuck on any step? Email hello@sixthrule.dev — a human answers within one business day.