diff --git a/.test-env b/.test-env
index 3b17bb19..df783a4f 100644
--- a/.test-env
+++ b/.test-env
@@ -3,6 +3,8 @@ SDK_TESTING_URL="https://github.com/algorand/algorand-sdk-testing"
 SDK_TESTING_BRANCH="master"
 SDK_TESTING_HARNESS="test-harness"
 
+INSTALL_ONLY=0
+
 VERBOSE_HARNESS=0
 
 # WARNING: If set to 1, new features will be LOST when downloading the test harness.
diff --git a/Makefile b/Makefile
index 8b51618a..b2be49e1 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,10 @@ display-all-python-steps:
 	find tests/steps -name "*.py" | xargs grep "behave" 2>/dev/null | cut -d: -f1 | sort | uniq | xargs awk "/@(given|step|then|when)/,/[)]/" | grep -E "(\".+\"|\'.+\')"
 
 harness:
-	./test-harness.sh
+	./test-harness.sh up
+
+harness-down:
+	./test-harness.sh down
 
 PYTHON_VERSION ?= 3.8
 docker-pysdk-build:
diff --git a/algosdk/v2client/algod.py b/algosdk/v2client/algod.py
index 67a21027..46d00214 100644
--- a/algosdk/v2client/algod.py
+++ b/algosdk/v2client/algod.py
@@ -440,6 +440,16 @@ def stateproofs(self, round_num, **kwargs):
         req = "/stateproofs/{}".format(round_num)
         return self.algod_request("GET", req, **kwargs)
 
+    def get_block_hash(self, round_num, **kwargs):
+        """
+        Get the block hash for the block on the given round.
+
+        Args:
+            round_num (int): The round in which the transaction appears.
+        """
+        req = "/blocks/{}/hash".format(round_num)
+        return self.algod_request("GET", req, **kwargs)
+
 
 def _specify_round_string(block, round_num):
     """
diff --git a/algosdk/v2client/indexer.py b/algosdk/v2client/indexer.py
index f1d0da3a..4dd4bd1c 100644
--- a/algosdk/v2client/indexer.py
+++ b/algosdk/v2client/indexer.py
@@ -211,20 +211,26 @@ def asset_balances(
             query["include-all"] = include_all
         return self.indexer_request("GET", req, query, **kwargs)
 
-    def block_info(self, block=None, round_num=None, **kwargs):
+    def block_info(
+        self, block=None, round_num=None, header_only=None, **kwargs
+    ):
         """
         Get the block for the given round.
 
         Args:
             block (int, optional): block number
             round_num (int, optional): alias for block; specify one of these
+            header_only (bool, optional):
         """
-        req = "/blocks/"
         if block is None and round_num is None:
             raise error.UnderspecifiedRoundError
         req = "/blocks/" + _specify_round_string(block, round_num)
 
-        return self.indexer_request("GET", req, **kwargs)
+        query = dict()
+        if header_only:
+            query["header-only"] = "true"
+
+        return self.indexer_request("GET", req, query, **kwargs)
 
     def account_info(
         self,
diff --git a/setup.py b/setup.py
index de62eb5e..76e49db5 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
     description="Algorand SDK in Python",
     author="Algorand",
     author_email="pypiservice@algorand.com",
-    version="v1.18.0",
+    version="v1.19.0",
     long_description=long_description,
     long_description_content_type="text/markdown",
     license="MIT",
diff --git a/test-harness.sh b/test-harness.sh
index 9ddda66b..7e1a4f75 100755
--- a/test-harness.sh
+++ b/test-harness.sh
@@ -1,7 +1,47 @@
 #!/usr/bin/env bash
-
 set -euo pipefail
 
+# test-harness.sh setup/start cucumber test environment.
+#
+# Configuration is managed with environment variables, the ones you
+# are most likely to reconfigured are stored in '.test-env'.
+#
+# Variables:
+#   SDK_TESTING_URL     - URL to algorand-sdk-testing, useful for forks.
+#   SDK_TESTING_BRANCH  - branch to checkout, useful for new tests.
+#   SDK_TESTING_HARNESS - local directory that the algorand-sdk-testing repo is cloned into.
+#   VERBOSE_HARNESS     - more output while the script runs.
+#   INSTALL_ONLY        - installs feature files only, useful for unit tests.
+#
+#   WARNING: If set to 1, new features will be LOST when downloading the test harness.
+#   REGARDLESS: modified features are ALWAYS overwritten.
+#   REMOVE_LOCAL_FEATURES - delete all local cucumber feature files before downloading these from github.
+#
+#   WARNING: Be careful when turning on the next variable.
+#   In that case you'll need to provide all variables expected by `algorand-sdk-testing`'s `.env`
+#   OVERWRITE_TESTING_ENVIRONMENT=0
+
+SHUTDOWN=0
+if [ $# -ne 0 ]; then
+  if [ $# -ne 1 ]; then
+    echo "this script accepts a single argument, which must be 'up' or 'down'."
+    exit 1
+  fi
+
+  case $1 in
+    'up')
+      ;; # default.
+    'down')
+      SHUTDOWN=1
+      ;;
+    *)
+      echo "unknown parameter '$1'."
+      echo "this script accepts a single argument, which must be 'up' or 'down'."
+      exit 1
+      ;;
+  esac
+fi
+
 START=$(date "+%s")
 
