diff --git a/apps/jetty/build.xml b/apps/jetty/build.xml
index 3e24fad189044f3912b149bd7611605960f02b5f..2cce85311f803bfd9c10710b6d3e20fbbc478d75 100644
--- a/apps/jetty/build.xml
+++ b/apps/jetty/build.xml
@@ -545,7 +545,7 @@
         <jar destfile="./build/servlet-i2p-${release.number}.jar" basedir="./build/obj" includes="net/i2p/servlet/filters/*.class" >
             <manifest>
                 <attribute name="Specification-Title" value="I2P Servlet classes" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Servlet classes" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -609,7 +609,7 @@
             <fileset dir="./build/servlet-i2p-javadoc" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Servlet classes" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Servlet classes" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -626,7 +626,7 @@
             <fileset dir="./java/src" includes="net/i2p/servlet/filters/**" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Servlet classes" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Servlet classes" />
                 <attribute name="Implementation-Version" value="${full.version}" />
diff --git a/apps/ministreaming/java/build.xml b/apps/ministreaming/java/build.xml
index 63b8ff54d4c82feafcb9dccf112aa5ee786edae3..c7224b3ba7f513343b4fdc2a6cd2a6efbfc9dd6a 100644
--- a/apps/ministreaming/java/build.xml
+++ b/apps/ministreaming/java/build.xml
@@ -84,7 +84,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="i2p.jar streaming.jar" />
                 <attribute name="Specification-Title" value="I2P Streaming API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -193,7 +193,7 @@
             <fileset dir="./build/javadoc" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Streaming API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -209,7 +209,7 @@
             <fileset dir="./src" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Streaming API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
diff --git a/apps/streaming/java/build.xml b/apps/streaming/java/build.xml
index a6e27f945a08f2a33ecdad41df532e3b85982554..914867ae93f82c59f6d6325198dac548c7b8bbaf 100644
--- a/apps/streaming/java/build.xml
+++ b/apps/streaming/java/build.xml
@@ -210,7 +210,7 @@
         <jar destfile="./build/streaming.jar" basedir="./build/obj" includes="**/*.class" >
             <manifest>
                 <attribute name="Specification-Title" value="I2P Streaming Implementation" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming Implementation" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -282,7 +282,7 @@
             <fileset dir="./build/javadoc" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Streaming Implementation" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming Implementation" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -299,7 +299,7 @@
             <fileset dir="./src" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Streaming Implementation" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Streaming Implementation" />
                 <attribute name="Implementation-Version" value="${full.version}" />
diff --git a/build.xml b/build.xml
index bfce629f0c748a6f95e70a8f1d7e3eaa14e6423c..19e66aa236fe906f7e595da4fa9719cba0e91dd9 100644
--- a/build.xml
+++ b/build.xml
@@ -1085,6 +1085,7 @@
         <echo message="Warning, javadoc embeds timestamps in the output, run with 'TZ=UTC ant javadoc' if you plan to distribute" />
     </target>
 
+    <!-- sets release.number and api.version -->
     <target name="getReleaseNumber">
         <loadfile srcfile="core/java/src/net/i2p/CoreVersion.java" property="release.number">
             <filterchain>
@@ -1098,8 +1099,41 @@
                 <trim/>
             </filterchain>
         </loadfile>
+        <loadfile srcfile="core/java/src/net/i2p/CoreVersion.java" property="api.version">
+            <filterchain>
+                <linecontains>
+                    <contains value="public final static String PUBLISHED_VERSION"/>
+                </linecontains>
+                <tokenfilter>
+                    <replaceregex pattern='.*"([^"]+)";' replace="\1" flags="gi" />
+                </tokenfilter>
+                <striplinebreaks/>
+                <trim/>
+            </filterchain>
+        </loadfile>
         <property name="release.number" value="unknown" />
-        <echo message="Release number is ${release.number}" />
+        <property name="api.version" value="unknown" />
+        <echo message="Release number: ${release.number}" />
+        <echo message="API version:    ${api.version}" />
+        <fail message="Bad API version, must start with 0.9." >
+            <condition>
+                <not>
+                    <matches pattern="^0\.9\." string="${api.version}" />
+                </not>
+            </condition>
+        </fail>
+        <fail message="Release number / API version mismatch" >
+            <condition>
+                <and>
+                    <not>
+                        <equals arg1="${release.number}" arg2="${api.version}"/>
+                    </not>
+                    <not>
+                        <matches pattern="^1\." string="${release.number}" />
+                    </not>
+                </and>
+            </condition>
+        </fail>
     </target>
 
