US Treasury yield history

Last N business days of US Treasury constant-maturity yields, oldest→newest. Send GET /api/treasury-yield-history with no required fields (1 optional) and pay $0.005 per call over x402 or MPP (there is no free tier). It returns a JSON object with days, count and history.

Source: FRED DGS* series (St. Louis Fed), public domain. ?days=30 (1-250, default 30).

Category: Live public data · Tags: treasury yield-curve history interest-rates rates macro bonds time-series

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Parameters

Example request

curl -i "https://agent402.tools/api/treasury-yield-history?days=30"

Without payment this returns HTTP 402 Payment Required with the exact price for treasury-yield-history; any x402 v2 or MPP client pays it and retries.

Example response

{
  "days": 30,
  "count": 30,
  "history": [
    {
      "recordDate": "2026-05-01",
      "yr2": 4.71,
      "yr10": 4.46
    }
  ]
}

From an MCP client

catalog.call {
  "slug": "treasury-yield-history",
  "params": {
    "days": 30
  }
}

The hosted connector at https://agent402.tools/mcp needs a payment for treasury-yield-history; the stdio package pays it from a wallet or from AGENT402_CREDITS_KEY. Local install: npx -y agent402-mcp.

Errors and behavior

• Every field is optional. An input the tool rejects returns an HTTP 4xx whose body carries error, tool, expected, required and example.
• A paid call that ends in any status of 400 or above is not charged over x402, MPP or a prepaid credits key: settlement is cancelled when the tool fails. The exception is a Tempo push credential, a transfer the buyer sent before the call: it settles before the tool runs, so if the tool then fails the payment is recorded as a refund owed to the paying wallet.
• Wallet-only: this tool reaches the network or stored state, so it has no proof-of-work tier. A prepaid card-credits key issued earlier (Authorization: Bearer a402_...) also pays it.
• A POST with a JSON body to /api/treasury-yield-history is served as this GET, with the body as the input.
• An Idempotency-Key header makes a retried paid call replay the first 200 instead of charging again (an answer larger than 1 MB is not replayed).

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
client.setSpendControls?.(false); // keep your own spending ceiling in code
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/treasury-yield-history?days=30");

Part of these workflows

US Treasury yield history is one step in this skill pack, each sold as a single call:

• Macro dashboard refresh - The full macro + crypto dashboard in one call: 5 FRED series, 5 Treasury reads, yield-curve spread, crypto market/trending/global, and live gas - the 14-tool basket recurring buyers refresh every cycle, bundled below its a la carte price.

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