diff --git a/src/hammer-vlsi/defaults.yml b/src/hammer-vlsi/defaults.yml
index a632713df..f4c8ef79c 100644
--- a/src/hammer-vlsi/defaults.yml
+++ b/src/hammer-vlsi/defaults.yml
@@ -434,6 +434,10 @@ drc.inputs:
   # Custom DRC command text to add after the boilerplate commands at the top of the run file
   additional_drc_text: ""
 
+vlsi.metrics:
+  # path to the metrics IR input (o1ptional string)
+  input_path: null
+
 # inherit settings from vlsi.submit but allow us to override them
 drc.submit:
   command: "${vlsi.submit.command}"
diff --git a/src/hammer-vlsi/hammer_utils/__init__.py b/src/hammer-vlsi/hammer_utils/__init__.py
index e72d5f598..e529c6f41 100644
--- a/src/hammer-vlsi/hammer_utils/__init__.py
+++ b/src/hammer-vlsi/hammer_utils/__init__.py
@@ -7,6 +7,8 @@
 
 import copy
 import inspect
+import os
+import errno
 from functools import reduce
 from typing import List, Any, Set, Dict, Tuple, TypeVar, Callable, Iterable, Optional
 from enum import Enum, unique
@@ -346,3 +348,13 @@ def get_filetype(filename: str) -> HammerFiletype:
         return HammerFiletype.VERILOG
     else:
         raise NotImplementedError("Unknown file extension: {e}. Please update {f}!".format(e=extension, f=__file__))
+
+
+def mkdir_p(filepath: str) -> None:
+    try:
+        os.makedirs(filepath)
+    except OSError as exc:
+        if exc.errno == errno.EEXIST and os.path.isdir(filepath):
+            pass
+        else:
+            raise
diff --git a/src/hammer-vlsi/hammer_vlsi/hammer_metrics.py b/src/hammer-vlsi/hammer_vlsi/hammer_metrics.py
new file mode 100644
index 000000000..15dce1b12
--- /dev/null
+++ b/src/hammer-vlsi/hammer_vlsi/hammer_metrics.py
@@ -0,0 +1,355 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+#  hammer_metrics.py
+#
+#  Design metrics traits and utilities for hammer-vlsi
+#
+#  See LICENSE for licence details.
+
+from hammer_utils import add_dicts, get_or_else
+from hammer_vlsi import HammerTool
+from abc import abstractmethod
+from typing import NamedTuple, Optional, List, Any, Dict, Callable, Union, TextIO
+from functools import reduce
+import yaml
+import copy
+import os
+
+# Note: Do not include the top module in the module spec
+# e.g. [] = root
+#      ['inst1'] = inst at first level of hierarchy
+class ModuleSpec(NamedTuple('ModuleSpec', [
+    ('path', List[str])
+])):
+    __slots__ = ()
+
+    @staticmethod
+    def from_str(s: str) -> 'ModuleSpec':
+        return ModuleSpec(list(filter(lambda x: x != '', s.split("/"))))
+
+    def append(self, child: str) -> 'ModuleSpec':
+        return ModuleSpec(self.path + [child])
+
+    @property
+    def is_top(self) -> bool:
+        return len(self.path) == 0
+
+    @property
+    def to_str(self) -> str:
+        return "/".join(self.path)
+
+class PortSpec(NamedTuple('PortSpec', [
+    ('module', ModuleSpec),
+    ('port', str)
+])):
+    __slots__ = ()
+
+    @staticmethod
+    def from_str(s: str) -> 'PortSpec':
+        tmp = s.split(':')
+        if len(tmp) != 2:
+            raise ValueError("Invalid port spec: " + s)
+        mod = ModuleSpec.from_str(tmp[0])
+        return PortSpec(mod, tmp[1])
+
+    @property
+    def to_str(self) -> str:
+        return self.module.to_str + ":" + self.port
+
+# TODO document me
+IRType = Dict[str, Union[str, List[str]]]
+
+class MetricsDBEntry:
+
+    @abstractmethod
+    def register(self, db: 'MetricsDB') -> None:
+        pass
+
+    @abstractmethod
+    def update(self, d: Dict[str, Any]) -> 'MetricsDBEntry':
+        pass
+
+    @abstractmethod
+    def to_dict(self) -> Dict[str, Any]:
+        pass
+
+class CriticalPathEntry(NamedTuple('CriticalPathEntry', [
+    ('module', ModuleSpec),
+    ('clock', Optional[PortSpec]), # TODO make this connect to HammerIR clock entry somehow (HammerClockSpec??)
