arena/PLAN.md

Arena build plan

Companion to MULTI_TURN.md (the scope). This is the sequencing: what gets built, in what order, what can run in parallel, and what collides.

Status: plan, 2026-08-21. ✅ = settled. ❓ = blocks the work under it. ⛔ = parked by decision.

Where Arena sits

Lumbridge is an open-source company shipping six self-hostable things: Compute (governed compute for unified-memory hardware), Bench (model quality and serving measured against one pinned host × quant × config tuple), Simulate (the Tera/Spaces 3D engine), Stream (a headless broadcast rig), Forge (post-training as a content-addressed build), and Arena. Four of the six are public. apps/web/src/data/projects.ts in lumbridge-v4 is the canonical list.

Arena is the RL-environment project — yes, /arena is the section. It is appended last in the project list for numbering reasons, but semantically it sits beside Bench and feeds Forge: Bench measures a model, Arena produces the gradient, Forge runs the training. That triangle is the reason Arena is worth doing well rather than as a side quest — we own all three corners, which nobody on the Hub does.

Arena spans two repositories on one page, and that is deliberate:

• git.karti.ai/lumbridge-public/arena — the Python data environments (this repo)
• git.karti.ai/lumbridge-public/tera — the TypeScript spatial environments

What we take from Prime Intellect, and what stays ours

All of PI's stack is open source and we use it rather than rebuild it. Checkouts are at ~/vendor/prime-intellect/ (46 repos; see its README).

We use, unmodified	We build
verifiers — the v1 spec, the taskset/harness/trace model, vf.Env	The environments
prime-rl — the trainer traces feed	The house rules
prime-agent (pi) — a harness, already embedded in Piggy	probe.py — the degenerate-policy gate
prime CLI — env push, env action	The Tera bridge
The Environments Hub — distribution	lumbridgecorp.com/arena — documentation

We do not build a harness, a trainer, or a hub. Every one of those exists, is permissively licensed, and is better than what we would write.

Decisions

✅ 1 — Hub org handle: lumbridge. Settled 2026-08-21. Environments will publish as lumbridge/<env-name>.

✅ 2 — Attribution: Lumbridge as author. Settled 2026-08-21. karti.ai stays the code host (git.karti.ai), Lumbridge is the author on every surface. One identity across all six projects; no per-project byline.

⛔ Hub push is ON HOLD. Decided 2026-08-21: keep building, publish nothing to the Prime Intellect Hub yet. Workstream E is parked — not cancelled, not blocked on anything technical. PRIME_API_KEY is therefore not urgent.

✅ 7 — Production brain: Qwen3.8-27B. Settled 2026-08-21. spark-1 serves brain-qwen38-dspark; that is the default. The Nemotron baseline is ARCHIVED, not deleted, and Arena's seven scores get re-run and republished against Qwen. ⚠️ --model brain does NOT 404 — it silently succeeds and records brain in the trace while the box serves Qwen. Verified by direct call 2026-08-21. Pin brain-qwen38-dspark in every reproduction command, everywhere.

✅ 8 — tera-drive-101 ships labelled. Settled 2026-08-21. Published as a bridge-correctness environment with NO rule-3 and NO rule-4 claim (its return is monotone in throttle; any positive constant scores ~0.95+). Site says four spatial environments. It is not listed as a fifth RL environment.

✅ 9 — app.lumbridgecorp.com is the ONLY authenticated origin. Settled 2026-08-21. The apex loses /login, /signup, /app, /go. All existing sessions sign out once on cutover; accepted cost for three accounts.

✅ 10 — Adopted defaults (technical, recommended by the synthesis, settled 2026-08-21): the agent seat is named agent everywhere (matching SingleAgentEnvConfig) — it becomes the TOML key in every configs/*.toml AND every prime-rl rl.toml, and renaming later parses fine while silently having no seat; D lives in the arena repo, not tera (amend the parallelization map); A ships the FLAT freeze, with per-item recorded as the identified strengthening; Arena transcripts are ADMIN-ONLY (they carry the held-out slice and oracle answers — a contamination question, not an org-politics one); the dashboard is the archive and eval-results.json a curated summary emitted from it, never two hand-maintained files; Forge integrates prime-rl with LoRA RL first.

✅ 3 — office-jobs-v1 EXISTS; the counts are twelve / five / twenty. Resolved 2026-08-21 15:50 when another session fast-forward-merged it into the shared tera tree mid-session. It is committed, in ARENA_MANIFESTS, and passes arena:source-hashes. The site's original copy was correct. ⚠️ tera has live concurrent sessions — re-check its HEAD before acting on any claim about its contents.

~~❓ 3 — office-jobs-v1. Advertised on the live page and in seo.ts; absent from ARENA_MANIFESTS. Build it, or correct the page to eleven. Blocks any copy that cites the count, including a Hub listing.

✅ 4 — Interactive envs get their own taskset id. Settled 2026-08-21. The first is grand-exchange-live, a separate wheel beside grand-exchange. One-shot scores stay comparable across time; the two forms are measured, not conflated.

✅ 5 — App is a subdomain: app.lumbridgecorp.com. Settled 2026-08-21. Matches the two-surface model (public site + private platform). Public site stays a site.

✅ 6 — Compute policy. Settled 2026-08-21. Training runs on rented GPUs (GH200-class, from Prime Intellect) — rented because it is faster, and because renting keeps the hardware choice open per run (the GB300-vs-alternatives call is one we want to keep making). Inference in production runs on the DGX Spark. We do not train on the Spark.

