CFR title hierarchy + node stats (eCFR) API

Return the hierarchical structure of a CFR title from the eCFR versioner with derived stats: node-type counts (chapters/parts/sections), section and part totals, reserved-node count, title byte size, and a shallow chapter outline. Answers 'How big is CFR Title 3 and how is it organized?', 'How many sections does this title contain?'.

Price$0.01per request

MethodPOST

Route/v1/gov/ecfr-title-structure

StatusLive

MIME typeapplication/json

Rate limit60/minute

Cache86400s public

govlegalregulationscfrecfrstructurehierarchyus

API URLhttps://x402.hexl.dev/v1/gov/ecfr-title-structure

Integration docs

Example request

{
  "title": 3
}

Example response

{
  "title": 3,
  "titleName": "The President",
  "asOfDate": "2026-06-01",
  "sizeBytes": 33536,
  "nodeCounts": {
    "title": 1,
    "chapter": 1,
    "part": 4,
    "section": 27
  },
  "sectionCount": 27,
  "partCount": 4,
  "reservedNodes": 8,
  "outline": [
    {
      "identifier": "I",
      "type": "chapter",
      "description": "Executive Office of the President",
      "reserved": false,
      "childCount": 4
    }
  ],
  "disclaimer": "Informational data product aggregated from public government / open-legal APIs. NOT legal advice. Verify against the official primary source before relying on it."
}

Input schema

{
  "type": "object",
  "required": [
    "title"
  ],
  "properties": {
    "title": {
      "type": "integer",
      "minimum": 1,
      "maximum": 50
    },
    "date": {
      "type": "string",
      "description": "Optional as-of date YYYY-MM-DD"
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}