inflation.rates

Current US inflation rates by measure, with the index level plus computed year-over-year and month-over-month % change. Pass measure for one, or omit for all. Measures: cpi, cpi-nsa, core-cpi, cpi-w, pce, core-pce, ppi, cpi-food, cpi-energy, cpi-shelter, cpi-medical, import-prices, export-prices — i.e. headline CPI (SA + NSA), core CPI, CPI-W, PCE, core PCE (the Fed's 2% target gauge), PPI final demand, and CPI by category (food, energy, shelter, medical) + import/export prices. The YoY change is the headline "inflation rate". Each result names the FRED series ID used. Source: BLS/BEA via FRED (St. Louis Fed). For raw access to any other series use bls.series; this is the curated, rate-computed layer.

price

$0.0014 USDC per call

method

GET/api/inflation/rates

payment

x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)

auth

None. Sign the payment, retry with PAYMENT-SIGNATURE.

tier

Tier 0 — no paid upstream

Parameters

Name	Type	Description
`measure`	string	one of: cpi \| cpi-nsa \| core-cpi \| cpi-w \| pce \| core-pce \| ppi \| cpi-food \| cpi-energy \| cpi-shelter \| cpi-medical \| import-prices \| export-prices

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/inflation/rates?measure=cpi'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/inflation/rates?measure=cpi' \
  -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/inflation/rates?measure=cpi'

TypeScript / Node — @2sio/sdktypescript

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.inflation.rates({
  "measure": "cpi"
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

Python — 2siopython

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.inflation.rates(measure="cpi")

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

MCP — Claude Desktop / AgentKit / any MCP hostjson

// 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": "inflation.rates",
    "arguments": {
      "measure": "cpi"
    }
  }
}

Response

Field	Type	Description
`ok`	boolean	one of: true
`items`	array
`total`	integer	Total matching rows upstream; null when unknown.
`source`	object

Example response datajson

{
  "ok": true,
  "items": [
    {
      "measure": "example",
      "seriesId": "example",
      "label": "example",
      "index": 1,
      "asOf": "example",
      "changeMoM": 1,
      "changeYoY": 1
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

Discovery

/api/directory — full catalog of every endpoint
/openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
/.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
/.well-known/mcp/server-card.json — MCP SEP-1649 server card
/llms.txt — plain-text manifest for LLM ingestion

2s.io is x402-native. Every call is paid per-request from a USDC-funded EVM wallet on Base — no signup, no API keys, no monthly fees. Source code: github.com/2s-io/sdk.