Runtime Composition¶

Runtime composition is the process of turning Atlas modules into a running server process with concrete configuration, limits, backends, and middleware.

Composition Model¶

flowchart LR
    Config[Runtime config] --> Runtime[Runtime composition]
    App[App services] --> Runtime
    Adapters[Concrete adapters] --> Runtime
    Runtime --> Server[Running server]

This composition model explains what runtime owns: taking abstract services, concrete adapters, and configuration and turning them into one running process.

Runtime Responsibilities¶

flowchart TD
    Runtime[Runtime] --> BuildState[Construct app state]
    Runtime --> Router[Assemble router and middleware]
    Runtime --> Limits[Apply limits and policy mode]
    Runtime --> Backends[Choose concrete backends]

This responsibility map is useful because runtime composition often grows opportunistically over time. The diagram keeps the intended boundary visible for future changes.

Architectural Boundary¶

Runtime is where concrete choices belong:

addresses and bind settings
store and cache roots
concurrency and rate-limiting settings
telemetry backends

Those choices should not leak backward and become domain rules.

Runtime Composition Smell Test¶

are you wiring concrete behavior or redefining domain meaning?
are you selecting a backend or sneaking infrastructure detail into a contract?
are you composing limits and middleware where operators expect them to live?

Purpose¶

This page explains the Atlas material for runtime composition and points readers to the canonical checked-in workflow or boundary for this topic.

Stability¶

This page is part of the canonical Atlas docs spine. Keep it aligned with the current repository behavior and adjacent contract pages.