weather

weather-402

Minimal Express TypeScript server with x402 402 paywall.

• Requires USDC payment to access GET /weather?city=....
• Price: $0.001 on base-sepolia.
• Weather data from Open-Meteo (no API key required).

Setup

cd weather
# create .env with your receiver address
cat > .env <<'EOF'
PAY_TO=0x0000000000000000000000000000000000000000
PORT=3100
TARGET_URL=http://localhost:3100/weather?city=San%20Francisco
# PRIVATE_KEY: used by header generator script
PRIVATE_KEY=
EOF

npm i
npm run dev

Open http://localhost:3100/weather?city=San%20Francisco. Without payment, you should get HTTP 402 with payment requirements or a paywall page. After paying with an x402 client, the response will be weather JSON for the requested city.

cURL

• Request without payment (JSON):

curl -i -H "Accept: application/json" "http://localhost:3100/weather?city=Paris"

• Request with paywall HTML (browser-like Accept):

curl -i "http://localhost:3100/weather?city=Paris"

• After generating an x402 payment header, include it to get weather:

# Replace <BASE64_XPAYMENT> with the value produced by the payment header script
curl -i -H 'X-PAYMENT: <BASE64_XPAYMENT>' "http://localhost:3100/weather?city=Paris"

• Pretty-print the 402 JSON response:

curl -s -H "Accept: application/json" "http://localhost:3100/weather?city=Paris" | jq .

Generate X-PAYMENT header and call with curl

1. Configure payer credentials (testnet):

# set PRIVATE_KEY to the payer EVM private key (Base Sepolia recommended)
# set TARGET_URL if different

2. Generate header:

npm run payment:header
# outputs a long Base64 string

3. Use the header with curl:

HEADER=$(npm run -s payment:header)
curl -i -H "X-PAYMENT: $HEADER" "$TARGET_URL"

Notes:

• The script first fetches /weather to read accepts from the 402 JSON, then signs an exact EVM payment using PRIVATE_KEY and prints the header.
• Works by default for base-sepolia.