diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 93c684a..a95b249 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,6 +1,6 @@
 name: CI Workflow
 
-on: [push, pull_request]
+on: [push]
 
 jobs:
 
diff --git a/contracts/StablecoinLens.vy b/contracts/StablecoinLens.vy
index 2ff97ed..671139e 100644
--- a/contracts/StablecoinLens.vy
+++ b/contracts/StablecoinLens.vy
@@ -2,28 +2,67 @@
 
 from interfaces import IPegKeeper
 from interfaces import IController
+from interfaces import IControllerFactory
+from interfaces import IMonetaryPolicy
 
-MAX_CONTROLLERS: constant(uint256) = 50000  # TODO check actual number
-MAX_PEG_KEEPERS: constant(uint256) = 100  # TODO check actual number
+# bound from factory
+MAX_CONTROLLERS: constant(uint256) = 50000
+# bound from monetary policy
+MAX_PEG_KEEPERS: constant(uint256) = 1001
+# could have been any other controller
+WETH_CONTROLLER_IDX: constant(uint256) = 3
 
-controllers: DynArray[address, MAX_CONTROLLERS]
-peg_keepers: DynArray[address, MAX_PEG_KEEPERS]
+# the crvusd controller factory
+factory: immutable(IControllerFactory)
+
+
+@deploy
+def __init__(_factory: IControllerFactory):
+    factory = _factory
 
 
 @view
 @external
 def circulating_supply() -> uint256:
-    total_supply: uint256 = 0
+    """
+    @notice Compute the circulating supply for crvUSD, `totalSupply` is
+        incorrect since it takes into account all minted crvUSD (i.e. flashloans)
+    @dev This function sacrifices some gas to fetch peg keepers from a
+        unique source of truth to avoid having to manually maintain multiple
+        lists across several contracts.
+        For this reason we read the list of peg keepers contained in
+        the monetary policy returned by a controller in the factory.
+        factory -> weth controller -> monetary policy -> peg keepers
+    """
+
+    circulating_supply: uint256 = 0
+
+    # Fetch the weth controller (index 3) under the assumption that
+    # weth will always be a valid collateral for crvUSD, therefore its
+    # monetary policy should always be up to date.
+    controller: IController = staticcall factory.controllers(3)
+
+    # We obtain the address of the current monetary policy used by the
+    # weth controller because it contains a list of all the peg keepers.
+    monetary_policy: IMonetaryPolicy = staticcall controller.monetary_policy()
 
-    # TODO how to optimize this
-    for pk: address in self.peg_keepers:
-        if pk != empty(address):
-            total_supply += staticcall IPegKeeper(pk).debt()
+    # Iterate over the peg keepers (since it's a fixed size array we
+    # wait for a zero address to stop iterating).
+    for i: uint256 in range(MAX_PEG_KEEPERS):
+        pk: IPegKeeper = staticcall monetary_policy.peg_keepers(i)
+
+        if pk.address == empty(address):
+            # end of array
+            break
+
+        circulating_supply += staticcall pk.debt()
+
+    n_controllers: uint256 = staticcall factory.n_collaterals()
 
-    # TODO get correct value for this
-    n_controllers: uint256 = 0
     for i: uint256 in range(n_controllers, bound=MAX_CONTROLLERS):
-        controller: address = self.controllers[i]
-        total_supply += staticcall IController(controller).total_debt()
+        controller = staticcall factory.controllers(i)
+
+        # add crvUSD minted by controller
+        circulating_supply += staticcall controller.total_debt()
 
