# Fathom Macroeconomic Data API — Category Tags

> Fathom Macroeconomic Data API — Category Tags is a paid API for AI agents from fredthom.vercel.app, paid per call via x402, $0.35/call, status unknown (last checked 2026-09-15).

Retrieves the tags associated with a specific FRED economic data category by category ID

## Facts

- Endpoint: POST https://fredthom.vercel.app/api/category-tags
- Price: $0.35/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-category-tags-08fcb53f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HPktIdj0iJ3KFSBqaHOia

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-08fcb53f -d '<json body>'
```

Example prompt: What tags are associated with FRED category 125 — the National Accounts category? I want to understand how it's classified in the Fathom macroeconomic data system.

## When to prefer this

Use this endpoint when you need to discover or enumerate the descriptive tags associated with a specific FRED economic data category — useful for metadata exploration, building search filters, or understanding category classification before fetching actual time series data.

## Known failure modes

- Invalid or non-existent FRED category ID returns empty tags array or error
- Missing required categoryId field results in validation error
- Upstream FRED API unavailability may cause failed or stale responses
- Malformed categoryId (non-numeric string) may return no results

## 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 associated with the specified FRED category, along with the category ID and a source identifier indicating the data origin (e.g. FRED).

## 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-08fcb53f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fredthom.vercel.app](https://www.zero.xyz/host/fredthom.vercel.app/llms.txt)