# NAME

Robots::Validate - Validate that IP addresses are associated with known robots

# SYNOPSIS

```perl
use Robots::Validate;

my $rv = Robots::Validate->new;

...

if ( my $res = $rs->validate( $ip, $user_agent ) ) {
   ...
}
```

# DESCRIPTION

This module allows one to validate a robot user-agent string against the IP addresses.

# RECENT CHANGES

Changes for version v0.4.0 (2026-09-01)

- Incompatible Changes
    - This is a complete rewrite, and the interface is not compatible.
    - Bumped minimum Perl version to v5.24;
- Enhancements
    - This uses the Aho-Corasick algorithm to match multiple user-agent strings efficiently.
    - The robot rules are in a configuration file, allowing the user to easily update their own rules.
    - The robot rules have been expanded and updated.
    - Support for caching the results has been added, GH#3.
    - Added the validation\_mode attribute to control how multiple user-agent matches are handled.
- Security
    - Add a max\_forward\_lookups attribute to limit the number of reverse DNS lookups. (CVE-2026-82309)
- Tests
    - Updated the tests to use Test2.
- Documentation
    - Updated the author email address.
    - Updated the copyright year.
    - Added a security policy.
    - Added AI\_POLICY.md.
- Toolchain
    - Use SigStore instead of Module::Signature to sign releases.

See the `Changes` file for more details.

# REQUIREMENTS

This module lists the following modules as runtime dependencies:

- [Algorithm::AhoCorasick::XS](https://metacpan.org/pod/Algorithm%3A%3AAhoCorasick%3A%3AXS)
- [File::ShareDir](https://metacpan.org/pod/File%3A%3AShareDir)
- [File::Slurper](https://metacpan.org/pod/File%3A%3ASlurper)
- [List::Util](https://metacpan.org/pod/List%3A%3AUtil)
- [Moo](https://metacpan.org/pod/Moo) version 1 or later
- [Net::DNS::Resolver](https://metacpan.org/pod/Net%3A%3ADNS%3A%3AResolver)
- [Net::IP](https://metacpan.org/pod/Net%3A%3AIP)
- [Net::Patricia](https://metacpan.org/pod/Net%3A%3APatricia)
- [PerlX::Maybe](https://metacpan.org/pod/PerlX%3A%3AMaybe)
- [Ref::Util](https://metacpan.org/pod/Ref%3A%3AUtil)
- [Sub::Util](https://metacpan.org/pod/Sub%3A%3AUtil) version 1.40 or later
- [TOML::XS](https://metacpan.org/pod/TOML%3A%3AXS)
- [Try::Tiny](https://metacpan.org/pod/Try%3A%3ATiny)
- [Types::Common](https://metacpan.org/pod/Types%3A%3ACommon)
- [constant](https://metacpan.org/pod/constant)
- [experimental](https://metacpan.org/pod/experimental)
- [namespace::autoclean](https://metacpan.org/pod/namespace%3A%3Aautoclean)
- [perl](https://metacpan.org/pod/perl) version v5.24.0 or later

See the `cpanfile` file for the full list of prerequisites.

[CHI](https://metacpan.org/pod/CHI) is required to use the caching features.

# INSTALLATION

The latest version of this module (along with any dependencies) can be installed from [CPAN](https://www.cpan.org) with the `cpan` tool that is included with Perl:

```
cpan Robots::Validate
```

You can also extract the distribution archive and install this module (along with any dependencies):

```
cpan .
```

You can also install this module manually using the following commands:

```
perl Makefile.PL
make
make test
make install
```

If you are working with the source repository, then it may not have a `Makefile.PL` file.  But you can use the [Dist::Zilla](https://dzil.org/) tool in anger to build and install this module:

```
dzil build
dzil test
dzil install --install-command="cpan ."
```

For more information, see [How to install CPAN modules](https://www.cpan.org/modules/INSTALL.html).

# SECURITY CONSIDERATIONS

When using the ["cache"](#cache), ensure that it is configured to expire the
data by setting ["expires\_in" in CHI](https://metacpan.org/pod/CHI#expires_in) and digest the keys by setting
["max\_key\_length" in CHI](https://metacpan.org/pod/CHI#max_key_length) to 0.  This is to keep the cache from growing
too large, and to reduce the likelihood of cache backend
vulnerabilities being exploited through user-agent strings.

When setting the `cache_failure` option, be aware that cached failures may need a shorter expiration time.

When specifying a `domain` for verification rules, ensure that there
is an initial dot in the suffix, or that the regular expression
matches the entire domain name.  Otherwise imposter domains with the
same suffix will be validated.

When the `network` list contains cloud addresses, it is important to
regularly update the addresses from the documented information, as an
imposter can use abandoned cloud IP addresses.

# SUPPORT

Only the latest release of this module will be supported.

This module requires Perl v5.24 or later.
Future releases may only support Perl versions released in the last ten (10) years.

## Reporting Bugs and Submitting Feature Requests

Please report any bugs or feature requests on the bugtracker website
[https://github.com/robrwo/Robots-Validate/issues](https://github.com/robrwo/Robots-Validate/issues)

When submitting a bug or request, please include a test-file or a
patch to an existing test-file that illustrates the bug or desired
feature.

If the bug you are reporting has security implications which make it inappropriate to send to a public issue tracker,
then see `SECURITY.md` for instructions how to report security vulnerabilities.

# SOURCE

The development version is on github at [https://github.com/robrwo/Robots-Validate](https://github.com/robrwo/Robots-Validate)
and may be cloned from [https://github.com/robrwo/Robots-Validate.git](https://github.com/robrwo/Robots-Validate.git)

# AUTHOR

Robert Rothenberg <perl@rhizomnic.com>

Some of the development of this module was sponsored by Science Photo Library [https://www.sciencephoto.com](https://www.sciencephoto.com).

# COPYRIGHT AND LICENSE

This software is Copyright (c) 2018-2026 by Robert Rothenberg.

This is free software, licensed under:

```
The Artistic License 2.0 (GPL Compatible)
```

# SEE ALSO

The file `robots.toml` included with this distribution contains links to documented rules.

The TOML specification can be found at [https://toml.io](https://toml.io).