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Contiki: The Open Source OS for the Internet of Things

Internet Standards

Contiki provides powerful low-power Internet communication. Contiki supports fully standard IPv6 and IPv4, along with the recent low-power wireless standards: 6lowpan, RPL, CoAP. With Contiki's ContikiMAC and sleepy routers, even wireless routers can be battery-operated.

Rapid Development

With Contiki, development is easy and fast: Contiki applications are written in standard C, with the Cooja simulator Contiki networks can be emulated before burned into hardware, and Instant Contiki provides an entire development environment in a single download.

Contiki development introduction »

A Selection of Hardware

Contiki runs on a range of low-power wireless devices, many of which can be easily purchased online.

Contiki platforms »

Active Community

Contiki is developed by a world-wide team of developers with contributions from Atmel, Cisco, ETH, Redwire LLC, SAP, Thingsquare, and many others, led by Adam Dunkels of Thingsquare.

Contiki community »

Open Source Software

Contiki is open source software: Contiki can be freely used both in commercial and non-commercial systems and the full source code is available.

Contiki open source license »

Community Support

Contiki provides community support through the Contiki developer community.

Contiki support »

Memory Allocation

Contiki is designed for tiny systems, having only a few kilobytes of memory available. Contiki is therefore highly memory efficient and provides a set of mechanisms for memory allocation: memory block allocation memb, a managed memory allocator mmem, as well as the standard C memory allocator malloc.

Find the code in contiki/core/lib/{memb,mmem}.[ch].

Full IP Networking

Contiki provides a full IP network stack, with standard IP protocols such as UDP, TCP, and HTTP, in addition to the new low-power standards like 6lowpan, RPL, and CoAP. The Contiki IPv6 stack, developed by and contributed to Contiki by Cisco, is fully certified under the IPv6 Ready Logo program.

Find the code in contiki/core/net/.

Power Awareness

Contiki is designed to operate in extremely low-power systems: systems that may need to run for years on a pair of AA batteries. To assist the development of low-power systems, Contiki provides mechanisms for estimating the system power consumption and for understanding where the power was spent.

Find the code in contiki/sys/energest.[ch].

6lowpan, RPL, CoAP

Contiki supports the recently standardized IETF protocols for low-power IPv6 networking, including the 6lowpan adaptation layer, the RPL IPv6 multi-hop routing protocol, and the CoAP RESTful application-layer protocol.

Find the code in contiki/core/net/rpl/ and contiki/apps/erbium/.

Dynamic Module Loading

Contiki supports dynamic loading and linking of modules at run-time. This is useful in applications in which the behavior is intended to be changed after deployment. The Contiki module loader can load, relocate, and link standard ELF files that can optionally be stripped off their debugging symbols to keep their size down.

Find the code in contiki/core/loader/.


There are plenty of examples in the Contiki source code tree to help you get started with your own code. Some examples show how to program network code, others show how to interact with the platform hardware, yet others demonstrate different aspects of the Contiki system. Most have a corresponding Cooja simulation available.

Find the code in contiki/examples/.

The Cooja Network Simulator

Contiki devices often make up large wireless networks. Developing and debugging software for such networks is really hard. Cooja, the Contiki network simulator, makes this tremendously easier by providing a simulation environment that allows developers to both see their applications run in large-scale networks or in extreme detail on fully emulated hardware devices.

Find the code in contiki/tools/cooja/.

Sleepy Routers

In wireless networks, nodes may need to relay messages from others to reach their destination. With Contiki, even relay nodes, so-called routers, can be battery-operated thanks to the ContikiMAC radio duty cycling mechanism which allows them to sleep between each relayed message. Some call this sleeping routers, we call it sleepy routers.

Find the code in contiki/core/net/mac/.

Hardware Platforms

Contiki runs on a wide range of tiny platforms, ranging from 8051-powered systems-on-a-chip through the MSP430 and the AVR to a variety of ARM devices. There are also a number of more exotic platforms thrown in there for good measure. Read more about Contiki hardware platforms:

Contiki hardware »

Find the code in contiki/platform/ and contiki/cpu/.


To save memory but provide a nice control flow in the code, Contiki uses a mechanism called protothreads. Protothreads is a mixture of the event-driven and the multi-threaded programming mechanisms. With protothreads, event-handlers can be made to block, waiting for events to occur.

Find the code in contiki/core/sys/pt.h.

Coffee flash file system

For devices that has an external flash memory chip, Contiki provides a lightweight flash file system, called Coffee. With Coffee, application programs can open, close, read from, write to, and append to files on the external flash, without having to worry about flash sectors needing to be erased before writing or flash wear-leveling. The performance of Coffee is within 95% of the raw throughput of the flash memory.

Find the code in contiki/core/cfs/cfs-coffee.[ch].

The Contiki shell

Contiki provides an optional command-line shell with a set of commands that are useful during development and debugging of Contiki systems. With Unix-style pipelines, shell commands can be combined in powerful ways. Applications can define their own shell commands that work together with existing commands.

Find the code in contiki/apps/shell/.

Regression Tests

To ensure that the Contiki code works as expected, the Contiki developers use a set of nightly regression tests that test important aspects of Contiki on a daily basis in the Cooja simulator. The regression test scripts can be used as a starting point for setting up simulations or to investigate how different Contiki mechanisms work.

Find the code in contiki/regression-tests/.

The Rime Stack

In situations when bandwidth is at a premium or where the full IPv6 networking stack is overkill, Contiki provides a tailored wireless networking stack called Rime. The Rime stack supports simple operations such as sending a message to all neighbors or to a specified neighbor, as well as more complex mechanisms such as network flooding and address-free multi-hop semi-reliable scalable data collection. Everything runs with sleepy routers to save power.

Find the code in contiki/core/net/rime/.

Build System

The Contiki build system makes it easy to compile applications for any of the available Contiki platforms. This makes it easy to try out applications on a range of different platforms. Don't have the hardware available? Use the Cooja simulator to emulate any of the available hardware devices!

Find the code in contiki/Makefile.include.


Contiki runs on a range of different hardware platforms and is designed to be easy to port to new hardware.

Contiki hardware »

Memory Footprint

Contiki is designed to run in small amounts of memory. A typical system with full IPv6 networking with sleepy routers and RPL routing needs less than 10 k RAM and 30 k ROM.


Contiki is designed to use well-known and well-tested standards such as IPv4, IPv6, and HTTP.

Instant Contiki

No need to install complex compiler tool chains on every development system: simply download and install Instant Contiki.

Contiki development introduction »

Open Source

Contiki is open source, which means that the source is and always will be available. Contiki may be used in both commercial and non-commercial systems without restrictions.


We run nightly regression tests on the Contiki code to make sure that it works as it should.

Hardcore Developers

Contiki is developed by a world-wide community of hardcore experts, many of which are happy to help out on the contiki-developers mailing list.

Community Support

Contiki provides a bunch of options for support.

Contiki resources »