This template ships optional pattern crates. For most new projects, keep one
application crate and delete the rest (./scripts/init-template.sh --minimal).
| Pattern | Crate | Copy when… |
|---|---|---|
| Trait-only storage | example-storage-pattern |
You want a storage trait + mock tests without SQL deps |
| Hybrid storage wrapper | hybrid-storage-template |
You need HybridStorage + working MemoryBackend |
| Registry dispatch | example-registry-pattern |
Handler map by name |
| Actor mailbox / supervision | actor-runtime-template |
Message-passing concurrency (hand-rolled, not ractor) |
| Checkpoints / migrations | checkpoint-template |
Serializable state + version migrations |
| MCP tool registry | mcp-server-template |
Tool trait + registry dispatch |
- Default choice: copy
example-storage-pattern(trait + mock). - In-memory multi-backend demo: use
hybrid-storage-templatewithMemoryBackend. - Do not treat
SqliteBackendas production code — it is a fail-closed stub under the optionalsqlitefeature.
See also: trait-only-storage.md, registry-dispatch.md.