aviation.metar

Current aviation weather observation (METAR) for one or more airports. Pass ids = comma-separated ICAO station ids (e.g. KATL, EGLL, KJFK). Returns the raw METAR plus decoded fields: flight category (VFR/MVFR/IFR/LIFR), temperature + dewpoint (°C), wind direction/speed/gust (kt), visibility, altimeter (inHg), and cloud layers. Source: NOAA Aviation Weather Center (keyless, public domain).

Overview

The METAR API returns the current aviation weather observation for one or more airports, both raw and decoded, from the NOAA Aviation Weather Center.

Pass comma-separated ICAO station ids (e.g. KATL, EGLL, KJFK) and get the raw METAR plus decoded fields: flight category (VFR/MVFR/IFR/LIFR), temperature and dewpoint in °C, wind direction/speed/gust in knots, visibility, altimeter in inHg, and cloud layers. The source is keyless public-domain NOAA data. No API key — pay per call with x402.

Use cases

• Give a flight-planning or drone-ops agent current conditions and flight category by airport.
• Trigger go/no-go automation off the decoded flight category for a set of stations.
• Surface plain-language airport weather in a travel assistant from the raw METAR.
• Log decoded conditions across a network of airports, paying per observation.

Parameters

Code samples

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/aviation/metar?ids=xxx'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/aviation/metar?ids=xxx' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/aviation/metar?ids=xxx'

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.aviation.metar({
  "ids": "xxx"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.aviation.metar(ids="xxx")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "aviation.metar",
    "arguments": {
      "ids": "xxx"
    }
  }
}

Response

{
  "ok": true,
  "items": [
    {
      "station": "example",
      "observedAt": "example",
      "raw": "example",
      "flightCategory": "example",
      "tempC": 1,
      "dewpointC": 1,
      "windDirDeg": 1,
      "windSpeedKt": 1,
      "windGustKt": 1,
      "visibility": "example",
      "altimeterInHg": 1,
      "clouds": [
        {
          "cover": "example",
          "baseFtAgl": 1
        }
      ],
      "name": "example"
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

FAQ

Can I request multiple airports at once?

Yes — pass ids as a comma-separated list of ICAO station ids (e.g. KATL,KJFK,EGLL).

Is the METAR decoded or raw?

Both. You get the raw METAR string plus decoded fields: flight category, temperature/dewpoint, wind, visibility, altimeter, and cloud layers.

Do I need an API key to use the metar API?

No. aviation.metar is x402-native — there is no signup and no API key. Your client makes the call, receives a 402 with payment requirements, signs a USDC payment, and retries. Funds come from a wallet you control.

How much does the metar API cost?

$0.0012 USDC per call, charged per request. There are no monthly fees, seats, or minimums — you pay only for the calls you make.

Can I try the metar API for free first?

Yes. Add ?trial=1 (or the header X-2s-Trial: 1) to get a free real call per endpoint per hour, so you can verify the response shape before wiring payment.

Which networks and tokens are supported?

USDC on Base (via EIP-3009 transferWithAuthorization) or Solana (SPL transfer), using the open x402 payment protocol.

How do I call aviation.metar from an AI agent or MCP host?

Use @2sio/sdk (TypeScript), 2sio (Python), or the @2sio/mcp server for any MCP host — each handles the probe → sign → retry loop for you. See the code samples on this page.

Discovery

• /api/directory — full catalog of every endpoint
• /openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
• /.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
• /.well-known/mcp/server-card.json — MCP SEP-1649 server card
• /llms.txt — plain-text manifest for LLM ingestion