econ.fred-categories

Browse the Federal Reserve FRED category tree to DISCOVER economic series. Pass a categoryId to get that category (name + parent), its child categories, and the most-popular series filed under it (id, title, units, frequency) — then pull the data with econ.fred. Omit categoryId (or pass 0) for the eight top-level categories: Money/Banking/Finance, Population/Employment/Labor, National Accounts, Production & Business Activity, Prices, International Data, U.S. Regional Data, Academic Data. Walk down via each child's id. Free, public-domain (FRED). The structured map of what FRED actually contains — far more reliable than guessing series ids. Companion to econ.fred (fetch/search) and econ.fred-releases (calendar).

price
$0.0012 USDC per call
method
GET/api/econ/fred-categories
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

NameTypeDescription
categoryIdinteger
min 0 · max 10000000
seriesLimitinteger
min 0 · max 50

Code samples

cURLbash
# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/econ/fred-categories?categoryId=0&seriesLimit=0'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/econ/fred-categories?categoryId=0&seriesLimit=0' \
  -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/econ/fred-categories?categoryId=0&seriesLimit=0'
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.econ.fredCategories({
  "categoryId": 0,
  "seriesLimit": 0
})

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.econ.fred_categories(categoryId=0, seriesLimit=0)

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": "econ.fred-categories",
    "arguments": {
      "categoryId": 0,
      "seriesLimit": 0
    }
  }
}

Response

FieldTypeDescription
okboolean
one of: true
itemsarray
totalintegerTotal matching rows upstream; null when unknown.
sourceobject
Example response datajson
{
  "ok": true,
  "items": [
    {
      "category": {
        "id": 1,
        "name": "example",
        "parentId": 1
      },
      "children": [
        {
          "id": 1,
          "name": "example",
          "parentId": 1
        }
      ],
      "series": [
        {
          "id": "example",
          "title": "example",
          "units": "example",
          "frequency": "example",
          "seasonalAdjustment": "example",
          "popularity": 1,
          "observationStart": "example",
          "observationEnd": "example"
        }
      ]
    }
  ],
  "total": 1,
  "source": {
    "provider": "example",
    "url": "example",
    "license": "example"
  }
}

Discovery

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.