Run an eval (/eval-run)¶

/eval-run is the execution engine of the harness. It takes an eval.yaml (produced by /eval-analyze) plus a dataset, runs the skill or prompt headlessly against every case, scores the outputs with your judges, and writes a scored HTML report under $AGENT_EVAL_RUNS_DIR/<eval-name>/<run-id>/.

What it produces

A per-run directory containing run_result.json, collection.json, summary.yaml, an analysis.md, and a report.html — plus per-case artifacts, logs, and traces.

The pipeline¶

The local runner walks a fixed sequence of steps. Each step is a script the skill orchestrates — it never duplicates their work.

flowchart TD
    A[Step 0: Discover config + parse flags] --> B[Step 1: Find dataset]
    B --> C[Step 2: Preflight check]
    C --> D[Step 3: Prepare workspace]
    D --> E{inputs.tools?}
    E -- yes --> F[Step 3a: Resolve tool interception]
    E -- no --> G[Step 4: Execute headlessly]
    F --> G
    G --> H[Step 5: Collect artifacts]
    H --> I[Step 6: Score with judges]
    I --> J[Step 7: Interpret + build report]
    J --> K[Step 8: Log to MLflow - optional]

Step	Script	What happens
0 Discover	`discover.py`	Auto-find `eval.yaml` (or use `--config`); parse flags; read the skill/prompt, runner, judges, models
1 Dataset	—	Read `dataset.path`; verify at least one case directory exists
2 Preflight	`preflight.py`	Check for stale artifacts and run-id / baseline collisions
3 Workspace	`workspace.py`	Build an isolated per-case (or batch) workspace with symlinked project resources
3a Interception	`workspace.py`	If `inputs.tools` is set, resolve `tool_handlers.yaml` into concrete runtime checks
4 Execute	`execute.py`	Invoke the agent headlessly, capture stdout/stderr, write `run_result.json`
5 Collect	`collect.py`	Distribute workspace outputs into per-case dirs; detect in-place edits via git diff
6 Score	`score.py`	Run judges (and pairwise, if `--baseline`); write `summary.yaml`
7 Report	`report.py`	Write `analysis.md` and `report.html`
8 MLflow	`/eval-mlflow`	Log params, metrics, and artifacts (only if `mlflow.experiment` is set)

Usually you just run one command

In practice you invoke the skill and it drives all of the above:

/eval-run --model opus

The step-level scripts are worth knowing when a run fails partway and you need to resume from a specific stage.

Case vs batch¶

execute.py auto-detects the execution mode from execution.mode in eval.yaml — there is no CLI flag for it.

case (default)batch

One invocation per test case. The harness loops over cases; each gets its own workspace, stdout.log, and subagent transcripts.

execution:
  mode: case
  skill: my-skill
  arguments: "{prompt}"      # resolved per case from input.yaml
  parallelism: 4             # optional: run cases concurrently

Cases run concurrently when execution.parallelism > 1 (or --parallelism), via a thread pool. Each case gets a log prefix like eval:case-003.
run_result.json records execution_mode: "case", a per_case breakdown, duration_s (sum of per-case durations), and wall_clock_s (actual elapsed time).

One invocation for all cases via batch.yaml. The skill/agent loops internally.

execution:
  mode: batch
  skill: my-skill
  arguments: "--input batch.yaml --headless"

workspace.py builds batch.yaml — one entry per case, each the full parsed input file — and case_order.yaml mapping position → case ID.
Collection maps output files back to cases by detected prefix or by position; set outputs[].batch_pattern (with {n}, 1-based) when files are named by index.

See the execution model for the full case-vs-batch and skill-vs-prompt matrix.

Flags¶

Parsed from $ARGUMENTS at Step 0. CLI flags override the corresponding eval.yaml keys.

Flag	Default	Effect
`--config <path>`	auto-discover	Path to the eval config
`--model <model>`	`models.skill`	Model for the skill/agent under test. Required if `models.skill` is unset.
`--subagent-model <model>`	`models.subagent` → falls back to `--model`	Model for subagents (e.g. sonnet subagents under an opus main)
`--skill <name>`	from config	Override the skill being tested
`--run-id <id>`	`YYYY-MM-DD-<model>`	Identifier for this run (names the output directory)
`--cases <id> [<id> …]`	all cases	Run only the listed case IDs
`--baseline <run-id>`	—	Add a pairwise A/B comparison against a prior run under the same eval-name
`--no-llm-judges`	false	Skip LLM judges (`prompt`, `prompt_file`, `llm_rubric`, LLM builtins); run only deterministic judges
`--gold`	false	After scoring, save collected artifacts back to the dataset cases as gold references
`--effort <level>`	`runner.effort`	Claude Code reasoning effort (`low`…`max`). Claude Code only — ignored by other runners
`--runner <type>`	`local`	`local` (default pipeline), `harbor` (containerized), or `evalhub` (platform)
`--env <name>`	`kubernetes`	Harbor execution environment: `podman`, `kubernetes`, `openshift` (only with `--runner harbor`)

--no-llm-judges is your fast, cheap dry run

It exercises the full execute → collect → score pipeline while skipping every judge that makes an API call. Deterministic check scripts, Python builtins, and external module/function judges still run.

