diff --git a/gds_compare.py b/gds_compare.py
new file mode 100644
index 0000000..4a5644f
--- /dev/null
+++ b/gds_compare.py
@@ -0,0 +1,27 @@
+# Usage:
+# klayout -b -r gds_compare.py -rd gds1=file1.gds -rd gds2=file2.gds
+
+import sys
+
+import pya
+
+
+def compare_gds(file1, file2):
+    diff = pya.LayoutDiff()
+
+    # Load the layouts
+    layout1 = pya.Layout()
+    layout1.read(file1)
+
+    layout2 = pya.Layout()
+    layout2.read(file2)
+
+    # Check if the layouts are identical
+    return diff.compare(layout1, layout2)
+
+
+if __name__ == "__main__":
+    if compare_gds(gds1, gds2):  # noqa: F821
+        sys.exit(0)
+    else:
+        sys.exit(-1)
diff --git a/reharden.py b/reharden.py
new file mode 100644
index 0000000..4817f2e
--- /dev/null
+++ b/reharden.py
@@ -0,0 +1,235 @@
+#!/usr/bin/env python3
+import argparse
+import csv
+import datetime
+import glob
+import json
+import logging
+import os
+import re
+import sys
+from typing import List
+
+import git
+
+ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), os.path.pardir))
+PROJECTS_DIR = os.path.join(ROOT, "projects")
+REHARDEN_DIR = os.path.join(ROOT, "reharden")
+
+
+def load_metrics(path):
+    try:
+        with open(os.path.join(path, "runs/wokwi/reports/metrics.csv")) as fh:
+            metrics = next(csv.DictReader(fh))
+            return metrics
+    except FileNotFoundError:
+        logging.warning(f"no metrics found for {path}")
+        return None
+
+
+# get cell count from synth report
+def get_cell_count_from_synth(path):
+    num_cells = 0
+    try:
+        yosys_report = (
+            f"{path}/runs/wokwi/reports/synthesis/1-synthesis.AREA_0.stat.rpt"
+        )
+        with open(yosys_report) as fh:
+            for line in fh.readlines():
+                m = re.search(r"Number of cells:\s+(\d+)", line)
+                if m is not None:
+                    num_cells = int(m.group(1))
+
+    except IndexError:
+        logging.warning(f"couldn't open yosys cell report for cell checking {path}")
+        return 0
+    except FileNotFoundError:
+        logging.warning(f"no cell count found for {path}")
+        return 0
+
+    return num_cells
+
+
+def get_cell_counts_from_gl(path):
+    cell_count = {}
+    total = 0
+
+    try:
+        gl_path = glob.glob(
+            os.path.join(path, "runs/wokwi/results/final/verilog/gl/*.nl.v")
+        )[0]
+    except IndexError:
+        logging.warning("no gl cell count found")
+        return 0
+    with open(gl_path) as fh:
+        for line in fh.readlines():
+            m = re.search(r"sky130_(\S+)__(\S+)_(\d+)", line)
+            if m is not None:
+                total += 1
+                cell_lib = m.group(1)
+                cell_name = m.group(2)
+                cell_drive = m.group(3)
+                assert cell_lib in ["fd_sc_hd", "ef_sc_hd"]
+                assert int(cell_drive) > 0
+                try:
+                    cell_count[cell_name] += 1
+                except KeyError:
+                    cell_count[cell_name] = 1
+    return cell_count
+
+
+def build_metrics(shuttle_index):
+    total_seconds = 0
+    total_wire_length = 0
+    total_wires_count = 0
+    total_physical_cells = 0
+    max_cells = 0
+    min_cells = 1000
+    max_cell_project = None
+    max_util = 0
+    min_util = 100
+    max_util_project = None
+
+    for project in shuttle_index["mux"]:
+        macro: str = shuttle_index["mux"][project]["macro"]
+        repo_dir = os.path.join(REHARDEN_DIR, macro)
+        metrics = load_metrics(repo_dir)
+        if metrics is None:
+            continue
+
+        try:
+            dt = datetime.datetime.strptime(metrics["total_runtime"][:-3], "%Hh%Mm%Ss")
+        except KeyError:
+            continue
+
+        delt = datetime.timedelta(hours=dt.hour, minutes=dt.minute, seconds=dt.second)
+        total_seconds += delt.total_seconds()
+
+        total_wire_length += int(metrics["wire_length"])
+        total_wires_count += int(metrics["wires_count"])
+        util = float(metrics["OpenDP_Util"])
+        num_cells = get_cell_count_from_synth(repo_dir)
+        total_physical_cells += num_cells
+
+        if num_cells > max_cells:
+            max_cells = num_cells
+            max_cell_project = project
+        if num_cells < min_cells:
+            min_cells = num_cells
+
+        if util > max_util:
+            max_util = util
+            max_util_project = project
+        if util < min_util:
+            min_util = util
+
