# 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 ✓
- verifiers 0.3.0, all 13 harnesses and 4 runtimes present ✓
- 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

---

## ⚠️ 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.