Patterns

Recipes for things people keep asking the framework to do but that compose cleanly from existing primitives.

The split between Concepts and Patterns is intentional: Concepts explain what OpenArmature is (typed state, nodes, edges, middleware, checkpointing, observers). Patterns explain ways to use it: opinionated shapes for common downstream questions like "how do I run an agent loop?" or "how do I skip work that's already been done?".

When to read which

• You don't know what a State is, or how nodes and edges fit together → start with Concepts.
• You know the primitives but you're asking "how do I do X with them?" → look here.

Patterns are user-level recipes, not framework contracts. New patterns can be added without spec coordination; they're how-to docs composing existing primitives.

The catalog

• Parameterized entry point: start the graph at an arbitrary node via state-driven routing.
• Tool dispatch as node: model an agent tool-call loop as a graph cycle.
• Session as checkpoint resume: carry multi-turn agent state across turns using the existing checkpointer.
• Bypass if output exists: short-circuit a node whose external output already exists, via middleware.
• State migration on resume: let older in-flight checkpoints resume against an evolved state schema without each node body having to handle multiple shapes.
• Caller-supplied trace identifiers: propagate tenant ID / request ID / feature flags into every observability span via invoke(metadata=...).
• Custom observer: reconciling started → completed pairs: thread per-call state between paired events using a per- invocation dict keyed on the spec's uniqueness tuple.