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).
/api/econ/fred-categoriesPAYMENT-SIGNATURE.The fred categories API is a pay-per-call econ endpoint built for AI agents and autonomous software. Browse the Federal Reserve FRED category tree to DISCOVER economic series.
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 fred categories data source for an agent tool-use loop, an MCP host, or a backend that needs econ data on demand without onboarding to yet another vendor portal.
| Name | Type | Description |
|---|---|---|
categoryId | integer | min 0 · max 10000000 |
seriesLimit | integer | min 0 · max 50 |
# 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'
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)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)// 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
}
}
}| Field | Type | Description |
|---|---|---|
ok | boolean | one of: true |
items | array | |
total | integer | Total matching rows upstream; null when unknown. |
source | object |
{
"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"
}
}