Can I get RavenDB to write to Seq using the NLog WebService target? - ravendb

Question

I'm trying to get RavenDB 3.0 log messages into Seq.
Seq supports posting of raw events using JSON: http://docs.getseq.net/docs/posting-raw-events
RavenDB uses NLog for logging. NLog supports a WebService target: https://github.com/NLog/NLog/wiki/WebService-target
My attempt so far is this:
<target type='WebService'
name='Seq'
url='http://localhost:5341/api/events/raw'
protocol='JsonPost'
encoding='UTF-8'>
<layout xsi:type="JsonLayout">
<attribute name='#t' layout="${longdate}" >
<attribute name='#mt' layout="${message}" >
</layout>
</target>
The full NLog.config file is:
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.netfx35.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<targets>
<target
xsi:type="AsyncWrapper"
name="AsyncLog">
<target xsi:type="SplitGroup">
<!-- create log files with a max size of 256 MB -->
<target
name="File"
xsi:type="File"
archiveAboveSize="268435456"
fileName="${basedir}\Logs\${shortdate}.log">
<layout xsi:type="CsvLayout">
<column name="time" layout="${longdate}" />
<column name="logger" layout="${logger}"/>
<column name="level" layout="${level}"/>
<column name="database" layout="${mdc:item=database}"/>
<column name="threadid" layout="${threadid}" />
<column name="message" layout="${message}" />
<column name="exception" layout="${exception:format=tostring}" />
</layout>
</target>
<target type='WebService'
name='Seq'
url='http://localhost:5341/api/events/raw'
protocol='JsonPost'
encoding='UTF-8'>
<layout xsi:type="JsonLayout">
<attribute name='#t' layout="${longdate}" >
<attribute name='#mt' layout="${message}" >
</layout>
</target>
</target>
</target>
<target
xsi:type="AsyncWrapper"
name="AsyncConflictLog">
<target xsi:type="SplitGroup">
<!-- create log files with a max size of 256 MB -->
<target
name="File"
xsi:type="File"
archiveAboveSize="268435456"
fileName="${basedir}\Logs\${shortdate}.conflicts.log">
<layout xsi:type="CsvLayout">
<column name="time" layout="${longdate}" />
<column name="logger" layout="${logger}"/>
<column name="level" layout="${level}"/>
<column name="database" layout="${mdc:item=database}"/>
<column name="threadid" layout="${threadid}" />
<column name="message" layout="${message}" />
<column name="exception" layout="${exception:format=tostring}" />
</layout>
</target>
</target>
</target>
</targets>
<rules>
<!--<logger name="Raven.Bundles.Replication.Plugins.*" writeTo="AsyncConflictLog" minlevel="Debug"/>-->
<logger name="Raven.*" writeTo="AsyncLog" minlevel="Trace"/>
</rules>
</nlog>
I'm having problems getting it working - I think my layout is invalid but I'm not getting any errors from RavenDB/NLog so it's very hard to work out what it doesn't like.
Has anyone done this or can you see what might be wrong?