API Quickstart
Make your first API call to the LexBuild Data API and retrieve legal content as JSON, Markdown, or plaintext.
Base URL
https://lexbuild.dev/api
All endpoints are prefixed with /api/. No authentication is required for read-only access.
Your First Request
Retrieve a single U.S. Code section as JSON:
curl https://lexbuild.dev/api/usc/documents/1-1
This returns the document for 1 USC Section 1 (“Words denoting number, gender, and so forth”):
{
"data": {
"identifier": "/us/usc/t1/s1",
"heading": "1 USC \u00a7 1 - Words denoting number, gender, and so forth",
"source": "usc",
"title_number": 1,
"section_number": "1",
"granularity": "section",
"body": "# \u00a7 1. Words denoting number, gender, and so forth\n\n...",
"token_estimate": 1250
}
}
Content Negotiation
Request the same document as Markdown:
curl https://lexbuild.dev/api/usc/documents/1-1 \
-H "Accept: text/markdown"
Or use the format query parameter:
curl "https://lexbuild.dev/api/usc/documents/1-1?format=markdown"
Supported formats:
| Format | Accept Header | Query Param |
|---|---|---|
| JSON | application/json (default) | ?format=json |
| Markdown | text/markdown | ?format=markdown |
| Plain text | text/plain | ?format=plaintext |
Browse Available Sources
List all available sources with document counts:
curl https://lexbuild.dev/api/sources
{
"data": [
{ "id": "usc", "name": "U.S. Code", "document_count": 60421 },
{ "id": "cfr", "name": "Code of Federal Regulations", "document_count": 232847 },
{ "id": "fr", "name": "Federal Register", "document_count": 785000 }
]
}
List Documents
List USC documents with pagination:
curl "https://lexbuild.dev/api/usc/documents?limit=5"
Filter by title:
curl "https://lexbuild.dev/api/usc/documents?title_number=18&limit=5"
Search
Search across all sources:
curl "https://lexbuild.dev/api/search?q=environmental+protection&limit=5"
Filter search results by source:
curl "https://lexbuild.dev/api/search?q=securities+fraud&source=cfr&limit=5"
[!TIP] The interactive API reference with request builder is available at lexbuild.dev/api/docs.
Next Steps
- API Overview — Base URL, key concepts, response structure
- Authentication — API keys, rate limits, tiers
- Documents Endpoint — Full document retrieval and filtering
- Content Negotiation — JSON, Markdown, and plaintext responses