# US Federal Register Search API

> US Federal Register Search API is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-01).

Searches the US Federal Register for proposed rules, final rules, notices, and presidential documents by topic keyword, with optional type and recency filters.

## Facts

- Endpoint: POST https://api.vextorium.com/reg-federal-eeuu-pago?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-federal-register-search-api-129b0b1a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__dL8VCVlPbfvyiyyNnSRD

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 us-federal-register-search-api-129b0b1a -d '<json body>'
```

Example prompt: Search the US Federal Register for any proposed rules, final rules, or notices about stablecoins from the last 60 days and show me up to 15 results with their agency, date, and a link to each document.

## When to prefer this

Use this endpoint when you need to search official US federal regulatory documents (proposed rules, final rules, notices, presidential documents) by topic keyword with optional type and date filters. Ideal for compliance monitoring, regulatory research, and tracking federal rulemaking activity. Prefer this over general web search when authoritative government-sourced metadata (agency, date, abstract, official link) is required. Complements SEC/CFTC RSS feeds for broader federal regulatory coverage.

## Known failure modes

- Missing required 'termino' field returns validation error
- Search term too vague or broad may return 0 results
- 'dias' or 'limite' out of allowed range returns schema error
- Federal Register API downtime causes upstream errors
- Non-English search terms may yield poor or no results

## How this service works

Search the US Federal Register (official public-domain government record) by topic: proposed rules, final rules, notices and presidential documents, with agency, publication date, abstract and official link. Filter by type and recency. Complements SEC/CFTC RSS tracking.

## Output

Returns a JSON object containing the search topic, document type filter applied, source label, total number of matches, and an array of up to 50 documents — each with title, document type, publication date, issuing agencies, a plain-text abstract/summary, and a direct link to the official Federal Register entry.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [
      "termino"
     ],
     "properties": {
      "dias": {
       "type": "integer",
       "description": "Only documents from the last N days (default 180)"
      },
      "tipo": {
       "enum": [
        "regla",
        "propuesta",
        "aviso",
        "presidencial"
       ],
       "type": "string",
       "description": "Document type"
      },
      "limite": {
       "type": "integer",
       "maximum": 50,
       "minimum": 1,
       "description": "Results (1-50, default 10)"
      },
      "termino": {
       "type": "string",
       "description": "Topic, e.g. cryptocurrency, digital asset, stablecoin, artificial intelligence"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": [
      "object",
      "null"
     ],
     "properties": {
      "tema": {
       "type": [
        "string",
        "null"
       ]
      },
      "tipo": {
       "type": [
        "string",
        "null"
       ]
      },
      "fuente": {
       "type": [
        "string",
        "null"
       ]
      },
      "documentos": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": [
         "null",
         "object"
        ],
        "properties": {
         "tipo": {
          "type": [
           "null",
           "string"
          ]
         },
         "fecha": {
          "type": [
           "null",
           "string"
          ]
         },
         "enlace": {
          "type": [
           "null",
           "string"
          ]
         },
         "titulo": {
          "type": [
           "null",
           "string"
          ]
         },
         "resumen": {
          "type": [
           "null",
           "string"
          ]
         },
         "agencias": {
          "type": [
    
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-federal-register-search-api-129b0b1a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)