# Mercury402 FRED Series Data API

> Mercury402 FRED Series Data API is a paid API for AI agents from mercury402.uk, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-13).

Fetches historical and current Federal Reserve Economic Data (FRED) observations for a given series ID, with optional date filtering

## Facts

- Endpoint: GET https://mercury402.uk/v1/fred/%7Bseries_id%7D
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mercury402-fred-series-data-api-1fe84126
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_W0Xhy4MnfSliMjlMQFdu6

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-1fe84126
```

Example prompt: Pull the FRED unemployment rate series (UNRATE) from January 2020 through December 2024, returning up to 60 observations, so I can see how joblessness trended over that period.

## When to prefer this

Choose this endpoint when you need programmatic, pay-per-call access to any FRED economic time series (unemployment, CPI, GDP, M2, etc.) with flexible date range filtering, especially in an autonomous agent context that pays via USDC on Base using the x402 protocol. Prefer over scraping FRED directly or using a general-purpose data API when you need clean JSON output with per-call pricing and no subscription overhead.

## Known failure modes

- Invalid or unknown series_id returns an error or empty observations array
- Malformed date strings (not YYYY-MM-DD) may cause a 400 bad request
- Date range with no available data returns empty observations
- Payment failure (insufficient USDC) results in HTTP 402 before data is returned
- observation_start after observation_end returns no results or an error

## 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

A JSON object containing the requested FRED series ID, a list of date-value observation pairs covering the requested range, and the realtime start/end window used for the query.

## 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-1fe84126/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mercury402.uk](https://www.zero.xyz/host/mercury402.uk/llms.txt)