Three findings from the PR-4 convergence round: (A) A root-undefined binding argument passed normalization untouched, so the sub-call DISPATCHED and only then failed the tool/code-dispatch append (Session.append rejects undefined event data) — a sub-call executed with no log record, violating the nothing-executes-unlogged contract. And the tool received the SAME object later handed to the append, so a tool mutating its args desynced the logged record from what was dispatched (or re-poisoned the append). jsonNormalizeArgs now rejects undefined up front with a model-correctable message and returns TWO independent parses of the canonical JSON text: the tool gets one, the event logs the sibling — identical by construction, mutation-proof. (B) The bridge built its bindings record with plain-object assignment, so a registered tool named __proto__ hit the prototype setter and silently vanished (the runtime host resolves binding names as own properties). The record is now null-prototype with defineProperty, mirroring the worker-side namespace build. (B) The header-pin sanity assertions ran only inside NON-pinning scenarios, so a class consisting solely of its pinning scenario (the two Code Mode classes) would accept a re-recorded pin carrying several headers or a header-delta. A fixtures meta-test now asserts every pinning fixture directly.
Examples
Runnable demos (not workspaces) that showcase how the harness is wired. Each example is now a thin leaf: a cordis.yml that picks the swappable backends (an LLM adapter, a bash executor), loads ONE app package, and may add optional product tools or demo-only mocks. The composition — the spine, the front-door cluster, and the boot glue — lives in the app packages (@deepseek-ai/dsh-stdio-agent, @deepseek-ai/dsh-acp-agent) and the @deepseek-ai/dsh-agent-core bundle they share. There is no start.ts; the demo:* scripts invoke each app package's bin.
echo-agent
A mock model + echo tool on the stdio chat app — the all-mock skeleton. The leaf swaps dsh-stdio-agent's LLM backend to a local mock-echo adapter and adds a local echo tool. Demonstrates:
- A thin leaf
cordis.ymlloading the@deepseek-ai/dsh-stdio-agentapp - Registering a mock
LlmAdapter(streaming scripted responses) - Registering a tool via
ctx.tools.register() - "Swap the backend, keep the app" — the only difference from
coding-agentis the adapter
Run with: pnpm run demo:echo. When prompted, type "echo " to trigger a tool call round-trip.
coding-agent
A REPL agent demo: DeepSeek V4 + the read/write/edit filesystem tools + the bash tool suite, subagent delegation, and the todo_write task tracker on the same @deepseek-ai/dsh-stdio-agent app. The UI is a terminal readline REPL.
Run with: pnpm run demo:repl (needs DEEPSEEK_API_KEY in the environment or a gitignored repo-root .env). See coding-agent/README.md for details.
code-agent
The coding agent flipped to Code Mode: the worker-thread code runtime is loaded and the tool registry runs mode: code, so the model gets exactly one wire tool — run_code — plus a generated TypeScript SDK section, and composes bash/read/write/edit/todo_write by writing a program whose output it curates.
Run with: pnpm run demo:code (needs DEEPSEEK_API_KEY). See code-agent/README.md for what to try and how it differs from coding-agent.
acp-agent
An agent demo exposed as an Agent Client Protocol (ACP) server over JSON-RPC stdio, via the @deepseek-ai/dsh-acp-agent app — drive it from Zed or any other ACP client. Also the home of the keyless snapshot tests.
Run with: pnpm run demo:acp (needs DEEPSEEK_API_KEY). See acp-agent/README.md for the Zed setup and the snapshot-test design.