dsh-btw

/btw for DeepSeek Harness (dsh) — a Claude-Code-style side question command.

Ask something in the middle of a task, get the answer rendered directly in the UI, and keep working. Neither the question nor the answer becomes a model message in the main conversation: your session log records only the log-only command/run / command/done pair, the token usage stays zero, and the prefix cache is untouched.

/btw what's the difference between Drop and DropImpl again?

The answer comes from a one-shot subagent (the fork provider by default), so it is aware of the ongoing conversation — but the conversation never sees the exchange.

Install

Requires Node.js ≥ 20 and a dsh installation (npx @deepseek-ai/dsh).

From npm (prebuilt, no build permission needed)

dsh plugin --profile web add dsh-btw

From GitHub

dsh plugin --profile web add github:<your-github-name>/dsh-btw

A git install runs the package's prepare build script, so allow it once in the profile's pnpm-workspace.yaml (pnpm ≥10 policy):

allowBuilds:
  dsh-btw: true

Re-run the add after adding the allowance. Pin a commit (github:<you>/dsh-btw#<sha>) if you want reproducibility.

Try it from a checkout without installing

dsh --profile web --patch ./smoke/btw.yml
# btw.yml:
#   - insert:
#       - id: btw
#         name: '/absolute/path/to/dsh-btw/src/index.ts'

Verify: dsh --profile web --dump-config shows a btw row; the Web UI's slash-command catalog lists btw beside plan and compact.

Configuration

The plugin row in cordis.patch.yml accepts a config block (fail-loud: unknown keys abort plugin load):

- insert:
    - id: btw
      name: dsh-btw
      config:
        provider: fork   # fork (default) | spawn
        persona: terse   # optional child persona

key	default	meaning
provider	fork	fork seeds the child with the main session's completed-turn prefix (context-aware answers); spawn starts a fully isolated child.
persona	—	Optional persona applied to the child (supported by the in-process fork/spawn providers).

How it works

1. The dsh commands registry dispatches /btw in the human-only command plane — zero model tokens by construction.
2. The handler starts a one-shot subagent via ctx.subagents.start(provider, …) with the exact receiving agent as parent and the UI's AbortSignal.
3. The run's result is awaited and the child is always disposed (allSettled settlement — a dispose failure is reported, never swallowed).
4. The child's visible text blocks are joined and returned as the direct CommandResult; failure paths map stop reasons to readable errors and preserve partial output.

Full requirements analysis, alternatives considered, and the TDD plan live in docs/DESIGN.md.

Compatibility

Targets the dsh 0.1.0-rc.x line (peer ranges >=0.1.0-rc.1 <0.2). dsh is a developer preview; expect API movement across rc versions.

Develop

pnpm install
pnpm test        # vitest, 30 cases
pnpm typecheck
pnpm build       # tsdown → lib/

License

MIT