Review follow-up (#196): a listed name with no registered tool was silently ignored; misconfiguration must block work instead. The check lives in the assembly — the earliest moment the registered tool set exists (tool plugins register after the service constructs) and the only universal one (cordis has no "all plugins loaded" event; registrations change at any time). assemble() is now async so the throw surfaces as a rejection rather than a synchronous escape from a Promise-returning method. Blast radius, pinned by a loop-level test: the rejection reaches the turn's outer catch — the turn closes balanced with an `error` reason, agent/error mirrors it, no step opens, no request/header is logged, no request reaches the adapter, and the agent returns to idle; every turn fails identically until the config is fixed. A boot-time validation pass was considered and rejected (recorded in the RFC). The general principle — misconfiguration fails loud, never a silent skip — is added to AGENTS.md.
ui/ — editor/client integration surfaces
Integrations that expose the agent to an external editor or client. These are product packages: a real surface a user drives the harness through.
| Package | Role | ctx key |
|---|---|---|
acp/ |
Agent Client Protocol bridge: serves the agent to an ACP editor (Zed) over JSON-RPC stdio | (drives ctx.agents/ctx.sessions) |
stdio-agent/ |
Terminal stdio chat APP: the agent-core spine + console logger + readline UI + a pre-created main agent, with a bin |
(composition + bin) |
acp-agent/ |
ACP server APP: the agent-core spine + JSONL persistence + the acp bridge (no stdout logger), with a bin |
(composition + bin) |
app-boot/ |
Shared boot glue for the two app bins: .env loading, fail-loud Loader guards, snapshot-aware config resolution, the settle-the-tree boot sequence |
(library for the bins) |
A UI integration is a client-driver plugin, not a loop change and not a capability seam: it consumes the existing agent/* event taxonomy and the dsh-agent factory. The readline UI is the unstructured analogue of the acp bridge and lives INSIDE the stdio app (the stdio-chat module of stdio-agent/): it is scaffolding for that one front door, not an independently swappable integration, so it carries no package boundary of its own.
stdio-agent and acp-agent are the two app packages: each composes the core/agent-core spine with its coupled front-door cluster (and owns the boot bin), so a leaf cordis.yml is the swappable backends plus one app entry plus any optional product tools. They live in ui/ because each IS a user-facing front door; the stdout-purity coupling (logger vs. no logger) becomes a property of the artifact rather than a leaf convention.