Glossary — the bread lexicon

The named concepts in this codebase, in one place. If a bread-themed term is not on this page, it is not part of the project's vocabulary.

Crumb (BreadCrumb)

The typed stream atom — every event a run emits (text:delta, tool:call, agent:run:end, loop:*, human:required, …) is one crumb dropped along the path of execution, and the run stream (NDJSON or SSE, depending on config.transport) is the breadcrumb trail a client follows to reconstruct what happened. Crumbs anchor the entire event model. See architecture.md and http-api.md.

Transport (BreadTransport), Frame (BusFrame), and seq

The transport is the crumb fabric between replicas of one app (config.transport): the replica executing a run publishes each client-visible crumb as a frame — { runId, seq, crumb } — and any replica can subscribe to a run's live tail, with a bounded seq-based (afterSeq) replay guarantee for duplex transports. seq is the crumb's per-run monotonic position in the durable crumb log (text:deltas carry the last durable seq as a watermark), which is what Last-Event-ID catch-up replays. The store is the durable, unbounded source of truth; a transport's own replay is a bounded convenience on top. Default is the embedded Stream transport; @breadai/transport-redis is the distributed implementation. See transports.md.

Plugin (BreadPlugin) — formerly Spread

Anything applied onto the core framework: pre-built agents, tools, auth strategies, HTTP routes, lifecycle hooks. (Model providers are a config-level seam, not a plugin one — see agents.md#providers.) Early versions called this a Spread (butter on bread); the alias was renamed to BreadPlugin for immediate legibility and the deprecated Spread/SpreadContext aliases have since been removed from the public API. See plugins.md.

Loaf, Slice, and other bread words

Not concepts. The project name and its logo lean on the bread metaphor, but no type or API is named Loaf, Slice, Knead, etc. If you half-remember such a term, this page is the authoritative "no".

The non-metaphor names

The rest of the vocabulary is deliberately literal: agent, tool, task (one-shot, stateless), skill (loadable instruction pack), loop (agent-driven iteration), pipeline (declared step sequence), decision (a pipeline step that records a System One label on its step-end crumb and leaves the value passed onward unchanged), branch (an exclusive pipeline step: one arm, strict string equality on on or the latest decision label, required default), supervisor (LLM-driven delegation to sub-agents via core_delegate), store (BreadStore persistence), session, checkpoint (HITL suspension point), HITL (human-in-the-loop), remote agent (RemoteAgent, remoteAgent() — the peer-transport seam to another bread instance), and frame (BusFrame/CrumbFrame — the local/wire envelope for a crumb). Each has a doc page under docs/.