ACP automation server

In short: @deepseek-ai/dsh-acp exposes a Harness runtime over ACP JSON-RPC stdio. Source 0.1.5-alpha.1 (5dda764ed3) expands the former automation-only surface with session navigation, model options, MCP, and richer updates.

See source/npm channels: these are source-build capabilities, not a claim about the older default npm release.

Launch and composition

# In a built official source checkout
pnpm dsh --profile acp --help
pnpm dsh --profile acp

The shipped profile is packages/bundle/acp-app, replacing the removed ACP demo bin. It supplies the application composition and a DeepSeek route; packages/acp/acp owns the protocol bridge. Keep stdout exclusively for protocol frames and send diagnostics to stderr.

Negotiated capabilities

initialize advertises ACP v1, HTTP MCP, and session list / resume / close. Standard stdio MCP is also accepted. Image input is conditional on durable attachment support and the configured model route; audio and embedded context are not advertised. The returned authMethods list is empty; this does not make remote MCP credentials unnecessary.

Read the returned capability set instead of hard-coding every feature as available.

Methods

Method	Current contract
session/new	Absolute cwd; validate and connect stdio/HTTP MCP servers before publishing a new Agent
session/list	Newest-first resumable root sessions; optional cwd filter and pagination
session/resume	Restore an inactive persisted session after canonical cwd validation; no transcript replay
session/close	Cancel and drain the target and descendants, flush/dispose; preserve the persisted log
session/set_config_option	Select model or reasoning_effort, returning the complete option state
session/prompt	Ordered text/resource links and supported images; one in-flight prompt per session; model route pinned for that turn
session/cancel / $/cancel_request	Cancel active work; session cancellation also covers autonomous activity
session/update	Committed assistant/thought content, generic tool lifecycle, config and context-usage updates
session/request_permission	Client answers the bridge's one-time allow/reject request

The AcpConfig provider/model fields are optional at the plugin seam; the shipped profile supplies its route. sessionListPageSize defaults to 100. Validate the selected model / reasoning option before starting work, not midway through a prompt.

MCP and permissions

MCP servers supplied by the ACP client are trusted process configuration: stdio commands/environment and HTTP URLs/headers can start processes or send credentials. Failed discovery rolls back the unpublished Agent. SSE MCP and ACP-transport MCP are outside this implementation.

The permission bridge offers one-time allow/reject choices. A client should reply based on the request rather than treating all tool calls as implicitly approved. Filesystem/network policy still belongs to the composed Harness services.

Updates and lifecycle

Updates are richer than the older committed-text-only bridge, but they are not raw uncommitted provider token deltas. Tool activity and thoughts have explicit update paths. Resume restores runtime state without replaying the transcript; a client needing history must account for that distinction.

Closing one session releases its owned tree without deleting logs. Disconnect or plugin disposal drains the connection-owned sessions and resources. An idle boundary can include injected work and descendants, so it is not an exclusive causal response to one prompt.

Boundaries and verification

No session/load, session deletion/fork, extra directories, ACP modes/commands/plans/terminals, client filesystem, or elicitation surface is advertised here. Consult current source before assuming an editor feature is implemented.

Use an ACP client to exercise initialize → new → prompt → updates → permission response → close, then list/resume the persisted root. A help command checks only the entry point, not a real model round trip.

Source owners: packages/acp/acp/src/index.ts, its request/session helpers, and packages/bundle/acp-app/cordis.patch.yml.

Next steps

• Subagents: the ACP backend as a delegation provider
• SDK: DSH-specific stdio protocol
• Permissions