Workstreams

Five, with the dependency edges called out. A and D can start immediately and in parallel. B must land before C or E.

A — grand-exchange interactive (start now)

The first tier-1 environment: quote → see fills → re-quote over a turn budget, inventory and unfilled orders carrying between turns. Chosen because the market simulation already steps, the counterweight (liquidity in gp/tick, the random-walk trap) already exists, and it is the smallest change that yields a genuinely new measurement.

Deliverable: a vf.Env subclass exported from the wheel's __init__.py, a config, and a measured run against spark-1's brain. Pattern to copy: verifiers/v1/tasksets/textarena/taskset.py.

This workstream is where rule 4 — the budget must bind gets written for real. Whatever it learns about degenerate trajectories is the input to B.

Depends on: nothing — ✅4 settled.

B — probe.py grows degenerate policies (after A's first draft)

Today the probe scores four fixed strings per environment. Tier 1 needs policies: the staller (never acts), the spammer (acts every turn at random), the impatient (answers turn 1 with no observation), the exhaustive (spends the whole budget, then answers). Same gate shape — inaction 0.000, oracle 1.000, exit 1 otherwise — plus a new assertion that exhaustive scores below oracle. If it does not, rule 4 is violated and the environment does not ship.

Do this before building a second interactive environment, not after. It is the differentiator: nothing across prime-envs (88) or community-environments (109) ships a degenerate-policy gate.

Depends on: A (needs one real interactive env to gate against). Blocks: C, E.

C — More interactive environments (after B)

In rough order of value:

1. drop-table-inference — buy observations under budget; measures when to stop looking
2. bot-detection — request labels one at a time (active learning)
3. fault-localisation — the log is not given; query it by service, window and level
4. redaction-pressure — two agents, redactor vs extractor; the counterweight becomes an opponent

Each is independently parallelizable once B exists. redaction-pressure is the most interesting and the least certain — a genuine multi-agent env, not a stepped one.

Depends on: B.

D — The Tera bridge (start now, independent repo)

One Python vf.Env driving the existing TypeScript tera.arena/v1 package over a process boundary, turning step() observations into interaction.turn() messages and existing component rewards into trace.record_reward calls.

Validated by replay: every bridged episode must replay() through the TS package to an identical FNV-1a-64 checksum, or the bridge is wrong. That property is rare and the bridge should be built around it.

Lands four environments at once and makes our strongest existing asset publishable. Larger and riskier than A — the process boundary and the action encoding are the unknowns. Touches the tera repo, not this one, so it does not collide with A/B/C.

Depends on: nothing.

E — First Hub push (PARKED)

Push once there are three to four interactive environments alongside the seven one-shot ones. prime env push <name> -v PUBLIC to our own namespace is primary — we keep authorship and versioning. A PR into community-environments is optional extra distribution that hands the namespace to primeintellect; secondary.

Then update lumbridgecorp.com/arena to document the same wheels.

⛔ On hold by decision, 2026-08-21. Resume when Karti says so; ❓3 still gates any copy that cites the environment count.

⚠️ The collision point

tests/test_probe.py and the wheel-build loop in .gitea/workflows/ci.yml hardcode the environment list. Every workstream that adds an environment edits both files. Two sessions adding environments concurrently will conflict there, and CI goes red if either is missed.

Mitigation, in order of preference: (1) B refactors both to discover environments from environments/*/pyproject.toml instead of a literal list — do this as part of B and the collision disappears; (2) failing that, one session at a time touches those two files.

Separately: this repo already took divergent remote pushes from concurrent sessions on 2026-08-19. Merge, never force. Use a worktree per workstream.

Parallelization map

now ──┬── A (grand-exchange interactive) ──┬── B (probe → policies, de-hardcode CI) ──┬── C1 drop-table
      │                                    │                                          ├── C2 bot-detection
      │                                    │                                          ├── C3 fault-localisation
      │                                    │                                          └── C4 redaction (2-agent)
      │                                    │
      └── D (Tera bridge, tera repo) ──────┴──────────────────────────────── E (Hub push) ⛔ PARKED

Two sessions can start today: A in this repo, D in tera. They share no files. Everything downstream of B fans out four ways.

Preconditions, verified on amd-server

• uv run eval @ configs/<env>.toml --dry-run → exit 0 ✓
• stable verifiers 0.3.1, using its upstream null harness and runtimes ✓
• Docker 29.1.3 (tier 2/3 only; tier 1 needs none) ✓
• spark-1 brain at http://100.127.247.67:8001/v1, model id brain ✓
• prime CLI 0.6.25 ✓
• PRIME_API_KEY ✗ — blocks E, which is parked anyway

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⚠️ Superseded by EXECUTION.md

The workstream descriptions and the parallelization map above were written before the 2026-08-21 design workflow. EXECUTION.md is now authoritative for sequencing, file ownership and risk. Three structural corrections it makes:

1. B splits. B1 (de-hardcode environment discovery) does NOT depend on A and ships immediately; the CI env list was never a matrix, just a bash for loop. B2 (degenerate-policy machinery) was found NOT FEASIBLE as written and must be calibrated against A's measured engine, not A's first draft.
2. D is no longer file-independent. It lives in arena and edits probe.py, ci.yml, test_probe.py, README.md plus two lumbridge-v4 files.
3. The top risk is that every Arena reward SATURATES, so house rule 4 ("exhaustive < oracle") may be structurally unreachable. If it is, every interactive environment is unfalsifiable and the reward shape must change before C1–C4 are built on it. This is also a compute-policy constraint: a non-binding turn budget burns rented GPU hours measuring nothing.