# Fathom Macroeconomic Data API — Category Tags

> Fathom Macroeconomic Data API — Category Tags is a paid API for AI agents from fsthum.vercel.app, paid per call via x402, $0.35/call, status unknown (last checked 2026-10-29).

Returns the tags associated with a specific FRED economic data category, enabling discovery and filtering of economic time series within that category.

## Facts

- Endpoint: POST https://fsthum.vercel.app/api/category-tags?utm_source=zero.xyz
- Price: $0.35/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fathom-macroeconomic-data-api-category-tags-b87ac165
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UHeD1djVN_ea6DcTP8lGi

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-category-tags-b87ac165 -d '<json body>'
```

Example prompt: What tags are available for FRED category 32992? I want to see how I can filter the time series within that category.

## When to prefer this

Use this endpoint when you need to discover the tagging taxonomy for a specific FRED economic category — ideal for building filter interfaces, exploring what labels organize a category's time series, or programmatically narrowing down which economic indicators to fetch. Prefer this over a general FRED series search when you already know the category and want metadata about how its data is organized.

## Known failure modes

- Invalid or non-existent FRED category ID returns empty tags array or error
- Network timeout on the Vercel deployment under high load
- FRED upstream API rate limits or outages causing failed lookups
- Missing required categoryId field returns 400 validation error
- Payment of 0.35 USDC not completed causes 402 Payment Required response

## How this service works

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

## Output

An object containing the category ID, the source ('FRED'), and an array of tag objects associated with that category — each tag typically includes a name, group ID, and series count that can be used to filter or discover time series within the category.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-category-tags-b87ac165/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fsthum.vercel.app](https://www.zero.xyz/host/fsthum.vercel.app/llms.txt)