# Fathom Macroeconomic Data API — Tags Endpoint

> Fathom Macroeconomic Data API — Tags Endpoint 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 list of available tags (category/topic labels) for browsing and filtering the 816,000+ FRED-powered economic time series

## Facts

- Endpoint: POST https://fathom-opal.vercel.app/api/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-tags-endpoint-f502d88f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__kuIjxyYvYBRynq3o7-CQ

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-tags-endpoint-f502d88f -d '<json body>'
```

Example prompt: Can you show me all the available economic data tags in Fathom's FRED-powered database — maybe filter by keyword 'inflation' and return up to 20 results?

## When to prefer this

Choose this endpoint when you need to discover or browse the taxonomy of available economic data categories before querying specific time series. It is the right first step when you don't know the exact tag name and want to explore what macroeconomic topics (GDP, inflation, unemployment, interest rates) are indexed. Prefer this over directly querying series if you need to enumerate valid filter terms.

## Known failure modes

- Empty tag list if search keyword matches nothing in the database
- Missing or malformed limit parameter may default to 50 results
- Service unavailability on the Vercel-hosted endpoint returning 5xx errors
- Payment failure if x402 USDC payment of $0.04 is not properly submitted
- Stale or cached results if the underlying FRED data source is not refreshed

## 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 an array of tag objects (each representing a category or topic label used to classify FRED economic time series) and a source identifier string indicating the data origin. Tags can be used to discover and filter specific economic time series data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "string",
   "description": "Max results (default: 50)"
  },
  "search": {
   "type": "string",
   "description": "Filter tags by keyword"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-tags-endpoint-f502d88f/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)