# Federal Register Search API

> Federal Register Search API is a paid API for AI agents from apiacre.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Search U.S. Federal Register documents by topic, agency, document type, and date, returning regulatory notices, rules, proposed rules, and presidential documents with links to official sources.

## Facts

- Endpoint: POST https://apiacre.com/v1/research/federal-register-search
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/federal-register-search-api-60f0100c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_141FnNTrSHATKrhOgyEvV

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 federal-register-search-api-60f0100c -d '<json body>'
```

Example prompt: Search the Federal Register for the newest proposed rules and notices from the EPA about clean air standards published in the last 30 days, and give me links to the official PDFs.

## When to prefer this

Choose this endpoint when you need structured, machine-readable metadata about U.S. Federal Register documents including regulatory notices, rules, proposed rules, or presidential documents, especially when you need direct links to official government sources. Prefer this over general web search when you need authoritative regulatory data filtered by agency, document type, or date, and when compliance, legal research, or policy monitoring is the goal.

## Known failure modes

- No matching documents found for the given query or date range — returns empty result set
- Invalid document type or agency name causes filter to return no results
- Overly broad query with no filters may return truncated result set
- Federal Register upstream API unavailability causing timeout or error response
- Date range too narrow returning zero results

## How this service works

Search newest U.S. Federal Register document metadata by topic, agency, type, and publication date, returning bounded regulatory notices, rules, proposed rules, presidential documents, and links to FederalRegister.gov and official govinfo.gov PDFs.

## Output

Returns structured metadata for matching Federal Register documents including document title, agency, document type (notice, rule, proposed rule, presidential document), publication date, abstract, and direct links to FederalRegister.gov pages and official GovInfo.gov PDFs. Results are bounded to the newest matching documents within the specified filters.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "query": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "null"
    }
   ]
  },
  "max_results": {
   "type": "integer"
  },
  "agency_slugs": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "published_to": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "null"
    }
   ]
  },
  "document_types": {
   "type": "array",
   "items": {
    "enum": [
     "RULE",
     "PRORULE",
     "NOTICE",
     "PRESDOCU"
    ],
    "type": "string"
   }
  },
  "published_from": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "null"
    }
   ]
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "query": {
    "term": "artificial intelligence",
    "agencySlugs": [
     "commerce-department"
    ],
    "publishedTo": null,
    "documentTypes": [
     "NOTICE",
     "PRORULE"
    ],
    "publishedFrom": "2026-01-01"
   },
   "source": "https://www.federalregister.gov/api/v1/documents.json",
   "documents": [
    {
     "type": "Notice",
     "title": "Request for Information (RFI) on Modernizing the National Vulnerability Datab...",
     "citation": "91 FR 52042",
     "documentNumber": "2026-16371",
     "publicationDate": "2026-08-12"
    }
   ],
   "disclaimer": "Public regulatory-document discovery for research only; verify the linked off...",
   "description": "Documents matching 'artificial intelligence', published on or after 01/01/202...",
   "limitations": [
    "Results are newest-first and bounded by max_results; totalMatches may exceed ...",
    "FederalRegister.gov is an unofficial informational display and does not repla...",
    "Search results, abstracts, dates text, agency metadata, and significance flag..."
   ],
   "retrievedAt": "2026-08-13T00:00:00Z",
   "totalMatches": 12,
   "documentation": "https://www.federalregister.gov/developers/documentation/api/v1",
   "documentsReturned": 1,
   "documentsTruncated": true
  },
  "meta": {
   "cached": false,
   "sources": [],
   "warnings": [],
   "duration_ms": 42,
   "next_actions": []
  },
  "service": "research.federal-register-search",
  "version": "1",
  "request_id": "018f1f54-7f38-7ba2-8dc3-5f90272d9f1a"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/federal-register-search-api-60f0100c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apiacre.com](https://www.zero.xyz/host/apiacre.com/llms.txt)