//////////////////////
 * Copyright (c) 2007-2012, Niclas Hedhman. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied.
 * See the License for the specific language governing permissions
 * and limitations under the License.
//////////////////////

[[core-spi,Extension SPI]]
= Core Extension SPI =

[devstatus]
--------------
source=core/spi/dev-status.xml
--------------

The Zest™ Core Runtime has a number of extension points, which we call the _Qi4j Core Extension SPI_. These are defined
interfaces used *only* by the Core Runtime and *never* directly by application code. <<extensions>> are assembled in
applications during the bootstrap phase.

include::../../build/docs/buildinfo/artifact.txt[]

There are currently 5 Core SPI extensions;

    * <<core-spi-valueserialization>>
    * <<core-spi-entitystore>>
    * <<core-spi-cache>>
    * <<core-spi-indexing>>
    * <<core-spi-metrics>>

Zest™ Runtime Extensions implementations may depend on Zest™ Libraries, but Libraries are NOT ALLOWED to depend on
Extensions. Applications code is NOT ALLOWED to depend on extensions. And application code SHOULD NOT depend on the
Core Extension SPI. If you think that is needed, please contact qi4j-dev forum at Google Groups, to see if your usecase
can be solved in a support manner, or that we need to extend the Core API to support it.

:leveloffset: {level3}

include::valueserialization.txt[]

:leveloffset: {level3}

include::entitystore.txt[]

:leveloffset: {level3}

include::cache.txt[]

:leveloffset: {level3}

include::indexing.txt[]

:leveloffset: {level3}

include::metrics.txt[]