-    return total_supply
+    return circulating_supply
diff --git a/contracts/interfaces/IController.vyi b/contracts/interfaces/IController.vyi
index 0628325..2eb27e6 100644
--- a/contracts/interfaces/IController.vyi
+++ b/contracts/interfaces/IController.vyi
@@ -1,4 +1,15 @@
+# pragma version ~=0.4.0
+
+import IMonetaryPolicy
+
+
 @view
 @external
 def total_debt() -> uint256:
     ...
+
+
+@view
+@external
+def monetary_policy() -> IMonetaryPolicy:
+    ...
diff --git a/contracts/interfaces/IControllerFactory.vyi b/contracts/interfaces/IControllerFactory.vyi
new file mode 100644
index 0000000..23e0239
--- /dev/null
+++ b/contracts/interfaces/IControllerFactory.vyi
@@ -0,0 +1,15 @@
+# pragma version ~=0.4.0
+
+import IController
+
+
+@external
+@view
+def controllers(i: uint256) -> IController:
+    ...
+
+
+@external
+@view
+def n_collaterals() -> uint256:
+    ...
diff --git a/contracts/interfaces/IMonetaryPolicy.vyi b/contracts/interfaces/IMonetaryPolicy.vyi
new file mode 100644
index 0000000..f49abf5
--- /dev/null
+++ b/contracts/interfaces/IMonetaryPolicy.vyi
@@ -0,0 +1,9 @@
+# pragma version ~=0.4.0
+
+import IPegKeeper
+
+
+@view
+@external
+def peg_keepers(i: uint256) -> IPegKeeper:
+    ...
diff --git a/contracts/interfaces/IPegKeeper.vyi b/contracts/interfaces/IPegKeeper.vyi
index b03a8c1..9c8b998 100644
--- a/contracts/interfaces/IPegKeeper.vyi
+++ b/contracts/interfaces/IPegKeeper.vyi
@@ -1,3 +1,5 @@
+# pragma version ~=0.4.0
+
 @view
 @external
 def debt() -> uint256:
diff --git a/contracts/interfaces/IStablecoinLens.vyi b/contracts/interfaces/IStablecoinLens.vyi
index 75f12b1..38708e7 100644
--- a/contracts/interfaces/IStablecoinLens.vyi
+++ b/contracts/interfaces/IStablecoinLens.vyi
@@ -1,4 +1,4 @@
-# Functions
+# pragma version ~=0.4.0
 
 @view
 @external
diff --git a/poetry.lock b/poetry.lock
index fe99c9c..290e607 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.7.1 and should not be changed by hand.
 
 [[package]]
 name = "annotated-types"
@@ -1545,18 +1545,18 @@ devel = ["colorama", "json-spec", "jsonschema", "pylint", "pytest", "pytest-benc
 
 [[package]]
 name = "filelock"
-version = "3.16.0"
+version = "3.16.1"
 description = "A platform independent file lock."
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "filelock-3.16.0-py3-none-any.whl", hash = "sha256:f6ed4c963184f4c84dd5557ce8fece759a3724b37b80c6c4f20a2f63a4dc6609"},
-    {file = "filelock-3.16.0.tar.gz", hash = "sha256:81de9eb8453c769b63369f87f11131a7ab04e367f8d97ad39dc230daa07e3bec"},
+    {file = "filelock-3.16.1-py3-none-any.whl", hash = "sha256:2082e5703d51fbf98ea75855d9d5527e33d8ff23099bec374a134febee6946b0"},
+    {file = "filelock-3.16.1.tar.gz", hash = "sha256:c249fbfcd5db47e5e2d6d62198e565475ee65e4831e2561c8e313fa7eb961435"},
 ]
 
 [package.extras]
-docs = ["furo (>=2024.8.6)", "sphinx (>=8.0.2)", "sphinx-autodoc-typehints (>=2.4)"]
-testing = ["covdefaults (>=2.3)", "coverage (>=7.6.1)", "diff-cover (>=9.1.1)", "pytest (>=8.3.2)", "pytest-asyncio (>=0.24)", "pytest-cov (>=5)", "pytest-mock (>=3.14)", "pytest-timeout (>=2.3.1)", "virtualenv (>=20.26.3)"]
+docs = ["furo (>=2024.8.6)", "sphinx (>=8.0.2)", "sphinx-autodoc-typehints (>=2.4.1)"]
+testing = ["covdefaults (>=2.3)", "coverage (>=7.6.1)", "diff-cover (>=9.2)", "pytest (>=8.3.3)", "pytest-asyncio (>=0.24)", "pytest-cov (>=5)", "pytest-mock (>=3.14)", "pytest-timeout (>=2.3.1)", "virtualenv (>=20.26.4)"]
 typing = ["typing-extensions (>=4.12.2)"]
 