+    ('target', Optional[float]),
+    ('value', Optional[float])
+]), MetricsDBEntry):
+    __slots__ = ()
+
+    @staticmethod
+    def from_ir(ir: IRType) -> 'CriticalPathEntry':
+        try:
+            module = ir["module"]
+            clock = ir["clock"] if "clock" in ir else ""
+            assert isinstance(module, str)
+            assert isinstance(clock, str)
+            return CriticalPathEntry(
+                ModuleSpec.from_str(module),
+                PortSpec.from_str(clock) if "clock" in ir else None,
+                None,
+                None)
+        except:
+            raise ValueError("Invalid IR for CriticalPathEntry: {}".format(ir))
+
+    @staticmethod
+    def type_string() -> str:
+        return 'critical path'
+
+    def to_dict(self) -> Dict[str, Any]:
+        d = {}
+        d['type'] = self.__class__.type_string()
+        d['module'] = self.module.to_str
+        d['clock'] = self.clock.to_str
+        d['target'] = str(get_or_else(self.target, "null"))
+        d['value'] = str(get_or_else(self.value, "null"))
+        return d
+
+    def register(self, db: 'MetricsDB') -> None:
+        db.module_tree.add_module(self.module)
+
+    def update(self, d: Dict[str, Any]) -> MetricsDBEntry:
+        target = d['target'] if 'target' in d else self.target
+        value = d['value'] if 'value' in d else self.value
+        return CriticalPathEntry(self.module, self.clock, target, value)
+
+class ModuleAreaEntry(NamedTuple('ModuleAreaEntry', [
+    ('module', ModuleSpec),
+    ('value', Optional[float])
+]), MetricsDBEntry):
+    __slots__ = ()
+
+    @staticmethod
+    def from_ir(ir: IRType) -> 'ModuleAreaEntry':
+        try:
+            mod = ir["module"]
+            assert isinstance(mod, str)
+            return ModuleAreaEntry(
+                ModuleSpec.from_str(mod),
+                None)
+        except:
+            raise ValueError("Invalid IR for ModuleAreaEntry: {}".format(ir))
+
+    @staticmethod
+    def type_string() -> str:
+        return 'area'
+
+    def to_dict(self) -> Dict[str, Any]:
+        d = {}
+        d['type'] = self.__class__.type_string()
+        d['module'] = self.module.to_str
+        d['value'] = str(get_or_else(self.value, "null"))
+        return d
+
+    def register(self, db: 'MetricsDB') -> None:
+        db.module_tree.add_module(self.module)
+
+    def update(self, d: Dict[str, Any]) -> MetricsDBEntry:
+        value = d['value'] if 'value' in d else self.value
+        return ModuleAreaEntry(self.module, value)
+
+# TODO document this
+#MetricsDBEntry = Union[CriticalPathEntry, ModuleAreaEntry]
+#SupportMap = Dict[str, Callable[[str, MetricsDBEntry], List[str]]]
+SupportMap = Dict[str, Callable[[str, Any], List[str]]]
+
+FromIRMap = {
+    CriticalPathEntry.type_string(): CriticalPathEntry.from_ir,
+    ModuleAreaEntry.type_string(): ModuleAreaEntry.from_ir
+} # type: Dict[str, Callable[[IRType], MetricsDBEntry]]
+
+class ModuleTree:
+
+    index = 0
+
+    def __init__(self):
+        self._children = {} # type: Dict[str, ModuleTree]
+        self._rename_id = ModuleTree.index
+        ModuleTree.index += 1
+        self._no_ungroup = False
+        # More properties go here
+
+    def get_or_create_node(self, name: str) -> 'ModuleTree':
+        if name in self._children:
+            return self._children[name]
+        else:
+            node = ModuleTree()
+            self._children[name] = node
+            return node
+
+    def get_no_ungroup_paths(self, prefix: Optional[ModuleSpec] = None) -> List[ModuleSpec]:
+        result = [] # type: List[ModuleSpec]
+        for name, child in self._children.items():
+            new_prefix = ModuleSpec([name])
+            if prefix is not None:
+                new_prefix = prefix.append(name)
+            if child.get_no_ungroup:
+                result.append(new_prefix)
+            result.extend(child.get_no_ungroup_paths(new_prefix))
+        return result
+
+    def add_module(self, m: ModuleSpec) -> 'ModuleTree':
+        child = self.get_or_create_node(m.path[0])
+        if len(m.path) > 1:
+            return child.add_module(ModuleSpec(m.path[1:]))
+        else:
+            return child
+
+    @property
+    def get_no_ungroup(self) -> bool:
+        return self._no_ungroup
+
+    def set_no_ungroup(self, val: bool = True) -> None:
+        self._no_ungroup = val
+
+    @property
+    def is_leaf(self) -> bool:
+        return len(self._children) == 0
+
+class MetricsDB:
+
+    def __init__(self):
+        self._db = {} # type: Dict[str, Dict[str, MetricsDBEntry]]
+        self._tree = ModuleTree()
+
+    def create_entry(self, namespace: str, key: str, entry: MetricsDBEntry) -> None:
+        if namespace not in self._db:
+            self._db[namespace] = {} # type = Dict[str, MetricsDBEntry]
+        if key in self._db[namespace]:
+            raise ValueError("Duplicate entry in MetricsDB: {}".format(key))
+        else:
