diff --git a/configure.ac b/configure.ac
index 95ccddd47..c2227d726 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,7 +3,7 @@ AC_PREREQ([2.60])
 define(_CLIENT_VERSION_MAJOR, 0)
 define(_CLIENT_VERSION_MINOR, 12)
 define(_CLIENT_VERSION_REVISION, 4)
-define(_CLIENT_VERSION_BUILD, 0)
+define(_CLIENT_VERSION_BUILD, 1)
 define(_CLIENT_VERSION_IS_RELEASE, true)
 define(_COPYRIGHT_YEAR, 2016)
 define(_COPYRIGHT_HOLDERS,[The %s developers])
diff --git a/doc/REST-interface.md b/doc/REST-interface.md
index 4323ba2b8..e274ec09d 100644
--- a/doc/REST-interface.md
+++ b/doc/REST-interface.md
@@ -14,10 +14,16 @@ Given a transaction hash: returns a transaction in binary, hex-encoded binary, o
 For full TX query capability, one must enable the transaction index via "txindex=1" command line / configuration option.
 
 #### Blocks
+`GET /rest/block/tip.<bin|hex|json>`
 `GET /rest/block/<BLOCK-HASH>.<bin|hex|json>`
+`GET /rest/block/<BLOCK-HEIGHT>.<bin|hex|json>`
+`GET /rest/block/notxdetails/tip.<bin|hex|json>`
 `GET /rest/block/notxdetails/<BLOCK-HASH>.<bin|hex|json>`
+`GET /rest/block/notxdetails/<BLOCK-HEIGHT>.<bin|hex|json>`
 
 Given a block hash: returns a block, in binary, hex-encoded binary or JSON formats.
+You can give a block height instead of a hash. Height 0 is not available, 
+but can be negative to go back that many blocks from the tip.
 
 The HTTP request and response are both handled entirely in-memory, thus making maximum memory usage at least 2.66MB (1 MB max block, plus hex encoding) per request.
 
diff --git a/src/claimtrie.h b/src/claimtrie.h
index 00c716532..ab1e1801c 100644
--- a/src/claimtrie.h
+++ b/src/claimtrie.h
@@ -304,7 +304,7 @@ class CClaimTrie
 {
 public:
     CClaimTrie(bool fMemory = false, bool fWipe = false, int nProportionalDelayFactor = 32)
-        : db(GetDataDir() / "claimtrie", 100, fMemory, fWipe, false), nCurrentHeight(0),
+        : db(GetDataDir() / "claimtrie", 20 * 1024 * 1024, fMemory, fWipe, false), nCurrentHeight(0),
         nExpirationTime(Params().GetConsensus().nOriginalClaimExpirationTime),
         nProportionalDelayFactor(nProportionalDelayFactor),
         root(uint256S("0000000000000000000000000000000000000000000000000000000000000001"))
diff --git a/src/clientversion.h b/src/clientversion.h
index fc069c480..8005ecd4c 100644
--- a/src/clientversion.h
+++ b/src/clientversion.h
@@ -17,7 +17,7 @@
 #define CLIENT_VERSION_MAJOR 0
 #define CLIENT_VERSION_MINOR 12
 #define CLIENT_VERSION_REVISION 4
-#define CLIENT_VERSION_BUILD 0
+#define CLIENT_VERSION_BUILD 1
 
 //! Set to true for release, false for prerelease or test build
 #define CLIENT_VERSION_IS_RELEASE true
diff --git a/src/rest.cpp b/src/rest.cpp
index 2dff8d7da..607db3bc0 100644
--- a/src/rest.cpp
+++ b/src/rest.cpp
@@ -210,17 +210,28 @@ static bool rest_block(HTTPRequest* req,
     const RetFormat rf = ParseDataFormat(hashStr, strURIPart);
 
     uint256 hash;
-    if (!ParseHashStr(hashStr, hash))
-        return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash: " + hashStr);
-
+    long int blockHeight = 0;
+    if (hashStr != "tip") {
+        blockHeight = hashStr.size() < 12 ? std::strtol(hashStr.c_str(), NULL, 10) : 0;
+        if (blockHeight == 0 && !ParseHashStr(hashStr, hash))
+            return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash or block height: " + hashStr);
+    }
     CBlock block;
     CBlockIndex* pblockindex = NULL;
     {
         LOCK(cs_main);
-        if (mapBlockIndex.count(hash) == 0)
+        if (blockHeight < 0) // negative block heights take us back from current tip
+            blockHeight += chainActive.Height();
+        if (blockHeight > 0 && blockHeight <= chainActive.Height())
+            pblockindex = chainActive[blockHeight];
+        else if (blockHeight != 0)
+            return RESTERR(req, HTTP_BAD_REQUEST, "Invalid hash or block height: " + hashStr);
+        else if (hashStr == "tip")
+            pblockindex = chainActive.Tip();
+        else if (mapBlockIndex.count(hash))
+            pblockindex = mapBlockIndex[hash];
+        if (!pblockindex)
             return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not found");
-
-        pblockindex = mapBlockIndex[hash];
         if (fHavePruned && !(pblockindex->nStatus & BLOCK_HAVE_DATA) && pblockindex->nTx > 0)
             return RESTERR(req, HTTP_NOT_FOUND, hashStr + " not available (pruned data)");