Implements the LSP capability seam RFC as three packages: dsh-lsp (the ctx.lsp interface — provider registry by branded id + exclusive extension mapping, per-query order-independent selection, closed request/result vocabulary, LspError taxonomy), dsh-lsp-local (a generic stdio language-server provider — Content-Length JSON-RPC framing, per-(provider, workspace) process single-flight, transient didOpen/query/didClose, an abortable per-instance queue, UTF-16 negotiation, host-namespace source reads outside ctx.fs, and bounded shutdown/kill teardown), and dsh-tool-lsp (the model-facing lsp tool — four operations, one-based UTF-16 cursor conversion, workspace-grouped location rendering, hover capping, a required session workspace, and a timeout budget). Why: an agent had text search and file reads but no way to identify a program symbol — follow an alias, connect an interface to implementations, or read an inferred type — before changing code. Splitting model contract, seam, and local subprocess behavior keeps the four semantic queries stable across future remote or sandbox-native providers without leaking a JSON-RPC escape hatch.
core/ — product API spine
The session log, system-prompt assembly, tool registry, agent vocabulary, and concrete loop that form the harness's default control spine. These are product packages — the stable surface plugins and consumers build against.
| Package | Role | ctx key |
|---|---|---|
scope/ |
Scoped-context registration primitive (scope tags, scope-filtered dispatch) | (library — no ctx key) |
session/ |
Event-sourced session log + in-memory store | ctx.sessions |
system-prompt/ |
Prompt-section + tool-schema assembly registry | ctx.systemPrompt |
tools/ |
Scoped tool registry + pre-policy, guards, around-dispatch, post-policy, and final-result observation | ctx.tools |
agent/ |
Agent interface, registry, agent/* event vocabulary |
ctx.agents |
agent-loop/ |
The concrete loop plugin: ReactLoopAgent + the loop driver |
ctx.agentLoop |
agent-core/ |
Bundle plugin: the default executor-less/UI-less spine as code | (loads the spine) |
scope/ is the one non-service package here: a dependency-free library (createScope/scopeOf/scopeTarget) the registries and the loop build per-agent scoping on — it sits below session/ and system-prompt/ in the module graph precisely so they can consume it without a cycle.
agent-loop is the one concrete implementation of the agent seam and lives here because it is the harness's default product loop; everything else in core/ is interface/vocabulary. Plugins depend on the agent vocabulary, never on agent-loop directly, so the loop stays swappable.
agent-core is the composition counterpart: one bundle plugin that loads the control spine plus selected default capabilities (timer + llm + sessions + system-prompt + tools + agents + invariants + the local skill family + tool-bash + agent-loop) and forwards agent-loop's agents list as its own config. App packages (ui/stdio-agent, ui/acp-agent) consume it and add only a front door; a leaf adds the swappable backends plus any optional product tools it wants to expose. It lives in core/ because it composes the shared control spine while leaving executors, LLM adapters, alternate skill providers, and UI front doors outside the bundle.