diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7a9004b..f5303dc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -65,12 +65,19 @@ jobs:
           uv run ruff format --check src tests
       - name: Mypy (best-effort, non-blocking)
         run: uv run mypy src || true
-      - name: Pytest
+      - name: Pytest (with coverage)
         run: |
           uv run pytest -q \
             -m "not network" \
             --ignore=tests/integration \
             --maxfail=5
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        with:
+          files: ./coverage.xml
+          flags: backend
+          fail_ci_if_error: false
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   frontend:
     name: Frontend (lint + build + test)
diff --git a/README.md b/README.md
index 1013897..ddf8569 100644
--- a/README.md
+++ b/README.md
@@ -12,8 +12,9 @@
 <p align="center">
   <a href="LICENSE"><img alt="License" src="https://img.shields.io/badge/license-PolyForm--Noncommercial--1.0.0-blue.svg" /></a>
   <a href="COMMERCIAL_LICENSE.md"><img alt="Commercial" src="https://img.shields.io/badge/commercial-on%20request-orange.svg" /></a>
-  <a href=".github/workflows/ci.yml"><img alt="CI" src="https://img.shields.io/badge/CI-GitHub%20Actions-success" /></a>
-  <a href="https://github.com/codexofc/cigarspace/releases"><img alt="Release" src="https://img.shields.io/badge/release-v1.0.0-brightgreen" /></a>
+  <a href="https://github.com/codexofc/cigarspace/actions/workflows/ci.yml"><img alt="CI" src="https://github.com/codexofc/cigarspace/actions/workflows/ci.yml/badge.svg?branch=main" /></a>
+  <a href="https://codecov.io/gh/codexofc/cigarspace"><img alt="Coverage" src="https://codecov.io/gh/codexofc/cigarspace/branch/main/graph/badge.svg" /></a>
+  <a href="https://github.com/codexofc/cigarspace/releases"><img alt="Release" src="https://img.shields.io/github/v/release/codexofc/cigarspace?display_name=tag&sort=semver" /></a>
   <img alt="Python" src="https://img.shields.io/badge/python-3.12-blue" />
   <img alt="Node" src="https://img.shields.io/badge/node-20-green" />
   <img alt="Postgres" src="https://img.shields.io/badge/postgres-16%2Bpgvector-336791" />
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 0000000..376e3a2
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,41 @@
+# Codecov configuration.
+# See https://docs.codecov.com/docs/codecov-yaml for the full reference.
+
+coverage:
+  # Round to one decimal in the UI / PR comments.
+  precision: 1
+  round: down
+  range: "70...95"
+
+  status:
+    project:
+      default:
+        # Project-wide gate matches the local pytest gate.
+        target: 82%
+        threshold: 1%   # tolerate a 1-point drop before failing
+        if_ci_failed: error
+    patch:
+      default:
+        # New code introduced in a PR must itself be well-tested.
+        target: 80%
+        threshold: 2%
+        if_ci_failed: error
+
+# Don't fail the upload if the same commit is processed twice.
+parsers:
+  v1:
+    include_full_missed_files: true
+
+ignore:
+  - "src/**/__init__.py"
+  - "src/presentation/cli/__main__.py"
+  - "tests/**"
+  - "migrations/**"
+  - "docs/**"
+
+comment:
+  layout: "header, diff, flags, components, files, footer"
+  behavior: default
+  require_changes: false
+  require_base: false
+  require_head: true
diff --git a/pyproject.toml b/pyproject.toml
index e17fcf0..b8dd77d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -68,6 +68,7 @@ dev = [
     "respx>=0.21,<1",
     "ruff>=0.4,<1",
     "mypy>=1.10,<2",
+    "pytest-cov>=7.1.0",
 ]
 
 [build-system]
@@ -127,9 +128,37 @@ asyncio_default_fixture_loop_scope = "session"
 asyncio_default_test_loop_scope = "session"
 pythonpath = ["src"]
 testpaths = ["tests"]
-addopts = ["-ra", "--strict-markers", "--strict-config"]
+addopts = [
+    "-ra",
+    "--strict-markers",
+    "--strict-config",
+    "--cov=src",
+    "--cov-report=term-missing:skip-covered",
+    "--cov-report=xml",
+    "--cov-fail-under=82",
+]
 markers = [
     "integration: tests requiring live services (PG, Redis)",
     "e2e: end-to-end pipeline tests",
     "network: tests that hit real remote hosts (kept out of default runs)",
 ]
+
+[tool.coverage.run]
+source = ["src"]
+branch = false
+omit = [
+    "src/**/__init__.py",
+    "src/presentation/cli/__main__.py",
+]
+
+[tool.coverage.report]
+exclude_also = [
+    "if TYPE_CHECKING:",
+    "raise NotImplementedError",
+    "@(abc\\.)?abstractmethod",
+    "\\.\\.\\.",
+    "pragma: no cover",
+]
+show_missing = true
+skip_covered = true
+precision = 1
diff --git a/uv.lock b/uv.lock
index 9b75488..7ddf002 100644
--- a/uv.lock
+++ b/uv.lock
@@ -375,6 +375,7 @@ dev = [
     { name = "mypy" },
     { name = "pytest" },
     { name = "pytest-asyncio" },
+    { name = "pytest-cov" },
     { name = "respx" },
     { name = "ruff" },
 ]
@@ -418,6 +419,7 @@ dev = [
     { name = "mypy", specifier = ">=1.10,<2" },
     { name = "pytest", specifier = ">=9.0.3,<10" },
     { name = "pytest-asyncio", specifier = ">=1.0,<2" },
+    { name = "pytest-cov", specifier = ">=7.1.0" },
     { name = "respx", specifier = ">=0.21,<1" },
     { name = "ruff", specifier = ">=0.4,<1" },
 ]
@@ -443,6 +445,30 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/d1/d6/3965ed04c63042e047cb6a3e6ed1a63a35087b6a609aa3a15ed8ac56c221/colorama-0.4.6-py2.py3-none-any.whl", hash = "sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6", size = 25335, upload-time = "2022-10-25T02:36:20.889Z" },
 ]
 
