# Mercury402 FRED Series Data API

> Mercury402 FRED Series Data API is a paid API for AI agents from api.mercury402.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Fetches Federal Reserve Economic Data (FRED) time-series observations for a specified series ID, optionally filtered by date range or limited in count.

## Facts

- Endpoint: GET https://api.mercury402.com/v1/fred/%7Bseries_id%7D
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mercury402-fred-series-data-api-66e56e99
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z_rFu5yH88ZsUbyNPFbvO

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability mercury402-fred-series-data-api-66e56e99
```

Example prompt: Pull the FRED series UNRATE (unemployment rate) for me from January 1, 2020 through December 31, 2023, returning up to 50 observations.

## When to prefer this

Choose this endpoint when you need structured, pay-per-call access to specific FRED economic time-series data without managing a FRED API key, especially in autonomous agent workflows that use x402 micropayments on Base. It's ideal when you need a single series by ID with optional date filtering and want machine-readable JSON output compatible with agent pipelines.

## Known failure modes

- Invalid or unknown series_id returns an error or empty observations array
- Date range with no available data returns empty observations
- Malformed date strings (not YYYY-MM-DD) may cause query errors
- Payment failure (insufficient USDC balance) results in 402 response before data is returned
- Rate limits or upstream FRED API unavailability may cause timeouts

## How this service works

76 live pay-per-call financial data APIs for AI agents. Treasury, FRED, forex, spreads, breakeven inflation, macro bundles, and composite dashboards. USDC on Base.

## Output

Returns a JSON object containing the FRED series ID, a list of observations (each with a date and value), and realtime start/end timestamps indicating data vintage.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "date": {
   "type": "string",
   "description": "Single date observation (YYYY-MM-DD)"
  },
  "limit": {
   "type": "integer",
   "description": "Max observations to return"
  },
  "observation_end": {
   "type": "string",
   "description": "End date for range query (YYYY-MM-DD)"
  },
  "observation_start": {
   "type": "string",
   "description": "Start date for range query (YYYY-MM-DD)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "series_id": "UNRATE",
  "observations": [
   {
    "date": "2024-01-01",
    "value": "3.7"
   }
  ],
  "realtime_end": "2026-03-11",
  "realtime_start": "2026-03-11"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mercury402-fred-series-data-api-66e56e99/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.mercury402.com](https://www.zero.xyz/host/api.mercury402.com/llms.txt)