Return the section index of a Markdown file as a nested tree.

Each node: {"heading": str, "level": int, "path": str, "children": [...]} The "path" field is the dot-separated address used by all other tools. Literal dots in heading text are represented as . in path strings.

Return the heading line(s) and body of the section at path.

path is a dot-separated heading path, e.g. "My README.Installation.Prerequisites". Matching is case-insensitive. Returns the raw Markdown text of the section.

depth controls how many levels of child sections are included:

• None (default): return the section and all descendants

• 0: return the heading and its own body only (no child sections)

• 1: heading + own body + immediate children

• 2: heading + own body + children + grandchildren etc.

Raises an error string if the path does not exist.

Search all section bodies for lines matching query (regex).

Returns a list of match objects — one per section that contains at least one hit — in file order:

[
  {
    "path": "Root.Child",
    "matches": [
      {"line": 12, "text": "...the matching line text..."},
      ...
    ]
  },
  ...
]

line is the 1-based line number within the file. Only each section's own body is searched (not its children), so results are never duplicated across parent and child sections. Note: heading text is not searched — only section bodies. If the term you are looking for may appear in a heading, call get_index first and scan the returned paths. query is a Python regex; raises an error string if the pattern is invalid.

Insert a new section into a Markdown file.

heading must start with 1–6 '#' characters followed by a space, e.g. "## New Section". content is the body text (no heading line). Placement: exactly one of under, before, after may be set, or all None to append.

• under: insert as the last child of the named section

• before: insert immediately before the named section

• after: insert immediately after the named section (and all its children) Returns "ok" on success.

Replace the body of a section, preserving its heading line.

The heading line is kept unchanged; only the body text is replaced. Returns "ok" on success.

Return a unified diff of what replace_section would do, without writing.

Useful for previewing changes before committing them. Returns the unified diff as a string (empty string if no changes).

Delete a section from a Markdown file.

With include_children=True (default): deletes the heading, its body, and all child sections. With include_children=False: deletes only the heading and its own body; child sections are promoted. Returns "ok" on success.