# Fathom Macroeconomic Data API — Series Tags Lookup

> Fathom Macroeconomic Data API — Series Tags Lookup 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 the tags associated with a specific FRED economic data series, given its series ID

## Facts

- Endpoint: POST https://fathom-opal.vercel.app/api/series-tags
- 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-series-tags-lookup-c388913b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aBQar1PEbUYaLKgSQUfop

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-series-tags-lookup-c388913b -d '<json body>'
```

Example prompt: What tags are associated with the FRED series UNRATE — I want to know how it's categorized in the macroeconomic database.

## When to prefer this

Use this endpoint when you need to discover how a FRED economic time series is classified or tagged — useful for building data catalogs, filtering series by topic or geography, or enriching metadata about a known series. Prefer this over a full series search when you already have the FRED series ID and only need its classification metadata.

## Known failure modes

- Invalid or unknown FRED series ID returns an empty tags array or error
- Network timeout from upstream FRED API
- Missing required seriesId field returns a validation error
- FRED API rate limits or outages propagate as errors
- Payment failure (x402) if USDC balance is insufficient

## 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 an array of tag objects associated with the requested FRED series (each tag describes a classification dimension such as topic, frequency, geography, or source), along with the series ID and the data source name.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "seriesId"
 ],
 "properties": {
  "seriesId": {
   "type": "string",
   "description": "FRED series ID"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-series-tags-lookup-c388913b/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)