deepseek-harness-acp

deepseek-harness-acp

Use DeepSeek Harness from Agent Client Protocol clients such as Zed.

---

The adapter composes the harness in-process and maps its session-event log onto the full ACP vocabulary: streamed text and reasoning, tool calls with diffs and display terminals, plans, permission requests, session modes, config options, slash commands, skills, and MCP servers. Credentials never touch your editor config — it reuses the key you saved in the dsh Web UI, or dsh-acp login saves one to the same store.

Two ways to plug it in

	A · Standalone server	B · dsh profile plugin
Best for	Getting started in one command	Living inside your dsh setup
Install	npm i -g @openma/deepseek-harness-acp	dsh plugin --profile acp add -w @openma/deepseek-harness-acp
Zed runs	dsh-acp	dsh --profile acp
Harness	Your installed dsh — or the vendored fallback when none exists	The dsh that owns the profile
Composition	dsh-base + this bundle (profile machinery booted in-process)	dsh-base + this bundle + your profile's own patches

Both shapes share $DSH_HOME: the same credential store, settings, presets, and session logs as dsh web — conversations started in the Web UI can be listed and loaded from the editor.

A · Standalone server

npm install -g @openma/deepseek-harness-acp
dsh-acp login        # interactive; or save the key in the dsh Web UI

// Zed settings.json
{
  "agent_servers": {
    "DeepSeek Harness": { "command": "dsh-acp" }
  }
}

Self-contained: it finds your DeepSeek Harness via --dsh-path / DSH_PATH, its own tree, ./node_modules, dsh on PATH, or npm root -g — and ships a vendored harness runtime as the last candidate, so it works out of the box and always prefers the dsh you installed. When a real $DSH_HOME/profiles/acp exists, that profile owns the composition.

B · dsh profile plugin

npm install -g @deepseek-ai/dsh
dsh web                                                  # save your API key once
dsh plugin --profile acp add -w @openma/deepseek-harness-acp

// Zed settings.json
{
  "agent_servers": {
    "DeepSeek Harness": { "command": "dsh", "args": ["--profile", "acp"] }
  }
}

This creates $DSH_HOME/profiles/acp and registers the package's dsh.bundle patch: the bridge mounts over @deepseek-ai/dsh-base — the same product baseline as dsh web, with the module-reload watcher off. Extend the profile in $DSH_HOME/profiles/acp/cordis.patch.yml like any other dsh profile.

Authentication

No keys in editor config, no ACP-mediated secrets. In order:

1. Harness credential store — $DSH_HOME/.credentials.yaml (mode 600), the file the dsh Web UI writes; hot-reloaded. Save a key with dsh-acp login, the Web UI (Settings → Models), or /login <key> in chat.
2. Process environment — DEEPSEEK_API_KEY / DEEPSEEK_BASE_URL in the environment that launches the agent.

The initialize handshake advertises Terminal Auth (dsh-acp login), so registry-driven clients can run the interactive setup for you.

Features

• Streaming — assistant text and reasoning deltas; assembled-message fallback.
• Tool calls — ACP kinds, human titles, file locations, real diffs from fs-tool hunks, raw input/output; command output on a display terminal when the client supports one, fenced output otherwise.
• Permission presets as session modes — read-only / workspace-write / danger-full-access, each a named {sandbox, approval} pair recorded as a durable session fact (also exposed as a config option for clients that only render those).
• Agent presets — standard / code / minimal / cordis as a config option; switching rebuilds the agent live with history preserved.
• Live model catalog — providers × models from the running composition (third-party providers added in the Web UI appear immediately), plus reasoning-effort selection that follows your product default.
• Slash commands — adapter built-ins (/status, /login, /logout, /model) plus the harness command registry (/compact, /goal, /permission, /plan, …) executed without a model turn, plus skills (/skill-name — the harness's own invocation gesture).
• Plans & usage — todo_write snapshots as ACP plans; token accounting as usage_update and per-turn usage.
• Sessions — session/load with full history replay, session/list, silent restore when a client prompts an old session after an agent restart, titles as session_info_update.
• MCP servers — per-session mcpServers mount @deepseek-ai/dsh-mcp-client instances (stdio + streamable HTTP); tools join as mcp__<server>__<tool>; a failing server never takes the session down.
• Real cancellation — session/cancel interrupts the live turn through the harness agent.

