# Threadsmith Design Stats

> Stitch count, colours, trims, thread, bobbin, sewing time and density of a DST/EXP file. Reads a Tajima DST or Melco EXP file (or a stitch list) and reports stitches, jumps, trims, colour changes, size and hoop fit, thread length per colour with a bobbin estimate, sewing time at your machine speed and a thread-density check with the densest spots, plus a thread-look preview.

Part of usefulweb.site (https://usefulweb.site/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://threadsmithdesignstats.usefulweb.site/ (interactive tool at https://threadsmithdesignstats.usefulweb.site/tool)
- JSON API: POST https://threadsmithdesignstats.usefulweb.site/api/v1/calculate with a JSON object of inputs (schema: https://threadsmithdesignstats.usefulweb.site/api/v1/tool)
- OpenAPI: https://threadsmithdesignstats.usefulweb.site/openapi.json
- MCP (Streamable HTTP): https://threadsmithdesignstats.usefulweb.site/mcp - tool `threadsmith_design_stats`

## Inputs
- file (file): Embroidery file - Tajima .dst or Melco .exp.
- stitches (textarea): Or: stitch list (JSON) - Same format as threadsmith-stitch-file.
- colors (list): Thread colours in sewing order - Optional #rrggbb per colour block (DST/EXP files store no colours).
- spm (integer): Machine speed
- trimSeconds (number): Time per trim
- colorSeconds (number): Time per colour change
- hoop (select): Hoop
- densityThreshold (number): Too-dense limit - Thread coverage per 1 mm cell above which the design is flagged (2.6 ≈ underlay + top + some overlap).

## Method
- DST records are decoded from balanced ternary (bits for ±1, ±3, ±9, ±27, ±81 per axis); runs of three or more jumps count as one trim, as on most machines. EXP bytes are two’s-complement 0.1 mm steps with 0x80 control codes.
- Sewn length = sum of stitch lengths per colour; top thread = sewn length + 0.8 mm take-up per penetration + 5 % waste; bobbin ≈ 33 % of sewn length.
- Sewing time = stitches ÷ speed + trims × trim time + colour changes × change time + 0.15 s per jump.
- Density: each stitch deposits length × 0.4 mm thread width into the 1 mm cells it crosses; values are thread layers (1 ≈ fully covered once).

## Limits
- Thread and time figures are planning estimates; real consumption depends on tension, fabric, stabiliser and machine.