# Melder Architecture and Design Melder is an AI-native Dependency Graph Runtime: it turns registered Python objects into a governed, scoped, inspectable object world. This documentation explains that world from its outside boundary down to the source files that implement it. ![Melder system context](../media/architecture/diagrams/rendered/system_context.svg) {download}`Editable diagram source <../media/architecture/diagrams/source/system_context.mmd>` ## Choose Your Path | Intent | Start here | What you will learn | | --- | --- | --- | | Understand Melder | [What Melder is](architecture/01_overview/what_melder_is.md) | Category, mental model, and value | | See the ceiling | [Capability ladder](architecture/01_overview/capability_ladder.md) | Which layers are optional | | Understand the runtime | [Runtime model](architecture/02_architecture/runtime_model.md) | Ownership and execution boundaries | | Follow the visual descent | [Engineering drawings](architecture/05_engineering_drawings/index.md) | C4 system context through C2 meld internals | | Build with it | [Compose an application](architecture/03_usage/compose_an_application.md) | The basic application shape | | Integrate subsystems | [Connect subsystems](architecture/03_usage/connect_subsystems.md) | Dynamic links and contracts | | Evaluate design costs | [Design tradeoffs](architecture/04_tradeoffs/design_tradeoffs.md) | Benefits and accepted costs | ## Three Reading Depths 1. **High-level orientation** explains what Melder is and where it sits. 2. **Mid-level architecture and use** explains boundaries, lifetimes, and flows. 3. **Source descent** links directly to implementation and integration evidence. Nothing in the advanced ceiling is required to use Melder as a dependency runtime. Start with the human core and stop when you have the depth you need. ## Architecture - [System context](architecture/02_architecture/system_context.md) - [Runtime model](architecture/02_architecture/runtime_model.md) - [Ownership and lifetimes](architecture/02_architecture/ownership_and_lifetimes.md) - [C4 → C3 → C2 engineering drawings](architecture/05_engineering_drawings/index.md) Advanced architecture follows in the optional ceiling: - [Governance and structural change](architecture/02_architecture/governance_and_change.md) - [Continuity and evolution](architecture/02_architecture/continuity_and_evolution.md) - [Mediated runtime access](architecture/02_architecture/mediated_access.md) ## Utilization Stories - [Compose an application](architecture/03_usage/compose_an_application.md) - [Scope work and resources](architecture/03_usage/scope_work.md) - [Connect independently owned subsystems](architecture/03_usage/connect_subsystems.md) - [Isolate worlds in one process](architecture/03_usage/isolate_worlds.md) - [Operate through a Rift](architecture/03_usage/operate_through_a_rift.md) - [Preserve and evolve a world](architecture/03_usage/preserve_and_evolve.md) ## Documentation Contract Every page answers one reader question, explains one dominant picture when a picture helps, states the mechanism behind each strength, names accepted tradeoffs, and ends with a deliberate next-depth route. Pictures never replace the adjacent text. The canonical diagram sources and generated assets follow the [diagram contract](architecture/diagrams/index.md). ## Current License Melder is licensed under GNU AGPL v3 or later (`AGPL-3.0-or-later`). See the repository [LICENSE](https://github.com/Synaptic724/melder/blob/1211e838099a342c9dde48f064b1e772b6060e13/LICENSE) and [NOTICE](https://github.com/Synaptic724/melder/blob/1211e838099a342c9dde48f064b1e772b6060e13/NOTICE). --- [Canonical source](https://github.com/Synaptic724/melder/blob/1211e838099a342c9dde48f064b1e772b6060e13/architecture_and_design/README.md) · [Full contents](../contents.md) ```{toctree} :hidden: What Melder Is Capability Ladder System Context Runtime Model Ownership and Lifetimes Compose an Application Scope Work and Resources Connect Independently Owned Subsystems Isolate Worlds in One Process Design Tradeoffs Governance and Structural Change Continuity and Evolution Mediated Runtime Access Operate Through a Rift Preserve and Evolve a World Melder Engineering Drawings Diagram Contract ```