deepseek-harness/packages/examples/acp-demo

@deepseek-ai/dsh-acp-demo

The ACP server app: a Cordis app plugin that composes the default agent spine (@deepseek-ai/dsh-agent-spine-demo) with the front-door cluster an Agent Client Protocol server needs, and a bin that boots a leaf cordis.yml speaking ACP JSON-RPC on stdio.

It is the structured counterpart to @deepseek-ai/dsh-tui-demo: both consume the same spine, but ACP creates sessions from its client and reserves stdout for its wire protocol.

What it bakes in — and what it deliberately omits

stdout is the ACP JSON-RPC channel, so the cluster is defined as much by what it LEAVES OUT as what it includes:

Plugin	Why
@deepseek-ai/dsh-agent-spine-demo	the spine, pre-creating no agents (ACP session/new creates them on demand)
@deepseek-ai/dsh-user-interaction	the human question/answer seam used by clients that can complete ACP elicitation requests
@deepseek-ai/dsh-session-persistence-jsonl	durable JSONL session log (the bridge advertises loadSession)
@deepseek-ai/dsh-acp	the bridge that owns stdout for JSON-RPC and provides ACP-backed user answers when a leaf explicitly exposes a user-question tool
@deepseek-ai/dsh-tool-ask-user	omitted by default — ACP elicitation support is still client-dependent, so leaves must opt in deliberately
@deepseek-ai/dsh-user-approval	omitted by default — permission policy is deployment-specific; sandbox/approval leaves opt in and the ACP bridge then supplies the answerer
console logger	omitted — it writes to stdout and would corrupt the protocol frames (the stdout-purity footgun)
hmr	omitted — the editor owns the subprocess

Because the package wires no logger entry, an ACP leaf has nothing to get wrong by default: it only picks backends. A leaf author can still add @cordisjs/plugin-logger-console as a sibling entry, so the rule remains: never add a stdout logger to an ACP leaf; use a stderr exporter instead.

Config

Key	Default	Routed to
provider	(required)	the initial provider route for each per-session agent the bridge creates; ACP model selection may replace it per session
model	(required)	the initial model for each per-session agent; ACP clients may switch among adapter-advertised models
maxParallelToolCalls	agent-loop default	positive-integer concurrent tool-call cap shared by the bundled loop's agents; 1 is serial
persona	—	the deployment persona template (may reference {{provider}}/{{model}}/{{cwd}}), routed to dsh-system-prompt
toolOrder	—	explicit model-facing tool order (a name list with one '<unlisted-tools>' rest entry; absent — lexicographic; an unregistered name fails each turn at prompt assembly), routed to dsh-system-prompt
dshHome	$DSH_HOME or ~/.dsh	Harness home exposed to model bash and used by local skill discovery
tools	{ mode: 'native' }	tool-registry presentation config (native / code / both), routed through dsh-agent-spine-demo
workspaceContext	(required)	workspace-instruction byte budget/config, or false; routed to the providerless-safe dsh-workspace-context plugin
skills	owner defaults	registry-cache, local-provider, and model-facing skill-tool config, routed through dsh-agent-spine-demo
toolBash	owner defaults	model-facing bash config routed through dsh-agent-spine-demo, including bash's producer-local enableRunInBackground
toolTasks	owner defaults	generic task_output wait bounds routed through dsh-agent-spine-demo
llmRetry	owner defaults	bounded transient model-request retry policy routed through dsh-agent-spine-demo
persistenceRoot	./.sessions	the JSONL backend's root directory
persistenceCompression	'zstd'	JSONL artifact encoding ('zstd' or raw 'none')

The leaf supplies the swappable backends: an LLM adapter (llm-deepseek for the real model, llm-replay for keyless snapshot replay), a bash executor, and optionally a ctx.fs provider. Workspace context becomes a no-op without ctx.fs; the shipped examples/acp-agent/cordis.yml selects dsh-sandbox-policy, dsh-fs-sandbox, dsh-fs-policy, and dsh-tool-fs so baseline instructions and model-facing read/write/edit share one provider, sandbox mode, workspace root, and observed-version policy.

The bin

dsh-acp-demo [--config path-to-cordis.yml] (short form -c; default ./cordis.yml):

• loads a gitignored .env from the cwd — skipped in snapshot REPLAY so a stray key can never trigger a live call;
• honors DSH_SNAPSHOT=replay by booting the sibling cordis.snapshot.yml (the keyless replay tree, llm-replay in place of llm-deepseek);
• in a snapshot run, disposes the context on stdin EOF so the session log is fully flushed before exit.

Run it under node --expose-internals, or Loader's optional node-addon-require-builtin fallback is required, so the cordis Loader can resolve the config's bare plugin specifiers through its internal module loader. (demo:acp runs under tsx, whose tsconfig paths map resolves them instead.)

All diagnostics go to stderr — stdout is the protocol.

Model Experience

Indirectly, through dsh-agent-spine-demo and dsh-acp, which compose each ACP agent's prompt, tools, and message history; this app bundle adds no model-bound content itself.

KV Cache effect

No direct invalidation; the named consumer owns any request-prefix changes.

Known Limitations and Deferred Work

• JSONL persistence is baked in — config chooses its root but cannot select a different backend; that requires a sibling entry or differently composed app package.
• User-question and approval mechanisms are omitted by default — the bridge can answer both when their services/tools are composed, but this front door does not enable those deployment policies itself.
• A leaf can still corrupt stdout — the app mounts no console logger, but it cannot prevent a sibling leaf entry from writing non-protocol bytes to the ACP channel.