> ## Documentation Index
> Fetch the complete documentation index at: https://developers.haia.finance/llms.txt
> Use this file to discover all available pages before exploring further.

# sample

> Assemble receipts from bundled fixtures — the zero-setup first taste.

```sh theme={null}
haia-trace sample [template]
```

`sample` replays a bundled fixture run through the *real* assembler, so you see a
Receipt with no setup. It defaults to the `x402-buyer` template (the paying
agent's view); `x402-seller` shows the resource server's view. The template
name selects both the template and its fixture set, so a new scenario is data — a
template file plus a fixture file — never a code change.

## Example

```sh theme={null}
haia-trace sample x402-buyer
```

Each fixture contains three operations, showing the whole model at once:

```text theme={null}
🧾 x402-buyer · op-1 · FULL

  ✔ challenge   confirmed
  ✔ payment     confirmed
  ✔ settlement  confirmed

  operation completed
  ────────────────────────────
🧾 x402-buyer · op-2 · PARTIAL

  ✔ challenge   confirmed
  ✔ payment     confirmed
  ✖ settlement  not confirmed  required

  missing
    settlement — the payment was submitted, but no settlement response was observed

  operation not complete
  ────────────────────────────
🧾 x402-buyer · op-3 · PARTIAL

  ✔ challenge   confirmed
  ✔ payment     confirmed
  ✖ settlement  not confirmed  required

  exceptions
    ⚠ x402.settle.failed

  missing
    settlement — the payment was submitted, but no settlement response was observed

  operation not complete
```

Note the difference between op-2 and op-3: the same unclosed milestone, but op-2
is *unknown* (nothing was observed) while op-3 carries an *observed fault* — the
server reported the settlement failed.

<Tip>
  `sample` and [`build`](/cli/build) run the identical assembler — the only
  difference is where the events come from. See [what a Receipt
  is](/concepts/operation-receipt).
</Tip>