Determine the FEMA flood zone for a coordinate. Pass lat and lon. Returns the FEMA flood zone code (e.g. AE, VE, X), its subtype, whether the point is in a Special Flood Hazard Area (isSFHA — the 1% annual-chance floodplain where flood insurance is mandatory for federally backed mortgages), a plain-language risk level (high / moderate / minimal / undetermined / unmapped) and description, the static base flood elevation and depth when published, and the source FIRM panel id. Data: FEMA National Flood Hazard Layer (NFHL), free and public-domain. When no flood polygon intersects the point, returns mapped=false (usually Zone X / minimal risk or unmapped — not a guarantee of zero risk). Use for property risk screening, insurance/mortgage context, and siting decisions; geocode an address with /api/geocode/address first to get the coordinate.
/api/geo/flood-zonePAYMENT-SIGNATURE.The flood zone API is a pay-per-call geo endpoint built for AI agents and autonomous software. Determine the FEMA flood zone for a coordinate.
There is no signup and no API key. An agent (or any HTTP client) hits the endpoint, receives an x402 "402 Payment Required" challenge, signs a sub-cent USDC payment on Base or Solana, and retries — the data comes back on the paid request. That makes it a drop-in flood zone data source for an agent tool-use loop, an MCP host, or a backend that needs geo data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
latrequired | number | min -90 · max 90 |
lonrequired | number | min -180 · max 180 |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/geo/flood-zone?lat=-90&lon=-180' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/geo/flood-zone?lat=-90&lon=-180' \ -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/geo/flood-zone?lat=-90&lon=-180'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.geo.floodZone({
"lat": -90,
"lon": -180
})
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.geo.flood_zone(lat=-90, lon=-180)
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": "geo.flood-zone",
"arguments": {
"lat": -90,
"lon": -180
}
}
}| Field | Type | Description |
|---|---|---|
query | object | |
mapped | boolean | |
floodZone | string | |
zoneSubtype | string | |
isSFHA | boolean | |
riskLevel | string | one of: high | moderate | minimal | undetermined | unmapped |
zoneDescription | string | |
staticBFE | number | |
depth | number | |
firmPanelId | string | |
sourceCitation | string | |
note | string | |
sources | array |
{
"query": {
"lat": 1,
"lon": 1
},
"mapped": false,
"floodZone": "example",
"zoneSubtype": "example",
"isSFHA": false,
"riskLevel": "high",
"zoneDescription": "example",
"staticBFE": 1,
"depth": 1,
"firmPanelId": "example",
"sourceCitation": "example",
"note": "example",
"sources": [
{
"provider": "example",
"url": "example",
"license": "example"
}
]
}