# US Federal Register Search

> US Federal Register Search is a paid API for AI agents from agents.crowdspark.me, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-31).

Search the US Federal Register for final rules, proposed rules, notices, and presidential documents with filtering by keyword, type, agency, and date range.

## Facts

- Endpoint: GET https://agents.crowdspark.me/v1/gov/federal-register?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-federal-register-search-8d989960
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aPvsxFp7brTxbyUhKNzMM

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-8d989960
```

Example prompt: Can you search the Federal Register for any proposed rules from the EPA about clean water standards published in the last 6 months, and show me which ones still have open comment periods?

## When to prefer this

Choose this endpoint when you need to search US federal regulatory documents — rules, proposed rules, notices, or presidential documents — with structured metadata like docket IDs, comment deadlines, and effective dates. Prefer it over raw web search when you need machine-readable regulatory data, want to filter by agency or document type, or need to identify open comment periods. It wraps the official federalregister.gov public API, so data is authoritative and public domain.

## Known failure modes

- No results returned if keyword or agency slug is misspelled or too specific
- Agency slug must be exact hyphenated format (e.g. 'environmental-protection-agency'), not abbreviation
- Date range or document type mismatch returns empty result set
- Free tier limit of 25 calls/day per IP exceeded returns 402 or rate-limit error
- Invalid date format (non-YYYY-MM-DD) may cause parameter rejection
- Limit values outside 1-20 range may return validation error

## How this service works

Pay-per-call utilities for AI agents over x402, USDC on Base.

## Output

Returns a JSON object with the total number of matching documents, a list of up to 20 documents each containing: title, document type, publishing agencies, docket IDs, publication date, effective date, comment close date, document number, and a direct URL to the full document on federalregister.gov. Also includes the source attribution and count of returned results.

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "q": {
       "type": "string",
       "description": "Optional keyword or phrase"
      },
      "to": {
       "type": "string",
       "description": "Optional publication date to, YYYY-MM-DD"
      },
      "from": {
       "type": "string",
       "description": "Optional publication date from, YYYY-MM-DD"
      },
      "sort": {
       "enum": [
        "relevance",
        "newest",
        "oldest"
       ],
       "type": "string"
      },
      "type": {
       "enum": [
        "rule",
        "proposed_rule",
        "notice",
        "presidential_document"
       ],
       "type": "string",
       "description": "Optional document type"
      },
      "limit": {
       "type": "string",
       "description": "1 to 20, default 10"
      },
      "agency": {
       "type": "string",
       "description": "Optional agency slug, e.g. environmental-protection-agency"
      },
      "comments_open": {
       "type": "string",
       "description": "true to keep only documents still open for comment"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "source": "federalregister.gov API (public domain)",
  "returned": 1,
  "documents": [
   {
    "url": "https://www.federalregister.gov/documents/2026/10/23/2026-21706/example",
    "type": "Proposed Rule",
    "title": "Example proposed rule",
    "agencies": [
     "Treasury Department"
    ],
    "docket_ids": [
     "Docket ID OCC-2025-0372"
    ],
    "effective_on": null,
    "document_number": "2026-21706",
    "publication_date": "2026-10-23",
    "comments_close_on": "2026-12-22"
   }
  ],
  "total_matches": 42
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-federal-register-search-8d989960/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.crowdspark.me](https://www.zero.xyz/host/agents.crowdspark.me/llms.txt)