---
id: object-model.overview
title: Object model
summary: Understand how project foundations, benchmark artifacts, contributions, evaluations, and improvement sessions connect.
kind: reference
product_area: reference
status: stable
updated: 2026-09-07
canonical: /docs/object-model
---

# Object model

Use this reference when a workflow depends on artifact ownership, identity, version history, or provenance. Teammately keeps reusable project foundations separate from benchmark-scoped evidence so a later reader can reconstruct what the agent knew, what was evaluated, who supplied judgment, and why a candidate was retained.

> Preserve scope and version
>
> An artifact name alone is not sufficient evidence. Preserve its project or benchmark scope, version or snapshot identity, lifecycle state, and provenance whenever it affects evaluation or improvement.

## Definition

A **Project** owns reusable foundations: the Project Agent Brief, Reference blocks, policies, rubrics, coverage facets, Cases, Harnesses, Review Screen configuration, Comparison Directions, and Project Input Schema. These objects can support more than one benchmark.

A **Benchmark** owns a particular correctness boundary. Its workspace selects Cases into Dataset snapshots, organizes benchmark-scoped coverage work, requests Expert Contributions, and creates Benchmark versions. A Benchmark version is the fixed boundary against which a saved Harness version is evaluated.

An **Evaluation Run** records the response, Rubric outcomes, mapping, settings, and metadata produced by one saved Harness Version against one Benchmark Version. It does not currently expose execution trajectories. An **Improvement Session** pins target evidence through a Goal Contract, evaluates candidates, retains canonical receipts and safe narrated session activity, and updates a Current frontier. The frontier is evidence-backed session state, not an unnamed replacement for the saved Harness.

## Decision checkpoint

| Question | Object boundary to preserve | Common mistake |
| --- | --- | --- |
| What did the agent understand? | Project Agent Brief and Reference block generation | Treating the latest source file as the knowledge used by an earlier run |
| What behavior was evaluated? | Case, Dataset snapshot, Benchmark version, and saved Harness version | Describing only a prompt and score |
| What standard applied? | Policy, applicability, Rubric, and provenance | Letting a Rubric stand in for the Policy it checks |
| Who supplied judgment? | Contribution, Task, Checkpoint, expert, and Contributed artifact | Treating an unattributed comment as governed truth |
| Why was a candidate retained? | Improvement Session, Goal Contract, evaluation receipt, and Current frontier | Treating an unsaved draft as the evaluated candidate |

## Fields, states, or lifecycle rules

### Project foundations

- **Project Agent Brief:** Published project understanding used to orient agents.
- **Reference block:** Indexed knowledge with source and generation identity.
- **Policy and Rubric:** Governed meaning and executable judgment criteria, with applicability and provenance.
- **Coverage Facet:** Reusable Dimensions, Project Topics, and Case Construction Patterns that describe important behavior space.
- **Case:** Canonical `content.input`, optional `content.case_materials`, metadata, and optional executable world reference.
- **Harness:** An agent configuration with mutable Draft state and immutable saved versions used for evaluation.
- **Project Input Schema:** The project-level architecture that governs canonical Case input and materials.

### Benchmark artifacts

- **Dataset snapshot:** A reproducible selection and representation of benchmark Cases.
- **Coverage Story:** Benchmark-scoped intent that connects coverage structure to concrete case work.
- **Expert Contribution:** A benchmark-scoped request containing Tasks, context, statuses, and optional Checkpoints.
- **Contributed artifact:** A policy, Rubric, Case, or coverage observation supplied through a Contribution with attributable provenance.
- **Benchmark version:** The fixed evaluation boundary used by Runs and Improvement Sessions.
- **Evaluation Run:** One execution with candidate, benchmark, response, Rubric outcomes, settings, mapping, and metadata identity.
- **Improvement Session:** A goal-directed candidate exploration process with pinned evidence, receipts, trajectories, and frontier state.

{% artifact-map title="How correctness artifacts connect" %}
{% /artifact-map %}

## Static materials and executable worlds

Case materials and executable worlds are intentionally different. `content.case_materials` holds canonical material data or references that can accompany the input. A `world_instance_ref` identifies an executable or queryable environment with a separate capability and lifecycle boundary. Rendering either for inspection does not create another authoring source.

{% example-demo title="From contribution to frontier" %}
A benchmark Contribution asks a procurement specialist to resolve three ambiguous Cases. The expert confirms a Policy and binary Rubric at a Checkpoint. The artifacts are reconciled into Correctness Governance while retaining their Contribution provenance. The Cases enter a Dataset snapshot and the standard enters Benchmark version 6. An Evaluation Run tests Harness version 11 and exposes two failures. An Improvement Session pins those failures, evaluates versions 12 and 13, and retains version 13 in the Current frontier with canonical evaluation receipts.
{% /example-demo %}

## Source confidence

Code-backed: current navigation establishes project and benchmark scopes; canonical case-content code establishes the input and materials boundary; the active Improve session contract establishes Goal Contract, candidate, receipt, and frontier concepts. This page describes public object semantics, not a public API or export schema.

## Related task pages

{% related-card-grid title="Related task pages" %}
- [First correctness loop](/docs/operating-manual/first-correctness-loop)
- [Request an Expert Contribution](/docs/expert-contributions/request-contribution)
- [Run a Benchmark Evaluation](/docs/benchmark-evaluations/run-evaluation)
- [Start an Improvement Session](/docs/improve/start-improvement-session)
{% /related-card-grid %}

## Related reference pages

{% related-card-grid title="Related reference pages" %}
- [Key objects and relationships](/docs/getting-oriented/key-objects-and-relationships)
- [Cases](/docs/assets/cases)
- [Harnesses](/docs/assets/harnesses)
- [Glossary](/docs/reference/glossary)
{% /related-card-grid %}