econ.fred-vintage

Point-in-time (vintage) economic data from FRED's ALFRED archive — what an economic figure was AS FIRST REPORTED / as known on a past date, before later revisions. Give a seriesId (e.g. GDP, GDPC1, PAYEMS, INDPRO) and an asOf date to get the observations exactly as they stood on that date; omit asOf to get the current (latest-revised) values. Also returns the series' vintage (revision) dates — every date the series was revised. Free, public-domain (FRED). Critical for honest backtesting and macro research: it eliminates look-ahead bias (e.g. GDP for 2020Q1 was first reported far lower than today's revised figure). No LLM and no real-time API gives this — it's the archived state of the data through time. Pair with econ.fred (current series) and econ.fred-releases (release calendar).

price

$0.0017 USDC per call

method

GET/api/econ/fred-vintage

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
`seriesId`required	string	min 1 chars · max 60 chars
`asOf`	string	match ^\d{4}-\d{2}-\d{2}$
`start`	string	match ^\d{4}-\d{2}-\d{2}$
`end`	string	match ^\d{4}-\d{2}-\d{2}$
`limit`	integer	min 1 · max 100

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/econ/fred-vintage?seriesId=example&asOf=2024-01-01&start=2024-01-01&end=2024-01-01&limit=1'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/econ/fred-vintage?seriesId=example&asOf=2024-01-01&start=2024-01-01&end=2024-01-01&limit=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/econ/fred-vintage?seriesId=example&asOf=2024-01-01&start=2024-01-01&end=2024-01-01&limit=1'

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.fredVintage({
  "seriesId": "example",
  "asOf": "2024-01-01",
  "start": "2024-01-01",
  "end": "2024-01-01",
  "limit": 1
})

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_vintage(seriesId="example", asOf="2024-01-01", start="2024-01-01", end="2024-01-01", limit=1)

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-vintage",
    "arguments": {
      "seriesId": "example",
      "asOf": "2024-01-01",
      "start": "2024-01-01",
      "end": "2024-01-01",
      "limit": 1
    }
  }
}

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": [
    {
      "seriesId": "example",
      "title": "example",
      "units": "example",
      "asOf": "example",
      "vintageDates": [
        "example"
      ],
      "observations": [
        {
          "date": "example",
          "value": 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.