Configuration

Flags win over environment variables, which win over defaults. All optional — with no flags, sessions follow your product defaults (settings.yaml).

Flag	Env	Default	Purpose
--dsh-path	DSH_PATH	auto-detect	DeepSeek Harness installation
--provider	DSH_PROVIDER	product default	Provider route override
--model	DSH_MODEL	product default	Model override
--max-tokens	DSH_MAX_TOKENS	provider default	Per-request output-token cap
--permission-mode	DSH_PERMISSION_MODE	workspace-write	Initial permission preset
--reasoning-effort	DSH_REASONING_EFFORT	product default	off / high / max
—	DEEPSEEK_API_KEY	—	API credential (fallback to the credential store)
—	DEEPSEEK_BASE_URL	DeepSeek endpoint	OpenAI-compatible endpoint override
—	DSH_ACP_DEBUG	off	Verbose stderr diagnostics

Subcommands: dsh-acp login [api-key] (interactive when omitted; input never echoes), dsh-acp update (self-update via npm).

Permissions and sandboxing

Sessions start in workspace-write: bash and file mutations are confined to the session's cwd (plus shared temp roots), and a model retry requesting wider access raises an ACP permission request. Always allow (this session) flips the approval policy to never for that session. danger-full-access disables both the sandbox and the prompts — use it only in disposable checkouts or containers. Each level is one durable preset (sandbox + approval together), the same three the Web UI offers.

Architecture

ACP client (Zed, …)
   │  ACP JSON-RPC over stdio
   ▼
dsh-acp
   ├─ src/profile-boot.ts     boots the harness's own profile machinery
   │                          (dsh-base + this bundle + $DSH_HOME layers)
   ├─ src/harness.ts          host discovery (DSH_PATH → cwd → PATH → npm -g → vendored)
   └─ src/bridge/             the ACP bridge (a cordis plugin)
        ├─ index.ts           sessions, prompts, cancel, modes, options,
        │                     commands, credentials, MCP mounts
        ├─ translate.ts       session-event → ACP update projection (pure)
        ├─ history.ts         stored-log replay for session/load (pure)
        └─ prompt.ts          ACP prompt blocks → harness content blocks (pure)
   ▼
your @deepseek-ai/dsh installation   (agent spine, llm, persistence, sandbox,
                                      tools, presets, skills, compaction, …)

The bridge consumes the harness session/event firehose — the same append-only log persistence stores — so live streaming, history replay, and session/list agree by construction. All harness modules, including cordis itself, load from one host tree: plugin and service identity is never split across copies.

Development

npm install         # dev deps include the harness packages (types + tests)
npm run typecheck   # tsc --noEmit
npm test            # vitest: unit + e2e smoke (boots the real composition; no model calls)
npm run build       # esbuild → dist/

To also run the e2e suite against a standalone host install:

npm install --prefix /tmp/dsh-host @deepseek-ai/dsh
DSH_ACP_TEST_HOST=/tmp/dsh-host npm test

Live iteration: paired profiles

Keep the profile your editor uses on the published package, and point a second profile at this worktree via a pnpm symlink:

dsh plugin --profile acp add -w @openma/deepseek-harness-acp   # stable
dsh plugin --profile acp-test add -w "link:$PWD"               # dev (symlink)

The dev loop is npm run build + restart — dist/ and cordis.patch.yml are read through the link. (pnpm treats file: as a copy install and caches same-version tarballs; link: avoids both.)

{
  "agent_servers": {
    "DeepSeek Harness": { "command": "dsh", "args": ["--profile", "acp"] },
    "DeepSeek Harness (dev)": { "command": "dsh", "args": ["--profile", "acp-test"] }
  }
}

License

Apache-2.0.