# Fathom Macroeconomic Data API — Tag Series Search

> Fathom Macroeconomic Data API — Tag Series Search is a paid API for AI agents from fathoms.vercel.app, paid per call via x402, $0.06/call, status unknown (last checked 2026-09-15).

Returns a list of FRED economic time series matching a given tag (e.g. 'gdp', 'inflation', 'monthly', 'nsa')

## Facts

- Endpoint: POST https://fathoms.vercel.app/api/tag-series
- Price: $0.06/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-tag-series-search-95a0a419
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xielYAZdQE_phWZXmuc-_

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-tag-series-search-95a0a419 -d '<json body>'
```

Example prompt: Can you search the Fathom FRED-powered API for all economic time series tagged 'inflation' and show me up to 30 results?

## When to prefer this

Use this endpoint when you need to discover which FRED economic time series exist under a particular topic or tag — ideal for browsing or enumerating available datasets before fetching actual data values. Prefer this over a direct series lookup when the user does not yet know the specific FRED series ID and wants to explore what is available under a broad macroeconomic theme like 'gdp', 'inflation', or 'unemployment'.

## Known failure modes

- Unknown or misspelled tag returns empty series array
- Missing required 'tag' field returns validation error
- Limit parameter as non-numeric string may cause unexpected defaults
- FRED upstream outage results in failed or stale response
- Rate limiting or payment failure (x402) blocks access

## 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 tag name queried, an array of matching FRED economic time series objects (each with series metadata such as ID, title, frequency, units, and observation dates), and a source attribution string. The number of series returned is capped by the optional limit parameter (default 20).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "tag"
 ],
 "properties": {
  "tag": {
   "type": "string",
   "description": "Tag name (e.g. gdp, monthly, inflation, nsa)"
  },
  "limit": {
   "type": "string",
   "description": "Max results (default: 20)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "source"
 ],
 "properties": {
  "tag": {
   "type": "string"
  },
  "series": {
   "type": "array",
   "items": {
    "type": "object"
   }
  },
  "source": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-tag-series-search-95a0a419/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fathoms.vercel.app](https://www.zero.xyz/host/fathoms.vercel.app/llms.txt)