---
title: "cpbenchy solve"
description: "Solves a single instance the way a competition runs a solver."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.cpbenchy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# cpbenchy solve

## What it does

Solves one instance in its own process, the way a competition runs a solver: the competition's own
tool limits and measures it, and reads its output. A submission's launchers run it.

- Competition output (from the rules' output observer) goes to stdout; progress and a summary come as
  comment lines (`c ...`).
- At its time limit (wall or CPU), or on SIGTERM, it prints the best solution it found.
- Time counts from when the process started, as the competition counts it.

## Use it

```sh
cpbenchy solve instance.xml -s ortools --rules xcsp3-2025 --cpu-time-limit 60 --seed 7
```

```
c [cpbenchy     0.81s] loading instance.xml
o 12
o 9
s OPTIMUM FOUND
v <instantiation type="optimum" cost="9">
...
c cpbenchy: optimal, objective 9; parse 0.07s, transform 0.00s, solve 0.38s
```

## Options

The options of `cpbenchy run`, for one instance, one solver and at most one seed: `-s`, `-t`,
`--cpu-time-limit`, `-m`, `--cores`, `--seed`, `-P`, `--loader`, `-p`, `--rules`. Files of the run go
to a fresh directory under `$TMPDIR`.

## Implementation

Source: https://docs.cpbenchy.com/library/solve/index.mdx