# Evaluation overview

How Tanomis turns a run into a trace, a trace into an assessment, assessments into experiments, and a verdict into a release gate.

Evaluation on Tanomis is built on the run you already have. Every run produces an execution trace;
evaluators score traces into assessments; a set of assessments over a dataset is an experiment;
and a comparison between experiments becomes a verdict that can gate a rollout.

> **Availability:** Evaluation is enabled per tenant, shadow-first. See [What is available where](/reference/availability).

- **Trace**: one OpenTelemetry trace per run, on the tenant's own trace plane, with content
  captured at the level tenant policy allows.
- **Assessment**: a scorer's verdict on one trace, with a reason and the evidence it used.
- **Experiment**: a candidate version replayed over a dataset version, with aggregate metrics.
- **Gate**: a candidate-versus-baseline comparison whose verdict can block promotion.

## The flow

| Step | What it is | Where you see it |
|---|---|---|
| Run | Any run, from the Console, the CLI, or your application | Sessions |
| Trace | The run's model calls, tool calls, timing, and captured content | Evidence, Evaluations |
| Assessment | A scorer's verdict on a trace | Evaluations |
| Experiment | A candidate replayed over a dataset, with rolled-up metrics | Evaluations |
| Verdict | Candidate compared with baseline against a threshold | `tanomis eval compare`, the promotion gate |

Nothing in this flow copies content into the audit ledger. The ledger records that a gate decision
was made and references the trace content by hash; the trace store holds the content under its
own capture, retention, and access rules. See [Audit and evidence](/guides/audit/audit-and-evidence).

## Offline and online

**Offline** evaluation scores a candidate before it serves traffic: pin a target, replay a dataset,
compare with the baseline. This is the path in [Evaluate a version](/guides/evaluate/evaluate-a-version).

**Online** evaluation samples live runs and scores them continuously so drift shows up early. It is
planned; see [Online monitoring](/guides/evaluate/online-monitoring).

## What decides a score

Scorers run over traces. Deterministic scorers check structure and outcomes; judge-model scorers
ask a model, through the same gateway agents use and under an allowlist your administrator
controls. Human feedback recorded beside an assessment is how a judge is calibrated before a gate
is allowed to enforce.

## Where to go next

- [Capture execution traces](/guides/evaluate/capture-traces): what a trace contains and how
  much content it carries.
- [Evaluate a version](/guides/evaluate/evaluate-a-version): the offline path, step by step.
- [Datasets and experiments](/guides/evaluate/datasets-and-experiments) and
  [Scorers and judge models](/guides/evaluate/scorers-and-judges): planned pages for the
  workbench.