Serval Mesh is an app for Android 2.2 “Froyo” and above. It provides free, secure phone-to-phone voice calling, SMS and file sharing over WiFi, without the need for a SIM card or a commercial mobile telephone carrier. In other words, it lets your Android phone communicate with other Android phones running Serval Mesh within WiFi range.

The latest release of Serval Mesh is available for download on Google Play.

Serval Mesh is free software produced by the Serval Project. The Java/XML source code of Serval Mesh is licensed to the public under the GNU General Public License version 3. The serval-dna component of Serval Mesh is licensed to the public under the GNU General Public License version 2. All source code is freely available from the Serval Project's batphone and serval-dna Git repositories on GitHub.

Serval Mesh version 0.90 is EXPERIMENTAL SOFTWARE. It has not yet reached version 1.0, and is intended for pre-production, demonstration purposes only. It may not work as advertised, it may lose or alter messages and files that it carries, it may consume a lot of space, speed and battery, and it may crash unexpectedly.

Serval Mesh requests root permission (super-user) on your Android device in order to put Wi-Fi into [Ad-Hoc mode][]. If you grant super-user permission to Serval Mesh, then it will take control of your device's Wi-Fi and use it to contact other Serval Mesh devices in the vicinity. This will cut off normal Wi-Fi network access.

If your device has no root access or if you deny super-user permission to Serval Mesh, or if no other Ad-Hoc mode devices are nearby, then Serval Mesh will revert to using Wi-Fi in the normal Client mode. This should not interrupt conventional network access, but it could do so. If there is no nearby access point like a home Wi-Fi router or public hot-spot then Serval Mesh will put your device's Wi-Fi into Access Point mode (turn on personal hotspot). This will give nearby devices access to your mobile data plan, and COULD COST YOU MONEY.

Serval Mesh telephony is a “best effort” service, primarily intended for when conventional telephony is not possible or cost effective, and MUST NOT BE RELIED UPON for emergencies in place of carrier-grade communications systems. The Serval Project cannot be held responsible for any performance or non-performance of the technologies that they provide in good will, and if you use these technologies you must agree to indemnify the Serval Project from any such claims.

The Serval Mesh software copies all files shared using the Rhizome file distribution service to other phones and devices running the Serval Mesh software, regardless of size, content or intended recipient. The Serval Project cannot be held responsible for the legality or propriety of any files received via Rhizome, nor for any loss, damage or offence caused by the transmission or receipt of any content via Rhizome.

• CURRENT-RELEASE.md (alternative link CURRENT-RELEASE.md) Release notes for the current release.

• INSTALL.md (alternative link INSTALL.md) Instructions for building the Android APK from the source code and installing manually.

• doc (alternative link doc) Technical documentation, including past release notes.

• CONTRIBUTORS.md (alternative link CONTRIBUTORS.md) All individuals who have contributed to the software.

• Serval Wiki contains helpful information for developers and users.

• GitHub Issues Tracking of bug reports and tasks. Please see the wiki pages on reporting bugs and managing issues before adding any new issues.