One principle: every fact in the assembled prompt has exactly one owner.
- dsh-system-prompt: merge-extensible AssembleContext on assemble();
a variable(name, provider) registry; {{name}} interpolation in
renderPrompt, strict (unknown/valueless/malformed references throw);
duplicate section and variable names rejected; assembly carries
resolved section text + variables through the assemble waterfall.
- dsh-agent declares AssembleContext.agent; dsh-agent-loop registers
the agent:persona section (order 0 - identity renders before tool
guidance) and the model/cwd variables, and drops its string join:
renderPrompt(assembly) IS the full prompt.
- Tool guidance moves to its owners: descriptions carry per-tool
semantics; sections only cross-call habits (tool:bash exit-code
habit at order 105; read's not-shell nudge). todo/subagent need no
section - their descriptions already carry the contract.
- SubagentProvider.inheritsParentContext (spawn/acp false, fork true);
dsh-tool-subagent derives truthful per-provider wording and resolves
the provider at load (backend must be listed first).
- Example personas shrink to identity + behavior with {{model}} (and
{{cwd}} in the ACP tree); the welcome banner stops enumerating tools.
RFC: docs/rfc/implemented/architecture/2026-07-05-prompt-variables-and-tool-guidance-ownership.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.