     <target name="getBuildNumber">
diff --git a/core/java/build.xml b/core/java/build.xml
index 4bb8bd6b2cf271414deef7fc1345302354684d94..2b02912f302912f6a13b54d6501d1abc9607306f 100644
--- a/core/java/build.xml
+++ b/core/java/build.xml
@@ -120,7 +120,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="${gettext.jar} ${getopt.jar} ${httpclient.jar}" />
                 <attribute name="Specification-Title" value="I2P Core API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Core API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -228,7 +228,7 @@
             <fileset dir="./build/javadoc" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Core API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Core API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -245,7 +245,7 @@
             <fileset dir="./src" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Core API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Core API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -342,7 +342,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="${gettext.jar} ${getopt.jar} ${httpclient.jar}" />
                 <attribute name="Specification-Title" value="I2P Core API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Core API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -368,7 +368,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="${gettext.jar} ${getopt.jar} ${httpclient.jar}" />
                 <attribute name="Specification-Title" value="I2P Core API" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Core API" />
                 <attribute name="Implementation-Version" value="${full.version}" />
diff --git a/core/java/src/net/i2p/CoreVersion.java b/core/java/src/net/i2p/CoreVersion.java
index 4687ffad2c9cc710a982d509e1f19617995b4957..7f851b27a4fa54b05f1f6b0697770493fad7edea 100644
--- a/core/java/src/net/i2p/CoreVersion.java
+++ b/core/java/src/net/i2p/CoreVersion.java
@@ -18,11 +18,13 @@ package net.i2p;
 public class CoreVersion {
 
     /** deprecated */
-    public final static String ID = "Monotone";
+    public final static String ID = "Git";
 
     /**
      *  The version used when checking for router updates,
      *  and exchanged between router and client over I2CP.
+     *  This is the marketing and user-visible version.
+     *
      *  If we ever need a point release for a specific
      *  architecture only, append ".1" to VERSION
      *  and leave PUBLISHED_VERSION unchanged.
@@ -33,6 +35,11 @@ public class CoreVersion {
 
     /**
      *  The version published in the netdb via StatisticsManager.
+     *  This is the API version.
+     *  It must not go to 1.x for several years, because through
+     *  0.9.49, the Sybil analyzer blocked releases that didn't
+     *  start with "0.9."
+     *
      *  If we ever need a point release for a specific
      *  architecture only, append ".1" to VERSION
      *  and leave PUBLISHED_VERSION unchanged.
@@ -41,7 +48,7 @@ public class CoreVersion {
      *
      *  @since 0.9.46
      */
-    public final static String PUBLISHED_VERSION = VERSION;
+    public final static String PUBLISHED_VERSION = "0.9.49";
 
     /**
      *  For Vuze.
@@ -54,6 +61,7 @@ public class CoreVersion {
 
     public static void main(String args[]) {
         System.out.println("I2P Core version: " + VERSION);
+        System.out.println("I2P API version:  " + PUBLISHED_VERSION);
         System.out.println("ID: " + ID);
     }
 }
diff --git a/core/java/src/net/i2p/client/impl/I2PSessionImpl.java b/core/java/src/net/i2p/client/impl/I2PSessionImpl.java
index cb4190d6c9ad13baf78da2ed8787f8c84c1cad99..5d902c302fed23df11dc9ffae691ab711b053ed7 100644
--- a/core/java/src/net/i2p/client/impl/I2PSessionImpl.java
+++ b/core/java/src/net/i2p/client/impl/I2PSessionImpl.java
@@ -769,7 +769,7 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
                 auth.setProperty(I2PClient.PROP_USER, _options.getProperty(I2PClient.PROP_USER));
                 auth.setProperty(I2PClient.PROP_PW, _options.getProperty(I2PClient.PROP_PW));
             }
-            sendMessage_unchecked(new GetDateMessage(CoreVersion.VERSION, auth));
+            sendMessage_unchecked(new GetDateMessage(CoreVersion.PUBLISHED_VERSION, auth));
             waitForDate();
 
             if (_log.shouldLog(Log.DEBUG)) _log.debug(getPrefix() + "Before producer.connect()");
@@ -1880,7 +1880,7 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
      */
     public String getRouterVersion() {
         if (_context.isRouterContext())
-            return CoreVersion.VERSION;
+            return CoreVersion.PUBLISHED_VERSION;
         return _routerVersion;
     }
 
