# Stellium Developer Docs (Agent Reference) > 🤖 **These docs are primarily for coding agents. Hello, Claude!** > This folder is written for AI coding agents (and human contributors) working > on Stellium. If you're an agent: read the relevant page here **before** > re-deriving the API from source — that's the whole point. When a doc disagrees > with the code, **the code wins** — please update the doc as you go. This folder is the durable reference for a coding agent working on Stellium — so you don't have to re-learn the API and architecture each session. The hub is [`/CLAUDE.md`](../../CLAUDE.md) (workflow, environment, conventions); these spokes hold the technical detail. ## Read in this order 1. **[ARCHITECTURE.md](./ARCHITECTURE.md)** — the mental model, layer map, dependency rules, and what `.calculate()` does. **Start here.** 2. **[CHART_BUILDING.md](./CHART_BUILDING.md)** — `Native`/`Notable`, `ChartBuilder`, `CalculatedChart`, config, registries. The core path. 3. **[ENGINES.md](./ENGINES.md)** — ephemeris, houses, aspects, orbs, dignities, patterns, dispositors, profections, fixed stars, etc. 4. **[COMPONENTS_AND_ANALYSIS.md](./COMPONENTS_AND_ANALYSIS.md)** — optional components, the pandas analysis toolkit, file IO, caching, utils. 5. **[VISUALIZATION_INTERNALS.md](./VISUALIZATION_INTERNALS.md)** — SVG pipeline, coordinate system, layers, themes/palettes, dial/vedic/atlas. 6. **[PRESENTATION_INTERNALS.md](./PRESENTATION_INTERNALS.md)** — `ReportBuilder`, sections, renderers (rich/markdown/html/pdf/prose). 7. **[SUBSYSTEMS.md](./SUBSYSTEMS.md)** — pointers: multi-chart, returns, electional, planner, Chinese/BaZi, CLI, progressions. 8. **[EXTENDING.md](./EXTENDING.md)** — how to plug in every protocol (engines, components, analyzers, layers, themes, palettes, report sections). ## How these docs are scoped Depth is concentrated on the most-used path (chart building, engines, components, visualization, reports); peripheral subsystems get lighter pointers to the entry point + the file to read. When a doc and the source disagree, the **source wins** — and please update the doc. User-facing guides live one level up in [`docs/`](../) (e.g. [`VISUALIZATION.md`](../VISUALIZATION.md), [`REPORTS.md`](../REPORTS.md), [`CHART_TYPES.md`](../CHART_TYPES.md)). See the full [documentation index](../DOCS_INDEX.md).