# Fathom Macroeconomic Data API — Tags Endpoint

> Fathom Macroeconomic Data API — Tags Endpoint is a paid API for AI agents from fredthom.vercel.app, paid per call via x402, $0.35/call, status unknown (last checked 2026-09-14).

Returns a list of available tags/categories used to organize FRED economic time series, with optional keyword filtering and result limiting

## Facts

- Endpoint: POST https://fredthom.vercel.app/api/tags
- Price: $0.35/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-538e6668
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iTnHva4MMZeBnzZDiDr-g

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-538e6668 -d '<json body>'
```

Example prompt: Search the Fathom macroeconomic data API for up to 20 tags related to 'inflation' so I can see what categories of FRED economic series are available on that topic.

## When to prefer this

Use this endpoint when an agent needs to discover what categories or topics of economic data are available in the FRED database before querying specific series. It is the right entry point for navigating the taxonomy of 816,000+ economic time series — ideal for building dynamic search flows, populating dropdown filters, or understanding what macroeconomic domains are covered.

## Known failure modes

- Invalid or missing limit parameter type (string expected, not integer)
- No tags found matching the search keyword — returns empty tags array
- API payment failure via x402 — 402 Payment Required if USDC not sent
- Network timeout on Vercel serverless function
- Search keyword too broad — returns full default 50 results without meaningful filtering

## 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 array of tag objects available in the FRED dataset, filtered by the search keyword if provided, plus a source identifier string. Each tag represents a category or label used to organize the 816,000+ economic time series in the database.

## 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-538e6668/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)