# Fathom Macroeconomic Data API — Search Tags

> Fathom Macroeconomic Data API — Search 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).

Search for FRED economic data series tags by keyword to discover available macroeconomic indicators

## Facts

- Endpoint: POST https://fathom-opal.vercel.app/api/search-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-search-tags-4ed4f76d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0b7IAUBVJpUSZN3VmhFLs

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-search-tags-4ed4f76d -d '<json body>'
```

Example prompt: Search the Fathom macroeconomic API for tags related to 'inflation' so I can find the right FRED economic series to pull CPI data from — limit the results to 10.

## When to prefer this

Use this endpoint when you need to discover what economic data tags exist in the FRED database before fetching actual time series data. It is the right first step for navigating 816,000+ FRED series by keyword, especially when the exact series ID is unknown. Prefer this over a direct series search when the goal is category/tag discovery rather than retrieving numeric data.

## Known failure modes

- Missing required 'query' field returns validation error
- Empty query string may return no results or an error
- Network timeout on Vercel serverless cold start
- FRED upstream unavailability causing 502/503 responses
- Limit parameter ignored or misformatted if not passed as a string

## 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 FRED tag objects matching the search keyword, along with the original query string and the data source identifier. Each tag object describes a category or label used to classify economic time series in the FRED database.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "limit": {
   "type": "string",
   "description": "Max results (default: 20)"
  },
  "query": {
   "type": "string",
   "description": "Search keyword"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fathom-macroeconomic-data-api-search-tags-4ed4f76d/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)