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Case study · Internal R&D

Benchception

Every RL environment is itself a task, so which frontier model is best at building them? Benchception makes environment-authoring the thing under test: models compete not by answering, but by teaching.

For this demo, our golden environment is Supply Chain Bench (code), a HUD benchmark we hold out from every model. The contest runs on SupChain-Bench Verified: the 33 tool questions that survived verification against the real grader.

Golden env
Supply Chain Bench
Authors
Opus 4.8 · GPT-5.5
Student
Qwen-8B
Walk the pipeline
!

No contamination. The golden environment is never shown to either author or student during authoring or training; it is revealed only at evaluation. Models can't memorize the test; they can only learn to teach.

Architecture
pipelinegolden bench
In-house · Build
Drag & drop blocks
describe the task to rebuild the env
Extracted
Environment spec
plain-language description (IR)
Author A
Claude Opus 4.8
generates an environment
Author B
GPT-5.5
generates an environment
Generated
Env by Opus
Generated
Env by GPT
Student
Qwen-8B
trained · Opus env
Baseline
Qwen-8B
untrained
Student
Qwen-8B
trained · GPT env
Held-out evaluation
Three-Way Contest on Golden Bench
all three play the held-out Supply Chain Bench
Winning student ⇒ the model that authored the better environment
Results

All three students tied

We ran the full pipeline end to end: both authors generated environments, both trained a Qwen-8B, and all three students played the held-out Supply Chain Bench. They finished in a dead heat.

When we looked closer, the environments the models authored were low-quality and, honestly, a little sloppy, so neither trained student learned much the untrained baseline didn't already know.

The tie is the signal. A flat leaderboard isn't a broken experiment; it is evidence that authoring a good RL environment is genuinely hard. The models fail for a valid reason, which is exactly what a strong benchmark should expose.

LeaderboardSupChain-Bench Verified · success rate
T-1
Qwen-8B · trained on GPT env35.7%
T-1
Qwen-8B · untrained baseline33.6%
T-1
Qwen-8B · trained on Opus env31.5%
Tied within noise (3% tie band). Neither trained student shows a reliable lift over the untrained baseline. Re-contested on the 33 verified tool questions with entity-scoped grading; the original run on the first 40 questions measured 44 to 45% for all three.
How we built the environments in-house

From blocks to a spec

Build is a Scratch-style canvas. We drag four kinds of blocks out of the tray (Environment, Tool, Task, Train), snap detail blocks into them, and describe each in plain language. The blocks form a recursive tree that the builder projects into a plain-language description, written to help a model rebuild Supply Chain Bench. That description, not code or JSON, is the only thing each model receives.

Why blocks
No-code authoring keeps the spec consistent and human-auditable across every environment we test.
What ships
A clean description object: the same input given to Opus 4.8 and GPT-5.5, identically.
Build · canvas
Environmenta supply-chain operator working a live order queue…
Toolcheck_inventory(sku) → units on hand
Taskfulfil the backlog without stocking out…
Trainalgorithm: auto · reward from rubric
extract description
spec handed to the models"Build an RL environment where an agent operates a supply chain: it queries inventory and supplier tools to clear an order backlog, scored by fill-rate without stock-outs. Train a policy to maximize the rubric reward."
Roadmap

How we'd improve it

Because every environment is a task in itself, the breadth and integrity of the golden set is the whole experiment. We're really measuring how well models build HUD tasks.

01

Harden the golden set

Broaden and diversify the golden environments so no single benchmark can be gamed. Variety is the defense against contamination and overfitting.

02

Harnesses & visibility

Add inspection harnesses into the environments models generate, surfacing reward hacks and degenerate setups before any training run begins.

03

Paper → environment

An automated pipeline that turns any research paper into a golden environment on HUD, scaling the golden set far beyond what we can hand-author.

04

Human verification

Human-in-the-loop review on every generated golden environment, guaranteeing the dataset stays correct, fair, and trustworthy.