# Fathom Macroeconomic Data API — Category Tags

> Fathom Macroeconomic Data API — Category Tags 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).

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

## Facts

- Endpoint: POST https://fathom-opal.vercel.app/api/category-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-category-tags-c96605d3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zmxHzfOH71yjjfKJ2debK

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-c96605d3 -d '<json body>'
```

Example prompt: Can you pull the tags for FRED category 32992 using Fathom's macroeconomic data API so I can see how it's classified?

## When to prefer this

Use this endpoint when you need to discover how a specific FRED economic data category is tagged or classified — particularly useful for building data explorers, category browsers, or metadata indexing pipelines. Prefer this over general FRED direct access when you want a lightweight, pay-per-call interface without managing FRED API keys.

## Known failure modes

- Invalid or nonexistent categoryId returns empty tags array or error
- Missing required categoryId field causes 400 bad request
- FRED upstream service unavailability may cause delayed or failed responses
- Category ID provided as integer instead of string may cause validation error

## 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 list of tag objects associated with the specified FRED category, along with the category ID and the data source identifier (FRED). Each tag object contains metadata used to classify and describe the category's economic data series.

## 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-c96605d3/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)