Preflight: run-id and baseline collisions¶

Skills write to the project directory (not just the workspace), so stale artifacts from a previous run can contaminate results — wrong IDs, stale reports, inflated file counts. Step 2 guards against this and against overwriting prior runs.

preflight.py inspects tmp/ state files, checks whether $AGENT_EVAL_RUNS_DIR/<eval-name>/<run-id> already has results, and (with --baseline) verifies the baseline run-id exists.

Result	Meaning	What to do
`CLEAN`	No stale artifacts, no collision	Proceed to workspace setup
`DIRTY`	Stale artifacts, or the run-id already has results	Force-clean, pick a new run-id, or abort (see below)
`MISSING_BASELINE` (exit 2)	The `--baseline` run-id wasn't found	The script lists nearby run-ids; confirm the correct one (typo? different date/variant?)

When a run is DIRTY, the three resolutions are:

Force cleanChange run-idAbort

Delete all stale artifacts, then proceed.

python3 preflight.py --config eval.yaml --clean --force

Keep the previous results by choosing a fresh id (e.g. a version suffix), then re-check. This still requires cleaning project artifacts, so re-run preflight with --clean and the new id.

/eval-run --run-id 2026-04-11-opus-v2

Stop and clean up manually.

A colliding run-id overwrites the previous run

The default run-id is YYYY-MM-DD-<model>, so two runs of the same model on the same day collide. Preflight will flag it — pick a distinct --run-id (a -v2 suffix is the convention) whenever you want to keep both.

Tool interception¶

If eval.yaml has inputs.tools entries, Step 3a is mandatory. workspace.py emits a skeleton tool_handlers.yaml; you must resolve each handler's natural-language prompt into concrete runtime checks (input_filters for Bash, env_checks for services, case_overrides for deterministic answers) before execution. The workspace is rebuilt fresh every run, so this happens even when eval.yaml is unchanged.

Headless runs can hang without interception

A skill that calls AskUserQuestion or hits an external API in headless mode will block forever unless the tool is intercepted. If a tool the skill uses isn't covered, the run stalls. See tool interception.

Scoring: what judges see¶

score.py loads every case's collected outputs into a record dict and hands it to each judge. The same record drives inline check scripts (as outputs), and its fields are exposed to LLM judges as Jinja2 template variables.

Record key / variable	Contents
`outputs["files"]`, `outputs["<dir>_content"]`	Collected artifact file contents (incl. `_modified/` in-place edits)
`outputs["conversation"]` / `{{ conversation }}`	Root-level assistant text from the event stream
`outputs["events"]`	Flat list of typed events (if `traces.events`)
`outputs["tool_calls"]`	Tool calls matching `outputs[].tool` patterns
`outputs["exit_code"]`, `["duration_s"]`, `["cost_usd"]`, `["num_turns"]`, `["token_usage"]`	Execution metadata (if `traces.metrics`)
`outputs["stdout"]`, `outputs["stderr"]`	Raw logs (if `traces.stdout`/`stderr`)
`outputs["annotations"]` / `{{ annotations }}`	Parsed `annotations.yaml` from the dataset case — for outcome-aware scoring
`{{ inputs }}`, `{{ evidence }}`, `{{ tool_trace }}`, `{{ arguments }}`	Case inputs, a verifiable-action summary, a chronological tool trace, and judge `arguments:`

Aggregation is by value type: boolean judges become a pass_rate (fraction True), numeric judges become a mean. Results land in summary.yaml under aggregated and per_case. LLM judges can be sampled N times (samples:) — bool judges reduce by majority vote, numeric by median. See pairwise & sampling.

Baseline → pairwise comparison

--baseline <run-id> triggers a position-swapped pairwise judge on top of the regular judges: each case is judged both A/B and B/A, and only a consistent preference counts as a win. summary.yaml gains a pairwise section with wins_a, wins_b, and ties. Gate on it with a min_win_rate threshold.

Reading the results¶

The run directory ($AGENT_EVAL_RUNS_DIR/<eval-name>/<run-id>/) contains:

run_result.json     # exit_code, durations, token usage, cost, per_case breakdown
collection.json     # per-case artifact counts
summary.yaml        # judges (mean/pass_rate), per_case, pairwise
analysis.md         # LLM interpretation, leading with a Recommendation
report.html         # scoring summary, per-case detail, diffs, cost/tokens
cases/<case-id>/    # per-case artifacts, logs, and traces

Open report.html first; it renders the whole run. To understand each panel, see reading the report.

Other backends¶

The same eval.yaml runs unchanged across substrates — the backend is only ever a flag.

Harbor (--runner harbor)

Containerized execution. Steps 2–6 collapse into one run.py call over self-contained task packages. Environments: Podman, Kubernetes, OpenShift.

Harbor guide
EvalHub (--runner evalhub)

Platform-triggered, in-process execution inside an EvalHub Job pod.

EvalHub guide

Where to go next¶

Review the results

Interactive human feedback that can propose config and prompt changes.

/eval-review
Optimize automatically

Iterate on the skill using failures as the signal.

/eval-optimize
Log to MLflow

Sync the dataset and push run metrics, params, and artifacts.

/eval-mlflow