deepseek-harness/examples/acp-agent

acp-agent example

The DeepSeek Harness SDK agent demo exposed as an Agent Client Protocol (ACP) server over JSON-RPC stdio — drive it from Zed or any other ACP client.

pnpm run demo:acp          # needs DEEPSEEK_API_KEY (repo-root .env or env)
pnpm run demo:code-mode acp   # the same server in Code Mode: one wire tool, run_code

The leaf config loads the ACP app, swappable backends, model-facing tools, and repeat guard. The app bundles the agent spine, JSONL persistence, and bridge, creates agents on session/new, and keeps stdout logger-free. code-mode.cordis.yml overlays the same tree with run_code; see Code Mode.

stdout is the protocol

This example loads no stdout logger — stdout carries the JSON-RPC frames, and any other write corrupts them. @deepseek-ai/dsh-acp-agent includes no logger entry, so this leaf has none to get wrong by default; do not add one (use a stderr exporter if you need logs).

Zed configuration

Add to your Zed settings.json under agent_servers:

{
  "agent_servers": {
    "DeepSeek Harness": {
      "command": "pnpm",
      "args": ["--dir", "/path/to/deepseek-harness", "run", "demo:acp"],
      "env": { "DEEPSEEK_API_KEY": "sk-…" }
    }
  }
}

The editor sets each session's cwd to the project it opens; both the agent's bash tools and the read/write/edit filesystem tools resolve relative paths against that per-session workspace (see the per-session cwd note in packages/ui/acp and the per-session cwd RFC), so the server can be launched anywhere and each session still acts on its own project directory.

Snapshot tests (record-once / replay-deterministic)

This example hosts the ACP snapshot suite. dsh-llm-replay reconstructs model streams from assistant/chunk events in each scenario's session JSONL, so replay is keyless. Recording runs the real agent and harvests that log; refresh keeps the committed transcript as mock input and rewrites current replay outputs. replay.override.json covers throw and hang cases that chunks cannot express, and an optional workspace/ seeds files. The snapshot RFC owns the full design.

MVP limitations

The bridge supports N concurrent sessions per connection, each in its own workspace cwd (RFC 011). Remaining limits: prompts support ACP's baseline text and resource_link blocks only, and additionalDirectories and mcpServers are rejected. Permission prompts (session/request_permission) are wired through the approval seam, but this example composes no ask-producing policy, so tools run with the executor's full authority. See packages/ui/acp/README.md for the full contract.