The host's message listener trusted the compile-time WorkerToHost shape on traffic from a peer that runs model code: postMessage(null) threw in the listener and crashed the host process; forged log/done messages bypassed maxLogBytes/maxValueBytes (the worker-side LogBuffer and prepareValue cap only honest flows); and the error-reply renegotiation re-echoed a forged non-cloneable call id, throwing outside any catch. Every inbound message now passes a runtime shape gate that validates and REBUILDS it field by field (junk drops without a throw; call ids must be numbers, so replies are always clone-plain; forged extra fields never ride along). One host-side ledger bounds everything landing in logs — honest port entries, forged ones, and stray pipe bytes — at the single documented maxLogBytes, with the shared in-band truncation marker emitted host-side when the ledger trips first; the completion value is re-capped host-side through the same prepareValue (with exactly the truncation suffix as slack so honest worker-capped values pass unchanged), and done error text is bounded. Also folds the stray-capture budget into that shared ledger (round-1 finding B: it was a second maxLogBytes on top of the documented shared cap).
Packages
Harness packages, all under the @deepseek-ai/dsh-* scope. Each package is a Cordis plugin (microkernel-style): it exports either a default Service subclass or a functional plugin, declares its ctx key/events through declaration merging, and exposes extension points through ctx.effect(), ctx.on(), and ctx.waterfall(). Authoring conventions: AGENTS.md (subtree) and the root AGENTS.md § Conventions.
Hierarchy
Packages are grouped by modular role at packages/<group>/<pkg>/. The group directory is a pure container (no package.json of its own); the package name stays @deepseek-ai/dsh-<pkg> regardless of group. Each group README is the canonical per-package map — package roles, ctx keys, and the product-vs-support split live there, next to the code.
| Group | Role | Release expectation |
|---|---|---|
core/ |
Product API spine: session, system-prompt, tools, agent, and the concrete loop | Product — stable surface |
llm/ |
LLM capability family: the abstract service + provider adapters | Product — stable surface |
bash/ |
Bash capability family: the executor seam, a local impl, and the model-facing tool | Product — stable surface |
code-runtime/ |
Code-execution capability family: the abstract runtime seam for model-written programs + a worker-thread backend | Product — stable surface |
fs/ |
Filesystem capability family: the abstract seam, a local impl, and the model-facing file tools | Product — stable surface |
compact/ |
Compaction capability family: the abstract seam + a basic backend (tool deferred) | Product — stable surface |
subagent/ |
Subagent capability family: the provider-registry seam and the model-facing delegation tool | Product — stable surface |
web/ |
Web capability family: the abstract seam, search/fetch provider impls, and the model-facing web tools | Product — stable surface |
todo/ |
Todo/planning family: the model-facing todo_write tool (whole-list task tracking on the session log) |
Product — stable surface |
hooks/ |
Hook bridges + the shared Claude Code / Codex wire-protocol library | Product — stable surface |
session-persistence/ |
Persistence capability family: the seam + JSONL/SQLite backends | Product — stable surface |
ui/ |
Editor/client integration surfaces (the ACP bridge) + the app packages | Product — stable surface |
support/ |
Dev/test/example infrastructure (invariants, replay adapter, subagent mock) | Support — lower compatibility expectations |
util/ |
Low-level zero-dependency utilities shared across groups (the Branded<B> primitive) |
Support — small, stable, harness-dep-free |
The split is the point: a package's group says whether it is part of the product API or support/test/example infrastructure, so release and removal decisions do not treat every package as an equal public contract. New packages join an existing group; adding a new top-level group is a deliberate act (extend the group READMEs and this table).
Dependencies
The inter-package dependency graph is generated: docs/module-graph.md (pnpm run gen-module-graph, freshness-gated in CI).
The rule it must obey: extension plugins depend on interfaces, never on the concrete loop. dsh-agent-loop is swappable — UI/hook/tool plugins keep working against the dsh-agent vocabulary if the loop is replaced. The sanctioned exception is a composition/bundle package like dsh-agent-core, whose whole job is to assemble the concrete spine: it depends on dsh-agent-loop (and the other concrete spine plugins) on purpose. The rule constrains plugins that EXTEND the system, not the bundle that COMPOSES it — swapping the loop means shipping a different bundle, not rewiring every extension. A swappable capability splits into interface / implementation / consumer packages (the bash trio is the template — see capability seams).
Each package has its own README.md with purpose, service API, events, extension points, and deliberate non-goals (TODOs).