 [[package]]
@@ -2379,13 +2379,13 @@ test = ["pytest"]
 
 [[package]]
 name = "mamushi"
-version = "0.0.4a1"
+version = "0.0.4a3"
 description = "Vyper formatter"
 optional = false
 python-versions = ">=3.9"
 files = [
-    {file = "mamushi-0.0.4a1-py3-none-any.whl", hash = "sha256:bdf47a66e1b727f8de93da24bdbbec6b468c4654ef6fb91afa002e61f39dc9b1"},
-    {file = "mamushi-0.0.4a1.tar.gz", hash = "sha256:7b5df8b436535240a0e356af18f0e19f46413639bc6837fdb0a18fcde372e85d"},
+    {file = "mamushi-0.0.4a3-py3-none-any.whl", hash = "sha256:e2c0edbb75c218d354105b3b4d75a5f95a23f3ce02919b81cf123aca0ecf374b"},
+    {file = "mamushi-0.0.4a3.tar.gz", hash = "sha256:2423a88c324405cff3fd2d6ff63140f57b5575bb5b315be9ae3e6b6c6d8081de"},
 ]
 
 [package.dependencies]
@@ -2866,13 +2866,13 @@ testing = ["pytest", "pytest-cov", "wheel"]
 
 [[package]]
 name = "platformdirs"
-version = "4.3.3"
+version = "4.3.6"
 description = "A small Python package for determining appropriate platform-specific dirs, e.g. a `user data dir`."
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "platformdirs-4.3.3-py3-none-any.whl", hash = "sha256:50a5450e2e84f44539718293cbb1da0a0885c9d14adf21b77bae4e66fc99d9b5"},
-    {file = "platformdirs-4.3.3.tar.gz", hash = "sha256:d4e0b7d8ec176b341fb03cb11ca12d0276faa8c485f9cd218f613840463fc2c0"},
+    {file = "platformdirs-4.3.6-py3-none-any.whl", hash = "sha256:73e575e1408ab8103900836b97580d5307456908a03e92031bab39e4554cc3fb"},
+    {file = "platformdirs-4.3.6.tar.gz", hash = "sha256:357fb2acbc885b0419afd3ce3ed34564c13c9b95c89360cd9563f73aa5e2b907"},
 ]
 
 [package.extras]
@@ -4292,7 +4292,7 @@ forking-recommended = ["requests-cache (>=1.2.1)", "ujson (>=5.10.0)"]
 [package.source]
 type = "git"
 url = "https://github.com/vyperlang/titanoboa.git"
-reference = "master"
+reference = "4768207288ec8fb23a4817ae193bd707ab9d1e8f"
 resolved_reference = "4768207288ec8fb23a4817ae193bd707ab9d1e8f"
 
 [[package]]
@@ -4461,13 +4461,13 @@ zstd = ["zstandard (>=0.18.0)"]
 
 [[package]]
 name = "virtualenv"
-version = "20.26.4"
+version = "20.26.5"
 description = "Virtual Python Environment builder"
 optional = false
 python-versions = ">=3.7"
 files = [
-    {file = "virtualenv-20.26.4-py3-none-any.whl", hash = "sha256:48f2695d9809277003f30776d155615ffc11328e6a0a8c1f0ec80188d7874a55"},
-    {file = "virtualenv-20.26.4.tar.gz", hash = "sha256:c17f4e0f3e6036e9f26700446f85c76ab11df65ff6d8a9cbfad9f71aabfcf23c"},
+    {file = "virtualenv-20.26.5-py3-none-any.whl", hash = "sha256:4f3ac17b81fba3ce3bd6f4ead2749a72da5929c01774948e243db9ba41df4ff6"},
+    {file = "virtualenv-20.26.5.tar.gz", hash = "sha256:ce489cac131aa58f4b25e321d6d186171f78e6cb13fafbf32a840cee67733ff4"},
 ]
 
