Koliseum

Private environments and benchmarks to evaluate your models.

Evaluate decisions over time.

We build private environments and benchmarks to evaluate your models. Define the task, compare your checkpoints, and inspect the decisions behind each result.

Environment design.

Your tasks might involve navigating and building in a spatial environment, allocating resources over many turns, negotiating with other agents, or controlling a simulated physical system. We design the environment around the decisions you want to test.

For each commission, we specify the state and transition rules, observation and action interfaces, episode length, and other participants. You can evaluate task completion alongside intermediate decisions, constraint violations, or predictions of future state.

Industries

These application areas illustrate our public work and research. Your evaluation can focus on the decisions, tools, and constraints of your own domain.

Finance

Can models make sound financial decisions as markets change?

Life sciences

Can models make biological predictions that hold up in experiments?

Physical systems

Can models predict the consequences of their actions in the physical world?

Enterprise workflows

Can models reliably carry complex work through to completion?

Cybersecurity

Can models defend systems against threats they have never seen?

Energy

Can models meet energy demand while managing cost and reliability?

Benchmarks for model development.

An environment defines the interaction. A benchmark specifies the task distribution, evaluation protocol, and scoring used to compare performance. Benchmarks can include interactive episodes with many decisions.

For commissioned benchmarks, we agree on held-out scenarios and baselines with your team. Validation checks whether the score measures the intended behavior, how results vary across repeated runs, and whether simple exploits can satisfy the grader.

Task performance

Define completion, constraint violations, and task-specific outcomes. Keep distinct capabilities visible in separate metrics.

Comparable runs

Record the model, prompt, tools, environment, and scorer versions. Specify episode budgets, starting conditions, and any opponent configuration.

Failure analysis

Inspect trajectories alongside cost and latency. Separate model errors from tool or environment failures so execution problems do not become capability claims.

Read the methodology

Run evaluations in parallel.

Many environment instances run at the same time. Each one advances at its own pace, and every finished run is written to one trajectory stream.

Instance 1Instance 2Instance 3Instance 4Instance 5Trajectory streamFinished runs
Instances start and finish on their own schedules. Finished runs join one stream.

Run many futures from the same state.

Reset, fork, and replay environments to measure which decisions lead to different outcomes.

  • The same starting state.
  • Different actions.
  • Different futures.
  • Comparable outcomes.
BaselineState 1Action 1Action 2Action 3Run 1Run 2Run 3Run 4Run 5Run 6StateActionsFutures
Example runs from one starting state. Select a node to read its observation, action, reward, and model version.

Run 1

Observation
Observation 5
Action
Action 5
Reward
+0.73
Model
Checkpoint 1
Environment
Version 1

Review the run record.

Running a model inside an environment produces a structured trajectory. Each step holds the observation, the action, the reward, and the state that followed, tagged with the model version and the environment version.

What a trajectory contains

Observations
What the model saw at each step.
Actions
What it did.
Rewards
The score assigned at each step.
State transitions
How the state changed after each action.
Outcomes
How the run ended.
Model version
The checkpoint that produced the run.
Environment version
The environment build it ran in.

Run 1

Trajectory 1

StepObservationActionReward
1Observation 1Action 1+0.12
2Observation 2Action 2+0.25
3Observation 3Action 3-0.08
4Observation 4Action 4+0.18
5Observation 5Action 5+0.26
Model
Checkpoint 1
Environment
Version 1
Steps
5
Reward
+0.73
Start state
State 1
An example trajectory with five steps.

Commission a benchmark or environment.

Commission an evaluation around your target capability or workflow. We agree on the task specification and acceptance criteria, build the environment or benchmark, and validate the scoring against baselines. Your agreed deliverables include versioned tasks, scoring methods, run records, and a validation report.