DXF to Markdown and Image

Convert a DXF CAD drawing into structured Markdown (metadata, layers, text, entity summary) and a PNG render of its line work. The source is supplied as raw bytes or an http(s) URL.

API

local dxf2md = require("dxf2md")

local drawing, err = dxf2md.open({ bytes = dxf_bytes })
if err ~= nil then
    return nil, err            -- err.kind / err.message / tostring(err)
end

dxf2md.open(request) -> handle, err

• request — a table with exactly one source:
  • { bytes = <binary string> } — the raw bytes of a DXF drawing, or
  • { url = "https://…" } — an http(s) URL, downloaded automatically.
• handle — on success, the table below; nil on failure.
• err — nil on success, otherwise a structured error.

handle.to_markdown() -> markdown, err

Returns structured Markdown describing the drawing (version, layers, text, entity summary), or nil and an error.

handle.to_image([dpi]) -> png, err

Renders the line work to a PNG.

• dpi — optional output resolution; defaults to 96. Must be a positive number no greater than 600.
• png — the render as PNG bytes (a binary Lua string), or nil on failure.

dxf2md.new(runtime) -> module

Advanced: build an instance with injected runtime dependencies ({ funcs?, http_client? }). See RFC 0001.

Errors

Every failure returns a structured error table with message, kind, and retryable. kind is one of invalid_input, download_failed, decode_failed, render_failed, internal. tostring(err) and string concatenation yield the message.

local md, err = drawing.to_markdown()
if err ~= nil and err.kind == "decode_failed" then ... end

Limits and safety

• Inputs (bytes or downloaded body) are capped at 128 MiB.
• URL fetches use an http(s)-only scheme allow-list, a 30s timeout, and a download size cap; private-IP targets are blocked by the runtime.

Build

make build-component builds the component and stages it; make test runs the suite.