  Laser-plasma accelerators (LPAs), producing high-quality electron beams,
provide an opportunity to reduce the size of free-electron lasers (FELs) to
only a few meters. A complete system is proposed here, which is based on FEL
technology and consists of an LPA, two undulators, and other magnetic devices.
The system is capable to generate carrier-envelope phase stable attosecond
pulses with engineered waveform. Pulses with up to~60~nJ energy and 90
to~400~attosecond duration in the 30 to 120~nm wavelength range are predicted
by numerical simulation. These pulses can be used to investigate ultrafast
field-driven electron dynamics in matter.
