# Prove a task

Source: https://redcrown.ai/docs/guides/prove-a-task/

Run every candidate model on your task and prove the cheapest one that clears your bar.

## 1. Describe the task

Give RedCrown a plain-language task and a few input/output examples. It uses these to build a scored experiment.

**UI**

Open **Prove** (`/`). Paste your task description and a few examples, then click **Use my data**. If you are signed out, you are redirected to log in and then back to Prove.

**CLI**

Build a dataset from a CSV with your inputs and reference outputs:

```
redcrown build-dataset --from-csv examples.csv --task summarize --input-col text --reference-col summary --out task.json
```

**MCP**

Call `scaffold_experiment` with a plain-language task and examples to get a validated experiment spec, or pass them directly to `prove_task` and let it handle scaffolding automatically:

```
{
  "task": "Summarize a customer support ticket in one sentence.",
  "examples": [
    {"input": "Ticket text here...", "output": "One-sentence summary."}
  ]
}
```

## 2. Run and rank

RedCrown fans your task across every candidate model, scores outputs against your examples, and ranks by the cheapest model that clears the quality bar.

**UI**

After clicking **Use my data**, Prove runs the experiment automatically and displays the ranked report inline. The winner row is highlighted in green.

**CLI**

```
redcrown eval task.json --report-json out.json
```

The ranked report prints to the terminal. `--report-json` also writes the full receipts to `out.json` for sharing or inspection.

**MCP**

Call `prove_task` with your task and examples. It runs the full experiment and returns the ranked winner and savings in one call:

```
{
  "task": "Summarize a customer support ticket in one sentence.",
  "examples": [
    {"input": "Ticket text here...", "output": "One-sentence summary."}
  ]
}
```

## 3. Share

Mint a shareable, no-login proof link so stakeholders can read the ranked report and receipts without an account.

**UI**

On the ranked report, click **Share proof**. RedCrown mints a public link at `app.redcrown.ai/proof/<token>`.

**CLI**

```
redcrown push out.json --proof-link
```

The proof URL is printed to the terminal after a successful push.

**MCP**

The `prove_task` response includes a `proof_url` field. Pass it to stakeholders directly; no additional call is needed.

Last verified 2026-07-02.