 [package.dependencies]
@@ -4691,4 +4691,4 @@ type = ["pytest-mypy"]
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.12.6"
-content-hash = "78db4cde815d6529a32a78d6d9fb6ac54e88b7a32de549404aa562bd2775445c"
+content-hash = "9aadea717f9d30d99508cddb559a63f84ab9c60324651698a04511b570ea231c"
diff --git a/pyproject.toml b/pyproject.toml
index fc34c91..263fce1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,6 @@ version = "0.1.0"
 description = ""
 authors = ["Curve.fi"]
 readme = "README.md"
-package-mode = false
 
 [tool.black]
 line-length = 100
@@ -14,11 +13,11 @@ target_version = ['py312']
 python = "^3.12.6"
 poetry = "^1.8.3"
 vyper = "0.4.0"
-titanoboa = { git = "https://github.com/vyperlang/titanoboa.git", branch = "master" }
+titanoboa = { git = "https://github.com/vyperlang/titanoboa.git", rev = "4768207288ec8fb23a4817ae193bd707ab9d1e8f" }
 snekmate = "0.1.0"
 
 [tool.poetry.group.dev.dependencies]
-mamushi = "0.0.4a1"
+mamushi = "0.0.4a3"
 pre-commit = "^3.8.0"
 black = "24.8.0"
 pytest = "^8.2.2"
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
new file mode 100644
index 0000000..85828ac
--- /dev/null
+++ b/tests/integration/conftest.py
@@ -0,0 +1,26 @@
+import os
+
+import boa
+import pytest
+
+boa.set_etherscan(api_key=os.getenv("ETHERSCAN_API_KEY"))
+
+
+@pytest.fixture(scope="module")
+def rpc_url():
+    return os.getenv("ETH_RPC_URL") or "https://rpc.ankr.com/eth"
+
+
+@pytest.fixture(scope="module", autouse=True)
+def forked_env(rpc_url):
+    boa.fork(rpc_url, block_identifier=18801970)
+
+
+@pytest.fixture(scope="module")
+def controller_factory():
+    return boa.from_etherscan("0xC9332fdCB1C491Dcc683bAe86Fe3cb70360738BC", "controller_factory")
+
+
+@pytest.fixture(scope="module")
+def lens(controller_factory):
+    return boa.load("contracts/StablecoinLens.vy", controller_factory)
diff --git a/tests/integration/test_fork_circulating_supply.py b/tests/integration/test_fork_circulating_supply.py
new file mode 100644
index 0000000..8863455
--- /dev/null
+++ b/tests/integration/test_fork_circulating_supply.py
@@ -0,0 +1,5 @@
+def test_fork_circulating_supply(lens):
+    # TODO mint more crvusd and make sure this increases accordingly
+    # TODO increase flashloan debt ceiling and make
+    #  sure supply doesn't increase
+    print("{:2e}".format(lens.circulating_supply()))
diff --git a/tests/mocks/MockController.vy b/tests/mocks/MockController.vy
new file mode 100644
index 0000000..532462f
--- /dev/null
+++ b/tests/mocks/MockController.vy
@@ -0,0 +1,14 @@
+# pragma version ~=0.4.0
+
+from contracts.interfaces import IController
+from contracts.interfaces import IMonetaryPolicy
+
+implements: IController
+
+_monetary_policy: address
+total_debt: public(uint256)
+
+@external
+@view
+def monetary_policy() -> IMonetaryPolicy:
+    return IMonetaryPolicy(self._monetary_policy)
diff --git a/tests/mocks/MockControllerFactory.vy b/tests/mocks/MockControllerFactory.vy
new file mode 100644
index 0000000..c5fd2a8
--- /dev/null
+++ b/tests/mocks/MockControllerFactory.vy
@@ -0,0 +1,18 @@
+# pragma version ~=0.4.0
+
+from contracts.interfaces import IControllerFactory
+from contracts.interfaces import IController
+
+implements: IControllerFactory
+
+_controllers: DynArray[IController, 10000]
+
+@external
+@view
+def controllers(i: uint256) -> IController:
+    return self._controllers[i]
+
+@external
+@view
+def n_collaterals() -> uint256:
+    return len(self._controllers)
diff --git a/tests/mocks/MockMonetaryPolicy.vy b/tests/mocks/MockMonetaryPolicy.vy
new file mode 100644
index 0000000..727535a
--- /dev/null
+++ b/tests/mocks/MockMonetaryPolicy.vy
@@ -0,0 +1,13 @@
+# pragma version ~=0.4.0
+
+from contracts.interfaces import IMonetaryPolicy
+from contracts.interfaces import IPegKeeper
+
+implements: IMonetaryPolicy
+
+peg_keeper: IPegKeeper
+
+@external
+@view
+def peg_keepers(i: uint256) -> IPegKeeper:
+    return self.peg_keeper
diff --git a/tests/unitary/conftest.py b/tests/unitary/conftest.py
index 860c6ad..fa79284 100644
--- a/tests/unitary/conftest.py
+++ b/tests/unitary/conftest.py
@@ -36,9 +36,7 @@ def role_manager():
 def vault(vault_factory, crvusd, role_manager):
     vault_deployer = boa.load_partial("contracts/yearn/Vault.vy")
 