+[[package]]
+name = "coverage"
+version = "7.14.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/23/7f/d0720730a397a999ffc0fd3f5bebef347338e3a47b727da66fbb228e2ff2/coverage-7.14.0.tar.gz", hash = "sha256:057a6af2f160a85384cde4ab36f0d2777bae1057bae255f95413cdd382aa5c74", size = 919489, upload-time = "2026-05-10T18:02:31.397Z" }
+wheels = [
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+    { url = "https://files.pythonhosted.org/packages/34/23/35c7aea1274aef7525bdd2dc92f710bdde6d11652239d71d1ec450067939/coverage-7.14.0-cp312-cp312-macosx_11_0_arm64.whl", hash = "sha256:829994cfe1aeb773ca27bf246d4badc1e764893e3bfb98fff820fcecd1ca4662", size = 220329, upload-time = "2026-05-10T18:00:15.264Z" },
+    { url = "https://files.pythonhosted.org/packages/75/cf/a8f4b43a16e194b0261257ad28ded5853ec052570afef4a84e1d81189f3b/coverage-7.14.0-cp312-cp312-manylinux1_i686.manylinux_2_28_i686.manylinux_2_5_i686.whl", hash = "sha256:b4f07cf7edcb7ec39431a5074d7ea83b29a9f71fcfc494f0f40af4e65180420f", size = 251839, upload-time = "2026-05-10T18:00:17.16Z" },
+    { url = "https://files.pythonhosted.org/packages/69/ff/6699e7b71e60d3049eb2bdcbc95ee3f35707b2b0e48f32e9e63d3ce30c08/coverage-7.14.0-cp312-cp312-manylinux1_x86_64.manylinux_2_28_x86_64.manylinux_2_5_x86_64.whl", hash = "sha256:ca3d9cf2c32b521bd9518385608787fa86f38daf993695307531822c3430ed67", size = 254576, upload-time = "2026-05-10T18:00:18.829Z" },
+    { url = "https://files.pythonhosted.org/packages/22/ec/c936d495fcd67f48f03a9c4ad3297ff80d1f222a5df3980f15b34c186c21/coverage-7.14.0-cp312-cp312-manylinux2014_aarch64.manylinux_2_17_aarch64.manylinux_2_28_aarch64.whl", hash = "sha256:92af52828e7f29d827346b0294e5a0853fa206db77db0395b282918d41e28db9", size = 255690, upload-time = "2026-05-10T18:00:20.648Z" },
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+    { url = "https://files.pythonhosted.org/packages/74/18/9f7fe62f659f24b7a82a0be56bf94c1bd0a89e0ae7ab4c668f6e82404294/coverage-7.14.0-cp312-cp312-win_arm64.whl", hash = "sha256:91b993743d959b8be85b4abf9d5478216a69329c321efe5be0433c1a841d691d", size = 221944, upload-time = "2026-05-10T18:00:37.014Z" },
+    { url = "https://files.pythonhosted.org/packages/61/e8/cb8e80d6f9f55b99588625062822bf946cf03ed06315df4bd8397f5632a1/coverage-7.14.0-py3-none-any.whl", hash = "sha256:8de5b61163aee3d05c8a2beab6f47913df7981dad1baf82c414d99158c286ab1", size = 211764, upload-time = "2026-05-10T18:02:29.538Z" },
+]
+
 [[package]]
 name = "cryptography"
 version = "48.0.0"
@@ -1472,6 +1498,20 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e5/35/f8b19922b6a25bc0880171a2f1a003eaeb93657475193ab516fd87cac9da/pytest_asyncio-1.3.0-py3-none-any.whl", hash = "sha256:611e26147c7f77640e6d0a92a38ed17c3e9848063698d5c93d5aa7aa11cebff5", size = 15075, upload-time = "2025-11-10T16:07:45.537Z" },
 ]
 
+[[package]]
+name = "pytest-cov"
+version = "7.1.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "coverage" },
+    { name = "pluggy" },
+    { name = "pytest" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/b1/51/a849f96e117386044471c8ec2bd6cfebacda285da9525c9106aeb28da671/pytest_cov-7.1.0.tar.gz", hash = "sha256:30674f2b5f6351aa09702a9c8c364f6a01c27aae0c1366ae8016160d1efc56b2", size = 55592, upload-time = "2026-03-21T20:11:16.284Z" }
+wheels = [
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+]
+
 [[package]]
 name = "python-dateutil"
 version = "2.9.0.post0"