# Fathom Macroeconomic Data API — Observations

> Fathom Macroeconomic Data API — Observations is a paid API for AI agents from fredthom.vercel.app, paid per call via x402, $0.4/call, status unknown (last checked 2026-09-15).

Fetches historical economic time series observations from FRED (Federal Reserve Economic Data) for any of 816,000+ macroeconomic indicators

## Facts

- Endpoint: POST https://fredthom.vercel.app/api/observations
- Price: $0.4/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fathom-macroeconomic-data-api-observations-d3f93d1a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0XFeMU9TeAH1EVFH2KUA0

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 fathom-macroeconomic-data-api-observations-d3f93d1a -d '<json body>'
```

Example prompt: Pull the last 20 quarterly observations of US GDP (FRED series GDP) in percent change from a year ago format, sorted ascending from 2019-01-01 to today.

## When to prefer this

Choose this endpoint when you need programmatic access to any of FRED's 816,000+ macroeconomic time series — GDP, unemployment, inflation, interest rates, money supply, trade data, etc. — with optional date filtering, frequency aggregation, and unit transformations (e.g. percent change). Prefer this over direct FRED API access when using x402 micropayment-based billing is acceptable and you want a simple POST interface without managing FRED API keys.

## Known failure modes

- Invalid or unknown FRED series ID returns an error or empty observations array
- Date range outside available data returns zero observations
- Invalid units or frequency parameter may return an error or fallback to default
- Rate limit or payment failure (402) blocks the request
- Network timeout on Vercel serverless function under heavy load

## How this service works

Free macroeconomic data API powered by FRED. 816,000+ economic time series. GDP, inflation, unemployment, interest rates, and more.

## Output

Returns a JSON object containing the FRED series ID, the data source label, a count of observations returned, and an array of observation objects — each with a date and value — filtered and transformed according to the requested parameters.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "seriesId"
 ],
 "properties": {
  "end": {
   "type": "string",
   "description": "End date YYYY-MM-DD"
  },
  "sort": {
   "type": "string",
   "description": "Sort order: asc or desc (default: desc)"
  },
  "limit": {
   "type": "string",
   "description": "Max observations (default: 10)"
  },
  "start": {
   "type": "string",
   "description": "Start date YYYY-MM-DD"
  },
  "units": {
   "type": "string",
   "description": "Units transformation (lin, chg, ch1, pch, pca, cch, cca, log)"
  },
  "seriesId": {
   "type": "string",
   "description": "FRED series ID (e.g. GDP, UNRATE, CPIAUCSL)"
  },
  "frequency": {
   "type": "string",
   "description": "Frequency (d, w, bw, m, q, sa, a)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "source"
 ],
 "properties": {
  "count": {
   "type": "number"
  },
  "source": {
   "type": "string"
  },
  "series_id": {
   "type": "string"
  },
  "observations": {
   "type": "array",
   "items": {
    "type": "object"
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-observations-d3f93d1a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fredthom.vercel.app](https://www.zero.xyz/host/fredthom.vercel.app/llms.txt)