 THIS=$(basename "$0")
@@ -23,12 +63,20 @@ if [ -d "$SDK_TESTING_HARNESS" ]; then
   ./scripts/down.sh
   popd
   rm -rf "$SDK_TESTING_HARNESS"
+  if [[ $SHUTDOWN == 1 ]]; then
+    echo "$THIS: network shutdown complete."
+    exit 0
+  fi
 else
   echo "$THIS: directory $SDK_TESTING_HARNESS does not exist - NOOP"
 fi
 
-git clone --depth 1 --single-branch --branch "$SDK_TESTING_BRANCH" "$SDK_TESTING_URL" "$SDK_TESTING_HARNESS"
+if [[ $SHUTDOWN == 1 ]]; then
+  echo "$THIS: unable to shutdown network."
+  exit 1
+fi
 
+git clone --depth 1 --single-branch --branch "$SDK_TESTING_BRANCH" "$SDK_TESTING_URL" "$SDK_TESTING_HARNESS"
 
 echo "$THIS: OVERWRITE_TESTING_ENVIRONMENT=$OVERWRITE_TESTING_ENVIRONMENT"
 if [[ $OVERWRITE_TESTING_ENVIRONMENT == 1 ]]; then
@@ -53,6 +101,11 @@ if [[ $VERBOSE_HARNESS == 1 ]]; then
 fi
 echo "$THIS: seconds it took to get to end of cloning and copying: $(($(date "+%s") - START))s"
 
+if [[ $INSTALL_ONLY == 1 ]]; then
+  echo "$THIS: configured to install feature files only. Not starting test harness environment."
+  exit 0
+fi
+
 ## Start test harness environment
 pushd "$SDK_TESTING_HARNESS"
 
diff --git a/tests/steps/other_v2_steps.py b/tests/steps/other_v2_steps.py
index 58f6295c..578d2e6c 100644
--- a/tests/steps/other_v2_steps.py
+++ b/tests/steps/other_v2_steps.py
@@ -39,9 +39,9 @@ def parse_string(text):
 register_type(MaybeString=parse_string)
 
 
-@parse.with_pattern(r"true|false")
+@parse.with_pattern(r"true|false|")
 def parse_bool(value):
-    if value not in ("true", "false"):
+    if value not in ("true", "false", ""):
         raise ValueError("Unknown value for include_all: {}".format(value))
     return value == "true"
 
@@ -623,9 +623,19 @@ def parse_txns_by_addr(context, roundNum, length, idx, sender):
         assert context.response["transactions"][int(idx)]["sender"] == sender
 
 
-@when("we make a Lookup Block call against round {block}")
+@when(
+    'we make a Lookup Block call against round {block:d} and header "{headerOnly:MaybeBool}"'
+)
+def lookup_block(context, block, headerOnly):
+    print("Header only = " + str(headerOnly))
+    context.response = context.icl.block_info(
+        block=block, header_only=headerOnly
+    )
+
+
+@when("we make a Lookup Block call against round {block:d}")
 def lookup_block(context, block):
-    context.response = context.icl.block_info(int(block))
+    context.response = context.icl.block_info(block)
 
 
 @when("we make any LookupBlock call")
@@ -1392,3 +1402,8 @@ def transaction_proof(context, round, txid, hashtype):
     context.response = context.acl.transaction_proof(
         round, txid, hashtype, "msgpack"
     )
+
+
+@when("we make a Lookup Block Hash call against round {round}")
+def get_block_hash(context, round):
+    context.response = context.acl.get_block_hash(round)
diff --git a/tests/unit.tags b/tests/unit.tags
index e9f95700..9ddbf8c2 100644
--- a/tests/unit.tags
+++ b/tests/unit.tags
@@ -5,6 +5,7 @@
 @unit.applications
 @unit.atc_method_args
 @unit.atomic_transaction_composer
+@unit.blocksummary
 @unit.dryrun
 @unit.dryrun.trace.application
 @unit.feetest
@@ -16,6 +17,7 @@
 @unit.rekey
 @unit.responses
 @unit.responses.231
+@unit.responses.blocksummary
 @unit.responses.participationupdates
 @unit.responses.unlimited_assets
 @unit.sourcemap