# 2s.io Federal Register Search

> 2s.io Federal Register Search is a paid API for AI agents from 2s.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Search US Federal Register documents — rules, proposed rules, notices, and presidential documents — by keyword, type, agency, and date range

## Facts

- Endpoint: GET https://2s.io/api/law/federal-register
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/2s-io-8e0ce7ac
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q7ZSkMA1yTaA-UJf3DNc9

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 2s-io-8e0ce7ac
```

Example prompt: Search the Federal Register for proposed rules from the EPA about clean air standards published since 2024-01-01 — show me up to 10 results with their titles, abstracts, and links.

## When to prefer this

Use this endpoint when you need real-time, post-training-cutoff US federal regulatory data — proposed rules, final rules, agency notices, or presidential documents — especially when filtering by agency (e.g. epa, fda, sec) or document type matters. Prefer this over general web search when you need structured metadata like effective dates, comment deadlines, FR citations, and direct PDF links from official government sources.

## Known failure modes

- Missing required 'q' parameter returns 400 Bad Request
- Invalid document type value (not RULE/PRORULE/NOTICE/PRESDOCU) returns 400
- Invalid agency slug format returns 400
- Invalid date format (not YYYY-MM-DD) returns 400
- No matching documents returns empty results array
- Limit exceeding 20 returns 400

## How this service works

Search the US Federal Register — proposed rules, final rules, notices, and presidential documents. Filter by free-text term, document type (RULE/PRORULE/NOTICE/PRESDOCU), agency slug (e.g., epa, fda, sec), and publication date range. Returns document_number, type, title, abstract, FR citation, agencies, publication_date, effective_on, comments_close_on, htmlUrl, pdfUrl, rawTextUrl. Public-domain US government data. Real-time — published daily, past LLM training cutoff.

## Output

Returns a list of Federal Register documents each containing: document_number, type (RULE/PRORULE/NOTICE/PRESDOCU), title, abstract, FR citation, list of agencies, publication_date, effective_on date, comments_close_on date, htmlUrl, pdfUrl, and rawTextUrl. Results are filtered by the provided query parameters and limited to the requested count (default 10, max 20).

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "q": "artificial intelligence",
   "type": "RULE",
   "limit": 10
  }
 }
}
```

## 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",
    "queryParams"
   ],
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "const": "GET"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "maxLength": 500,
       "minLength": 1
      },
      "type": {
       "enum": [
        "RULE",
        "PRORULE",
        "NOTICE",
        "PRESDOCU"
       ],
       "type": "string"
      },
      "limit": {
       "type": "integer",
       "default": 10,
       "maximum": 20,
       "minimum": 1
      },
      "since": {
       "type": "string"
      },
      "until": {
       "type": "string"
      },
      "agency": {
       "type": "string"
      }
     },
     "additionalProperties": false
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/2s-io-8e0ce7ac/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)