get-alerts
Fetch real-time weather alerts for any US state by providing a two-letter state code using the MCP Weather Server.
Instructions
Get weather alerts for a state
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| state | Yes | Two-letter state code (e.g. CA, NY) |
Implementation Reference
- src/index.ts:92-133 (handler)The main handler function for the 'get-alerts' tool. Fetches alerts from the National Weather Service API for a given state code, handles errors and empty results, formats the alerts using the formatAlert helper, and returns them as formatted text content.async ({ state }) => { const stateCode = state.toUpperCase(); const alertsUrl = `${NWS_API_BASE}/alerts?area=${stateCode}`; const alertsData = await makeNWSRequest<AlertsResponse>(alertsUrl); if (!alertsData) { return { content: [ { type: 'text', text: 'Failed to retrieve alerts data' } ] }; } const features = alertsData.features || []; if (features.length === 0) { return { content: [ { type: 'text', text: `No active alerts for ${stateCode}` } ] }; } const formattedAlerts = features.map(formatAlert); const alertsText = `Active alerts for ${stateCode}:\n\n${formattedAlerts.join( '\n' )}`; return { content: [ { type: 'text', text: alertsText } ] }; }
- src/index.ts:89-91 (schema)Input schema for the 'get-alerts' tool, validating the 'state' parameter as a two-letter string using Zod.{ state: z.string().length(2).describe('Two-letter state code (e.g. CA, NY)') },
- src/index.ts:86-134 (registration)Registration of the 'get-alerts' tool on the MCP server, specifying name, description, input schema, and inline handler function.server.tool( 'get-alerts', 'Get weather alerts for a state', { state: z.string().length(2).describe('Two-letter state code (e.g. CA, NY)') }, async ({ state }) => { const stateCode = state.toUpperCase(); const alertsUrl = `${NWS_API_BASE}/alerts?area=${stateCode}`; const alertsData = await makeNWSRequest<AlertsResponse>(alertsUrl); if (!alertsData) { return { content: [ { type: 'text', text: 'Failed to retrieve alerts data' } ] }; } const features = alertsData.features || []; if (features.length === 0) { return { content: [ { type: 'text', text: `No active alerts for ${stateCode}` } ] }; } const formattedAlerts = features.map(formatAlert); const alertsText = `Active alerts for ${stateCode}:\n\n${formattedAlerts.join( '\n' )}`; return { content: [ { type: 'text', text: alertsText } ] }; } );
- src/index.ts:48-58 (helper)Helper function to format a single weather alert feature into a multi-line string, used within the get-alerts handler.function formatAlert(feature: AlertFeature): string { const props = feature.properties; return [ `Event: ${props.event || 'Unknown'}`, `Area: ${props.areaDesc || 'Unknown'}`, `Severity: ${props.severity || 'Unknown'}`, `Status: ${props.status || 'Unknown'}`, `Headline: ${props.headline || 'No headline'}`, '---' ].join('\n'); }
- src/index.ts:19-35 (helper)Generic helper function for making authenticated requests to the National Weather Service API, used by the get-alerts handler.async function makeNWSRequest<T>(url: string): Promise<T | null> { const headers = { 'User-Agent': USER_AGENT, Accept: 'application/geo+json' }; try { const response = await fetch(url, { headers }); if (!response.ok) { throw new Error(`HTTP error! status: ${response.status}`); } return (await response.json()) as T; } catch (error) { console.error('Error making NWS request:', error); return null; } }