HUD Fair Market Rents (FMR) for a US county or state — HUD’s annual gross-rent estimate (rent + utilities) by bedroom size (efficiency through 4-bedroom), the basis for Housing Choice Voucher payment standards and other HUD programs. Look up by 5-digit county FIPS (returns the county/metro rents, broken out per ZIP where HUD publishes Small Area FMRs) or by 2-letter state (returns every metro area + county). Optional year (defaults to latest). Source: HUD USER FMR API (US public domain).
/api/gov/fair-market-rentPAYMENT-SIGNATURE.The fair market rent API is a pay-per-call gov endpoint built for AI agents and autonomous software. HUD Fair Market Rents (FMR) for a US county or state — HUD’s annual gross-rent estimate (rent + utilities) by bedroom size (efficiency through 4-bedroom), the basis for Housing Choice Voucher payment standards and other HUD programs.
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 fair market rent data source for an agent tool-use loop, an MCP host, or a backend that needs gov data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
fips | string | 5-digit US county FIPS, e.g. 06037 (Los Angeles County). match ^\d{5}$ |
state | string | 2-letter US state abbreviation, e.g. CA. match ^[A-Za-z]{2}$ |
year | string | FMR year, e.g. 2026. Omit for the latest. match ^\d{4}$ |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/gov/fair-market-rent?fips=12345&state=example&year=12345' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/gov/fair-market-rent?fips=12345&state=example&year=12345' \ -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/gov/fair-market-rent?fips=12345&state=example&year=12345'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.gov.fairMarketRent({
"fips": "12345",
"state": "example",
"year": "12345"
})
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.gov.fair_market_rent(fips="12345", state="example", year="12345")
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": "gov.fair-market-rent",
"arguments": {
"fips": "12345",
"state": "example",
"year": "12345"
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"ok": true,
"items": [
{
"scope": "county",
"fips": "example",
"state": "example",
"year": "example",
"countyName": "example",
"metroName": "example",
"areaName": "example",
"areas": [
{
"level": "county",
"name": "example",
"zipCode": "example",
"fipsCode": "example",
"rents": {
"efficiency": 1,
"oneBedroom": 1,
"twoBedroom": 1,
"threeBedroom": 1,
"fourBedroom": 1
},
"fmrPercentile": 1
}
]
}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
}
}