Official US Treasury exchange rates via US Treasury Fiscal Data. Used by federal agencies to report foreign-currency transactions in USD. Quarterly + ad-hoc updates per country/currency pair. Each row carries record_date, country, currency, country_currency_desc, exchange_rate, effective_date. Pair with `/api/fx/rates` (ECB Frankfurter, daily market rates) for cross-validation. Use Fiscal Data filter syntax — e.g. `filter=country:eq:Brazil` to scope to a single country.
/api/treasury/exchange-ratesPAYMENT-SIGNATURE.The exchange rates API is a pay-per-call treasury endpoint built for AI agents and autonomous software. Official US Treasury exchange rates via US Treasury Fiscal Data.
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 exchange rates data source for an agent tool-use loop, an MCP host, or a backend that needs treasury data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
fields | string | max 400 chars · match ^[a-z][a-z0-9_]*(,[a-z][a-z0-9_]*)*$ |
filter | string | max 800 chars · match ^[a-z][a-z0-9_]*:(eq|ne|lt|lte|gt|gte|in):[A-Za-z0-9._:\-+/, ]+(,[a-z][a-z0-9_]*:(eq|ne|lt|lte|gt|gte|in):[A-Za-z0-9._:\-+/, ]+)*$ |
sort | string | max 200 chars · match ^-?[a-z][a-z0-9_]*(,-?[a-z][a-z0-9_]*)*$ |
pageSize | integer | min 1 · max 10000 |
pageNumber | integer | min 1 |
# 1. Probe with no auth → 402 envelope with PaymentRequirements curl -sS 'https://2s.io/api/treasury/exchange-rates?fields=example&filter=example&sort=example&pageSize=100&pageNumber=1' # 2. Sign + retry with PAYMENT-SIGNATURE: curl -sS 'https://2s.io/api/treasury/exchange-rates?fields=example&filter=example&sort=example&pageSize=100&pageNumber=1' \ -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/treasury/exchange-rates?fields=example&filter=example&sort=example&pageSize=100&pageNumber=1'
import { TwoS } from '@2sio/sdk'
const client = new TwoS({
privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})
const result = await client.treasury.exchangeRates({
"fields": "example",
"filter": "example",
"sort": "example",
"pageSize": 100,
"pageNumber": 1
})
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.treasury.exchange_rates(fields="example", filter="example", sort="example", pageSize=100, pageNumber=1)
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": "treasury.exchange-rates",
"arguments": {
"fields": "example",
"filter": "example",
"sort": "example",
"pageSize": 100,
"pageNumber": 1
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object | |
page | object | |
meta | object |
{
"ok": true,
"items": [
{}
],
"total": 1,
"source": {
"provider": "example",
"url": "example",
"license": "example"
},
"page": {
"number": 1,
"size": 1,
"pages": 1
},
"meta": {}
}