# Outline Markdown headings

Build-time release reference. Runtime readiness, deployment, payment settlement and external indexing are not evaluated here. Prices are proposed; this file cannot authorize execution or payment.

Use to build a lightweight navigation index or section slicer. Finds ATX headings (# through ######) with up to three leading spaces, ignores fenced code, and supplies parent indexes and exact section offsets. Heading text remains inline Markdown. Does not parse Setext headings, indented code, block quotes, HTML blocks, or a full CommonMark AST. At most 5,000 headings.

Release: 0.29.0. Built: 2026-10-06T15:38:00Z.

## Choose for
- Find supported ATX headings and exact section offsets.

## Outside this profile
- A complete CommonMark AST or Setext/HTML heading support.

Proposed nominal USD 0.005 per successful call; payer fees excluded. No verified runtime availability.

- [Exact release contract](/reference/services/markdown-outline.json)
- [Input schema](/reference/schemas/markdown-outline.input.json)
- [Output schema](/reference/schemas/markdown-outline.output.json)
- [Fixed example](/reference/examples/markdown-outline.json)
- [Complete HTML reference](/discover/tools/markdown-outline)