+    logging.info(f"build time for all projects {total_seconds / 3600} hrs")
+    logging.info(f"total wire length {total_wire_length} um")
+    logging.info(f"total cells {total_physical_cells}")
+    logging.info(f"max cells {max_cells} for project {max_cell_project}")
+    logging.info(f"min cells {min_cells}")
+    logging.info(f"max util {max_util} for project {max_util_project}")
+    logging.info(f"min util {min_util}")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="TT reharden tool")
+    parser.add_argument(
+        "--debug",
+        help="debug logging",
+        action="store_const",
+        dest="loglevel",
+        const=logging.DEBUG,
+        default=logging.INFO,
+    )
+    parser.add_argument(
+        "--clone", help="clone the repos", action="store_const", const=True
+    )
+    parser.add_argument(
+        "--harden", help="harden the projects", action="store_const", const=True
+    )
+    parser.add_argument("--start-from", help="start from", type=int, default=0)
+    parser.add_argument("--end-at", help="end at", type=int, default=100000)
+    parser.add_argument("--build-metrics", action="store_const", const=True)
+
+    args = parser.parse_args()
+
+    # setup log
+    log_format = logging.Formatter(
+        "%(asctime)s - %(module)-10s - %(levelname)-8s - %(message)s"
+    )
+    # configure the client logging
+    log = logging.getLogger("")
+    # has to be set to debug as is the root logger
+    log.setLevel(args.loglevel)
+
+    # create console handler and set level to info
+    ch = logging.StreamHandler(sys.stdout)
+    # create formatter for console
+    ch.setFormatter(log_format)
+    log.addHandler(ch)
+
+    shuttle_index = json.load(open("shuttle_index.json"))
+    differences: List[str] = []
+    for number, project in enumerate(shuttle_index["mux"]):
+        if number < args.start_from:
+            continue
+        if number > args.end_at:
+            continue
+
+        repo = shuttle_index["mux"][project]["repo"]
+        commit = shuttle_index["mux"][project]["commit"]
+        macro = shuttle_index["mux"][project]["macro"]
+        repo_dir = os.path.join(REHARDEN_DIR, macro)
+
+        if args.clone:
+            if not os.path.exists(repo_dir):
+                logging.info(f"cloning {number :03} {repo}")
+                git.Repo.clone_from(repo, repo_dir)
+                cloned_repo = git.Repo(repo_dir)
+                cloned_repo.git.submodule("update", "--init")
+                cloned_repo.git.checkout(commit)
+
+            # get tt tools setup.
+            # can't run tt from another directory because gitpython fails
+            # can't run symlinked because openlane fails
+            # simple copy won't work because of tt is a submodule and not a standalone repo.
+            tt_tools_path = os.path.join(repo_dir, "tt")
+            if not os.path.exists(tt_tools_path):
+                logging.info(f"cloning tt to {tt_tools_path}")
+                git.Repo.clone_from("tt", tt_tools_path, depth=1)
+
+        if args.harden:
+            logging.info(f"hardening {number :03} {repo_dir}")
+            cwd = os.getcwd()
+            os.chdir(repo_dir)
+            new_gds = f"runs/wokwi/results/final/gds/{macro}.gds"
+            prev_commit = None
+            if os.path.isfile("commit.txt"):
+                with open("commit.txt", "r") as f:
+                    prev_commit = f.read().strip()
+            if not os.path.exists(new_gds) or prev_commit != commit:
+                os.system(f"tt/tt_tool.py --create-user-config > reharden.log")
+                res = os.system(f"tt/tt_tool.py --harden --debug >> reharden.log")
+                if res != 0:
+                    logging.warning(f"failed to harden {macro}")
+                else:
+                    with open("commit.txt", "w") as f:
+                        f.write(commit)
+            orig_gds = os.path.join(PROJECTS_DIR, f"{macro}/{macro}.gds")
+            logging.info(f"Comparing {orig_gds} with {new_gds}")
+            res = os.system(
+                f"klayout -b -r tt/gds_compare.py -rd 'gds1={orig_gds}' -rd 'gds2={new_gds}'"
+            )
+            if res != 0:
+                logging.warning(f"GDS compare failed for {macro}")
+                differences.append(macro)
+            os.chdir(cwd)
+
+    if args.harden:
+        print(f"Found total of {len(differences)} different projects: ")
+        for diff in differences:
+            print("- ", diff)
+
+    if args.build_metrics:
+        build_metrics(shuttle_index)