+            self._db[namespace][key] = entry
+
+    def get_entry(self, namespace: str, key: str) -> MetricsDBEntry:
+        if namespace in self._db:
+            if key in self._db[namespace]:
+                return self._db[namespace][key]
+            else:
+                raise ValueError("Entry not found in MetricsDB: {}".format(key))
+        else:
+            raise ValueError("Namespace not found in MetricsDB: {}".format(namespace))
+
+    def update_entry(self, namespace: str, key: str, d: Dict[str, Any]) -> MetricsDBEntry:
+        if namespace in self._db:
+            if key in self._db[namespace]:
+                self._db[namespace][key] = self._db[namespace][key].update(d)
+                return self._db[namespace][key]
+            else:
+                raise ValueError("Entry not found in MetricsDB: {}".format(key))
+        else:
+            raise ValueError("Namespace not found in MetricsDB: {}".format(namespace))
+
+
+    def entries(self, namespace: str) -> Dict[str, MetricsDBEntry]:
+        if namespace in self._db:
+            return self._db[namespace]
+        else:
+            raise ValueError("Namespace not found in MetricsDB: {}".format(namespace))
+
+    def serialize(self) -> str:
+        d = {}
+        for namespace in self._db:
+            d[namespace] = {}
+            for testcase in self._db[namespace]:
+                d[namespace][testcase] = self._db[namespace][testcase].to_dict()
+        return yaml.dump(d)
+
+
+    @property
+    def module_tree(self) -> ModuleTree:
+        return self._tree
+
+class HasMetricSupport(HammerTool):
+
+    @property
+    def _support_map(self) -> SupportMap:
+        return {}
+
+    def _is_supported(self, entry: MetricsDBEntry) -> bool:
+        return (entry.__class__.__name__ in self._support_map)
+
+    def create_metrics_db_from_ir(self, ir: Union[str, TextIO]) -> MetricsDB:
+        # convert to a dict
+        y = yaml.load(ir) # type: Optional[Dict[str, Any]]
+        if y is None:
+            y = {}
+        assert(isinstance(y, dict))
+        # create a db
+        db = MetricsDB()
+        for namespace in y:
+            testcases = y[namespace]
+            for testcase in testcases:
+                testcase_data = testcases[testcase]
+                if "type" not in testcase_data:
+                    raise ValueError("Missing \"type\" field in testcase {}".format(testcase))
+                mtype = testcase_data["type"] # type: str
+                if mtype in FromIRMap:
+                    entry = FromIRMap[mtype](testcase_data) # type: MetricsDBEntry
+                    db.create_entry(namespace, testcase, entry)
+                else:
+                    raise ValueError("Metric IR field <{}> is not supported. Did you forget to update FromIRMap?".format(mtype))
+        return db
+
+    def generate_metric_requests_from_db(self, db: MetricsDB) -> List[str]:
+        output = [] # type: List[str]
+        for key in db.entries(self.namespace):
+            entry = db.get_entry(self.namespace, key)
+            if self._is_supported(entry):
+                output.extend(self._support_map[entry.__class__.__name__](key, entry))
+        return output
+
+    def generate_metric_requests_from_ir(self, ir: Union[str, TextIO]) -> List[str]:
+        # TODO initialize this elsewhere
+        self.metrics_db = self.create_metrics_db_from_ir(ir)
+        return self.generate_metric_requests_from_db(self.metrics_db)
+
+    def generate_metric_requests_from_file(self, filename: str) -> List[str]:
+        if not os.path.isfile(filename):
+            raise ValueError("Metrics IR file {} does not exist or is not a file".format(filename))
+        with open(filename, "r") as f:
+            return self.generate_metric_requests_from_ir(f)
+
+    # This will be the key phrase used in the IR
+    @property
+    @abstractmethod
+    def namespace(self) -> str:
+        pass
+
+    def read_results_into_db(self, d: Dict[str, Any]) -> str:
+        for testcase in d:
+            testcase_data = d[testcase]
+            self.metrics_db.update_entry(self.namespace, testcase, testcase_data)
+
+class HasAreaMetricSupport(HasMetricSupport):
+
+    @property
+    def _support_map(self) -> SupportMap:
+        x = copy.copy(super()._support_map) # type: SupportMap
+        x.update({
+            'ModuleAreaEntry': self.get_module_area
+        })
+        return x
+
+    @abstractmethod
+    def get_module_area(self, key: str, entry: ModuleAreaEntry) -> List[str]:
+        pass
+
+class HasTimingPathMetricSupport(HasMetricSupport):
+
+    @property
+    def _support_map(self) -> SupportMap:
+        x = copy.copy(super()._support_map) # type: SupportMap
+        x.update({
+            'CriticalPathEntry': self.get_critical_path
+        })
+        return x
+
+    @abstractmethod
+    def get_critical_path(self, key: str, entry: CriticalPathEntry) -> List[str]:
+        pass
+