# Fathom Macroeconomic Data API — Popular Series

> Fathom Macroeconomic Data API — Popular Series is a paid API for AI agents from fathom-opal.vercel.app, paid per call via x402, $0.04/call, status unknown (last checked 2026-09-14).

Returns a curated list of the most popular macroeconomic time series (GDP, inflation, unemployment, interest rates) sourced from the FRED database

## Facts

- Endpoint: POST https://fathom-opal.vercel.app/api/popular
- Price: $0.04/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fathom-macroeconomic-data-api-popular-series-509fd7d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VFRiXCo1jTAtAMvQ9Debn

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-popular-series-509fd7d0 -d '<json body>'
```

Example prompt: Can you pull up the most popular macroeconomic data series available — things like GDP, inflation, and unemployment — so I can see what economic indicators are most commonly tracked?

## When to prefer this

Choose this endpoint when you need a curated starting set of macroeconomic indicators without knowing specific series IDs — ideal for bootstrapping dashboards, exploratory macro research, or letting an agent discover the most relevant economic time series before drilling into specific data. Prefer over raw FRED API access when you want a pre-filtered popular list via a simple paid call rather than navigating FRED's full 800k+ series catalog.

## Known failure modes

- Payment failure: x402 payment of 0.04 USDC not processed, returns 402 Payment Required
- Service unavailable: Vercel deployment offline, returns 503
- FRED upstream outage: underlying data provider unavailable, returns 502 or timeout
- Empty response: no popular series returned if data pipeline is stale

## How this service works

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

## Output

A list of the most popular macroeconomic time series from the FRED database, each likely including the series ID, name, description, units, frequency (e.g. monthly/quarterly), and a popularity or relevance signal — covering categories such as GDP, CPI inflation, unemployment rate, federal funds rate, and other widely tracked U.S. economic indicators.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-popular-series-509fd7d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fathom-opal.vercel.app](https://www.zero.xyz/host/fathom-opal.vercel.app/llms.txt)