excalidraw_to_prompt

A CLI that converts Excalidraw diagrams into LLM-friendly flowcharts. Excalidraw's JSON export is verbose and full of rendering metadata that's useless to an LLM. This tool distills it down to a clean Mermaid flowchart TD representation that language models understand natively.

Features

• Hierarchy from nesting — rectangles visually nested inside other rectangles are emitted as subgraph blocks, with support for arbitrary nesting depth.
• Proximity-based binding — arrow endpoints that aren't formally bound to a node in the Excalidraw data are matched to the nearest node by edge distance (within a 50px threshold), so loosely-drawn diagrams still produce correct graphs.
• Tolerance for imprecision — containment detection uses a 20px tolerance so slightly misaligned nested boxes are still recognized.

Installation

cargo build --release
cp target/release/excalidraw_to_prompt /usr/local/bin/  # optional

Usage

excalidraw_to_prompt --path <path_to_excalidraw_file>

The tool reads an Excalidraw JSON export (.excalidraw file) and prints the flowchart to stdout.

Example

Given an Excalidraw diagram with three boxes — "Frontend", "API Gateway", and "Database" — connected by arrows labeled "REST" and "SQL":

flowchart TD
    frontend["Frontend"]
    apiGateway["API Gateway"]
    database["Database"]
    frontend -->|"REST"| apiGateway
    apiGateway -->|"SQL"| database

Nested boxes produce subgraphs:

flowchart TD
    subgraph backend["Backend"]
        authService["Auth Service"]
        userService["User Service"]
    end
    frontend["Frontend"]
    frontend --> authService

Piping into a prompt

echo "Here is my system architecture:

$(excalidraw_to_prompt --path ./design.excalidraw)

Suggest improvements for scalability." | pbcopy

Running tests

cargo test