-    address = vault_factory.deploy_new_vault(
-        crvusd, "Staked crvUSD", "st-crvUSD", role_manager, 0
-    )
+    address = vault_factory.deploy_new_vault(crvusd, "Staked crvUSD", "st-crvUSD", role_manager, 0)
 
     return vault_deployer.at(address)
 
diff --git a/tests/unitary/rewards_handler/test_process_rewards.py b/tests/unitary/rewards_handler/test_process_rewards.py
deleted file mode 100644
index 9f8df19..0000000
--- a/tests/unitary/rewards_handler/test_process_rewards.py
+++ /dev/null
@@ -1,16 +0,0 @@
-import boa
-
-
-def test_default_behavior(crvusd, vault, rewards_handler, lens, role_manager):
-
-    boa.deal(crvusd, rewards_handler, 10**23)
-    rewards_handler.eval(f"self.lens = {lens.address}")
-    # rewards_handler.take_snapshot()
-
-    print(vault.roles(rewards_handler))
-
-    # vault.add_strategy(vault, sender=rewards_handler.address)
-
-    rewards_handler.process_rewards()
-
-    assert crvusd.balanceOf(rewards_handler) == 0
diff --git a/tests/unitary/twa/test_twa.py b/tests/unitary/twa/test_twa.py
index 0364520..3412258 100644
--- a/tests/unitary/twa/test_twa.py
+++ b/tests/unitary/twa/test_twa.py
@@ -66,9 +66,7 @@ def test_twa_two_deposits(vault, crvusd, rewards_handler, lens, vault_god):
     ), "TWA does not match expected deposit amount"
 
 
-def test_twa_multiple_deposits(
-    vault, crvusd, rewards_handler, lens, vault_god
-):
+def test_twa_multiple_deposits(vault, crvusd, rewards_handler, lens, vault_god):
     # Prepare Alice's balance
     alice = boa.env.generate_address()
     boa.deal(crvusd, alice, 100_000_000 * 10**18)
@@ -84,9 +82,7 @@ def test_twa_multiple_deposits(
     AMT_DEPOSIT = 10 * 10**18  # Amount to deposit per iteration
     TWA_WINDOW = rewards_handler.twa_window()  # TWA window (e.g., one week)
     N_ITERATIONS = 5  # Number of deposits
-    TIME_BETWEEN_DEPOSITS = (
-        TWA_WINDOW // N_ITERATIONS
-    )  # Time between each deposit
+    TIME_BETWEEN_DEPOSITS = TWA_WINDOW // N_ITERATIONS  # Time between each deposit
 
     # Store the staked supply rates after each snapshot
     staked_supply_rates = []
@@ -163,9 +159,5 @@ def test_twa_multiple_deposits(
     print(f"Staked rate: {staked_rate}, Contract TWA: {twa}")
 
     # Compare the TWA from the contract against the expected values
-    assert (
-        twa <= staked_rate
-    ), "TWA is unexpectedly higher than the staked rate"
-    assert (
-        twa == expected_twa
-    ), f"TWA {twa} does not match expected {expected_twa}"
+    assert twa <= staked_rate, "TWA is unexpectedly higher than the staked rate"
+    assert twa == expected_twa, f"TWA {twa} does not match expected {expected_twa}"