# US Federal Register Incremental Change Feed

> US Federal Register Incremental Change Feed is a paid API for AI agents from store.cryptotradecalc.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Returns an incremental feed of US Federal Register rules, proposed rules, and notices published since a given date, filtered by topic, for scheduled polling workflows.

## Facts

- Endpoint: GET https://store.cryptotradecalc.com/api/reg-changes
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/us-federal-register-incremental-change-feed-ea8b32da
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5ci9w-c35ibSr7Ysow1Nz

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-incremental-change-feed-ea8b32da
```

Example prompt: Check the US Federal Register for any new rules, proposed rules, or notices about 'cryptocurrency' published since 2024-06-01, and give me each document's number, agency, type, date, and link along with the next polling date.

## When to prefer this

Choose this endpoint when you need an incremental, poll-friendly feed of US Federal Register documents filtered by topic — particularly for scheduled compliance monitoring, regulatory alerting pipelines, or any workflow that needs to process only new documents since the last run. The nextSince cursor makes it ideal for building idempotent polling loops without duplicates. Prefer it over full-text search APIs when you want lightweight metadata (not full document text) and structured deduplication via documentNumber.

## Known failure modes

- Federal Register source unreachable — endpoint fails closed, returning an error rather than an empty feed, so agents can distinguish a true no-results from a data source failure
- Missing required topic parameter — request rejected with an error
- Invalid since date format — should be YYYY-MM-DD; malformed dates may cause an error or be ignored
- No new documents matching topic since the given date — returns empty feed with nextSince set
- Rate limiting or payment failure (x402) — call is rejected if USDC payment is not processed

## How this service works

reg-watch-changes: Incremental feed of US Federal Register rules, proposed rules, and notices published since a date you supply. Built for scheduled polling: pass since=YYYY-MM-DD and get only documents you have not seen, each with its document number, agency, type, date, and direct link, plus nextSince for your next poll. Dedupe on documentNumber. Fails closed if the source is unreachable, so an empty feed always means no new rules. Query: topic (required), since (optional).

## Output

A list of Federal Register documents matching the topic filter published after the supplied since date, each containing document number, issuing agency, document type (rule/proposed rule/notice), publication date, and a direct URL to the document; plus a nextSince field to use as the cursor for the next polling call. An empty list definitively means no new documents were published (not an error).

## 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",
     "properties": {
      "since": {
       "type": "string"
      },
      "topic": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/us-federal-register-incremental-change-feed-ea8b32da/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from store.cryptotradecalc.com](https://www.zero.xyz/host/store.cryptotradecalc.com/llms.txt)