Project- and owner-scoped secret storage for the trusty-* tools: key, scope and reference types, a names-only index, and an OS Keychain backend (DOC-74 §15).
Disk cache primitive with a hard size cap, LRU eviction that survives restarts, atomic writes and group invalidation, plus stable-prefix prompt-cache keys.
Bellows, the AI-agent support of the Smeltery framework: an MCP server inside the app (routes, schema, config keys, errors, docs, generators, tests, agents).