package ortools

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Build and export Google OR-Tools models

Install 

dune-project
 Dependency

github.com Readme Changelog Edit opam file Versions (1)

Authors

  1. T
    Timothy Bourke <tim@tbrk.org>

Maintainers

  1. T
    Timothy Bourke <tim@tbrk.org>

Sources

ortools-9.14.0.tbz
sha256=3967abe3ecfdaa6c2c098be954825f792d0b925b5342a4ddb1ce5cf2d9f81e50
sha512=5d6feb4b5d664812aad0e103f9a9991405739b4d3532a86059e069f7d4a5f5804d444e15937217af1e7838024305802176ccd8be0268467dfa0f68cfe60e7fe7

Description

Google OR-Tools is an open source software suite for optimization, tuned for tackling the world's toughest problems in vehicle routing, flows, integer and linear programming, and constraint programming. This package provides OCaml functions for working with the Protocol Buffer formats that are read and written by the different solvers. It does not actually depend on the OR-Tools software, which need not even be installed. The interface currently only supports a subset of the features provided by the CP-SAT solver. Pull requests for more features and solvers are welcome.

Published: 22 Jan 2026

README

OCaml interface to Google OR-Tools

Currently only a subset of CP-SAT is supported.

Pull requests providing the missing features are welcome, but please pay attention to documentation and tests.

This project provides two packages:

  • ortools is an OCaml interface for building CP-SAT models. It does not require an installation of OR-Tools as it simply works with the protocol buffer format. See utils/sat_solve_pb.{c,py} for examples of interfacing with the CP-SAT solver.
  • ortools_solvers builds on ortools to provide a simple OCaml interface for calling CP-SAT. Building and installing it requires an OR-Tools installation (see below).

Building with Google OR-Tools

Ensure that libortools.9.dylib (macOS) or libortools.so.9 (Linux), and the other runtime libraries, are accessible by your compiler and loader.

For example, on macOS, set the LIBRARY_PATH (for compilation) and DYLD_LIBRARY_PATH (for execution) environment variables.

On Linux, set the LD_LIBRARY_PATH (for compilation and execution) environment variable.

There are several options for obtaining the runtime libraries.

  • Download or build from source following the official instructions (see the C++ section).
  • Install the Python libraires with pip. The OR-Tools runtime can be found in site-packages/ortools/.libs.
  • From the or-tools releases on github, download Google.OrTools.runtime.<os>-<arch>.9.<minor>.<patch>.nupkg where os ∈ { linux, osx, win } and arch ∈ { arm64, x64 } and unzip it. The required files are in runtimes/*/native.

I would have liked all this to be automatic, but:

  • There do not seem to be suitable brew/linux packages that could be linked from opam;
  • Vendoring the source in the opam package and building it on install is error-prone and resource-intensive;
  • Including several binary versions in the opam package is tedious to maintain and wasteful to download; and
  • Dynamically downloading the library on build is prevented by opam sandboxing (see the download branch for a prototype).

Protocol Buffer Interfaces

The Protocol Buffers interfaces have been generated with ocaml-protc (with pull/263).

If required, they can be regenerated as follows.

git clone git@github.com:google/or-tools.git
cd or-tools
git checkout v9.14      % TODO: update with required version
opam install ocaml-protoc
ocaml-protoc --binary --pp --make --ml_out src/model \
    <path-to-or-tools>/ortools/sat/cp_model.proto
ocaml-protoc --binary --pp --make --ml_out src/model \
    <path-to-or-tools>/ortools/sat/sat_parameters.proto

Dependencies (3)

  1. ocaml >= "4.14.2"
  2. pbrt >= "4.0"
  3. dune >= "3.20"

Dev Dependencies (1)

  1. odoc with-doc

Used by (1)

  1. ortools_solvers

Conflicts

None