The first alpha of the Rotifer Playground is here. This release establishes the full gene development lifecycle in a single CLI, backed by a Rust core that takes WASM sandboxing, fitness computation, and algebraic composition seriously from day one.

10 CLI Commands

The CLI covers the entire gene lifecycle out of the box:

rotifer init          # scaffold a project with genesis genes
rotifer scan          # discover candidate functions from source
rotifer wrap          # wrap functions as genes (phenotype generation)
rotifer test          # sandbox testing
rotifer compile       # phenotype validation + fingerprinting
rotifer arena submit  # submit to local Arena with admission gate
rotifer arena list    # view rankings: F(g), V(g), Fidelity
rotifer arena watch   # placeholder for live ranking updates
rotifer agent create  # create Agents with gene genomes
rotifer agent list    # view all registered Agents

Rust Core

The rotifer-core crate provides the foundational type system and engines:

Type System — Context, GeneResult, Phenotype, Gene, Agent, AlgebraExpr
WASM Sandbox — wasmtime-based with resource limits, fuel consumption, and epoch interruption
Arena Engine — local ranking with fitness-based sorting
Algebra Executor — Seq, Par, Cond, Try, Transform composition operators
Fitness Computation — simplified fitness score (F(g)) model with admission threshold
SQLite Storage — persistent genes, agents, and arena entries

5 Genesis Genes

Every new project ships with 5 pre-installed genes:

Gene	Domain
`genesis-web-search`	Full search with multiple results
`genesis-web-search-lite`	Lightweight single-answer search
`genesis-file-read`	Local file reading
`genesis-code-format`	Source code formatting
`genesis-l0-constraint`	L0 sandbox constraint checker

Developer Experience

Following the "Three-Act Demo" design pattern:

Wow (30s) — rotifer init scaffolds a working project with Arena preview
Aha (5min) — wrap your own function, submit to Arena, see it ranked
Hooked (30min) — compose genes, create Agents, explore fitness dynamics

Error messages follow Rust conventions: error codes, actionable suggestions, and documentation links.

By the Numbers

10 CLI commands
29 tests (unit + E2E)
5 genesis genes
napi-rs bridge connecting Rust core to TypeScript CLI

Get Started

npm install -g @rotifer/playground
rotifer init my-project

Full Changelog