DSH Arena

Blind, fair, local Agent arena inside DSH Web.

Same task. Same commit. Isolated worktrees. Shared verification. Judge before you reveal.

DSH Arena turns your DeepSeek Harness (DSH) Web into a model-vs-model fight club: pick a task, pick 2–4 contestants (any provider/model DSH supports), and let them race on the exact same repository state. Lane identities are kept secret until you decide — no label bias, no prompt leaks, no cherry-picked baselines.

Why this exists

Benchmarks lie. Leaderboards are curated. When you evaluate an agent, the simple act of knowing which model you're looking at biases everything downstream: your prompts, your patience, your verdict.

DSH Arena removes that bias structurally:

• One repository state — every lane starts from the same commit, in its own git worktree. No drift, no stale forks.
• Random lane assignment — participants are shuffled onto lanes A/B/C/D at creation. The host knows; the wire doesn't.
• Identity-free protocol — the public experiment record contains no participant identity. Identities live in a server-side secrets.json and merge into the view only after you call reveal.
• Shared verification — the same user-defined verify command runs against every lane, in the same environment.
• Blind verdict — pick the winner from behavior alone (tests, diff, final answer, token/time cost). Then reveal and see who actually won.

Features

• 🏟 2–4 lane races with live progress feed (tool calls, turns, tokens) per lane
• 🔒 Anonymity contract enforced at the type level: the wire type ArenaExperiment has no identity field; redactExperiment strips everything before serve
• ✅ Shared verification — user-defined commands, per-lane exit code / timeout / duration, visible in the race view
• 🏁 Blind verdict → reveal flow with per-lane diffs and final answers
• 📤 Offline export — self-contained HTML report + raw JSON + per-lane unified patch, no network
• 🌿 Winner branch — promote the winning lane's worktree to arena/<id>/<label> (real lanes only)
• 🎬 Zero-cost demo mode — deterministic scripted lanes (focused / verbose / broken / timeout) that exercise the entire pipeline with no API key, no spend: worktree → change → verify → diff → review → reveal
• 🧹 Cleanup — prune stale worktrees and experiment state from the UI
• 🖥 Full client UI injected into DSH Web: create / list / live race / review / reveal

Quick start

1. Install the plugin into your DSH Web profile (Cordis bundle — see cordis.patch.yml):

   npm install dsh-blind-arena

2. Open DSH Web → the Arena plugin row appears.
3. Create an experiment: point at a local repo, write a task, add verify commands, pick contestants.
4. Watch the race live. Judge blind. Reveal. Export the report.

No credentials? Run the demo mode first — it walks the full product loop with scripted lanes so you can evaluate the flow before spending a single token.

Architecture

DSH Web client (React, injected)          Host plugin (Cordis service `arena`)
┌───────────────────────────┐             ┌──────────────────────────────────────┐
│ CreateView / ListView     │  /api RPC   │ ArenaService (Typert remotes)        │
│ RaceView / ReviewView    │◄───────────►│  preflight · create · cancel ·        │
│ RevealView                │  (redacted  │  verdict · reveal · diff · export ·  │
└───────────────────────────┘   until     │  createWinnerBranch · cleanup        │
                               reveal)    │          │                           │
                                          │          ▼                           │
                                          │  ArenaEngine                         │
                                          │  preflight → worktrees → lanes →     │
                                          │  verify → diff → persisted record   │
                                          └──────────────────────────────────────┘

• src/engine.ts — orchestration: preflight → worktrees → lanes → verification → diff → persistence; implements the anonymity contract
• src/runner.ts — one lane's agent lifecycle on top of @deepseek-ai/dsh-agent (session, model selection, consumed-work folding)
• src/verify.ts — shared verification runner
• src/git.ts — worktree / diff / branch primitives
• src/store.ts — durable store under ~/.dsh/arena/<id>/: public experiment.json + server-only secrets.json
• src/export.ts — offline HTML report + JSON + winner branch
• src/demo.ts — deterministic demo lanes (no API cost)
• src/client/ — React UI injected into DSH Web

Storage: ~/.dsh/arena/. Everything is local; nothing leaves your machine except your own browser.

Requirements

• Node ^22.19.0 || >=24.0.0
• DSH (DeepSeek Harness) with Web client runtime
• @deepseek-ai/dsh-agent, @deepseek-ai/dsh-llm, @deepseek-ai/dsh-session (0.1.0-rc.7)

License

MIT