diff --git a/core/java/src/net/i2p/client/impl/I2PSimpleSession.java b/core/java/src/net/i2p/client/impl/I2PSimpleSession.java
index 3c332ae0ade61d9171691dc3848b7aa5d9b7f504..ade2afbe902ed5007374a422c3ee80ffeec6a2a2 100644
--- a/core/java/src/net/i2p/client/impl/I2PSimpleSession.java
+++ b/core/java/src/net/i2p/client/impl/I2PSimpleSession.java
@@ -123,11 +123,11 @@ public class I2PSimpleSession extends I2PSessionImpl2 {
                     Properties auth = new OrderedProperties();
                     auth.setProperty(I2PClient.PROP_USER, opts.getProperty(I2PClient.PROP_USER));
                     auth.setProperty(I2PClient.PROP_PW, opts.getProperty(I2PClient.PROP_PW));
-                    sendMessage_unchecked(new GetDateMessage(CoreVersion.VERSION, auth));
+                    sendMessage_unchecked(new GetDateMessage(CoreVersion.PUBLISHED_VERSION, auth));
                 } else {
                     // we must now send a GetDate even in SimpleSession, or we won't know
                     // what version we are talking with and cannot use HostLookup
-                    sendMessage_unchecked(new GetDateMessage(CoreVersion.VERSION));
+                    sendMessage_unchecked(new GetDateMessage(CoreVersion.PUBLISHED_VERSION));
                 }
                 waitForDate();
             }
diff --git a/router/java/build.xml b/router/java/build.xml
index 8ff50285ea85947974d69efc9d082d7ce11a5497..22133cb46142863eed807959ad5014ea13d15487 100644
--- a/router/java/build.xml
+++ b/router/java/build.xml
@@ -79,7 +79,7 @@
                 <!-- so people with very old wrapper.config files will still work with Jetty 6 -->
                 <attribute name="${manifest.classpath.name}" value="i2p.jar addressbook.jar jetty-i2p.jar jetty-rewrite-handler.jar jetty-start.jar jetty-util.jar" />
                 <attribute name="Specification-Title" value="I2P Router" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Router" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -189,7 +189,7 @@
             <fileset dir="./build/javadoc" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Router" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Router" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -206,7 +206,7 @@
             <fileset dir="./src" />
             <manifest>
                 <attribute name="Specification-Title" value="I2P Router" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Router" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -300,7 +300,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="i2p.jar" />
                 <attribute name="Specification-Title" value="I2P Router" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Router" />
                 <attribute name="Implementation-Version" value="${full.version}" />
@@ -320,7 +320,7 @@
             <manifest>
                 <attribute name="${manifest.classpath.name}" value="i2p.jar" />
                 <attribute name="Specification-Title" value="I2P Router" />
-                <attribute name="Specification-Version" value="${release.number}" />
+                <attribute name="Specification-Version" value="${api.version}" />
                 <attribute name="Specification-Vendor" value="The I2P Project https://geti2p.net/" />
                 <attribute name="Implementation-Title" value="I2P Java Router" />
                 <attribute name="Implementation-Version" value="${full.version}" />
diff --git a/router/java/src/net/i2p/router/client/ClientManager.java b/router/java/src/net/i2p/router/client/ClientManager.java
index fc94b17b8b872b0bdfab18afd30bc00183345c19..b4757d032085e1010ff78b6f0c8224e1adc8afdb 100644
--- a/router/java/src/net/i2p/router/client/ClientManager.java
+++ b/router/java/src/net/i2p/router/client/ClientManager.java
@@ -835,7 +835,7 @@ class ClientManager {
                 try {
                     // only send version if the client can handle it (0.8.7 or greater)
                     runner.doSend(new SetDateMessage(runner.getClientVersion() != null ?
-                                                     CoreVersion.VERSION : null));
+                                                     CoreVersion.PUBLISHED_VERSION : null));
                 } catch (I2CPMessageException ime) {}
             }
             if (_isStarted)
diff --git a/router/java/src/net/i2p/router/sybil/Analysis.java b/router/java/src/net/i2p/router/sybil/Analysis.java
index c3f86ae190b8770a79103782df240855936175f0..a8e655e2702a35e5f51ede1a39b8643a24eaf493 100644
--- a/router/java/src/net/i2p/router/sybil/Analysis.java
+++ b/router/java/src/net/i2p/router/sybil/Analysis.java
@@ -89,10 +89,12 @@ public class Analysis extends JobImpl implements RouterApp {
     private static final double PAIR_DISTANCE_FACTOR = 2.0;
     private static final double OUR_KEY_FACTOR = 4.0;
     private static final double VERSION_FACTOR = 1.0;
-    private static final double POINTS_BAD_VERSION = 50.0;
+    private static final double POINTS_BAD_VERSION = 20.0;
     private static final double POINTS_UNREACHABLE = 4.0;
     private static final double POINTS_NEW = 4.0;
-    private static final double POINTS_BANLIST = 25.0;
+    // since we're blocking by default now, don't make this too high,
+    // so we don't always turn a temporary block into a permanent one.
+    private static final double POINTS_BANLIST = 10.0;
     public static final boolean DEFAULT_BLOCK = true;
     public static final double DEFAULT_BLOCK_THRESHOLD = 50.0;
     public static final long DEFAULT_BLOCK_TIME = 7*24*60*60*1000L;
@@ -775,6 +777,7 @@ public class Analysis extends JobImpl implements RouterApp {
         RouterInfo us = _context.router().getRouterInfo();
         if (us == null) return;
         String ourVer = us.getVersion();
+        // TODO do the math once we hit version 1.0.0
         if (!ourVer.startsWith("0.9.")) return;
         ourVer = ourVer.substring(4);
         int dot = ourVer.indexOf('.');
@@ -793,7 +796,9 @@ public class Analysis extends JobImpl implements RouterApp {
                 addPoints(points, h, POINTS_NONFF, "Non-floodfill");
             String hisFullVer = info.getVersion();
             if (!hisFullVer.startsWith("0.9.")) {
-                addPoints(points, h, POINTS_BAD_VERSION, "Strange version " + DataHelper.escapeHTML(hisFullVer));
+                if (!hisFullVer.startsWith("1."))
+                    addPoints(points, h, POINTS_BAD_VERSION, "Strange version " + DataHelper.escapeHTML(hisFullVer));
+                // TODO do the math once we hit version 1.0.0
                 continue;
             }
             String hisVer = hisFullVer.substring(4);