WattBuy MCP server

Connect to the WattBuy MCP Server

Use WattBuy's electricity, solar, and utility data right inside your favorite AI assistant. The WattBuy MCP server is a Model Context Protocol connector you can add to Claude, ChatGPT, Google Gemini, or any MCP-compatible client. You sign in with your WattBuy developer account, and every request is metered to your own WattBuy API key.

📘

New to WattBuy? You'll need a free developer account and an API key — see Before you start. It takes about a minute.

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MCP server details

Setting	Value
Endpoint URL	https://mcp.wattbuy.com/mcp
Transport	Streamable HTTP
Authentication	OAuth 2.1 (authorization code + PKCE) with Dynamic Client Registration
Scope	mcp/access

You never paste your API key into the AI client. When you connect, you log in once through WattBuy's secure sign-in page, and the server automatically uses the API key tied to your account.

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Before you start

1. Create a WattBuy developer account (free) at https://wattbuy.readme.io. Confirming your email automatically provisions your WattBuy API key and attaches it to a usage plan — no extra setup.
2. Use a supported client — Claude, ChatGPT (Plus/Pro), or Gemini CLI. See Add WattBuy to your client.

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Add WattBuy to your AI client

Claude (Claude.ai & Claude Desktop)

Available on Claude Pro, Max, Team, and Enterprise.

1. In a chat, click the + menu → Connectors (or Settings → Connectors).
2. Click Add custom connector.
3. Enter — Name: WattBuy, URL: https://mcp.wattbuy.com/mcp.
4. Click Add, then Connect — a browser window opens to sign in.
5. Sign in with your WattBuy developer account. WattBuy's tools now appear in the connectors menu.

ChatGPT (Developer mode)

Available on ChatGPT Plus and Pro, via the web app.

1. Enable developer mode: Settings → Apps & Connectors → Advanced settings → toggle on Developer mode. (Web only; can't be set from the desktop app.)
2. In Settings → Apps & Connectors, click Create (new connector).
3. Enter — Name: WattBuy, MCP Server URL: https://mcp.wattbuy.com/mcp, Authentication: OAuth.
4. Acknowledge the custom-connector confirmation and click Create.
5. In a chat, open the + menu, select WattBuy, and click Connect — sign in when prompted.

💡

Coming soon: a one-click WattBuy ChatGPT app — no manual setup needed. Until then, use the Developer-mode steps above.

Google Gemini (Gemini CLI)

Add the server to your ~/.gemini/settings.json:

JSON

{
  "mcpServers": {
    "wattbuy": {
      "httpUrl": "https://mcp.wattbuy.com/mcp"
    }
  }
}

Then start Gemini CLI and authenticate with /mcp auth wattbuy. A browser opens for WattBuy sign-in; after that, /mcp will list the WattBuy tools.

Any other MCP client

Add a remote / Streamable HTTP server pointing at https://mcp.wattbuy.com/mcp. The client discovers the login automatically (OAuth 2.1 + PKCE, with Dynamic Client Registration) — no manual endpoint or key config needed.

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Available tools

Ask naturally ("what's my utility?", "estimate solar for my ZIP", "find rebates near me") — your assistant picks the right tool.

Electricity & utility

Tool	What it does
Get Utility Info	Utility serving an address — name, phone, website, housing characteristics
Estimate Electricity Usage & Bills	12-month usage, expected bills, and carbon footprint for a home
Estimate Carbon Footprint	Carbon footprint estimate from location + electricity usage
Get Retail Electricity Rates	Retail rates and tariffs for a utility
Get Net Metering Rates	Surplus-generation (net-metering) rates for a state or utility
Look Up Texas ESI ID	ESI ID (Electric Service Identifier) for a Texas address
Get Full Electricity Details	Comprehensive property view: estimation, solar, cost, and carbon in one call
Get Energy Offers	Available energy offers for a location — electricity plans, solar, smart devices
Find Energy Incentives & Rebates	Residential incentives/rebates across solar, battery, heat pump, EV, and more

Solar & local market

Tool	What it does
Get Local Solar Market Data	Aggregate solar market data for a state, county, or city
Find Solar Installers	Curated solar installation companies operating in an area
Get Average Solar Cost	Average residential solar installation cost metrics for an area

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Available widgets

Interactive UIs that some clients (e.g. ChatGPT) render inline:

Widget	What it does
Solar Cost Estimate Widget	Interactive rooftop-solar cost estimator
Heat Pump Cost Estimate Widget	Interactive heat-pump cost estimator

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Fair-use rate limits

Requests you make through the MCP server are metered to your own WattBuy API key — the same key and usage plan that apply to direct WattBuy REST API use. Your plan governs your request rate and daily quota; if you exceed it, calls are throttled until the window resets.

You can review your plan and usage anytime in the developer portal at https://wattbuy.readme.io. Need higher limits? Contact WattBuy to upgrade your plan.

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Troubleshooting

Symptom	Fix
"Token invalid or expired" / asked to sign in again	Reconnect in your client — it will refresh or restart the sign-in flow.
"No WattBuy API key is provisioned for your account. Provision one in the developer portal, then retry."	Log in at https://wattbuy.readme.io to provision your key, then retry.
Connector won't discover the login	Use a client that supports remote MCP + OAuth (see the client list above).
Tools disappear after a while / need to reconnect	The connection reset (routine) — your client re-initializes automatically. No re-login needed unless your session also expired.
A tool call is rejected for rate limits	You've hit your plan's quota/rate — wait for the window to reset or upgrade your plan.

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Reference

Purpose	URL
MCP endpoint	https://mcp.wattbuy.com/mcp
Developer portal / API keys	https://wattbuy.readme.io
ChatGPT app	Coming soon

🔧

Behind a corporate firewall or proxy? Allowlist these WattBuy domains so the connector and sign-in can complete: mcp.wattbuy.com (MCP endpoint), mcp-auth.wattbuy.com (OAuth authorization), and auth.wattbuy.com (sign-in page). Most users don't need this.

Questions or trouble connecting? Contact WattBuy developer support at [email protected].