playdough

GDSFactory's next-gen routing engine — robust, collision-aware Manhattan routing with optional gradient-based finetuning for photonic IC design.

Features

• Search-based Manhattan routing — performant, collision-aware, instant results
• Gradient-based finetuning — flexible constraint satisfaction (path length matching, collision avoidance) via automatic differentiation
• Multi-bundle routing — grouped port bundles with independent tangent directions
• Polyline output — get corner-point coordinates as numpy arrays, with optional smooth euler-bend curves

Installation

pip install playdough

Use playdough from a coding agent

playdough ships an Agent Skill that teaches Claude Code, Codex, Cursor, Gemini CLI or Kiro how to route with it, without the agent reading playdough's source:

playdough skills install     # this project; `playdough skills --help` for options

It writes .claude/skills/, .agents/skills/ and .kiro/skills/, so you need not know which convention your agent reads. playdough skills remove takes it back out.

Importing playdough inside a project a coding agent manages prints a one-line reminder to stderr that this command exists, with the installed version — at most three times per project, never in an ordinary directory, and never once the skill is installed. PLAYDOUGH_NO_HINT=1 silences it, as do CI and a GDSFactory+ worker.

Quick Start

import gdsfactory as gf
import playdough as pld

c = gf.Component()
waveguides = gf.components.array(gf.c.straight, columns=1, rows=3, row_pitch=3)
left = c << waveguides
right = c << waveguides
right.move((100, 50))

obs = c << gf.components.rectangle(size=(80, 10))
obs.ymin = 20

router = pld.add_route_bundle(
    c,
    start_ports=list(left.ports.filter(orientation=0)),
    end_ports=list(right.ports.filter(orientation=180)),
    obstacles=[obs],
)

# Optionally finetune for length matching
router.finetune(length_matching=5.0, lr=0.5)

Documentation

See the documentation site for tutorials and API reference.

License

Requires a valid GDSFactory account. Authenticate with gfp configure.