Implements the split-the-filesystem-seam RFC. ctx.fs shrinks to a text-storage provider seam (resolve/stat/readText/streamText/writeText/editText with branded FsTargetKey/FsVersion and an explicit FsWriteExpectation); the new dsh-file-context package owns the model-facing policy (read windowing, observed-state, write/edit freshness) as the concrete ctx.fileContext service. Authorization is now freshness-based rather than full/partial view: a windowed read records the file version and authorizes a later edit when the file is unchanged, removing the dead-end where reading lines 100-150 of a large file could not edit line 120. editText stays a provider primitive so version guard + literal match + atomic rewrite remain one critical section, and the stale check runs before matching so a stale edit reports FS_STALE_VERSION. tool-fs injects fileContext, never reaching around to ctx.fs (the no-bypass contract).
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) and loads ONE app package, plus any 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
The real thing: DeepSeek V4 + the bash tool suite on the same @deepseek-ai/dsh-stdio-agent app. Where echo-agent proves the skeleton with mocks, this is a usable coding assistant.
Run with: pnpm run demo:coding (needs DEEPSEEK_API_KEY in the environment or a gitignored repo-root .env). See coding-agent/README.md for details.
acp-agent
The same coding agent 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.