iggi — code that grows like moss

A spreading-algorithm library for resilient, distributed computation. Seed a cell, define adjacency rules, and watch your system colonize available substrate — modest, but unstoppable.

npm install iggi or pnpm add iggi

Root — the substrate

Everything begins at the root: a typed grid of cells over which growth propagates. The root holds no opinion about geometry — it is merely a field of states that spreading rules act upon.

import { Substrate, grow } from 'iggi'

const field = Substrate.of({ width: 40, height: 30 })
field.seed(12, 8)            // drop a spore
grow(field, { rate: 0.3, decay: 'natural' })

Branches — spreading rules

Branches define how a colonized cell reaches its neighbours. The default rule colonizes the four orthogonal neighbours with probability 0.3 per tick; cells pass through a brief growing phase before becoming fully active. Click the field below to seed it yourself.

click any cell to plant a spore

Leaves — fine configuration

Leaves are the tuning surface: per-edge weights, anisotropic spread, density caps, and adaptation hooks. Configure once and the colony self-regulates.

Adaptive spread velocity with substrate-aware backpressure
Anisotropic growth — bias colonization along any axis
Deterministic replay from a single integer seed
Zero-dependency core; runs in Node, the browser, and at the edge

API reference

Substrate.of(dims)

Create a new growth field of the given { width, height } dimensions.

field.seed(x, y)

Plant a spore at cell (x, y). Multiple seeds compose into one colony.

grow(field, opts)

Run the spreading loop. opts.rate sets per-tick colonization probability; opts.decay controls senescence.

field.adapt(env)

Re-weight spreading rules in response to a changed environment descriptor.

Spores — distribution

Spores are lightweight, self-contained colonies you can serialize and ship anywhere. Drop one into a new substrate and growth resumes exactly where it left off — the colony in the panel below is releasing them now.

Ecosystem

iggi grows alongside the tools you already use. Compatible substrates and integrations: